//! Messages that can be sent to a renderer thread (`renderer/message.zig`).
use std::sync::Arc;

use ghostty_config::config::Config;
use ghostty_font::{SharedGrid, SharedGridSet, shared_grid_set::Key as SharedGridKey};
use ghostty_terminal::highlight::Flattened;

use crate::{
    generic::DerivedConfig as RendererDerivedConfig,
    link,
    size::Size,
    thread::DerivedConfig as ThreadDerivedConfig,
};

/// The messages that can be sent to a renderer thread.
pub enum Message {
    /// Purposely crash the renderer. This is used for testing and debugging.
    /// See the "crash" binding action.
    Crash,

    /// A change in state in the window focus that this renderer is
    /// rendering within. This is only sent when a change is detected so
    /// the renderer is expected to handle all of these.
    Focus(bool),

    /// A change in the view occlusion state. This can be used to determine
    /// if the window is visible or not. A window can be not visible (occluded)
    /// and still have focus.
    Visible(bool),

    /// Reset the cursor blink by immediately showing the cursor then
    /// restarting the timer.
    ResetCursorBlink,

    /// Change the font grid. This can happen for any number of reasons
    /// including a font size change, family change, etc.
    FontGrid(Box<FontGridChange>),

    /// Changes the size. The screen size might change, padding, grid, etc.
    Resize(Size),

    /// The derived configuration to update the renderer with.
    ChangeConfig {
        thread: Box<ThreadDerivedConfig>,
        r#impl: Box<RendererDerivedConfig>,
    },

    /// Matches for the current viewport from the search thread. These happen
    /// async so they may be off for a frame or two from the actually rendered
    /// viewport. The renderer must handle this gracefully.
    SearchViewportMatches(Vec<Flattened>),

    /// The selected match from the search thread. May be None to indicate
    /// no match currently.
    SearchSelectedMatch(Option<Flattened>),

    /// Activate or deactivate the inspector.
    Inspector(bool),

    /// The macOS display ID has changed for the window.
    MacosDisplayId(u32),
}

/// Payload of [`Message::FontGrid`].
pub struct FontGridChange {
    pub grid: Arc<SharedGrid>,
    pub set: Arc<SharedGridSet>,

    /// The key for the new grid. If adopting the new grid fails for any
    /// reason, the old grid should be kept but the new key should be
    /// dereferenced.
    pub new_key: SharedGridKey,

    /// After accepting the new grid, the old grid must be dereferenced
    /// using this key.
    pub old_key: SharedGridKey,
}

impl Message {
    /// Initialize a change_config message (`initChangeConfig`).
    pub fn init_change_config(config: &Config) -> Result<Message, link::Error> {
        Ok(Message::ChangeConfig {
            thread: Box::new(ThreadDerivedConfig::new(config)),
            r#impl: Box::new(RendererDerivedConfig::new(config)?),
        })
    }
}

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

    #[test]
    fn change_config_message_roundtrip() {
        let m = Message::init_change_config(&Config::default()).unwrap();
        assert!(matches!(m, Message::ChangeConfig { .. }));
    }
}