use std::ptr::NonNull;

use lyra_engine::{math::{self, Vec3}, math::Transform, input::{KeyCode, ActionHandler, Action, ActionKind, LayoutId, ActionMapping, ActionSource, ActionMappingId, InputActionPlugin}, game::Game, render::{window::{CursorGrabMode, WindowOptions}, light::{PointLight, directional::DirectionalLight, SpotLight}}, change_tracker::Ct, ecs::{system::{Criteria, CriteriaSchedule, BatchedSystem, IntoSystem}, world::World, Component}, DeltaTime, scene::{TransformComponent, ModelComponent, CameraComponent}};
use lyra_engine::assets::{ResourceManager, Model};

mod free_fly_camera;
use free_fly_camera::{FreeFlyCameraPlugin, FreeFlyCamera};
use tracing::debug;

struct FixedTimestep {
    max_tps: u32,
    fixed_time: f32,
    accumulator: f32,
}

impl FixedTimestep {
    pub fn new(max_tps: u32) -> Self {
        Self {
            max_tps,
            fixed_time: Self::calc_fixed_time(max_tps),
            accumulator: 0.0,
        }
    }

    fn calc_fixed_time(max_tps: u32) -> f32 {
        1.0 / max_tps as f32
    }

    fn set_tps(&mut self, tps: u32) {
        self.max_tps = tps;
        self.fixed_time = Self::calc_fixed_time(tps);
    }

    fn tps(&self) -> u32 {
        self.max_tps
    }

    fn fixed_time(&self) -> f32 {
        self.fixed_time
    }
}

impl Criteria for FixedTimestep {
    fn can_run(&mut self, mut world: NonNull<World>, check_count: u32) -> CriteriaSchedule {
        let world = unsafe { world.as_mut() };
        if check_count == 0 {
            let delta_time = world.get_resource::<DeltaTime>();
            self.accumulator += **delta_time;
        }

        if self.accumulator >= self.fixed_time {
            self.accumulator -= self.fixed_time;
            return CriteriaSchedule::YesAndLoop;
        }

        CriteriaSchedule::No
    }
}

#[derive(Clone)]
struct TpsAccumulator(f32);

#[derive(Component)]
struct CubeFlag;

#[async_std::main]
async fn main() {
    let setup_sys = |world: &mut World| -> anyhow::Result<()> {
        {
            let mut window_options = world.get_resource_mut::<Ct<WindowOptions>>();
            window_options.cursor_grab = CursorGrabMode::Confined;
            window_options.cursor_visible = false;
        }

        let mut resman = world.get_resource_mut::<ResourceManager>();
        //let diffuse_texture = resman.request::<Texture>("assets/happy-tree.png").unwrap();
        let antique_camera_model = resman.request::<Model>("assets/AntiqueCamera.glb").unwrap();
        //let cube_model = resman.request::<Model>("assets/cube-texture-bin.glb").unwrap();
        let cube_model = resman.request::<Model>("assets/texture-sep/texture-sep.gltf").unwrap();
        let crate_model = resman.request::<Model>("assets/crate/crate.gltf").unwrap();
        drop(resman);

        world.spawn((
            ModelComponent(antique_camera_model),
            TransformComponent::from(Transform::from_xyz(0.0, -5.0, -10.0)),
        ));

        {
            let cube_tran = Transform::from_xyz(-3.5, 0.0, -8.0);
            //cube_tran.rotate_y(math::Angle::Degrees(180.0));
            world.spawn((
                TransformComponent::from(cube_tran),
                ModelComponent(crate_model.clone()),
                CubeFlag,
            ));
        }

        {
            let mut light_tran = Transform::from_xyz(1.5, 2.5, 0.0);
            light_tran.scale = Vec3::new(0.5, 0.5, 0.5);
            light_tran.rotate_x(math::Angle::Degrees(-45.0));
            light_tran.rotate_y(math::Angle::Degrees(25.0));
            world.spawn((
                DirectionalLight {
                    color: Vec3::new(1.0, 1.0, 1.0),
                    ambient: 0.3,
                    diffuse: 1.0,
                    specular: 1.3,
                },
                TransformComponent::from(light_tran),
                ModelComponent(cube_model.clone()),
            ));
        }

        {
            let mut light_tran = Transform::from_xyz(-3.5, 0.2, -4.5);
            light_tran.scale = Vec3::new(0.5, 0.5, 0.5);
            world.spawn((
                SpotLight {
                    color: Vec3::new(1.0, 0.2, 0.2),
                    cutoff: math::Angle::Degrees(12.5),
                    outer_cutoff: math::Angle::Degrees(17.5),

                    constant: 1.0,
                    linear: 0.007,
                    quadratic: 0.0002,

                    ambient: 0.0,
                    diffuse: 7.0,
                    specular: 1.0,
                },
                TransformComponent::from(light_tran),
                ModelComponent(cube_model.clone()),
            ));
        }
        
