use std::{f32::consts::PI, iter};
use std::sync::Arc;
use cgmath::prelude::*;
use wgpu::util::DeviceExt;
use winit::{
    event::*,
    event_loop::EventLoop,
    keyboard::{KeyCode, PhysicalKey},
    window::Window,
};
use winit::application::ApplicationHandler;
use winit::dpi::{PhysicalPosition, PhysicalSize};
use winit::event_loop::ActiveEventLoop;
use winit::window::WindowId;

mod camera;
mod hdr;
mod model;
mod resources;
mod texture;

#[cfg(feature = "debug")]
mod debug;

use model::{DrawLight, DrawModel, Vertex};

const NUM_INSTANCES_PER_ROW: u32 = 10;

#[repr(C)]
#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
struct CameraUniform {
    view_position: [f32; 4],
    view: [[f32; 4]; 4],
    view_proj: [[f32; 4]; 4],
    inv_proj: [[f32; 4]; 4],
    inv_view: [[f32; 4]; 4],
}

impl CameraUniform {
    fn new() -> Self {
        Self {
            view_position: [0.0; 4],
            view: cgmath::Matrix4::identity().into(), // NEW!
            view_proj: cgmath::Matrix4::identity().into(),
            inv_proj: cgmath::Matrix4::identity().into(), // NEW!
            inv_view: cgmath::Matrix4::identity().into(), // NEW!
        }
    }

    fn update_view_proj(&mut self, camera: &camera::Camera, projection: &camera::Projection) {
        self.view_position = camera.position.to_homogeneous().into();
        let proj = projection.calc_matrix();
        let view = camera.calc_matrix();
        let view_proj = proj * view;
        self.view = view.into();
        self.view_proj = view_proj.into();
        self.inv_proj = proj.invert().unwrap().into();
        self.inv_view = view.transpose().into();
    }
}

struct Instance {
    position: cgmath::Vector3<f32>,
    rotation: cgmath::Quaternion<f32>,
}

impl Instance {
    fn to_raw(&self) -> InstanceRaw {
        InstanceRaw {
            model: (cgmath::Matrix4::from_translation(self.position)
                * cgmath::Matrix4::from(self.rotation))
                .into(),
            normal: cgmath::Matrix3::from(self.rotation).into(),
        }
    }
}

#[repr(C)]
#[derive(Debug, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
#[allow(dead_code)]
struct InstanceRaw {
    model: [[f32; 4]; 4],
    normal: [[f32; 3]; 3],
}

impl model::Vertex for InstanceRaw {
    fn desc() -> wgpu::VertexBufferLayout<'static> {
        use std::mem;
        wgpu::VertexBufferLayout {
            array_stride: mem::size_of::<InstanceRaw>() as wgpu::BufferAddress,
            // We need to switch from using a step mode of Vertex to Instance
            // This means that our shaders will only change to use the next
            // instance when the shader starts processing a new instance
            step_mode: wgpu::VertexStepMode::Instance,
            attributes: &[
                wgpu::VertexAttribute {
                    offset: 0,
                    // While our vertex shader only uses locations 0, and 1 now, in later tutorials we'll
                    // be using 2, 3, and 4, for Vertex. We'll start at slot 5 not conflict with them later
                    shader_location: 5,
                    format: wgpu::VertexFormat::Float32x4,
                },
                // A mat4 takes up 4 vertex slots as it is technically 4 vec4s. We need to define a slot
                // for each vec4. We don't have to do this in code though.
                wgpu::VertexAttribute {
                    offset: mem::size_of::<[f32; 4]>() as wgpu::BufferAddress,
                    shader_location: 6,
                    format: wgpu::VertexFormat::Float32x4,
                },
                wgpu::VertexAttribute {
                    offset: mem::size_of::<[f32; 8]>() as wgpu::BufferAddress,
                    shader_location: 7,
                    format: wgpu::VertexFormat::Float32x4,
                },
                wgpu::VertexAttribute {
                    offset: mem::size_of::<[f32; 12]>() as wgpu::BufferAddress,
                    shader_location: 8,
                    format: wgpu::VertexFormat::Float32x4,
                },
                wgpu::VertexAttribute {
                    offset: mem::size_of::<[f32; 16]>() as wgpu::BufferAddress,
                    shader_location: 9,
                    format: wgpu::VertexFormat::Float32x3,
                },
                wgpu::VertexAttribute {
                    offset: mem::size_of::<[f32; 19]>() as wgpu::BufferAddress,
                    shader_location: 10,
                    format: wgpu::VertexFormat::Float32x3,
                },
                wgpu::VertexAttribute {
                    offset: mem::size_of::<[f32; 22]>() as wgpu::BufferAddress,
                    shader_location: 11,
                    format: wgpu::VertexFormat::Float32x3,
                },
            ],
        }
    }
}

