lanspread/crates/lanspread-tauri-deno-ts/src-tauri/src/lib.rs

use std::{
    collections::{HashMap, HashSet},
    fs::{self, OpenOptions},
    io::{self, Read as _, Seek as _, SeekFrom, Write as _},
    path::{Component, Path, PathBuf},
    sync::{
        Arc,
        Mutex,
        OnceLock,
        atomic::{AtomicU64, Ordering},
    },
    time::{Duration, SystemTime, UNIX_EPOCH},
};

use eyre::bail;
use lanspread_compat::eti::get_games;
use lanspread_db::db::{Availability, Game, GameCatalog, GameDB, GameFileDescription};
use lanspread_peer::{
    ActiveOperation,
    ActiveOperationKind,
    CallToPlayEvent,
    ExternalUnrarStreamProvider,
    NoopStreamInstallProvider,
    PeerCommand,
    PeerEvent,
    PeerGameDB,
    PeerRuntimeHandle,
    PeerStartOptions,
    StreamInstallProvider,
    UnpackFuture,
    Unpacker,
    migrate_legacy_state,
    start_peer_with_options,
};
use tauri::{AppHandle, Emitter as _, Manager};
use tauri_plugin_shell::{
    ShellExt,
    process::{Command, CommandChild, CommandEvent},
};
use tokio::sync::{
    RwLock,
    mpsc::{UnboundedReceiver, UnboundedSender},
    oneshot,
};
use tracing::{Event, Level, Metadata, Subscriber, field::Visit};
use tracing_subscriber::{
    layer::{Context, Layer},
    prelude::*,
    registry::LookupSpan,
};

// Learn more about Tauri commands at https://tauri.app/develop/calling-rust/

type OutboundTransfers =
    Arc<RwLock<std::collections::HashMap<String, Vec<(u64, tokio_util::sync::CancellationToken)>>>>;

const OUTBOUND_TRANSFER_EMIT_DEBOUNCE: Duration = Duration::from_millis(100);

#[derive(Default)]
struct OutboundTransferEmitState {
    scheduled: bool,
    generation: u64,
}

impl OutboundTransferEmitState {
    fn record_change(&mut self) -> bool {
        self.generation = self.generation.saturating_add(1);
        if self.scheduled {
            return false;
        }

        self.scheduled = true;
        true
    }

    fn observed_generation(&self) -> u64 {
        self.generation
    }

    fn finish_emit(&mut self, observed_generation: u64) -> bool {
        if self.generation != observed_generation {
            return true;
        }

        self.scheduled = false;
        false
    }
}

/// Tauri-managed runtime state shared by commands and setup tasks.
#[derive(Default)]
struct LanSpreadState {
    peer_ctrl: Arc<RwLock<Option<UnboundedSender<PeerCommand>>>>,
    peer_runtime: Arc<RwLock<Option<PeerRuntimeHandle>>>,
    local_peer_id: Arc<RwLock<Option<String>>>,
    games: Arc<RwLock<GameDB>>,
    active_operations: Arc<RwLock<HashMap<String, UiOperationKind>>>,
    games_folder: Arc<RwLock<String>>,
    peer_game_db: Arc<RwLock<PeerGameDB>>,
    catalog: Arc<RwLock<GameCatalog>>,
    unpack_logs: Arc<RwLock<Vec<UnpackLogEntry>>>,
    state_dir: OnceLock<PathBuf>,
    main_log_sink: OnceLock<MainLogSink>,
    active_outbound_transfers: OutboundTransfers,
    outbound_transfer_emit: Arc<RwLock<OutboundTransferEmitState>>,
    /// Live unrar sidecar processes, so they can be killed if the launcher exits
    /// mid-unpack. The shell plugin does not kill spawned children on app exit,
    /// and the OS does not cascade-kill child processes, so without this an
    /// in-progress unrar keeps running after the launcher closes.
    active_unrar_children: Arc<Mutex<UnrarChildRegistry>>,
}

/// Live unrar sidecar children plus a shutdown latch.
///
/// Children are keyed by a monotonic id (not pid) so a finishing install never
/// deregisters another install's child after a pid is recycled. The
/// `shutting_down` latch closes a time-of-check/time-of-use hole: the exit kill
/// sweep drains the map only once, so a child registered *after* the sweep (an
/// install task caught between `spawn()` and registration, or a later archive in
/// a multi-archive install — `unpack_archives` does not observe the shutdown
/// token) would be orphaned. Once the latch is set under this mutex, registration
/// kills the child immediately instead of inserting it where nothing will reap it.
#[derive(Default)]
struct UnrarChildRegistry {
    shutting_down: bool,
    children: HashMap<u64, CommandChild>,
}

/// Monotonic id source for [`UnrarChildRegistry`] entries.
static UNRAR_CHILD_SEQ: AtomicU64 = AtomicU64::new(0);

#[derive(Clone, Debug, PartialEq, Eq)]
struct InstallSettings {
    account_name: String,
    language: String,
}

struct PeerEventTx(UnboundedSender<PeerEvent>);

#[derive(Clone, Copy, Debug, PartialEq, Eq, serde::Serialize)]
enum UiOperationKind {
    Downloading,
    Installing,
    Updating,
    Uninstalling,
    RemovingDownload,
}

#[derive(Clone, Debug, PartialEq, Eq, serde::Serialize)]
struct UiActiveOperation {
    id: String,
    operation: UiOperationKind,
}

#[derive(Clone, Debug, serde::Serialize)]
struct GamesListPayload {
    games: Vec<LauncherGame>,
    active_operations: Vec<UiActiveOperation>,
}

#[derive(Clone, Debug, serde::Serialize)]
struct LauncherGame {
    #[serde(flatten)]
    game: Game,
    can_host_server: bool,
    active_outbound_transfers: usize,
    installed_peer_count: u32,
}

#[derive(Clone, Debug, serde::Deserialize, serde::Serialize)]
struct UnpackLogEntry {
    archive: String,
    destination: String,
    status_code: Option<i32>,
    stdout: String,
    stderr: String,
    started_at_ms: u64,
    finished_at_ms: u64,
    success: bool,
}

#[derive(Clone, Debug, serde::Serialize)]
struct MainLogLinePayload {
    line: String,
    level: String,
    sequence: Option<u64>,
}

#[derive(Clone, Debug, serde::Serialize)]
#[serde(rename_all = "camelCase")]
struct MainLogHistoryPayload {
    contents: String,
    last_sequence: u64,
}

struct SidecarUnpacker {
    app_handle: AppHandle,
}

const MAX_UNPACK_LOGS: usize = 20;
const UNPACK_LOGS_FILE_NAME: &str = "unpack-logs.json";
const MAIN_LOG_FILE_NAME: &str = "lanspread.log";
const MAX_MAIN_LOG_BYTES: u64 = 2 * 1024 * 1024;
const MAIN_LOG_TRIM_SLACK_BYTES: u64 = 64 * 1024;

impl Unpacker for SidecarUnpacker {
    fn unpack<'a>(&'a self, archive: &'a Path, dest: &'a Path) -> UnpackFuture<'a> {
        Box::pin(async move {
            let app_handle = self.app_handle.clone();
            let sidecar = app_handle.shell().sidecar("unrar")?;
            do_unrar(&app_handle, sidecar, archive, dest).await
        })
    }
}

#[tauri::command]
async fn get_unpack_logs(
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<Vec<UnpackLogEntry>> {
    Ok(state.inner().unpack_logs.read().await.clone())
}

#[tauri::command]
async fn get_main_logs(
    app_handle: tauri::AppHandle,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<MainLogHistoryPayload> {
    if let Some(sink) = state.inner().main_log_sink.get() {
        return Ok(sink.read_history()?);
    }

    let state_dir = app_handle.path().app_data_dir()?;
    fs::create_dir_all(&state_dir)?;
    let path = main_log_path(&state_dir);

    match read_main_log_file_to_limit(&path, MAX_MAIN_LOG_BYTES) {
        Ok(contents) => Ok(MainLogHistoryPayload {
            contents,
            last_sequence: 0,
        }),
        Err(err) if err.kind() == io::ErrorKind::NotFound => Ok(MainLogHistoryPayload {
            contents: String::new(),
            last_sequence: 0,
        }),
        Err(err) => Err(err.into()),
    }
}

#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
const GAME_SETUP_SCRIPT: &str = "game_setup.cmd";
#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
const GAME_START_SCRIPT: &str = "game_start.cmd";
const SERVER_START_SCRIPT: &str = "server_start.cmd";
#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
const DEFAULT_LANGUAGE: &str = "en";
#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
const DEFAULT_USERNAME: &str = "Commander";
#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
const MAX_USERNAME_CHARS: usize = 24;

#[tauri::command]
async fn request_games(state: tauri::State<'_, LanSpreadState>) -> tauri::Result<()> {
    log::debug!("request_games");

    let peer_ctrl_arc = state.inner().peer_ctrl.clone();
    let peer_ctrl = peer_ctrl_arc.read().await.clone();

    if let Some(peer_ctrl) = peer_ctrl {
        if let Err(e) = peer_ctrl.send(PeerCommand::ListGames) {
            log::error!("Failed to send message to peer: {e:?}");
        }
    } else {
        log::warn!("Peer system not initialized yet");
    }

    Ok(())
}

#[tauri::command]
async fn request_call_to_play_events(
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<Option<String>> {
    let peer_ctrl = state.inner().peer_ctrl.read().await.clone();
    let Some(peer_ctrl) = peer_ctrl else {
        log::warn!("Peer system not initialized yet");
        return Ok(None);
    };

    if peer_ctrl
        .send(PeerCommand::GetCallToPlayEvents { reply: None })
        .is_err()
    {
        return Ok(None);
    }
    Ok(state.inner().local_peer_id.read().await.clone())
}

#[tauri::command]
async fn publish_call_to_play(
    event: CallToPlayEvent,
    state: tauri::State<'_, LanSpreadState>,
) -> Result<bool, String> {
    let peer_ctrl = state.inner().peer_ctrl.read().await.clone();
    let Some(peer_ctrl) = peer_ctrl else {
        log::warn!("Peer system not initialized yet");
        return Ok(false);
    };

    let (reply, result) = oneshot::channel();
    peer_ctrl
        .send(PeerCommand::PublishCallToPlay { event, reply })
        .map_err(|err| err.to_string())?;
    result.await.map_err(|err| err.to_string())?.map(|()| true)
}

#[tauri::command]
async fn install_game(
    id: String,
    language: String,
    username: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<bool> {
    if state
        .inner()
        .active_operations
        .read()
        .await
        .contains_key(&id)
    {
        log::warn!("Game already has an active operation: {id}");
        return Ok(false);
    }

    let peer_ctrl_arc = state.inner().peer_ctrl.clone();
    let peer_ctrl = peer_ctrl_arc.read().await.clone();
    let Some((downloaded, installed)) = state
        .inner()
        .games
        .read()
        .await
        .get_game_by_id(&id)
        .map(|game| (game.downloaded, game.installed))
    else {
        log::warn!("Ignoring install request for unknown game: {id}");
        return Ok(false);
    };

    let _ = (language, username);
    let handled = if let Some(peer_ctrl) = peer_ctrl {
        let command = if !downloaded {
            PeerCommand::GetGame(id.clone())
        } else if !installed {
            PeerCommand::InstallGame { id: id.clone() }
        } else {
            log::info!("Game is already installed: {id}");
            return Ok(false);
        };

        if let Err(e) = peer_ctrl.send(command) {
            log::error!("Failed to send message to peer: {e:?}");
            return Ok(false);
        }
        true
    } else {
        log::warn!("Peer system not initialized yet");
        false
    };

