use crate::services::windows::window::{Window, WindowId};
use crate::task::TaskId;
use crate::windows::WindowOwner;
use prometeu_hal::color::Color;
use prometeu_hal::primitives::Rect;

/// PROMETEU Window Manager.
pub struct WindowManager {
    pub windows: Vec<Window>,
    pub focused: Option<WindowId>,
}

impl Default for WindowManager {
    fn default() -> Self {
        Self::new()
    }
}

impl WindowManager {
    pub fn new() -> Self {
        Self { windows: Vec::new(), focused: None }
    }

    pub fn add_window(
        &mut self,
        title: String,
        owner: WindowOwner,
        viewport: Rect,
        color: Color,
    ) -> WindowId {
        let id = WindowId(self.windows.len() as u32);
        let window = Window { id, owner, viewport, has_focus: false, title, color };
        self.windows.push(window);
        id
    }

    pub fn remove_window(&mut self, id: WindowId) {
        self.windows.retain(|w| w.id != id);
        if self.focused == Some(id) {
            self.focused = None;
        }
    }

    pub fn remove_all_windows(&mut self) {
        self.windows.clear();
        self.focused = None;
    }

    pub fn set_focus(&mut self, id: WindowId) {
        self.focused = Some(id);
        for window in &mut self.windows {
            window.has_focus = window.id == id;
        }
    }

    pub fn focused_window_belongs_to_task(&self, task_id: TaskId) -> bool {
        let Some(focused_id) = self.focused else {
            return false;
        };

        self.windows
            .iter()
            .find(|window| window.id == focused_id)
            .is_some_and(|window| window.owner == WindowOwner::Task(task_id))
    }
}

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

    #[test]
    fn test_window_manager_focus() {
        let mut wm = WindowManager::new();
        let id1 = wm.add_window(
            "Window 1".to_string(),
            WindowOwner::Hub,
            Rect { x: 0, y: 0, w: 10, h: 10 },
            Color::WHITE,
        );
        let id2 = wm.add_window(
            "Window 2".to_string(),
            WindowOwner::Hub,
            Rect { x: 10, y: 10, w: 10, h: 10 },
            Color::WHITE,
        );

        assert_eq!(wm.windows.len(), 2);
        assert_eq!(wm.focused, None);

        wm.set_focus(id1);
        assert_eq!(wm.focused, Some(id1));
        assert!(wm.windows[0].has_focus);
        assert!(!wm.windows[1].has_focus);

        wm.set_focus(id2);
        assert_eq!(wm.focused, Some(id2));
        assert!(!wm.windows[0].has_focus);
        assert!(wm.windows[1].has_focus);
    }

    #[test]
    fn test_window_manager_remove_window() {
        let mut wm = WindowManager::new();
        let id = wm.add_window(
            "Window".to_string(),
            WindowOwner::Hub,
            Rect { x: 0, y: 0, w: 10, h: 10 },
            Color::WHITE,
        );
        wm.set_focus(id);
        assert_eq!(wm.focused, Some(id));

        wm.remove_window(id);
        assert_eq!(wm.windows.len(), 0);
        assert_eq!(wm.focused, None);
    }

    #[test]
    fn focused_window_belongs_to_task_returns_false_without_focus() {
        let mut wm = WindowManager::new();
        wm.add_window(
            "Task Window".to_string(),
            WindowOwner::Task(crate::task::TaskId(1)),
            Rect { x: 0, y: 0, w: 10, h: 10 },
            Color::WHITE,
        );

        assert!(!wm.focused_window_belongs_to_task(crate::task::TaskId(1)));
    }

    #[test]
    fn focused_window_belongs_to_task_matches_focused_task_owner() {
        let mut wm = WindowManager::new();
        let id = wm.add_window(
            "Task Window".to_string(),
            WindowOwner::Task(crate::task::TaskId(1)),
            Rect { x: 0, y: 0, w: 10, h: 10 },
            Color::WHITE,
        );

        wm.set_focus(id);

        assert!(wm.focused_window_belongs_to_task(crate::task::TaskId(1)));
    }

    #[test]
    fn focused_window_belongs_to_task_rejects_other_task_owner() {
        let mut wm = WindowManager::new();
        let id = wm.add_window(
            "Task Window".to_string(),
            WindowOwner::Task(crate::task::TaskId(2)),
            Rect { x: 0, y: 0, w: 10, h: 10 },
            Color::WHITE,
        );

        wm.set_focus(id);

        assert!(!wm.focused_window_belongs_to_task(crate::task::TaskId(1)));
    }

    #[test]
    fn focused_window_belongs_to_task_rejects_hub_owner() {
        let mut wm = WindowManager::new();
        let id = wm.add_window(
            "Hub Window".to_string(),
            WindowOwner::Hub,
            Rect { x: 0, y: 0, w: 10, h: 10 },
            Color::WHITE,
        );

        wm.set_focus(id);

        assert!(!wm.focused_window_belongs_to_task(crate::task::TaskId(1)));
    }

    #[test]
    fn focused_window_belongs_to_task_rejects_overlay_owner() {
        let mut wm = WindowManager::new();
        let id = wm.add_window(
            "Overlay Window".to_string(),
            WindowOwner::Overlay,
            Rect { x: 0, y: 0, w: 10, h: 10 },
            Color::WHITE,
        );

        wm.set_focus(id);

        assert!(!wm.focused_window_belongs_to_task(crate::task::TaskId(1)));
    }

    #[test]
    fn focused_window_belongs_to_task_rejects_stale_focus() {
        let mut wm = WindowManager::new();
        wm.add_window(
            "Task Window".to_string(),
            WindowOwner::Task(crate::task::TaskId(1)),
            Rect { x: 0, y: 0, w: 10, h: 10 },
            Color::WHITE,
        );
        wm.focused = Some(WindowId(999));

        assert!(!wm.focused_window_belongs_to_task(crate::task::TaskId(1)));
    }
}