        /* {
            let mut light_tran = Transform::from_xyz(-5.0, 2.5, -9.5);
            light_tran.scale = Vec3::new(0.5, 0.5, 0.5);
            world.spawn((
                PointLight {
                    color: Vec3::new(1.0, 1.0, 1.0),

                    intensity: 1.0,

                    constant: 1.0,
                    linear: 0.045,
                    quadratic: 0.0075,
                    
                    ambient: 0.1,
                    diffuse: 1.0,
                    specular: 1.3,
                },
                TransformComponent::from(light_tran),
                ModelComponent(cube_model.clone()),
            ));
        } */

        {
            let mut light_tran = Transform::from_xyz(2.0, 2.5, -9.5);
            light_tran.scale = Vec3::new(0.5, 0.5, 0.5);
            world.spawn((
                PointLight {
                    color: Vec3::new(0.0, 0.0, 1.0),

                    intensity: 3.3,

                    constant: 1.0,
                    linear: 0.09,
                    quadratic: 0.032,
                    
                    ambient: 0.2,
                    diffuse: 1.0,
                    specular: 1.3,
                },
                TransformComponent::from(light_tran),
                ModelComponent(cube_model),
            ));
        }

        let mut camera = CameraComponent::new_3d();
        camera.transform.translation += math::Vec3::new(0.0, 0.0, 5.5);
        world.spawn(( camera, FreeFlyCamera::default() ));

        Ok(())
    };

    let fps_system = |world: &mut World| -> anyhow::Result<()> {
        let mut counter = world.get_resource_mut::<fps_counter::FPSCounter>();

        let fps = counter.tick();

        println!("FPS: {fps}");

        Ok(())
    };
    let fps_plugin = move |game: &mut Game| {
        let world = game.world();
        world.add_resource(fps_counter::FPSCounter::new());
    };

    let spin_system = |world: &mut World| -> anyhow::Result<()> {
        const SPEED: f32 = 4.0;
        let delta_time = **world.get_resource::<DeltaTime>();

        for (mut transform, _) in world.view_iter::<(&mut TransformComponent, &CubeFlag)>() {
            let t = &mut transform.transform;
            t.rotate_y(math::Angle::Degrees(SPEED * delta_time));
        }

        for (mut transform, _s) in world.view_iter::<(&mut TransformComponent, &mut SpotLight)>() {
            let t = &mut transform.transform;
            t.rotate_x(math::Angle::Degrees(SPEED * delta_time));
        }

        Ok(())
    };

    let jiggle_plugin = move |game: &mut Game| {
        game.world().add_resource(TpsAccumulator(0.0));
        
        let mut sys = BatchedSystem::new();
        sys.with_criteria(FixedTimestep::new(45));
        sys.with_system(spin_system.into_system());
        //sys.with_system(fps_system);

        game.with_system("fixed", sys, &[]);
        fps_plugin(game);
    };

    let action_handler_plugin = |game: &mut Game| {
        let action_handler = ActionHandler::new()
            .add_layout(LayoutId::from(0))
            .add_action("forward_backward", Action::new(ActionKind::Button))
            .add_action("left_right", Action::new(ActionKind::Button))
            .add_mapping(ActionMapping::new(LayoutId::from(0), ActionMappingId::from(0))
                .bind("forward_backward", &[
                    ActionSource::Keyboard(KeyCode::W).into_binding_modifier(1.0),
                    ActionSource::Keyboard(KeyCode::S).into_binding_modifier(-1.0)
                ])
                .bind("left_right", &[
                    ActionSource::Keyboard(KeyCode::A).into_binding_modifier(1.0),
                    ActionSource::Keyboard(KeyCode::D).into_binding_modifier(-1.0)
                ])
                .finish()
            );

        let test_system = |world: &mut World| -> anyhow::Result<()> {
            let handler = world.get_resource::<ActionHandler>();
            
            if let Some(alpha) = handler.get_pressed_modifier("forward_backward") {
                debug!("'forward_backward': {alpha}");
            }

            if let Some(alpha) = handler.get_pressed_modifier("left_right") {
                debug!("'left_right': {alpha}");
            }

            Ok(())
        };

        game.world().add_resource(action_handler);
        game.with_plugin(InputActionPlugin);
        //game.with_system("test_actions", test_system, &[]);
    };
    
    Game::initialize().await
        .with_plugin(lyra_engine::DefaultPlugins)
        .with_startup_system(setup_sys.into_system())
        .with_plugin(action_handler_plugin)
        //.with_plugin(fps_plugin)
        .with_plugin(jiggle_plugin)
        .with_plugin(FreeFlyCameraPlugin)
        .run().await;
}