use std::path::{Path, PathBuf};

const PEER_ID_FILE: &str = "peer_id";
const LOCAL_LIBRARY_DIR: &str = "local_library";
const LOCAL_LIBRARY_INDEX_FILE: &str = "index.json";
const GAMES_DIR: &str = "games";
const SETUP_DONE_FILE: &str = "setup_done";
const LAUNCH_SETTINGS_APPLIED_FILE: &str = "launch_settings_applied";

pub(crate) fn resolve_state_dir(explicit: Option<&Path>) -> PathBuf {
    if let Some(dir) = explicit {
        return dir.to_path_buf();
    }

    if let Some(dir) = std::env::var_os("LANSPREAD_STATE_DIR") {
        return PathBuf::from(dir);
    }

    if let Some(home) = std::env::var_os("HOME").or_else(|| std::env::var_os("USERPROFILE")) {
        return PathBuf::from(home).join(".lanspread");
    }

    std::env::temp_dir().join("lanspread")
}

pub(crate) fn peer_id_path(state_dir: &Path) -> PathBuf {
    state_dir.join(PEER_ID_FILE)
}

pub(crate) fn local_library_index_path(state_dir: &Path) -> PathBuf {
    state_dir
        .join(LOCAL_LIBRARY_DIR)
        .join(LOCAL_LIBRARY_INDEX_FILE)
}

pub(crate) fn game_state_dir(state_dir: &Path, game_id: &str) -> PathBuf {
    state_dir.join(GAMES_DIR).join(game_id)
}

#[must_use]
pub fn setup_done_path(state_dir: &Path, game_id: &str) -> PathBuf {
    game_state_dir(state_dir, game_id).join(SETUP_DONE_FILE)
}

#[must_use]
pub fn launch_settings_applied_path(state_dir: &Path, game_id: &str) -> PathBuf {
    game_state_dir(state_dir, game_id).join(LAUNCH_SETTINGS_APPLIED_FILE)
}