    Ok(handled)
}

#[tauri::command]
async fn stream_install_game(
    id: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<bool> {
    if state
        .inner()
        .active_operations
        .read()
        .await
        .contains_key(&id)
    {
        log::warn!("Game already has an active operation: {id}");
        return Ok(false);
    }

    let Some((downloaded, installed, peer_count)) = state
        .inner()
        .games
        .read()
        .await
        .get_game_by_id(&id)
        .map(|game| (game.downloaded, game.installed, game.peer_count))
    else {
        log::warn!("Ignoring streamed install request for unknown game: {id}");
        return Ok(false);
    };
    if downloaded || installed || peer_count == 0 {
        log::warn!(
            "Ignoring streamed install request for {id}: downloaded={downloaded}, \
             installed={installed}, peer_count={peer_count}"
        );
        return Ok(false);
    }

    let peer_ctrl_arc = state.inner().peer_ctrl.clone();
    let peer_ctrl = peer_ctrl_arc.read().await.clone();
    let Some(peer_ctrl) = peer_ctrl else {
        log::warn!("Peer system not initialized yet");
        return Ok(false);
    };

    if let Err(e) = peer_ctrl.send(PeerCommand::StreamInstallGame { id }) {
        log::error!("Failed to send PeerCommand::StreamInstallGame: {e:?}");
        return Ok(false);
    }

    Ok(true)
}

#[tauri::command]
async fn update_game(
    id: String,
    language: String,
    username: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<bool> {
    if state
        .inner()
        .active_operations
        .read()
        .await
        .contains_key(&id)
    {
        log::warn!("Game already has an active operation: {id}");
        return Ok(false);
    }

    log::info!("Starting update for game: {id}");
    let peer_ctrl_arc = state.inner().peer_ctrl.clone();
    let peer_ctrl = peer_ctrl_arc.read().await.clone();

    let _ = (language, username);
    if let Some(peer_ctrl) = peer_ctrl {
        if let Err(e) = peer_ctrl.send(PeerCommand::FetchLatestFromPeers { id: id.clone() }) {
            log::error!("Failed to send message to peer: {e:?}");
            return Ok(false);
        }
        Ok(true)
    } else {
        log::warn!("Peer system not initialized yet");
        Ok(false)
    }
}

#[tauri::command]
async fn uninstall_game(
    id: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<bool> {
    if state
        .inner()
        .active_operations
        .read()
        .await
        .contains_key(&id)
    {
        log::warn!("Game already has an active operation: {id}");
        return Ok(false);
    }

    let peer_ctrl_arc = state.inner().peer_ctrl.clone();
    let peer_ctrl = peer_ctrl_arc.read().await.clone();
    if let Some(peer_ctrl) = peer_ctrl {
        if let Err(e) = peer_ctrl.send(PeerCommand::UninstallGame { id }) {
            log::error!("Failed to send message to peer: {e:?}");
            return Ok(false);
        }
        Ok(true)
    } else {
        log::warn!("Peer system not initialized yet");
        Ok(false)
    }
}

#[tauri::command]
async fn remove_downloaded_game(
    id: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<bool> {
    if state
        .inner()
        .active_operations
        .read()
        .await
        .contains_key(&id)
    {
        log::warn!("Game already has an active operation: {id}");
        return Ok(false);
    }

    let Some((downloaded, installed)) = state
        .inner()
        .games
        .read()
        .await
        .get_game_by_id(&id)
        .map(|game| (game.downloaded, game.installed))
    else {
        log::warn!("Ignoring downloaded-file removal for unknown game: {id}");
        return Ok(false);
    };
    if !downloaded || installed {
        log::warn!(
            "Ignoring downloaded-file removal for {id}: downloaded={downloaded}, installed={installed}"
        );
        return Ok(false);
    }

    let peer_ctrl_arc = state.inner().peer_ctrl.clone();
    let peer_ctrl = peer_ctrl_arc.read().await.clone();
    if let Some(peer_ctrl) = peer_ctrl {
        if let Err(e) = peer_ctrl.send(PeerCommand::RemoveDownloadedGame { id }) {
            log::error!("Failed to send message to peer: {e:?}");
            return Ok(false);
        }
        Ok(true)
    } else {
        log::warn!("Peer system not initialized yet");
        Ok(false)
    }
}

#[tauri::command]
async fn cancel_download(
    id: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<bool> {
    let is_active_download = {
        let active_operations = state.inner().active_operations.read().await;
        matches!(
            active_operations.get(&id),
            Some(UiOperationKind::Downloading)
        )
    };
    if !is_active_download {
        log::warn!("Ignoring cancel request for inactive download: {id}");
        return Ok(false);
    }

    let peer_ctrl_arc = state.inner().peer_ctrl.clone();
    let peer_ctrl = peer_ctrl_arc.read().await.clone();
    if let Some(peer_ctrl) = peer_ctrl {
        if let Err(e) = peer_ctrl.send(PeerCommand::CancelDownload { id }) {
            log::error!("Failed to send message to peer: {e:?}");
            return Ok(false);
        }
        Ok(true)
    } else {
        log::warn!("Peer system not initialized yet");
        Ok(false)
    }
}

#[tauri::command]
async fn open_game_files(
    id: String,
    app_handle: AppHandle,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<bool> {
    let Some(target) = resolve_game_root_for_open(&id, &state).await else {
        return Ok(false);
    };

    #[allow(deprecated)]
    if let Err(e) = app_handle.shell().open(target.display().to_string(), None) {
        log::error!("Failed to open file viewer for {}: {e}", target.display());
        return Ok(false);
    }

    Ok(true)
}

async fn resolve_game_root_for_open(
    id: &str,
    state: &tauri::State<'_, LanSpreadState>,
) -> Option<PathBuf> {
    if !is_single_component_game_id(id) {
        log::warn!("Ignoring file viewer request for invalid game id: {id}");
        return None;
    }
    if state
        .inner()
        .games
        .read()
        .await
        .get_game_by_id(id)
        .is_none()
    {
        log::warn!("Ignoring file viewer request for unknown game: {id}");
        return None;
    }

    let games_folder = PathBuf::from(state.inner().games_folder.read().await.clone());
    let Ok(root) = games_folder.canonicalize() else {
        log::warn!(
            "Cannot open files because game directory is unavailable: {}",
            games_folder.display()
        );
        return None;
    };
    let target = root.join(id);
    let Ok(target) = target.canonicalize() else {
        log::warn!(
            "Cannot open files because game root is unavailable: {}",
            target.display()
        );
        return None;
    };
    if !target.is_dir() || !target.starts_with(&root) {
        log::warn!(
            "Refusing to open file viewer outside game directory: {}",
            target.display()
        );
        return None;
    }

    Some(target)
}

fn is_single_component_game_id(id: &str) -> bool {
    let mut components = Path::new(id).components();
    matches!(components.next(), Some(Component::Normal(_))) && components.next().is_none()
}

#[derive(Clone, Debug, PartialEq, Eq)]
#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
struct LaunchSettings {
    language: String,
    username: String,
}

#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
fn launch_settings(language: &str, username: &str) -> LaunchSettings {
    LaunchSettings {
        language: sanitize_language(language),
        username: sanitize_username(username),
    }
}

fn install_settings(language: &str, username: &str) -> InstallSettings {
    InstallSettings {
        account_name: sanitize_username(username),
        language: install_language(language),
    }
}

fn install_language(language: &str) -> String {
    match sanitize_language(language).as_str() {
        "de" => "german".to_string(),
        _ => "english".to_string(),
    }
}

#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
fn sanitize_language(language: &str) -> String {
    match language.trim().to_ascii_lowercase().as_str() {
        "de" => "de".to_string(),
        "en" => "en".to_string(),
        _ => DEFAULT_LANGUAGE.to_string(),
    }
}

#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
fn sanitize_username(username: &str) -> String {
    let cleaned = username
        .trim()
        .chars()
        .filter(|c| !c.is_control() && *c != '"' && *c != '%')
        .take(MAX_USERNAME_CHARS)
        .collect::<String>();

    if cleaned.is_empty() {
        DEFAULT_USERNAME.to_string()
    } else {
        cleaned
    }
}

#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
fn script_params(script_path: &Path, id: &str, settings: &LaunchSettings) -> String {
    script_params_with_mode("/c", script_path, id, settings)
}

#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
fn server_script_params(script_path: &Path, id: &str, settings: &LaunchSettings) -> String {
    script_params_with_mode("/k", script_path, id, settings)
}

#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
fn script_params_with_mode(
    cmd_mode: &str,
    script_path: &Path,
    id: &str,
    settings: &LaunchSettings,
) -> String {
    format!(
        r#"/d /s {cmd_mode} ""{}" "local" "{}" "{}" "{}"""#,
        script_path.display(),
        id,
        settings.language,
        settings.username,
    )
}

#[tauri::command]
async fn get_peer_count(state: tauri::State<'_, LanSpreadState>) -> tauri::Result<usize> {
    let peer_ctrl_arc = state.inner().peer_ctrl.clone();
    let peer_ctrl = peer_ctrl_arc.read().await.clone();

    if let Some(peer_ctrl) = peer_ctrl {
        // Send a request to get peer count
        if let Err(e) = peer_ctrl.send(PeerCommand::GetPeerCount) {
            log::error!("Failed to send GetPeerCount message to peer: {e:?}");
        }
    }

    // For now, we'll return 0 and rely on the event-based updates
    // The UI will get the actual count through peer-count-updated events
    Ok(0)
}

#[tauri::command]
async fn get_game_thumbnail(
    game_id: String,
    app_handle: tauri::AppHandle,
) -> tauri::Result<String> {
    use base64::Engine;

    let resource_path = app_handle.path().resolve(
        format!("assets/{game_id}.jpg"),
        tauri::path::BaseDirectory::Resource,
    )?;

    dbg!(&resource_path);

    let image_data = std::fs::read(&resource_path)?;
    let base64_data = base64::engine::general_purpose::STANDARD.encode(&image_data);
    Ok(format!("data:image/jpeg;base64,{base64_data}"))
}

#[cfg(target_os = "windows")]
fn run_as_admin(
    file: &str,
    params: &str,
    dir: &str,
    show_cmd: windows::Win32::UI::WindowsAndMessaging::SHOW_WINDOW_CMD,
) -> bool {
    use std::{ffi::OsStr, os::windows::ffi::OsStrExt};

    use windows::{Win32::UI::Shell::ShellExecuteW, core::PCWSTR};

    let file_wide: Vec<u16> = OsStr::new(file).encode_wide().chain(Some(0)).collect();
    let params_wide: Vec<u16> = OsStr::new(params).encode_wide().chain(Some(0)).collect();
    let dir_wide: Vec<u16> = OsStr::new(dir).encode_wide().chain(Some(0)).collect();
    let runas_wide: Vec<u16> = OsStr::new("runas").encode_wide().chain(Some(0)).collect();

    let result = unsafe {
        ShellExecuteW(
            None,
            PCWSTR::from_raw(runas_wide.as_ptr()),
            PCWSTR::from_raw(file_wide.as_ptr()),
            PCWSTR::from_raw(params_wide.as_ptr()),
            PCWSTR::from_raw(dir_wide.as_ptr()),
            show_cmd,
        )
    };