#[repr(C)]
#[derive(Debug, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
struct LightUniform {
    position: [f32; 3],
    // Due to uniforms requiring 16 byte (4 float) spacing, we need to use a padding field here
    _padding: u32,
    color: [f32; 3],
    _padding2: u32,
}

struct StateApplication<'a> {
    state: Option<State<'a>>,
    last_render_time: instant::Instant,
}

impl<'a> StateApplication<'a> {
    pub fn new() -> Self {
        Self {
            state: None,
            last_render_time: instant::Instant::now(),
        }
    }
}

impl<'a> ApplicationHandler for StateApplication<'a>{
    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
        let window = event_loop
            .create_window(Window::default_attributes().with_title(env!("CARGO_PKG_NAME")))
            .unwrap();
        self.state = Some(pollster::block_on(State::new(window)));
    }

    fn window_event(&mut self, event_loop: &ActiveEventLoop, window_id: WindowId, event: WindowEvent) {
        let window = self.state.as_ref().unwrap().window();

        if window.id() == window_id {
            if !self.state.as_mut().unwrap().input(&event) {
                match event {
                    WindowEvent::CloseRequested => {
                        event_loop.exit();
                    }
                    WindowEvent::Resized(physical_size) => {
                        self.state.as_mut().unwrap().resize(physical_size);
                    }
                    WindowEvent::RedrawRequested => {
                        let now = instant::Instant::now();
                        let dt = now - self.last_render_time;
                        self.last_render_time = now;

                        self.state.as_mut().unwrap().update(dt);
                        self.state.as_mut().unwrap().render().unwrap();
                    }
                    _ => {},
                }
            }
        }
    }

    fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
        let window = self.state.as_ref().unwrap().window();
        window.request_redraw();
    }
}

struct State<'a> {
    window: Arc<Window>,
    size: PhysicalSize<u32>,
    surface: wgpu::Surface<'a>,
    device: wgpu::Device,
    queue: wgpu::Queue,
    config: wgpu::SurfaceConfiguration,
    render_pipeline: wgpu::RenderPipeline,
    obj_model: model::Model,
    camera: camera::Camera,
    projection: camera::Projection,
    camera_controller: camera::CameraController,
    camera_uniform: CameraUniform,
    camera_buffer: wgpu::Buffer,
    camera_bind_group: wgpu::BindGroup,
    last_mouse_position: PhysicalPosition<f64>,
    instances: Vec<Instance>,
    #[allow(dead_code)]
    instance_buffer: wgpu::Buffer,
    depth_texture: texture::Texture,
    light_uniform: LightUniform,
    light_buffer: wgpu::Buffer,
    light_bind_group: wgpu::BindGroup,
    light_render_pipeline: wgpu::RenderPipeline,
    #[allow(dead_code)]
    debug_material: model::Material,
    mouse_pressed: bool,
    hdr: hdr::HdrPipeline,
    environment_bind_group: wgpu::BindGroup,
    sky_pipeline: wgpu::RenderPipeline,
    #[cfg(feature = "debug")]
    debug: debug::Debug,
}

fn create_render_pipeline(
    device: &wgpu::Device,
    layout: &wgpu::PipelineLayout,
    color_format: wgpu::TextureFormat,
    depth_format: Option<wgpu::TextureFormat>,
    vertex_layouts: &[wgpu::VertexBufferLayout],
    topology: wgpu::PrimitiveTopology, // NEW!
    shader: wgpu::ShaderModuleDescriptor,
) -> wgpu::RenderPipeline {
    let shader = device.create_shader_module(shader);

