use glam::{Quat, Vec3};
use winit::event::DeviceEvent::MouseMotion;
use winit::event::{ElementState, Event, MouseButton, WindowEvent};
use winit::keyboard::{KeyCode, PhysicalKey};
use winit::window::CursorGrabMode;
use raidillon_app::prelude::*;

use crate::systems::common::{camera_front, is_camera_mode_valid, is_mouse_look_enabled};
use crate::systems::menu::MenuState;

pub struct FPSDebugCameraSystem {
    mouse_delta: (f64, f64),
    position: Vec3,
    yaw:   f32,
    pitch: f32,
    speed: f32,
    sensitivity: f32,
}

impl Default for FPSDebugCameraSystem {
    fn default() -> Self {
        Self {
            mouse_delta: Default::default(),
            position: Vec3::new(0.0, 0.0, 2.0),
            yaw: -90.0,
            pitch: 0.0,
            speed: 8.0,
            sensitivity: 0.1,
        }
    }
}

impl System for FPSDebugCameraSystem {
    fn handle_event(&mut self, res: &mut EngineResources, scene: &mut Scene) {
        if !(is_camera_mode_valid(scene, CameraMode::Debug) && is_mouse_look_enabled(scene)) {
            return
        }
        let pctx = res.get::<PlatformContext>().unwrap();
        let event2 = pctx.current_event.clone();
        match event2 {
            Event::DeviceEvent { device_id, event} => {
                match event {
                    MouseMotion { delta } => {
                        self.mouse_delta.0 += delta.0;
                        self.mouse_delta.1 += delta.1;
                    },
                    _ => {}
                }
            },
            _ => {},
        }
    }

    fn frame_update(&mut self, res: &mut EngineResources, scene: &mut Scene) {
        let (pctx, input) = res.get_many::<(PlatformContext, InputState)>().unwrap();

        if is_mouse_look_enabled(scene) {
            self.yaw += self.mouse_delta.0 as f32 * self.sensitivity;
            self.pitch -= self.mouse_delta.1 as f32 * self.sensitivity;
            self.pitch = self.pitch.clamp(-89.0, 89.0);
        }

        let front = camera_front(self.yaw, self.pitch);
        let right_vec = front.cross(Vec3::Y).normalize();

        if is_mouse_look_enabled(scene) {
            if input.key_held(KeyCode::KeyW) {
                self.position += front * pctx.time_ctx.frame_dt * self.speed;
            }
            if input.key_held(KeyCode::KeyS) {
                self.position -= front * pctx.time_ctx.frame_dt * self.speed;
            }
            if input.key_held(KeyCode::KeyA) {
                self.position -= right_vec * pctx.time_ctx.frame_dt * self.speed;
            }
            if input.key_held(KeyCode::KeyD) {
                self.position += right_vec * pctx.time_ctx.frame_dt * self.speed;
            }
        }

        if is_camera_mode_valid(scene, CameraMode::Debug) {
            scene.world.query_mut::<&mut Camera>().into_iter().for_each(|(_, camera)| {
                camera.eye = self.position;
                camera.center = self.position + front;
            });
        }
        self.mouse_delta = (0.0, 0.0);
    }
}