    (result.0 as usize) > 32 // Success if greater than 32
}

#[cfg(target_os = "windows")]
async fn run_game_windows(
    id: String,
    language: String,
    username: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<()> {
    if !is_single_component_game_id(&id) {
        log::warn!("Ignoring run request for invalid game id: {id}");
        return Ok(());
    }

    let settings = launch_settings(&language, &username);
    let games_folder_lock = state.inner().games_folder.clone();
    let games_folder = {
        let guard = games_folder_lock.read().await;
        guard.clone()
    };

    let games_folder = PathBuf::from(games_folder);
    if !games_folder.exists() {
        log::error!("games_folder {} does not exist", games_folder.display());
        return Ok(());
    }

    let game_path = games_folder.join(id.clone());

    let game_setup_bin = game_path.join(GAME_SETUP_SCRIPT);
    let game_start_bin = game_path.join(GAME_START_SCRIPT);
    let Some(state_dir) = state.inner().state_dir.get().cloned() else {
        log::error!("app state directory is not initialized; cannot run game");
        return Ok(());
    };

    let setup_done_file = lanspread_peer::setup_done_path(&state_dir, &id);
    if !setup_done_file.exists() && game_setup_bin.exists() {
        if !local_install_is_present(&game_path) {
            log::warn!(
                "local install is missing for {}; skipping game_setup",
                game_path.display()
            );
            return Ok(());
        }

        let result = run_as_admin(
            "cmd.exe",
            &script_params(&game_setup_bin, &id, &settings),
            &game_path.display().to_string(),
            windows::Win32::UI::WindowsAndMessaging::SW_HIDE,
        );

        if !result {
            log::error!("failed to run {GAME_SETUP_SCRIPT}");
            return Ok(());
        }

        if let Some(parent) = setup_done_file.parent()
            && let Err(e) = std::fs::create_dir_all(parent)
        {
            log::error!(
                "failed to create setup marker directory {}: {e}",
                parent.display()
            );
        }

        if let Err(e) = std::fs::File::create(&setup_done_file) {
            log::error!(
                "failed to create setup marker {}: {e}",
                setup_done_file.display()
            );
        }
    }

    apply_launch_settings(&state_dir, &game_path, &id, &language, &username).await;

    if game_start_bin.exists() {
        let result = run_as_admin(
            "cmd.exe",
            &script_params(&game_start_bin, &id, &settings),
            &game_path.display().to_string(),
            windows::Win32::UI::WindowsAndMessaging::SW_HIDE,
        );

        if !result {
            log::error!("failed to run {GAME_START_SCRIPT}");
        }
    }

    Ok(())
}

/// Stamp the launcher's username and language into the installed game's setting
/// files the first time it is played. Uses the same processed values the install
/// transaction used to write before this step moved to play time.
#[cfg_attr(not(target_os = "windows"), allow(dead_code))]
async fn apply_launch_settings(
    state_dir: &Path,
    game_path: &Path,
    id: &str,
    language: &str,
    username: &str,
) {
    let settings = install_settings(language, username);
    match lanspread_peer::apply_launch_settings_once(
        state_dir,
        game_path,
        id,
        Some(&settings.account_name),
        Some(&settings.language),
    )
    .await
    {
        Ok(outcome) => log::info!("launch settings for {id}: {outcome:?}"),
        Err(e) => log::error!("failed to apply launch settings for {id}: {e}"),
    }
}

#[tauri::command]
async fn run_game(
    id: String,
    language: String,
    username: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<()> {
    #[cfg(target_os = "windows")]
    {
        run_game_windows(id, language, username, state).await?;
    }

    #[cfg(not(target_os = "windows"))]
    {
        let _ = (state, language, username);
        log::error!("run_game not implemented for this platform: id={id}");
    }

    Ok(())
}

#[cfg(target_os = "windows")]
async fn start_server_windows(
    id: String,
    language: String,
    username: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<bool> {
    if !is_single_component_game_id(&id) {
        log::warn!("Ignoring server start request for invalid game id: {id}");
        return Ok(false);
    }

    let settings = launch_settings(&language, &username);
    let games_folder = PathBuf::from(state.inner().games_folder.read().await.clone());
    if !games_folder.exists() {
        log::error!("games_folder {} does not exist", games_folder.display());
        return Ok(false);
    }

    let game_path = games_folder.join(id.clone());
    if !local_install_is_present(&game_path) {
        log::warn!(
            "local install is missing for {}; skipping {SERVER_START_SCRIPT}",
            game_path.display()
        );
        return Ok(false);
    }

    let server_start_bin = game_path.join(SERVER_START_SCRIPT);
    if !server_start_bin.is_file() {
        log::warn!(
            "server start script is missing for {}: {}",
            id,
            server_start_bin.display()
        );
        return Ok(false);
    }

    let Some(state_dir) = state.inner().state_dir.get().cloned() else {
        log::error!("app state directory is not initialized; cannot start server");
        return Ok(false);
    };
    apply_launch_settings(&state_dir, &game_path, &id, &language, &username).await;

    let result = run_as_admin(
        "cmd.exe",
        &server_script_params(&server_start_bin, &id, &settings),
        &game_path.display().to_string(),
        windows::Win32::UI::WindowsAndMessaging::SW_SHOWNORMAL,
    );

    if !result {
        log::error!("failed to run {SERVER_START_SCRIPT}");
    }

    Ok(result)
}

#[tauri::command]
async fn start_server(
    id: String,
    language: String,
    username: String,
    state: tauri::State<'_, LanSpreadState>,
) -> tauri::Result<bool> {
    #[cfg(target_os = "windows")]
    {
        start_server_windows(id, language, username, state).await
    }

    #[cfg(not(target_os = "windows"))]
    {
        let _ = (state, language, username);
        log::error!("start_server not implemented for this platform: id={id}");
        Ok(false)
    }
}

#[cfg(target_os = "windows")]
fn local_install_is_present(game_path: &Path) -> bool {
    game_path.join("local").is_dir()
}

fn clear_local_game_state(game: &mut Game) {
    game.set_downloaded(false);
    game.installed = false;
    game.local_version = None;
}

fn has_local_game_state(game: &Game) -> bool {
    game.downloaded
        || game.installed
        || game.local_version.is_some()
        || game.availability != Availability::LocalOnly
}

fn apply_peer_local_state(existing: &mut Game, local_game: &Game) {
    existing.set_downloaded(local_game.downloaded);
    existing.installed = local_game.installed;
    existing.local_version.clone_from(&local_game.local_version);
    existing.availability = local_game.normalized_availability();
}

fn apply_peer_local_games(game_db: &mut GameDB, local_games: &[Game]) {
    let local_game_ids = local_games
        .iter()
        .map(|game| game.id.clone())
        .collect::<HashSet<_>>();

    for local_game in local_games {
        if let Some(existing_game) = game_db.get_mut_game_by_id(&local_game.id) {
            apply_peer_local_state(existing_game, local_game);
            log::debug!("Updated local game status for: {}", local_game.id);
        }
    }

    for game in game_db.games.values_mut() {
        if !local_game_ids.contains(&game.id) && has_local_game_state(game) {
            log::info!(
                "Game {} missing from peer local snapshot; marking as unavailable locally",
                game.id
            );
            clear_local_game_state(game);
        }
    }
}

fn apply_peer_remote_games(game_db: &mut GameDB, peer_games: Vec<Game>) {
    // Peer events update availability, but catalog metadata stays anchored to game.db.
    for game in game_db.games.values_mut() {
        game.peer_count = 0;
    }

    for peer_game in peer_games {
        if let Some(existing) = game_db.get_mut_game_by_id(&peer_game.id) {
            existing.peer_count = peer_game.peer_count;
        } else {
            log::debug!(
                "Peer advertised unknown game {id}; ignoring because game.db is ground truth",
                id = peer_game.id
            );
        }
    }
}

fn clear_all_local_game_states(game_db: &mut GameDB) {
    for game in game_db.games.values_mut() {
        clear_local_game_state(game);
    }
}

async fn emit_games_list(app_handle: &AppHandle) {
    let state = app_handle.state::<LanSpreadState>();

    let installed_peer_counts = state
        .peer_game_db
        .read()
        .await
        .peer_snapshots()
        .into_iter()
        .flat_map(|peer| peer.games)
        .filter(|game| game.installed)
        .fold(HashMap::<String, u32>::new(), |mut counts, game| {
            *counts.entry(game.id).or_default() += 1;
            counts
        });

    let games_db_lock = state.games.clone();
    let game_db = games_db_lock.read().await;
    let games_folder = state.games_folder.read().await.clone();

    if game_db.games.is_empty() {
        log::debug!("Game database empty; skipping emit");
        return;
    }

    let active_transfers = state.active_outbound_transfers.read().await;

    let games_to_emit = game_db
        .all_games()
        .into_iter()
        .cloned()
        .map(|game| {
            let active_outbound_transfers = active_transfers.get(&game.id).map_or(0, Vec::len);
            LauncherGame {
                can_host_server: game_can_host_server(&games_folder, &game),
                active_outbound_transfers,
                installed_peer_count: installed_peer_counts.get(&game.id).copied().unwrap_or(0),
                game,
            }
        })
        .collect::<Vec<LauncherGame>>();

    drop(game_db);
    drop(active_transfers);

    let active_operations = {
        let active_operations = state.active_operations.read().await;
        ui_active_operations_from_map(&active_operations)
    };

    let payload = GamesListPayload {
        games: games_to_emit,
        active_operations,
    };

    if let Err(e) = app_handle.emit("games-list-updated", Some(payload)) {
        log::error!("Failed to emit games-list-updated event: {e}");
    } else {
        log::info!("Emitted games-list-updated event");
    }
}

fn game_can_host_server(games_folder: &str, game: &Game) -> bool {
    if !game.installed || games_folder.is_empty() || !is_single_component_game_id(&game.id) {
        return false;
    }

    PathBuf::from(games_folder)
        .join(&game.id)
        .join(SERVER_START_SCRIPT)
        .is_file()
}

fn ui_active_operations_from_map(
    active_operations: &HashMap<String, UiOperationKind>,
) -> Vec<UiActiveOperation> {
    let mut snapshot = active_operations
        .iter()
        .map(|(id, operation)| UiActiveOperation {
            id: id.clone(),
            operation: *operation,
        })
        .collect::<Vec<_>>();
    snapshot.sort_by(|left, right| left.id.cmp(&right.id));
    snapshot
}

fn reconcile_active_operations(
    active_operations: &mut HashMap<String, UiOperationKind>,
    snapshot: &[ActiveOperation],
) {
    active_operations.clear();
    active_operations.extend(snapshot.iter().map(|operation| {
        (
            operation.id.clone(),
            ui_operation_from_peer(operation.operation),
        )
    }));
}

fn ui_operation_from_peer(operation: ActiveOperationKind) -> UiOperationKind {
    match operation {
        ActiveOperationKind::Downloading => UiOperationKind::Downloading,
        ActiveOperationKind::Installing => UiOperationKind::Installing,
        ActiveOperationKind::Updating => UiOperationKind::Updating,
        ActiveOperationKind::Uninstalling => UiOperationKind::Uninstalling,
        ActiveOperationKind::RemovingDownload => UiOperationKind::RemovingDownload,
    }
}