    device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
        label: Some(&format!("{:?}", shader)),
        layout: Some(layout),
        vertex: wgpu::VertexState {
            module: &shader,
            entry_point: "vs_main",
            buffers: vertex_layouts,
            compilation_options: Default::default(),
        },
        fragment: Some(wgpu::FragmentState {
            module: &shader,
            entry_point: "fs_main",
            targets: &[Some(wgpu::ColorTargetState {
                format: color_format,
                blend: None,
                write_mask: wgpu::ColorWrites::ALL,
            })],
            compilation_options: Default::default(),
        }),
        primitive: wgpu::PrimitiveState {
            topology, // NEW!
            strip_index_format: None,
            front_face: wgpu::FrontFace::Ccw,
            cull_mode: Some(wgpu::Face::Back),
            // Setting this to anything other than Fill requires Features::NON_FILL_POLYGON_MODE
            polygon_mode: wgpu::PolygonMode::Fill,
            // Requires Features::DEPTH_CLIP_CONTROL
            unclipped_depth: false,
            // Requires Features::CONSERVATIVE_RASTERIZATION
            conservative: false,
        },
        depth_stencil: depth_format.map(|format| wgpu::DepthStencilState {
            format,
            depth_write_enabled: true,
            depth_compare: wgpu::CompareFunction::LessEqual, // UDPATED!
            stencil: wgpu::StencilState::default(),
            bias: wgpu::DepthBiasState::default(),
        }),
        multisample: wgpu::MultisampleState {
            count: 1,
            mask: !0,
            alpha_to_coverage_enabled: false,
        },
        // If the pipeline will be used with a multiview render pass, this
        // indicates how many array layers the attachments will have.
        multiview: None,
        cache: None,
    })
}

impl<'a> State<'a> {
    async fn new(window: Window) -> Self {
        let window_arc = Arc::new(window);
        let size = window_arc.inner_size();

        // The instance is a handle to our GPU
        // BackendBit::PRIMARY => Vulkan + Metal + DX12 + Browser WebGPU
        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
            backends: wgpu::Backends::PRIMARY,
            ..Default::default()
        });

        let surface = instance.create_surface(window_arc.clone()).unwrap();

        let adapter = instance
            .request_adapter(&wgpu::RequestAdapterOptions {
                power_preference: wgpu::PowerPreference::default(),
                compatible_surface: Some(&surface),
                force_fallback_adapter: false,
            })
            .await
            .unwrap();
        let (device, queue) = adapter
            .request_device(
                &wgpu::DeviceDescriptor {
                    label: None,
                    // UPDATED!
                    required_features: wgpu::Features::empty(),
                    // UPDATED!
                    required_limits: wgpu::Limits::downlevel_defaults(),
                    memory_hints: Default::default(),
                },
                None, // Trace path
            )
            .await
            .unwrap();

        let surface_caps = surface.get_capabilities(&adapter);
        // Shader code in this tutorial assumes an Srgb surface texture. Using a different
        // one will result all the colors comming out darker. If you want to support non
        // Srgb surfaces, you'll need to account for that when drawing to the frame.
        let surface_format = surface_caps
            .formats
            .iter()
            .copied()
            .find(|f| f.is_srgb())
            .unwrap_or(surface_caps.formats[0]);
        let config = wgpu::SurfaceConfiguration {
            usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
            format: surface_format,
            width: size.width,
            height: size.height,
            present_mode: surface_caps.present_modes[0],
            alpha_mode: surface_caps.alpha_modes[0],
            // NEW!
            view_formats: vec![surface_format.add_srgb_suffix()],
            desired_maximum_frame_latency: 2,
        };

        let texture_bind_group_layout =
            device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
                entries: &[
                    wgpu::BindGroupLayoutEntry {
                        binding: 0,
                        visibility: wgpu::ShaderStages::FRAGMENT,
                        ty: wgpu::BindingType::Texture {
                            multisampled: false,
                            sample_type: wgpu::TextureSampleType::Float { filterable: true },
                            view_dimension: wgpu::TextureViewDimension::D2,
                        },
                        count: None,
                    },
                    wgpu::BindGroupLayoutEntry {
                        binding: 1,
                        visibility: wgpu::ShaderStages::FRAGMENT,
                        ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
                        count: None,
                    },
                    // normal map
                    wgpu::BindGroupLayoutEntry {
                        binding: 2,
                        visibility: wgpu::ShaderStages::FRAGMENT,
                        ty: wgpu::BindingType::Texture {
                            multisampled: false,
                            sample_type: wgpu::TextureSampleType::Float { filterable: true },
                            view_dimension: wgpu::TextureViewDimension::D2,
                        },
                        count: None,
                    },
                    wgpu::BindGroupLayoutEntry {
                        binding: 3,
                        visibility: wgpu::ShaderStages::FRAGMENT,
                        ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
                        count: None,
                    },
                ],
                label: Some("texture_bind_group_layout"),
            });