#[tauri::command]
fn game_directory_exists(path: String) -> bool {
    PathBuf::from(path).is_dir()
}

#[tauri::command]
async fn update_game_directory(app_handle: tauri::AppHandle, path: String) -> tauri::Result<()> {
    log::info!("update_game_directory: {path}");

    let games_folder = PathBuf::from(&path);
    if !games_folder.is_dir() {
        log::error!("game dir {} does not exist", games_folder.display());
        return Ok(());
    }

    let state = app_handle.state::<LanSpreadState>();
    let current_path = state.games_folder.read().await.clone();
    let active_ids = state
        .active_operations
        .read()
        .await
        .keys()
        .cloned()
        .collect::<Vec<_>>();
    if current_path != path && !active_ids.is_empty() {
        log::warn!(
            "Rejecting game directory change to {} while UI operations are active for: {}",
            games_folder.display(),
            active_ids.join(", ")
        );
        return Ok(());
    }

    let path_changed = current_path != path;
    let Some(state_dir) = state.state_dir.get().cloned() else {
        log::error!("app state directory is not initialized; cannot update game directory");
        return Ok(());
    };

    if path_changed || state.peer_ctrl.read().await.is_none() {
        let migration = migrate_legacy_state(&games_folder, &state_dir).await;
        if migration.failures > 0 {
            log::warn!(
                "Legacy state migration completed with {} failure(s)",
                migration.failures
            );
        }
    }

    *state.games_folder.write().await = path;

    ensure_bundled_game_db_loaded(&app_handle).await;
    if path_changed {
        let mut game_db = state.games.write().await;
        clear_all_local_game_states(&mut game_db);
    }

    emit_games_list(&app_handle).await;
    ensure_peer_started(&app_handle, &games_folder).await;

    Ok(())
}

async fn update_game_db(games: Vec<Game>, app: AppHandle) {
    for game in &games {
        log::trace!("peer event ListGames iter: {game:?}");
    }

    let state = app.state::<LanSpreadState>();

    {
        let mut game_db = state.games.write().await;
        apply_peer_remote_games(&mut game_db, games);
    }

    emit_games_list(&app).await;
}

async fn update_local_games_in_db(local_games: Vec<Game>, app: AppHandle) {
    let state = app.state::<LanSpreadState>();

    {
        let mut game_db = state.games.write().await;
        apply_peer_local_games(&mut game_db, &local_games);
    }

    emit_games_list(&app).await;
}

fn add_final_slash(path: &str) -> String {
    #[cfg(target_os = "windows")]
    const SLASH_CHAR: char = '\\';

    #[cfg(not(target_os = "windows"))]
    const SLASH_CHAR: char = '/';

    if path.ends_with(SLASH_CHAR) {
        path.to_string()
    } else {
        format!("{path}{SLASH_CHAR}")
    }
}

async fn do_unrar(
    app_handle: &AppHandle,
    sidecar: Command,
    rar_file: &Path,
    dest_dir: &Path,
) -> eyre::Result<()> {
    let started_at_ms = now_millis();
    let paths = prepare_unrar_paths(app_handle, rar_file, dest_dir, started_at_ms).await?;

    log::info!(
        "unrar game: {} to {}",
        paths.archive.display(),
        paths.destination.display()
    );

    run_unrar_sidecar(app_handle, sidecar, &paths, started_at_ms).await
}

struct UnrarPaths {
    archive: PathBuf,
    destination: PathBuf,
    destination_arg: String,
}

async fn prepare_unrar_paths(
    app_handle: &AppHandle,
    rar_file: &Path,
    dest_dir: &Path,
    started_at_ms: u64,
) -> eyre::Result<UnrarPaths> {
    let original_archive = rar_file.display().to_string();
    let original_destination = dest_dir.display().to_string();

    if let Err(err) = std::fs::create_dir_all(dest_dir) {
        let stderr = format!("failed to create directory {}: {err}", dest_dir.display());
        record_unpack_failure(
            app_handle,
            original_archive,
            original_destination,
            started_at_ms,
            stderr.clone(),
        )
        .await;
        bail!("{stderr}");
    }

    let rar_file = match rar_file.canonicalize() {
        Ok(path) => path,
        Err(err) => {
            let stderr = format!(
                "rar_file canonicalize failed for {}: {err}",
                rar_file.display()
            );
            record_unpack_failure(
                app_handle,
                original_archive,
                original_destination,
                started_at_ms,
                stderr.clone(),
            )
            .await;
            bail!("{stderr}");
        }
    };
    let dest_dir = match dest_dir.canonicalize() {
        Ok(path) => path,
        Err(err) => {
            let stderr = format!(
                "dest_dir canonicalize failed for {}: {err}",
                dest_dir.display()
            );
            record_unpack_failure(
                app_handle,
                rar_file.display().to_string(),
                original_destination,
                started_at_ms,
                stderr.clone(),
            )
            .await;
            bail!("{stderr}");
        }
    };
    let Some(dest_dir_arg) = dest_dir.to_str().map(add_final_slash) else {
        let stderr = format!("failed to get str of dest_dir {}", dest_dir.display());
        record_unpack_failure(
            app_handle,
            rar_file.display().to_string(),
            dest_dir.display().to_string(),
            started_at_ms,
            stderr.clone(),
        )
        .await;
        bail!("{stderr}");
    };

    Ok(UnrarPaths {
        archive: rar_file,
        destination: dest_dir,
        destination_arg: dest_dir_arg,
    })
}

async fn run_unrar_sidecar(
    app_handle: &AppHandle,
    sidecar: Command,
    paths: &UnrarPaths,
    started_at_ms: u64,
) -> eyre::Result<()> {
    // Spawn (instead of `.output()`) so we keep a killable handle. The shell
    // plugin's `output()` drops the `CommandChild` immediately and only drains
    // the event channel, leaving the unrar process orphaned if the launcher
    // exits before extraction finishes.
    let (mut events, child) = match sidecar
        .arg("x") // extract files
        .arg(&paths.archive)
        .arg("-y") // Assume Yes on all queries
        .arg("-o") // Set overwrite mode
        .arg(&paths.destination_arg)
        .spawn()
    {
        Ok(spawned) => spawned,
        Err(err) => {
            let stderr = format!("failed to run unrar sidecar: {err}");
            record_unpack_failure(
                app_handle,
                paths.archive.display().to_string(),
                paths.destination.display().to_string(),
                started_at_ms,
                stderr.clone(),
            )
            .await;
            bail!("{stderr}");
        }
    };

    // Register the live child so a launcher exit can kill it, and deregister it
    // automatically on every exit path via the RAII guard.
    let registry = app_handle
        .state::<LanSpreadState>()
        .active_unrar_children
        .clone();
    let child_id = UNRAR_CHILD_SEQ.fetch_add(1, Ordering::Relaxed);
    register_unrar_child(&registry, child_id, child);
    let _child_guard = UnrarChildGuard { registry, child_id };

    let mut stdout_bytes = Vec::new();
    let mut stderr_bytes = Vec::new();
    let mut status_code = None;
    while let Some(event) = events.recv().await {
        match event {
            CommandEvent::Stdout(line) => {
                stdout_bytes.extend(line);
                stdout_bytes.push(b'\n');
            }
            CommandEvent::Stderr(line) => {
                stderr_bytes.extend(line);
                stderr_bytes.push(b'\n');
            }
            CommandEvent::Terminated(payload) => {
                status_code = payload.code;
            }
            CommandEvent::Error(err) => {
                log::warn!("unrar sidecar event error: {err}");
            }
            _ => {}
        }
    }

    let stdout = clean_terminal_log(&String::from_utf8_lossy(&stdout_bytes));
    let stderr = clean_terminal_log(&String::from_utf8_lossy(&stderr_bytes));
    let success = status_code == Some(0);

    record_unpack_log(
        app_handle,
        UnpackLogEntry {
            archive: paths.archive.display().to_string(),
            destination: paths.destination.display().to_string(),
            status_code,
            stdout: stdout.clone(),
            stderr: stderr.clone(),
            started_at_ms,
            finished_at_ms: now_millis(),
            success,
        },
    )
    .await;

    if !success {
        if !stdout.trim().is_empty() {
            log::error!("unrar stdout: {stdout}");
        }
        if !stderr.trim().is_empty() {
            log::error!("unrar stderr: {stderr}");
        }
        bail!("unrar failed with status {status_code:?}: {stderr}");
    }

    Ok(())
}

/// Tracks a spawned unrar sidecar so the launcher can kill it on shutdown.
///
/// If shutdown has already begun (or the registry is poisoned), the child is
/// killed immediately instead of inserted, since the exit kill sweep has already
/// run and would never reap a late registration.
fn register_unrar_child(
    registry: &Arc<Mutex<UnrarChildRegistry>>,
    child_id: u64,
    child: CommandChild,
) {
    let Ok(mut guard) = registry.lock() else {
        // A poisoned registry means we can no longer guarantee the child is
        // killed on exit, so kill it now rather than risk orphaning it.
        let pid = child.pid();
        log::warn!("unrar child registry is poisoned; killing pid {pid} immediately");
        if let Err(err) = child.kill() {
            log::warn!("Failed to kill untracked unrar child (pid {pid}): {err}");
        }
        return;
    };

    if guard.shutting_down {
        drop(guard);
        let pid = child.pid();
        log::info!("Killing unrar child (pid {pid}) that spawned during shutdown");
        if let Err(err) = child.kill() {
            log::warn!("Failed to kill unrar child (pid {pid}) spawned during shutdown: {err}");
        }
        return;
    }

    guard.children.insert(child_id, child);
}

/// Removes an unrar sidecar from the registry when its `run_unrar_sidecar` call
/// returns, regardless of success, error, or early bail.
struct UnrarChildGuard {
    registry: Arc<Mutex<UnrarChildRegistry>>,
    child_id: u64,
}

impl Drop for UnrarChildGuard {
    fn drop(&mut self) {
        if let Ok(mut guard) = self.registry.lock() {
            guard.children.remove(&self.child_id);
        }
    }
}

/// Kills every in-progress unrar sidecar and latches the registry into shutdown
/// so any install task that spawns unrar after this point kills it on
/// registration. Called on app exit so a game install that is mid-extraction does
/// not leave `unrar` running after the launcher closes.
fn kill_active_unrar_children(app_handle: &AppHandle) {
    let state = app_handle.state::<LanSpreadState>();
    let children = {
        let Ok(mut guard) = state.active_unrar_children.lock() else {
            log::warn!("unrar child registry is poisoned; cannot kill children on shutdown");
            return;
        };
        guard.shutting_down = true;
        guard.children.drain().collect::<Vec<_>>()
    };

    for (_child_id, child) in children {
        let pid = child.pid();
        match child.kill() {
            Ok(()) => log::info!("Killed in-progress unrar child (pid {pid}) on shutdown"),
            Err(err) => log::warn!("Failed to kill unrar child (pid {pid}) on shutdown: {err}"),
        }
    }
}

async fn record_unpack_failure(
    app_handle: &AppHandle,
    archive: String,
    destination: String,
    started_at_ms: u64,
    stderr: String,
) {
    record_unpack_log(
        app_handle,
        UnpackLogEntry {
            archive,
            destination,
            status_code: None,
            stdout: String::new(),
            stderr,
            started_at_ms,
            finished_at_ms: now_millis(),
            success: false,
        },
    )
    .await;
}

async fn record_unpack_log(app_handle: &AppHandle, entry: UnpackLogEntry) {
    let state = app_handle.state::<LanSpreadState>();
    let mut entry = entry;
    clean_unpack_log_entry(&mut entry);
    let logs = {
        let mut logs = state.inner().unpack_logs.write().await;
        logs.push(entry);
        trim_unpack_logs(&mut logs);
        logs.clone()
    };

    persist_unpack_logs(app_handle, &logs).await;

    if let Err(err) = app_handle.emit("unpack-logs-updated", ()) {
        log::warn!("Failed to emit unpack-logs-updated event: {err}");
    }
}

fn trim_unpack_logs(logs: &mut Vec<UnpackLogEntry>) {
    if logs.len() > MAX_UNPACK_LOGS {
        let overflow = logs.len() - MAX_UNPACK_LOGS;
        logs.drain(..overflow);
    }
}

fn clean_unpack_log_entry(entry: &mut UnpackLogEntry) {
    let stdout = clean_terminal_log(&entry.stdout);
    let stderr = clean_terminal_log(&entry.stderr);
    entry.stdout = stdout;
    entry.stderr = stderr;
}

fn clean_terminal_log(input: &str) -> String {
    let mut output = String::new();
    let mut line = String::new();
    let mut chars = input.chars().peekable();

    while let Some(ch) = chars.next() {
        match ch {
            '\r' if chars.peek() == Some(&'\n') => {
                let _ = chars.next();
                output.push_str(&line);
                output.push('\n');
                line.clear();
            }
            '\r' => {
                line.clear();
            }
            '\n' => {
                output.push_str(&line);
                output.push('\n');
                line.clear();
            }
            '\u{8}' => {
                let _ = line.pop();
            }
            '\t' => line.push(ch),
            ch if ch.is_control() => {}
            ch => line.push(ch),
        }
    }

    output.push_str(&line);
    output
}

fn unpack_logs_path(state_dir: &Path) -> PathBuf {
    state_dir.join(UNPACK_LOGS_FILE_NAME)
}

fn main_log_path(state_dir: &Path) -> PathBuf {
    state_dir.join(MAIN_LOG_FILE_NAME)
}

#[cfg(test)]
fn trim_main_log_file_to_limit(path: &Path, max_bytes: u64) -> io::Result<()> {
    let mut file = match OpenOptions::new().read(true).write(true).open(path) {
        Ok(file) => file,
        Err(err) if err.kind() == io::ErrorKind::NotFound => return Ok(()),
        Err(err) => return Err(err),
    };

    trim_main_log_file_to_limit_with_file(&mut file, max_bytes)
}

fn trim_main_log_file_to_limit_with_file(file: &mut fs::File, max_bytes: u64) -> io::Result<()> {
    let metadata = file.metadata()?;

    if metadata.len() <= max_bytes {
        file.seek(SeekFrom::End(0))?;
        return Ok(());
    }

    let tail = if max_bytes == 0 {
        String::new()
    } else {
        file.seek(SeekFrom::Start(metadata.len() - max_bytes))?;

        let mut bytes = Vec::with_capacity(usize::try_from(max_bytes).unwrap_or(usize::MAX));
        file.read_to_end(&mut bytes)?;
        valid_utf8_tail(bytes)
    };

    file.set_len(0)?;
    file.seek(SeekFrom::Start(0))?;
    file.write_all(tail.as_bytes())?;
    file.seek(SeekFrom::End(0))?;
    Ok(())
}

fn read_main_log_file_to_limit(path: &Path, max_bytes: u64) -> io::Result<String> {
    let mut file = fs::File::open(path)?;
    read_main_log_file_to_limit_with_file(&mut file, max_bytes)
}

fn read_main_log_file_to_limit_with_file(
    file: &mut fs::File,
    max_bytes: u64,
) -> io::Result<String> {
    let metadata = file.metadata()?;
    if metadata.len() == 0 || max_bytes == 0 {
        file.seek(SeekFrom::End(0))?;
        return Ok(String::new());
    }

    let start = metadata.len().saturating_sub(max_bytes);
    file.seek(SeekFrom::Start(start))?;

    let capacity = usize::try_from(metadata.len() - start).unwrap_or(usize::MAX);
    let mut bytes = Vec::with_capacity(capacity);
    file.read_to_end(&mut bytes)?;
    file.seek(SeekFrom::End(0))?;

    if start == 0 {
        Ok(String::from_utf8_lossy(&bytes).into_owned())
    } else {
        Ok(valid_utf8_tail(bytes))
    }
}

fn valid_utf8_tail(bytes: Vec<u8>) -> String {
    for offset in 0..bytes.len().min(4) {
        if let Ok(tail) = std::str::from_utf8(&bytes[offset..]) {
            return tail.to_string();
        }
    }

    String::from_utf8_lossy(&bytes).into_owned()
}

#[derive(Clone)]
struct MainLogSink {
    app_handle: AppHandle,
    path: PathBuf,
    file_state: Arc<Mutex<MainLogFileState>>,
}

#[derive(Default)]
struct MainLogFileState {
    file: Option<fs::File>,
    last_sequence: u64,
}

impl MainLogSink {
    fn new(app_handle: AppHandle, path: PathBuf) -> Self {
        Self {
            app_handle,
            path,
            file_state: Arc::new(Mutex::new(MainLogFileState::default())),
        }
    }

    fn write_line(&self, line: String, level: Level) {
        write_main_log_stdout(&line);
        let sequence = self.append_file_line(&line);

        let _ = self.app_handle.emit(
            "main-log-line",
            MainLogLinePayload {
                line,
                level: level.as_str().to_string(),
                sequence,
            },
        );
    }

    fn read_history(&self) -> io::Result<MainLogHistoryPayload> {
        let mut file_state = self
            .file_state
            .lock()
            .map_err(|_| io::Error::other("main log file lock poisoned"))?;

        if file_state.file.is_none() && !self.path.exists() {
            return Ok(MainLogHistoryPayload {
                contents: String::new(),
                last_sequence: file_state.last_sequence,
            });
        }

        let contents = {
            let file = self.cached_file(&mut file_state.file)?;
            trim_main_log_file_to_limit_with_file(file, MAX_MAIN_LOG_BYTES)?;
            read_main_log_file_to_limit_with_file(file, MAX_MAIN_LOG_BYTES)?
        };

        Ok(MainLogHistoryPayload {
            contents,
            last_sequence: file_state.last_sequence,
        })
    }

    fn append_file_line(&self, line: &str) -> Option<u64> {
        let Ok(mut file_state) = self.file_state.lock() else {
            return None;
        };

        let write_result = self.cached_file(&mut file_state.file).and_then(|file| {
            file.seek(SeekFrom::End(0))
                .and_then(|_| writeln!(file, "{line}"))
        });

        if write_result.is_err() {
            file_state.file = None;
            return None;
        }

        file_state.last_sequence = file_state.last_sequence.saturating_add(1);
        let sequence = file_state.last_sequence;

        let should_trim = file_state.file.as_ref().is_some_and(|file| {
            file.metadata().is_ok_and(|metadata| {
                metadata.len() > MAX_MAIN_LOG_BYTES.saturating_add(MAIN_LOG_TRIM_SLACK_BYTES)
            })
        });

        if should_trim && let Some(file) = file_state.file.as_mut() {
            let _ = trim_main_log_file_to_limit_with_file(file, MAX_MAIN_LOG_BYTES);
        }

        Some(sequence)
    }

    fn cached_file<'a>(&self, file: &'a mut Option<fs::File>) -> io::Result<&'a mut fs::File> {
        if file.is_none() {
            *file = Some(open_main_log_file(&self.path)?);
        }

        file.as_mut()
            .ok_or_else(|| io::Error::other("main log file was not opened"))
    }
}

fn open_main_log_file(path: &Path) -> io::Result<fs::File> {
    if let Some(parent) = path.parent() {
        fs::create_dir_all(parent)?;
    }

    OpenOptions::new()
        .create(true)
        .truncate(false)
        .read(true)
        .write(true)
        .open(path)
}

struct MainLogLayer {
    sink: MainLogSink,
}

impl MainLogLayer {
    fn new(sink: MainLogSink) -> Self {
        Self { sink }
    }
}

impl<S> Layer<S> for MainLogLayer
where
    S: Subscriber + for<'span> LookupSpan<'span>,
{
    fn enabled(&self, metadata: &Metadata<'_>, _ctx: Context<'_, S>) -> bool {
        should_capture_main_log_metadata(metadata)
    }

    fn on_event(&self, event: &Event<'_>, _ctx: Context<'_, S>) {
        let metadata = event.metadata();
        if !should_capture_main_log_metadata(metadata) {
            return;
        }

        let mut visitor = MainLogFieldVisitor::default();
        event.record(&mut visitor);
        let target = visitor
            .log_target
            .clone()
            .unwrap_or_else(|| metadata.target().to_string());
        let message = visitor.into_message();
        let (date, time) = current_main_log_timestamp();
        let line =
            format_main_log_line_parts(&date, &time, &target, metadata.level().as_str(), &message);

        self.sink.write_line(line, *metadata.level());
    }
}

#[derive(Default)]
struct MainLogFieldVisitor {
    message: Option<String>,
    log_target: Option<String>,
    fields: Vec<String>,
}

impl MainLogFieldVisitor {
    fn record_value(&mut self, field_name: &str, value: String) {
        match field_name {
            "message" => self.message = Some(value),
            "log.target" => self.log_target = Some(value),
            "log.module_path" | "log.file" | "log.line" => {}
            _ => self.fields.push(format!("{field_name}={value}")),
        }
    }

    fn into_message(self) -> String {
        let mut parts = Vec::new();
        if let Some(message) = self.message
            && !message.is_empty()
        {
            parts.push(message);
        }
        parts.extend(self.fields);

        if parts.is_empty() {
            String::from("(no message)")
        } else {
            normalize_main_log_message(&parts.join(" "))
        }
    }
}

impl Visit for MainLogFieldVisitor {
    fn record_bool(&mut self, field: &tracing::field::Field, value: bool) {
        self.record_value(field.name(), value.to_string());
    }

    fn record_i64(&mut self, field: &tracing::field::Field, value: i64) {
        self.record_value(field.name(), value.to_string());
    }

    fn record_u64(&mut self, field: &tracing::field::Field, value: u64) {
        self.record_value(field.name(), value.to_string());
    }

    fn record_str(&mut self, field: &tracing::field::Field, value: &str) {
        self.record_value(field.name(), value.to_string());
    }

    fn record_debug(&mut self, field: &tracing::field::Field, value: &dyn std::fmt::Debug) {
        self.record_value(field.name(), format!("{value:?}"));
    }
}

fn should_capture_main_log_metadata(metadata: &Metadata<'_>) -> bool {
    if metadata.target().starts_with("mdns_sd::service_daemon") {
        return false;
    }

    matches!(*metadata.level(), Level::ERROR | Level::WARN | Level::INFO)
}

fn current_main_log_timestamp() -> (String, String) {
    let now = time::OffsetDateTime::now_local().unwrap_or_else(|_| time::OffsetDateTime::now_utc());
    let date = now.date();
    let clock = now.time();