        let camera = camera::Camera::new((0.0, 5.0, 10.0), cgmath::Deg(-90.0), cgmath::Deg(-20.0));
        let projection =
            camera::Projection::new(config.width, config.height, cgmath::Deg(45.0), 0.1, 100.0);
        let camera_controller = camera::CameraController::new(4.0, 0.4);

        let mut camera_uniform = CameraUniform::new();
        camera_uniform.update_view_proj(&camera, &projection);

        let camera_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
            label: Some("Camera Buffer"),
            contents: bytemuck::cast_slice(&[camera_uniform]),
            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
        });

        const SPACE_BETWEEN: f32 = 3.0;
        let instances = (0..NUM_INSTANCES_PER_ROW)
            .flat_map(|z| {
                (0..NUM_INSTANCES_PER_ROW).map(move |x| {
                    let x = SPACE_BETWEEN * (x as f32 - NUM_INSTANCES_PER_ROW as f32 / 2.0);
                    let z = SPACE_BETWEEN * (z as f32 - NUM_INSTANCES_PER_ROW as f32 / 2.0);

                    let position = cgmath::Vector3 { x, y: 0.0, z };

                    let rotation = if position.is_zero() {
                        cgmath::Quaternion::from_axis_angle(
                            cgmath::Vector3::unit_z(),
                            cgmath::Deg(0.0),
                        )
                    } else {
                        cgmath::Quaternion::from_axis_angle(position.normalize(), cgmath::Deg(45.0))
                    };

                    Instance { position, rotation }
                })
            })
            .collect::<Vec<_>>();

        let instance_data = instances.iter().map(Instance::to_raw).collect::<Vec<_>>();
        let instance_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
            label: Some("Instance Buffer"),
            contents: bytemuck::cast_slice(&instance_data),
            usage: wgpu::BufferUsages::VERTEX,
        });

        let camera_bind_group_layout =
            device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
                entries: &[wgpu::BindGroupLayoutEntry {
                    binding: 0,
                    visibility: wgpu::ShaderStages::VERTEX | wgpu::ShaderStages::FRAGMENT,
                    ty: wgpu::BindingType::Buffer {
                        ty: wgpu::BufferBindingType::Uniform,
                        has_dynamic_offset: false,
                        min_binding_size: None,
                    },
                    count: None,
                }],
                label: Some("camera_bind_group_layout"),
            });

        let camera_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
            layout: &camera_bind_group_layout,
            entries: &[wgpu::BindGroupEntry {
                binding: 0,
                resource: camera_buffer.as_entire_binding(),
            }],
            label: Some("camera_bind_group"),
        });

        let obj_model =
            resources::load_model("cube.obj", &device, &queue, &texture_bind_group_layout)
                .await
                .unwrap();

        let light_uniform = LightUniform {
            position: [2.0, 2.0, 2.0],
            _padding: 0,
            color: [1.0, 1.0, 1.0],
            _padding2: 0,
        };

        let light_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
            label: Some("Light VB"),
            contents: bytemuck::cast_slice(&[light_uniform]),
            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
        });

        let light_bind_group_layout =
            device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
                entries: &[wgpu::BindGroupLayoutEntry {
                    binding: 0,
                    visibility: wgpu::ShaderStages::VERTEX | wgpu::ShaderStages::FRAGMENT,
                    ty: wgpu::BindingType::Buffer {
                        ty: wgpu::BufferBindingType::Uniform,
                        has_dynamic_offset: false,
                        min_binding_size: None,
                    },
                    count: None,
                }],
                label: None,
            });

        let light_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
            layout: &light_bind_group_layout,
            entries: &[wgpu::BindGroupEntry {
                binding: 0,
                resource: light_buffer.as_entire_binding(),
            }],
            label: None,
        });

        let depth_texture =
            texture::Texture::create_depth_texture(&device, &config, "depth_texture");

        let hdr = hdr::HdrPipeline::new(&device, &config);