    (
        format!(
            "{:04}-{:02}-{:02}",
            date.year(),
            u8::from(date.month()),
            date.day()
        ),
        format!(
            "{:02}:{:02}:{:02}",
            clock.hour(),
            clock.minute(),
            clock.second()
        ),
    )
}

fn format_main_log_line_parts(
    date: &str,
    time: &str,
    target: &str,
    level: &str,
    message: &str,
) -> String {
    format!(
        "[{date}][{time}][{}][{level}] {}",
        normalize_main_log_target(target),
        normalize_main_log_message(message)
    )
}

fn normalize_main_log_target(target: &str) -> String {
    target.replace(['\r', '\n'], " ")
}

fn normalize_main_log_message(message: &str) -> String {
    message.replace('\r', "\\r").replace('\n', "\\n")
}

fn write_main_log_stdout(line: &str) {
    let stdout = std::io::stdout();
    let mut stdout = stdout.lock();
    let _ = writeln!(stdout, "{line}");
}

fn init_main_logging(sink: MainLogSink) -> Result<(), Box<dyn std::error::Error>> {
    let subscriber = tracing_subscriber::registry().with(MainLogLayer::new(sink));
    tracing::subscriber::set_global_default(subscriber)?;
    tracing_log::LogTracer::builder()
        .with_max_level(log::LevelFilter::Info)
        .init()?;
    Ok(())
}

fn load_unpack_logs(state_dir: &Path) -> Vec<UnpackLogEntry> {
    let path = unpack_logs_path(state_dir);
    let contents = match std::fs::read_to_string(&path) {
        Ok(contents) => contents,
        Err(err) if err.kind() == std::io::ErrorKind::NotFound => return Vec::new(),
        Err(err) => {
            log::warn!("Failed to read unpack logs from {}: {err}", path.display());
            return Vec::new();
        }
    };

    let mut logs = match serde_json::from_str::<Vec<UnpackLogEntry>>(&contents) {
        Ok(logs) => logs,
        Err(err) => {
            log::warn!("Failed to parse unpack logs from {}: {err}", path.display());
            return Vec::new();
        }
    };
    logs.iter_mut().for_each(clean_unpack_log_entry);
    trim_unpack_logs(&mut logs);
    logs
}

async fn persist_unpack_logs(app_handle: &AppHandle, logs: &[UnpackLogEntry]) {
    let state = app_handle.state::<LanSpreadState>();
    let Some(state_dir) = state.state_dir.get().cloned() else {
        log::warn!("Cannot persist unpack logs before app state directory is initialized");
        return;
    };
    let path = unpack_logs_path(&state_dir);
    let contents = match serde_json::to_vec_pretty(logs) {
        Ok(contents) => contents,
        Err(err) => {
            log::warn!(
                "Failed to serialize unpack logs for {}: {err}",
                path.display()
            );
            return;
        }
    };

    if let Err(err) = tokio::fs::write(&path, contents).await {
        log::warn!("Failed to persist unpack logs to {}: {err}", path.display());
    }
}

fn now_millis() -> u64 {
    SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .map_or(0, |duration| {
            u64::try_from(duration.as_millis()).unwrap_or(u64::MAX)
        })
}

/// Resolve the bundled catalog database packaged with the Tauri application.
fn resolve_bundled_game_db_path(app_handle: &AppHandle) -> PathBuf {
    app_handle
        .path()
        .resolve("game.db", tauri::path::BaseDirectory::Resource)
        .unwrap_or_else(|e| {
            log::error!("Failed to resolve game.db resource: {e}");
            panic!("game.db resource is required - cannot continue");
        })
}

/// Load the bundled catalog into the in-memory game database used by the UI.
async fn load_bundled_game_db(app_handle: &AppHandle) -> GameDB {
    let game_db_path = resolve_bundled_game_db_path(app_handle);
    let eti_games = get_games(&game_db_path).await.unwrap_or_else(|e| {
        log::error!("Failed to load ETI games: {e}");
        panic!("game.db resource is required - cannot continue");
    });

    log::info!("Loaded {} ETI games from game.db", eti_games.len());

    let games: Vec<Game> = eti_games.into_iter().map(Into::into).collect();
    GameDB::from(games)
}

async fn ensure_bundled_game_db_loaded(app_handle: &AppHandle) {
    let state = app_handle.state::<LanSpreadState>();
    let needs_load = { state.games.read().await.games.is_empty() };

    if needs_load {
        let game_db = load_bundled_game_db(app_handle).await;
        let catalog = GameCatalog::from_game_db(&game_db);
        *state.games.write().await = game_db;
        *state.catalog.write().await = catalog;
    }
}

async fn ensure_peer_started(app_handle: &AppHandle, games_folder: &Path) {
    let state = app_handle.state::<LanSpreadState>();
    let mut peer_ctrl = state.peer_ctrl.write().await;

    if let Some(peer_ctrl) = peer_ctrl.as_ref() {
        if let Err(e) = peer_ctrl.send(PeerCommand::SetGameDir(games_folder.to_path_buf())) {
            log::error!("Failed to send PeerCommand::SetGameDir: {e}");
        }
        return;
    }

    let Some(state_dir) = state.state_dir.get().cloned() else {
        log::error!("app state directory is not initialized; cannot start peer");
        return;
    };
    let tx_peer_event = app_handle.state::<PeerEventTx>().inner().0.clone();
    let unpacker = Arc::new(SidecarUnpacker {
        app_handle: app_handle.clone(),
    });
    let stream_install_provider = stream_install_provider_for_app(app_handle);
    match start_peer_with_options(
        games_folder.to_path_buf(),
        tx_peer_event,
        state.peer_game_db.clone(),
        unpacker,
        state.catalog.clone(),
        PeerStartOptions {
            state_dir: Some(state_dir),
            active_outbound_transfers: Some(state.active_outbound_transfers.clone()),
            stream_install_provider: Some(stream_install_provider),
        },
    ) {
        Ok(handle) => {
            let sender = handle.sender();
            *peer_ctrl = Some(sender.clone());
            *state.peer_runtime.write().await = Some(handle);
            if let Err(e) = sender.send(PeerCommand::ListGames) {
                log::error!("Failed to send initial PeerCommand::ListGames: {e}");
            }
            log::info!("Peer system initialized successfully with games directory");
        }
        Err(e) => {
            log::error!("Failed to initialize peer system: {e}");
        }
    }
}

fn stream_install_provider_for_app(app_handle: &AppHandle) -> Arc<dyn StreamInstallProvider> {
    match resolve_unrar_sidecar_program(app_handle) {
        Ok(program) => Arc::new(ExternalUnrarStreamProvider::new(program)),
        Err(err) => {
            log::error!("Failed to resolve streamed-install unrar sidecar: {err}");
            Arc::new(NoopStreamInstallProvider)
        }
    }
}

fn resolve_unrar_sidecar_program(app_handle: &AppHandle) -> eyre::Result<PathBuf> {
    let sidecar = app_handle.shell().sidecar("unrar")?;
    let command: std::process::Command = sidecar.into();
    Ok(PathBuf::from(command.get_program()))
}

fn emit_game_id_event(app_handle: &AppHandle, event: &str, id: &str, label: &str) {
    if let Err(e) = app_handle.emit(event, Some(id.to_owned())) {
        log::error!("{label}: Failed to emit {event} event: {e}");
    }
}

fn spawn_peer_event_loop(app_handle: AppHandle, mut rx_peer_event: UnboundedReceiver<PeerEvent>) {
    tauri::async_runtime::spawn(async move {
        while let Some(event) = rx_peer_event.recv().await {
            handle_peer_event(&app_handle, event).await;
        }
    });
}

async fn schedule_outbound_transfer_emit(app_handle: &AppHandle) {
    let state = app_handle.state::<LanSpreadState>();
    let should_spawn = {
        let mut emit_state = state.outbound_transfer_emit.write().await;
        emit_state.record_change()
    };

    if !should_spawn {
        return;
    }

    let app_handle = app_handle.clone();
    tauri::async_runtime::spawn(async move {
        loop {
            tokio::time::sleep(OUTBOUND_TRANSFER_EMIT_DEBOUNCE).await;

            let observed_generation = {
                let state = app_handle.state::<LanSpreadState>();
                state
                    .outbound_transfer_emit
                    .read()
                    .await
                    .observed_generation()
            };
            emit_games_list(&app_handle).await;

            let needs_follow_up_emit = {
                let state = app_handle.state::<LanSpreadState>();
                let mut emit_state = state.outbound_transfer_emit.write().await;
                emit_state.finish_emit(observed_generation)
            };
            if !needs_follow_up_emit {
                break;
            }
        }
    });
}

#[allow(clippy::too_many_lines)]
async fn handle_peer_event(app_handle: &AppHandle, event: PeerEvent) {
    match event {
        PeerEvent::LocalPeerReady { peer_id, addr } => {
            log::info!("Local peer ready: {peer_id} at {addr}");
            *app_handle
                .state::<LanSpreadState>()
                .local_peer_id
                .write()
                .await = Some(peer_id);
        }
        PeerEvent::ListGames(games) => {
            log::info!("PeerEvent::ListGames received");
            update_game_db(games, app_handle.clone()).await;
        }
        PeerEvent::LocalLibraryChanged { games: local_games } => {
            log::info!("PeerEvent::LocalLibraryChanged received");
            update_local_games_in_db(local_games, app_handle.clone()).await;
        }
        PeerEvent::ActiveOperationsChanged { active_operations } => {
            log::info!("PeerEvent::ActiveOperationsChanged received");
            let state = app_handle.state::<LanSpreadState>();
            {
                let mut ui_active_operations = state.active_operations.write().await;
                reconcile_active_operations(&mut ui_active_operations, &active_operations);
            }
            emit_games_list(app_handle).await;
        }
        PeerEvent::CallToPlayEvents(events) => {
            if let Err(err) = app_handle.emit("call-to-play-events", Some(events)) {
                log::error!("Failed to emit call-to-play-events event: {err}");
            }
        }
        PeerEvent::OutboundTransferCountChanged => {
            log::info!("PeerEvent::OutboundTransferCountChanged received");
            schedule_outbound_transfer_emit(app_handle).await;
        }
        PeerEvent::GotGameFiles {
            id,
            file_descriptions,
        } => {
            handle_got_game_files(app_handle, id, file_descriptions).await;
        }
        PeerEvent::NoPeersHaveGame { id } => {
            log::warn!("PeerEvent::NoPeersHaveGame received for {id}");
            emit_game_id_event(
                app_handle,
                "game-no-peers",
                &id,
                "PeerEvent::NoPeersHaveGame",
            );
        }
        PeerEvent::DownloadGameFilesBegin { id } => {
            log::info!("PeerEvent::DownloadGameFilesBegin received for {id}");
        }
        PeerEvent::DownloadGameFileChunkFinished {
            id,
            peer_addr,
            relative_path,
            offset,
            length,
        } => {
            log::debug!(
                "PeerEvent::DownloadGameFileChunkFinished received for {id}: \
                 {relative_path} offset {offset} length {length} from {peer_addr}"
            );
        }
        PeerEvent::DownloadGameFilesProgress(progress) => {
            if let Err(e) = app_handle.emit("game-download-progress", Some(progress)) {
                log::error!("Failed to emit game-download-progress event: {e}");
            }
        }
        PeerEvent::DownloadGameFilesFinished { id } => {
            log::info!("PeerEvent::DownloadGameFilesFinished received for {id}");
        }
        PeerEvent::DownloadGameFilesFailed { id } => {
            log::warn!("PeerEvent::DownloadGameFilesFailed received");
            emit_game_id_event(
                app_handle,
                "game-download-failed",
                &id,
                "PeerEvent::DownloadGameFilesFailed",
            );
        }
        PeerEvent::DownloadGameFilesAllPeersGone { id } => {
            log::warn!("PeerEvent::DownloadGameFilesAllPeersGone received for {id}");
            emit_game_id_event(
                app_handle,
                "game-download-peers-gone",
                &id,
                "PeerEvent::DownloadGameFilesAllPeersGone",
            );
        }
        PeerEvent::InstallGameFinished { id } => {
            log::info!("PeerEvent::InstallGameFinished received for {id}");
            emit_game_id_event(
                app_handle,
                "game-install-finished",
                &id,
                "PeerEvent::InstallGameFinished",
            );
        }
        PeerEvent::InstallGameFailed { id } => {
            log::warn!("PeerEvent::InstallGameFailed received for {id}");
            emit_game_id_event(
                app_handle,
                "game-install-failed",
                &id,
                "PeerEvent::InstallGameFailed",
            );
        }
        PeerEvent::UninstallGameFinished { id } => {
            log::info!("PeerEvent::UninstallGameFinished received for {id}");
        }
        PeerEvent::UninstallGameFailed { id } => {
            log::warn!("PeerEvent::UninstallGameFailed received for {id}");
            emit_game_id_event(
                app_handle,
                "game-uninstall-failed",
                &id,
                "PeerEvent::UninstallGameFailed",
            );
        }
        PeerEvent::RemoveDownloadedGameFinished { id } => {
            log::info!("PeerEvent::RemoveDownloadedGameFinished received for {id}");
            emit_game_id_event(
                app_handle,
                "game-remove-download-finished",
                &id,
                "PeerEvent::RemoveDownloadedGameFinished",
            );
        }
        PeerEvent::RemoveDownloadedGameFailed { id } => {
            log::warn!("PeerEvent::RemoveDownloadedGameFailed received for {id}");
            emit_game_id_event(
                app_handle,
                "game-remove-download-failed",
                &id,
                "PeerEvent::RemoveDownloadedGameFailed",
            );
        }
        PeerEvent::PeerConnected(addr) => {
            log::info!("Peer connected: {addr}");
        }
        PeerEvent::PeerDisconnected(addr) => {
            log::info!("Peer disconnected: {addr}");
        }
        PeerEvent::PeerDiscovered(addr) => {
            log::info!("Peer discovered: {addr}");
        }
        PeerEvent::PeerLost(addr) => {
            log::info!("Peer lost: {addr}");
        }
        PeerEvent::PeerCountUpdated(count) => {
            log::info!("Peer count updated: {count}");
            if let Err(e) = app_handle.emit("peer-count-updated", Some(count)) {
                log::error!("Failed to emit peer-count-updated event: {e}");
            }
        }
        PeerEvent::RuntimeFailed { component, error } => {
            let component_name: &'static str = (&component).into();
            log::error!("Peer runtime component {component_name} failed: {error}");
            if let Err(e) = app_handle.emit(
                "peer-runtime-failed",
                Some((component_name.to_string(), error)),
            ) {
                log::error!("Failed to emit peer-runtime-failed event: {e}");
            }
        }
    }
}

async fn handle_got_game_files(
    app_handle: &AppHandle,
    id: String,
    file_descriptions: Vec<GameFileDescription>,
) {
    log::info!("PeerEvent::GotGameFiles received");

    let state = app_handle.state::<LanSpreadState>();
    let peer_ctrl = state.peer_ctrl.read().await.clone();
    if let Some(peer_ctrl) = peer_ctrl
        && let Err(e) = peer_ctrl.send(PeerCommand::DownloadGameFiles {
            id,
            file_descriptions,
        })
    {
        log::error!("Failed to continue queued game transfer: {e}");
    }
}

#[allow(clippy::missing_panics_doc)]
#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
    // channel to receive events from the peer
    let (tx_peer_event, rx_peer_event) = tokio::sync::mpsc::unbounded_channel::<PeerEvent>();

    tauri::Builder::default()
        .plugin(tauri_plugin_store::Builder::new().build())
        .plugin(tauri_plugin_dialog::init())
        .plugin(tauri_plugin_shell::init())
        .invoke_handler(tauri::generate_handler![
            request_games,
            request_call_to_play_events,
            publish_call_to_play,
            install_game,
            stream_install_game,
            run_game,
            start_server,
            game_directory_exists,
            update_game_directory,
            update_game,
            uninstall_game,
            remove_downloaded_game,
            cancel_download,
            open_game_files,
            get_peer_count,
            get_game_thumbnail,
            get_unpack_logs,
            get_main_logs
        ])
        .manage(LanSpreadState::default())
        .manage(PeerEventTx(tx_peer_event))
        .setup(move |app| {
            let state_dir = app.path().app_data_dir()?;
            std::fs::create_dir_all(&state_dir)?;
            let main_log_sink = MainLogSink::new(app.handle().clone(), main_log_path(&state_dir));
            let state = app.state::<LanSpreadState>();
            if state.main_log_sink.set(main_log_sink.clone()).is_err() {
                log::warn!("main log sink was already initialized");
            }
            init_main_logging(main_log_sink)?;
            let unpack_logs = load_unpack_logs(&state_dir);
            tauri::async_runtime::block_on(async {
                *state.unpack_logs.write().await = unpack_logs;
            });
            if state.state_dir.set(state_dir).is_err() {
                log::warn!("app state directory was already initialized");
            }
            spawn_peer_event_loop(app.handle().clone(), rx_peer_event);
            Ok(())
        })
        .build(tauri::generate_context!())
        .expect("error while building tauri application")
        .run(|app_handle, event| {
            if matches!(event, tauri::RunEvent::Exit) {
                // Kill unrar first: an in-progress extraction would otherwise keep
                // running after the launcher closes, and killing it lets the
                // install task unwind so the peer runtime can stop promptly.
                kill_active_unrar_children(app_handle);
                shutdown_peer_runtime(app_handle);
            }
        });
}

fn shutdown_peer_runtime(app_handle: &AppHandle) {
    let state = app_handle.state::<LanSpreadState>();
    let peer_runtime = state.peer_runtime.clone();

    tauri::async_runtime::block_on(async move {
        let Some(mut handle) = peer_runtime.write().await.take() else {
            return;
        };
        handle.shutdown();
        if tokio::time::timeout(std::time::Duration::from_secs(2), handle.wait_stopped())
            .await
            .is_err()
        {
            log::warn!("Peer runtime did not stop within 2s of shutdown request");
        }
    });
}

#[cfg(test)]
mod tests {
    use super::*;

    fn unpack_log_fixture(index: usize) -> UnpackLogEntry {
        let timestamp = u64::try_from(index).unwrap_or(u64::MAX);
        UnpackLogEntry {
            archive: format!("archive-{index}.rar"),
            destination: format!("destination-{index}"),
            status_code: Some(0),
            stdout: format!("stdout {index}"),
            stderr: String::new(),
            started_at_ms: timestamp,
            finished_at_ms: timestamp,
            success: true,
        }
    }

    fn game_fixture(id: &str, name: &str) -> Game {
        Game {
            id: id.to_string(),
            name: name.to_string(),
            description: format!("{name} description"),
            release_year: "2000".to_string(),
            publisher: "publisher".to_string(),
            max_players: 4,
            version: "1.0".to_string(),
            genre: "genre".to_string(),
            size: 123,
            downloaded: false,
            installed: false,
            availability: Availability::LocalOnly,
            eti_game_version: None,
            local_version: None,
            peer_count: 0,
        }
    }

    fn eti_game_fixture(game_id: &str, game_version: &str) -> lanspread_compat::eti::EtiGame {
        lanspread_compat::eti::EtiGame {
            game_id: game_id.to_string(),
            game_title: "Catalog Game".to_string(),
            game_key: "catalog-game".to_string(),
            game_release: "2000".to_string(),
            game_publisher: "publisher".to_string(),
            game_size: 1.0,
            game_readme_de: "description".to_string(),
            game_readme_en: "description".to_string(),
            game_readme_fr: "description".to_string(),
            game_maxplayers: 4,
            game_master_req: 0,
            genre_de: "genre".to_string(),
            game_version: game_version.to_string(),
        }
    }

    #[test]
    fn eti_game_conversion_uses_catalog_version_as_authoritative_eti_version() {
        let game = Game::from(eti_game_fixture("alpha", "20200721"));

        assert_eq!(game.version, "20200721");
        assert_eq!(game.eti_game_version.as_deref(), Some("20200721"));
        assert_eq!(game.local_version, None);
    }

    #[test]
    fn terminal_log_cleanup_preserves_crlf_and_collapses_redrawn_lines() {
        let input = "Extracting foo 10%\rExtracting foo 80%\rExtracting foo OK\r\nAll done\r\n";

        assert_eq!(clean_terminal_log(input), "Extracting foo OK\nAll done\n");
    }

    #[test]
    fn terminal_log_cleanup_applies_backspaces() {
        assert_eq!(clean_terminal_log("abc\u{8}\u{8}de\n"), "ade\n");
    }

    #[test]
    fn terminal_log_cleanup_removes_other_controls() {
        assert_eq!(clean_terminal_log("a\u{7}b\tc"), "ab\tc");
    }

    #[test]
    fn unpack_log_retention_keeps_last_twenty_entries() {
        let mut logs = (0..25).map(unpack_log_fixture).collect::<Vec<_>>();

        trim_unpack_logs(&mut logs);

        assert_eq!(logs.len(), MAX_UNPACK_LOGS);
        assert_eq!(
            logs.first().map(|entry| entry.archive.as_str()),
            Some("archive-5.rar")
        );
        assert_eq!(
            logs.last().map(|entry| entry.archive.as_str()),
            Some("archive-24.rar")
        );
    }