        let hdr_loader = resources::HdrLoader::new(&device);
        let sky_bytes = resources::load_binary("pure-sky.hdr").await.unwrap();
        let sky_texture = hdr_loader.from_equirectangular_bytes(
            &device,
            &queue,
            &sky_bytes,
            1080,
            Some("Sky Texture"),
        ).unwrap();

        let environment_layout =
            device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
                label: Some("environment_layout"),
                entries: &[
                    wgpu::BindGroupLayoutEntry {
                        binding: 0,
                        visibility: wgpu::ShaderStages::FRAGMENT,
                        ty: wgpu::BindingType::Texture {
                            sample_type: wgpu::TextureSampleType::Float { filterable: false },
                            view_dimension: wgpu::TextureViewDimension::Cube,
                            multisampled: false,
                        },
                        count: None,
                    },
                    wgpu::BindGroupLayoutEntry {
                        binding: 1,
                        visibility: wgpu::ShaderStages::FRAGMENT,
                        ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::NonFiltering),
                        count: None,
                    },
                ],
            });

        let environment_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
            label: Some("environment_bind_group"),
            layout: &environment_layout,
            entries: &[
                wgpu::BindGroupEntry {
                    binding: 0,
                    resource: wgpu::BindingResource::TextureView(&sky_texture.view()),
                },
                wgpu::BindGroupEntry {
                    binding: 1,
                    resource: wgpu::BindingResource::Sampler(sky_texture.sampler()),
                },
            ],
        });

        let render_pipeline_layout =
            device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
                label: Some("Render Pipeline Layout"),
                bind_group_layouts: &[
                    &texture_bind_group_layout,
                    &camera_bind_group_layout,
                    &light_bind_group_layout,
                    &environment_layout, // UPDATED!
                ],
                push_constant_ranges: &[],
            });

        let render_pipeline = {
            let shader = wgpu::ShaderModuleDescriptor {
                label: Some("Normal Shader"),
                source: wgpu::ShaderSource::Wgsl(include_str!("shader.wgsl").into()),
            };
            create_render_pipeline(
                &device,
                &render_pipeline_layout,
                hdr.format(),
                Some(texture::Texture::DEPTH_FORMAT),
                &[model::ModelVertex::desc(), InstanceRaw::desc()],
                wgpu::PrimitiveTopology::TriangleList,
                shader,
            )
        };

        let light_render_pipeline = {
            let layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
                label: Some("Light Pipeline Layout"),
                bind_group_layouts: &[&camera_bind_group_layout, &light_bind_group_layout],
                push_constant_ranges: &[],
            });
            let shader = wgpu::ShaderModuleDescriptor {
                label: Some("Light Shader"),
                source: wgpu::ShaderSource::Wgsl(include_str!("light.wgsl").into()),
            };
            create_render_pipeline(
                &device,
                &layout,
                hdr.format(),
                Some(texture::Texture::DEPTH_FORMAT),
                &[model::ModelVertex::desc()],
                wgpu::PrimitiveTopology::TriangleList,
                shader,
            )
        };

        // NEW!
        let sky_pipeline = {
            let layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
                label: Some("Sky Pipeline Layout"),
                bind_group_layouts: &[&camera_bind_group_layout, &environment_layout],
                push_constant_ranges: &[],
            });
            let shader = wgpu::include_wgsl!("sky.wgsl");
            create_render_pipeline(
                &device,
                &layout,
                hdr.format(),
                Some(texture::Texture::DEPTH_FORMAT),
                &[],
                wgpu::PrimitiveTopology::TriangleList,
                shader,
            )
        };

        let debug_material = {
            let diffuse_bytes = include_bytes!("../res/cobble-diffuse.png");
            let normal_bytes = include_bytes!("../res/cobble-normal.png");

            let diffuse_texture = texture::Texture::from_bytes(
                &device,
                &queue,
                diffuse_bytes,
                "res/alt-diffuse.png",
                false,
            )
                .unwrap();
            let normal_texture = texture::Texture::from_bytes(
                &device,
                &queue,
                normal_bytes,
                "res/alt-normal.png",
                true,
            )
                .unwrap();

            model::Material::new(
                &device,
                "alt-material",
                diffuse_texture,
                normal_texture,
                &texture_bind_group_layout,
            )
        };

        #[cfg(feature = "debug")]
        let debug = debug::Debug::new(&device, &camera_bind_group_layout, surface_format);

        Self {
            window: window_arc,
            size,
            surface,
            device,
            queue,
            config,
            render_pipeline,
            obj_model,
            camera,
            projection,
            camera_controller,
            camera_buffer,
            camera_bind_group,
            last_mouse_position: PhysicalPosition::new(0.0, 0.0),
            camera_uniform,
            instances,
            instance_buffer,
            depth_texture,
            light_uniform,
            light_buffer,
            light_bind_group,
            light_render_pipeline,
            #[allow(dead_code)]
            debug_material,
            mouse_pressed: false,
            hdr,
            environment_bind_group,
            sky_pipeline,

            #[cfg(feature = "debug")]
            debug,
        }
    }

    pub fn window(&self) -> &Window {
        &self.window
    }

    fn resize(&mut self, new_size: winit::dpi::PhysicalSize<u32>) {
        if new_size.width > 0 && new_size.height > 0 {
            println!("Resizing to {:?}", new_size);

            // Begrenzen der Dimensionen auf GPU-Limits
            let max_texture_dimension = self.device.limits().max_texture_dimension_2d as u32;
            let width = new_size.width.min(max_texture_dimension);
            let height = new_size.height.min(max_texture_dimension);

            self.projection.resize(width, height);
            self.hdr.resize(&self.device, width, height);
            self.size = PhysicalSize { width, height }; // Aktualisieren auf die begrenzten Dimensionen
            self.config.width = width;
            self.config.height = height;

            self.surface.configure(&self.device, &self.config);
            self.depth_texture =
                texture::Texture::create_depth_texture(&self.device, &self.config, "depth_texture");
        }
    }

    fn input(&mut self, event: &WindowEvent) -> bool {
        println!("Handle event {:?}", event);
        match event {
            WindowEvent::KeyboardInput {
                event:
                KeyEvent {
                    physical_key: PhysicalKey::Code(key),
                    state,
                    ..
                },
                ..
            } => self.camera_controller.process_keyboard(*key, *state),
            WindowEvent::MouseWheel { delta, .. } => {
                self.camera_controller.process_scroll(delta);
                true
            }
            WindowEvent::MouseInput {
                button: MouseButton::Left,
                state,
                ..
            } => {
                self.mouse_pressed = *state == ElementState::Pressed;
                true
            }
            WindowEvent::CursorMoved { position, .. } => {
                if self.mouse_pressed {
                    let delta_x = position.x as f64 - self.last_mouse_position.x as f64;
                    let delta_y = position.y as f64 - self.last_mouse_position.y as f64;
                    self.camera_controller.process_mouse(delta_x, delta_y);
                }
                self.last_mouse_position = *position;
                true
            }
            _ => false,
        }
    }

    fn update(&mut self, dt: std::time::Duration) {
        self.camera_controller.update_camera(&mut self.camera, dt);
        self.camera_uniform
            .update_view_proj(&self.camera, &self.projection);
        self.queue.write_buffer(
            &self.camera_buffer,
            0,
            bytemuck::cast_slice(&[self.camera_uniform]),
        );

        // Update the light
        let old_position: cgmath::Vector3<_> = self.light_uniform.position.into();
        self.light_uniform.position = (cgmath::Quaternion::from_axis_angle(
            (0.0, 1.0, 0.0).into(),
            cgmath::Deg(PI * dt.as_secs_f32()),
        ) * old_position)
            .into();
        self.queue.write_buffer(
            &self.light_buffer,
            0,
            bytemuck::cast_slice(&[self.light_uniform]),
        );
    }

    fn render(&mut self) -> Result<(), wgpu::SurfaceError> {
        let output = self.surface.get_current_texture()?;
        let view = output.texture.create_view(&wgpu::TextureViewDescriptor {
            format: Some(self.config.format.add_srgb_suffix()),
            ..Default::default()
        });

        let mut encoder = self
            .device
            .create_command_encoder(&wgpu::CommandEncoderDescriptor {
                label: Some("Render Encoder"),
            });