    #[test]
    fn unpack_logs_load_from_app_state_dir_and_apply_retention() {
        let root = std::env::temp_dir().join(format!(
            "lanspread-unpack-logs-test-{}",
            SystemTime::now()
                .duration_since(UNIX_EPOCH)
                .expect("clock should be after epoch")
                .as_nanos()
        ));
        std::fs::create_dir_all(&root).expect("test state dir should be created");
        let logs = (0..25).map(unpack_log_fixture).collect::<Vec<_>>();
        std::fs::write(
            unpack_logs_path(&root),
            serde_json::to_vec(&logs).expect("logs should serialize"),
        )
        .expect("logs should be written");

        let loaded = load_unpack_logs(&root);

        assert_eq!(loaded.len(), MAX_UNPACK_LOGS);
        assert_eq!(
            loaded.first().map(|entry| entry.archive.as_str()),
            Some("archive-5.rar")
        );
        assert_eq!(
            loaded.last().map(|entry| entry.archive.as_str()),
            Some("archive-24.rar")
        );

        let _ = std::fs::remove_dir_all(root);
    }

    #[test]
    fn main_log_line_format_is_stable_and_single_line() {
        let line = format_main_log_line_parts(
            "2026-06-07",
            "12:34:56",
            "lanspread\napp",
            "WARN",
            "first line\nsecond line",
        );

        assert_eq!(
            line,
            "[2026-06-07][12:34:56][lanspread app][WARN] first line\\nsecond line"
        );
    }

    #[test]
    fn main_log_trim_keeps_utf8_tail_at_char_boundary() {
        let root = std::env::temp_dir().join(format!(
            "lanspread-main-log-test-{}",
            SystemTime::now()
                .duration_since(UNIX_EPOCH)
                .expect("clock should be after epoch")
                .as_nanos()
        ));
        std::fs::create_dir_all(&root).expect("test state dir should be created");
        let path = main_log_path(&root);
        std::fs::write(&path, format!("{}{}", "a".repeat(11), "é".repeat(20)))
            .expect("main log should be written");

        trim_main_log_file_to_limit(&path, 21).expect("main log should trim");

        let trimmed = std::fs::read_to_string(&path).expect("trimmed log should remain utf-8");
        assert!(trimmed.len() <= 21);
        assert!(trimmed.starts_with('é'));
        assert!(trimmed.ends_with('é'));

        let _ = std::fs::remove_dir_all(root);
    }

    #[test]
    fn active_operation_reconciliation_replaces_stale_ui_history() {
        let mut active_operations = HashMap::from([
            ("stale".to_string(), UiOperationKind::Installing),
            ("keep".to_string(), UiOperationKind::Downloading),
        ]);
        let snapshot = vec![
            ActiveOperation {
                id: "keep".to_string(),
                operation: ActiveOperationKind::Updating,
            },
            ActiveOperation {
                id: "new".to_string(),
                operation: ActiveOperationKind::Uninstalling,
            },
        ];

        reconcile_active_operations(&mut active_operations, &snapshot);

        assert_eq!(active_operations.len(), 2);
        assert_eq!(
            active_operations.get("keep"),
            Some(&UiOperationKind::Updating)
        );
        assert_eq!(
            active_operations.get("new"),
            Some(&UiOperationKind::Uninstalling)
        );
        assert!(
            !active_operations.contains_key("stale"),
            "snapshot reconciliation should drop stale UI operations"
        );
    }

    #[test]
    fn local_snapshot_without_finish_clears_stale_ui_operation() {
        let mut active_operations =
            HashMap::from([("game".to_string(), UiOperationKind::Downloading)]);

        reconcile_active_operations(&mut active_operations, &[]);

        assert!(
            active_operations.is_empty(),
            "an authoritative snapshot without the game should clear a missed finish event"
        );
    }

    #[test]
    fn local_snapshot_without_begin_restores_active_ui_operation() {
        let mut active_operations = HashMap::new();
        let snapshot = vec![ActiveOperation {
            id: "game".to_string(),
            operation: ActiveOperationKind::Installing,
        }];

        reconcile_active_operations(&mut active_operations, &snapshot);

        assert_eq!(
            active_operations.get("game"),
            Some(&UiOperationKind::Installing),
            "an authoritative snapshot should recover a missed begin event"
        );
    }

    #[test]
    fn active_operation_payload_is_sorted_for_stable_ui_updates() {
        let active_operations = HashMap::from([
            ("zeta".to_string(), UiOperationKind::Downloading),
            ("alpha".to_string(), UiOperationKind::Installing),
        ]);

        let snapshot = ui_active_operations_from_map(&active_operations);

        assert_eq!(
            snapshot,
            vec![
                UiActiveOperation {
                    id: "alpha".to_string(),
                    operation: UiOperationKind::Installing,
                },
                UiActiveOperation {
                    id: "zeta".to_string(),
                    operation: UiOperationKind::Downloading,
                },
            ]
        );
    }

    #[test]
    fn outbound_transfer_emit_state_coalesces_bursts_without_losing_updates() {
        let mut state = OutboundTransferEmitState::default();

        assert!(
            state.record_change(),
            "first change should schedule an emit"
        );
        assert_eq!(state.observed_generation(), 1);
        assert!(
            !state.record_change(),
            "second change should reuse the scheduled emit"
        );
        assert_eq!(state.observed_generation(), 2);

        assert!(
            state.finish_emit(1),
            "a generation observed before the latest change needs a follow-up emit"
        );
        assert!(
            !state.finish_emit(2),
            "the latest observed generation clears the scheduled emit"
        );
        assert!(state.record_change(), "a later burst should schedule again");
    }

    #[test]
    fn game_file_viewer_ids_must_be_single_path_components() {
        assert!(is_single_component_game_id("game"));
        assert!(is_single_component_game_id("game.v1"));
        assert!(!is_single_component_game_id(""));
        assert!(!is_single_component_game_id("../game"));
        assert!(!is_single_component_game_id("nested/game"));
        assert!(!is_single_component_game_id("/game"));
    }

    #[test]
    fn launch_settings_sanitize_script_arguments() {
        assert_eq!(
            launch_settings("DE", "  Alice \"Ace\"%PATH%\n  "),
            LaunchSettings {
                language: "de".to_string(),
                username: "Alice AcePATH".to_string(),
            }
        );
        assert_eq!(
            launch_settings("fr", ""),
            LaunchSettings {
                language: DEFAULT_LANGUAGE.to_string(),
                username: DEFAULT_USERNAME.to_string(),
            }
        );
    }

    #[test]
    fn install_settings_use_language_file_values() {
        assert_eq!(
            install_settings("de", "  Alice \"Ace\"%PATH%\n  "),
            InstallSettings {
                account_name: "Alice AcePATH".to_string(),
                language: "german".to_string(),
            }
        );
        assert_eq!(
            install_settings("fr", ""),
            InstallSettings {
                account_name: DEFAULT_USERNAME.to_string(),
                language: "english".to_string(),
            }
        );
    }

    #[test]
    fn script_params_use_common_argument_shape() {
        let start_params = script_params(
            Path::new("C:/Games/My Game")
                .join(GAME_START_SCRIPT)
                .as_path(),
            "my-game",
            &LaunchSettings {
                language: "en".to_string(),
                username: "Alice".to_string(),
            },
        );

        assert_eq!(
            start_params,
            r#"/d /s /c ""C:/Games/My Game/game_start.cmd" "local" "my-game" "en" "Alice"""#
        );

        let server_params = server_script_params(
            Path::new("C:/Games/My Game")
                .join(SERVER_START_SCRIPT)
                .as_path(),
            "my-game",
            &LaunchSettings {
                language: "en".to_string(),
                username: "Alice".to_string(),
            },
        );

        assert_eq!(
            server_params,
            r#"/d /s /k ""C:/Games/My Game/server_start.cmd" "local" "my-game" "en" "Alice"""#
        );
    }

    #[test]
    fn server_host_capability_requires_installed_game_with_script() {
        let root = std::env::temp_dir().join(format!(
            "lanspread-server-test-{}",
            SystemTime::now()
                .duration_since(UNIX_EPOCH)
                .expect("clock should be after epoch")
                .as_nanos()
        ));
        let game_root = root.join("game");
        std::fs::create_dir_all(&game_root).expect("game root should be created");
        std::fs::write(game_root.join(SERVER_START_SCRIPT), b"").expect("script should be written");

        let mut game = game_fixture("game", "Game");
        assert!(!game_can_host_server(
            root.to_string_lossy().as_ref(),
            &game
        ));

        game.installed = true;
        assert!(game_can_host_server(root.to_string_lossy().as_ref(), &game));

        let _ = std::fs::remove_dir_all(root);
    }

    #[test]
    fn peer_local_snapshot_replaces_local_state_without_overwriting_catalog_metadata() {
        let mut alpha = game_fixture("alpha", "Catalog Alpha");
        alpha.size = 999;
        alpha.peer_count = 3;

        let mut beta = game_fixture("beta", "Catalog Beta");
        beta.set_downloaded(true);
        beta.installed = true;
        beta.local_version = Some("20240101".to_string());

        let mut game_db = GameDB::from(vec![alpha, beta]);

        let mut local_alpha = game_fixture("alpha", "Peer Alpha");
        local_alpha.size = 42;
        local_alpha.set_downloaded(true);
        local_alpha.local_version = Some("20240202".to_string());

        let mut unknown = game_fixture("unknown", "Unknown");
        unknown.set_downloaded(true);
        unknown.installed = true;

        apply_peer_local_games(&mut game_db, &[local_alpha, unknown]);

        let alpha = game_db.get_game_by_id("alpha").expect("alpha remains");
        assert_eq!(alpha.name, "Catalog Alpha");
        assert_eq!(alpha.size, 999);
        assert_eq!(alpha.peer_count, 3);
        assert!(alpha.downloaded);
        assert!(!alpha.installed);
        assert_eq!(alpha.availability, Availability::Ready);
        assert_eq!(alpha.local_version.as_deref(), Some("20240202"));

        let beta = game_db.get_game_by_id("beta").expect("beta remains");
        assert!(!beta.downloaded);
        assert!(!beta.installed);
        assert_eq!(beta.availability, Availability::LocalOnly);
        assert_eq!(beta.local_version, None);

        assert!(game_db.get_game_by_id("unknown").is_none());
    }

    #[test]
    fn peer_remote_snapshot_updates_counts_without_overwriting_catalog_version() {
        let mut alpha = game_fixture("alpha", "Catalog Alpha");
        alpha.size = 999;
        alpha.eti_game_version = Some("20200721".to_string());

        let mut beta = game_fixture("beta", "Catalog Beta");
        beta.peer_count = 2;
        beta.eti_game_version = Some("20200101".to_string());

        let mut game_db = GameDB::from(vec![alpha, beta]);

        let mut peer_alpha = game_fixture("alpha", "Peer Alpha");
        peer_alpha.size = 42;
        peer_alpha.peer_count = 3;
        peer_alpha.eti_game_version = Some("20990101".to_string());

        let mut unknown = game_fixture("unknown", "Unknown");
        unknown.peer_count = 1;
        unknown.eti_game_version = Some("20990101".to_string());

        apply_peer_remote_games(&mut game_db, vec![peer_alpha, unknown]);

        let alpha = game_db.get_game_by_id("alpha").expect("alpha remains");
        assert_eq!(alpha.name, "Catalog Alpha");
        assert_eq!(alpha.size, 999);
        assert_eq!(alpha.peer_count, 3);
        assert_eq!(alpha.eti_game_version.as_deref(), Some("20200721"));

        let beta = game_db.get_game_by_id("beta").expect("beta remains");
        assert_eq!(beta.peer_count, 0);
        assert_eq!(beta.eti_game_version.as_deref(), Some("20200101"));

        assert!(game_db.get_game_by_id("unknown").is_none());
    }
}