        {
            let mut render_pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                label: Some("Render Pass"),
                color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                    view: self.hdr.view(), // UPDATED!
                    resolve_target: None,
                    ops: wgpu::Operations {
                        load: wgpu::LoadOp::Clear(wgpu::Color {
                            r: 0.1,
                            g: 0.2,
                            b: 0.3,
                            a: 1.0,
                        }),
                        store: wgpu::StoreOp::Store,
                    },
                })],
                depth_stencil_attachment: Some(wgpu::RenderPassDepthStencilAttachment {
                    view: &self.depth_texture.view,
                    depth_ops: Some(wgpu::Operations {
                        load: wgpu::LoadOp::Clear(1.0),
                        store: wgpu::StoreOp::Store,
                    }),
                    stencil_ops: None,
                }),
                occlusion_query_set: None,
                timestamp_writes: None,
            });

            render_pass.set_vertex_buffer(1, self.instance_buffer.slice(..));
            render_pass.set_pipeline(&self.light_render_pipeline);
            render_pass.draw_light_model(
                &self.obj_model,
                &self.camera_bind_group,
                &self.light_bind_group,
            );

            render_pass.set_pipeline(&self.render_pipeline);
            render_pass.draw_model_instanced(
                &self.obj_model,
                0..self.instances.len() as u32,
                &self.camera_bind_group,
                &self.light_bind_group,
                &self.environment_bind_group,
            );

            render_pass.set_pipeline(&self.sky_pipeline);
            render_pass.set_bind_group(0, &self.camera_bind_group, &[]);
            render_pass.set_bind_group(1, &self.environment_bind_group, &[]);
            render_pass.draw(0..3, 0..1);
        }

        // NEW!
        // Apply tonemapping
        self.hdr.process(&mut encoder, &view);

        #[cfg(feature = "debug")]
        {
            let mut pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
                label: Some("Debug"),
                color_attachments: &[Some(wgpu::RenderPassColorAttachment {
                    view: &view,
                    resolve_target: None,
                    ops: wgpu::Operations {
                        load: wgpu::LoadOp::Load,
                        store: wgpu::StoreOp::Store,
                    },
                })],
                depth_stencil_attachment: None,
                occlusion_query_set: None,
                timestamp_writes: None,
            });
            self.debug.draw_axis(&mut pass, &self.camera_bind_group);
        }

        self.queue.submit(iter::once(encoder.finish()));
        output.present();

        Ok(())
    }
}

pub async fn run() {
    env_logger::init();

    let event_loop = EventLoop::new().unwrap();
    /*let title = env!("CARGO_PKG_NAME");
    let window = winit::window::WindowBuilder::new()
        .with_title(title)
        // Limit dimensions to 1080p
        .with_inner_size(winit::dpi::PhysicalSize::new(1920, 1080))
        .build(&event_loop)
        .unwrap();*/

    let mut window_state = StateApplication::new();
    let _ = event_loop.run_app(&mut window_state);

    /*let mut state = State::new(&window).await.unwrap();
    let mut last_render_time = instant::Instant::now();
    event_loop.run(move |event, control_flow| {
        match event {
            Event::DeviceEvent {
                event: DeviceEvent::MouseMotion{ delta, },
                .. // We're not using device_id currently
            } => if state.mouse_pressed {
                state.camera_controller.process_mouse(delta.0, delta.1)
            }
            // UPDATED!
            Event::WindowEvent {
                ref event,
                window_id,
            } if window_id == state.window().id() && !state.input(event) => {
                match event {
                    WindowEvent::CloseRequested
                    | WindowEvent::KeyboardInput {
                        event:
                        KeyEvent {
                            state: ElementState::Pressed,
                            physical_key: PhysicalKey::Code(KeyCode::Escape),
                            ..
                        },
                        ..
                    } => control_flow.exit(),
                    WindowEvent::Resized(physical_size) => {
                        state.resize(*physical_size);
                    }
                    WindowEvent::RedrawRequested => {
                        state.window().request_redraw();
                        let now = instant::Instant::now();
                        let dt = now - last_render_time;
                        last_render_time = now;
                        state.update(dt);
                        match state.render() {
                            Ok(_) => {}
                            // Reconfigure the surface if it's lost or outdated
                            Err(wgpu::SurfaceError::Lost | wgpu::SurfaceError::Outdated) => state.resize(state.size),
                            // The system is out of memory, we should probably quit
                            Err(wgpu::SurfaceError::OutOfMemory) => control_flow.exit(),
                            // We're ignoring timeouts
                            Err(wgpu::SurfaceError::Timeout) => log::warn!("Surface timeout"),
                        }
                    }
                    _ => {}
                }
            }
            _ => {}
        }
    }).unwrap();*/
}