use std::iter;

use debug_triangle::DEBUG_VERT;
use simple_plane::generate_square;
use wgpu::util::DeviceExt;

mod vertex;
use vertex::Vertex;
mod simple_plane;
use simple_plane::generate_simple_plane;

mod debug_triangle;
mod camera;
use camera::Camera;
use camera::CameraUniform;

mod wave;
mod texture;
use winit::{
    event::*,
    event_loop::EventLoop,
    keyboard::{KeyCode, PhysicalKey},
    window::{Window, WindowBuilder},
};




impl Vertex {
    fn desc() -> wgpu::VertexBufferLayout<'static> {
        wgpu::VertexBufferLayout {
            array_stride: std::mem::size_of::<Vertex>() as wgpu::BufferAddress,
            step_mode: wgpu::VertexStepMode::Vertex,
            attributes: &[
                wgpu::VertexAttribute {
                    offset: 0,
                    shader_location: 0,
                    format: wgpu::VertexFormat::Float32x3,
                },
                wgpu::VertexAttribute {
                    offset: std::mem::size_of::<[f32; 3]>() as wgpu::BufferAddress,
                    shader_location: 1,
                    format: wgpu::VertexFormat::Float32x3,
                },
            ],
        }
    }
}


// // Changed
// const VERTICES: &[Vertex] = &[
//     // Changed
//     Vertex { position: [-0.0868241, 0.49240386, 0.0], tex_coords: [0.4131759, 0.00759614], }, // A
//     Vertex { position: [-0.49513406, 0.06958647, 0.0], tex_coords: [0.0048659444, 0.43041354], }, // B
//     Vertex { position: [-0.21918549, -0.44939706, 0.0], tex_coords: [0.28081453, 0.949397], }, // C
//     Vertex { position: [0.35966998, -0.3473291, 0.0], tex_coords: [0.85967, 0.84732914], }, // D
//     Vertex { position: [0.44147372, 0.2347359, 0.0], tex_coords: [0.9414737, 0.2652641], }, // E
// ];



// const INDICES: &[u16] = &[
//     0, 1, 4,
//     1, 2, 4,
//     2, 3, 4,
// ];

fn creer_plan_simple(largeur: f32, hauteur: f32) -> Vec<Vertex> {
    // Vecteur pour stocker les vertices
    let mut vertices: Vec<Vertex> = Vec::new();

    // Coordonnées des quatre coins du plan
    let coin_sup_gauche = [0.0, hauteur, 0.0];
    let coin_sup_droit = [largeur, hauteur, 0.0];
    let coin_inf_droit = [largeur, 0.0, 0.0];
    let coin_inf_gauche = [0.0, 0.0, 0.0];
  
    // Couleur par défaut (ajustez selon vos besoins)
    let couleur = [1.0, 1.0, 1.0];
  
    // Ajout des vertices
    vertices.push(Vertex { position: coin_sup_gauche, color: couleur });
    vertices.push(Vertex { position: coin_sup_droit, color: couleur });
    vertices.push(Vertex { position: coin_inf_droit, color: couleur });
    vertices.push(Vertex { position: coin_inf_gauche, color: couleur });
  
    // Retourne le vecteur de vertices
    vertices
  }
  
struct State<'a> {
    surface: wgpu::Surface<'a>,
    device: wgpu::Device,
    queue: wgpu::Queue,
    config: wgpu::SurfaceConfiguration,
    size: winit::dpi::PhysicalSize<u32>,
    // The window must be declared after the surface so
    // it gets dropped after it as the surface contains
    // unsafe references to the window's resources.
    window: &'a Window,
    render_pipeline: wgpu::RenderPipeline,

    vertex_buffer: wgpu::Buffer,
    //index_buffer: wgpu::Buffer,
    num_vertices: u32,
    //num_indices: u32,

    diffuse_bind_group: wgpu::BindGroup,
    diffuse_texture: texture::Texture,

    camera: Camera,
    camera_uniform: CameraUniform,
    camera_buffer: wgpu::Buffer,
    camera_bind_group: wgpu::BindGroup,
}

impl<'a> State<'a> {
    async fn new(window: &'a Window) -> State<'a> {
        let size = window.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::all(),
            ..Default::default()
        });

        let surface = instance.create_surface(window).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,
                    required_features: wgpu::Features::empty(),
                    // WebGL doesn't support all of wgpu's features, so if
                    // we're building for the web we'll have to disable some.
                    required_limits: if cfg!(target_arch = "wasm32") {
                        wgpu::Limits::downlevel_webgl2_defaults()
                    } else {
                        wgpu::Limits::default()
                    },
                },
                // Some(&std::path::Path::new("trace")), // Trace path
                None,
            )
            .await
            .unwrap();

        let surface_caps = surface.get_capabilities(&adapter);
        //println!("{:?}", &surface_caps.present_modes);
        // 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],
            desired_maximum_frame_latency: 2,
            view_formats: vec![],
        };
        surface.configure(&device, &config);
        //Camera

        let camera = Camera{
            eye: glam::Vec3::new(0.0, 1.0, 2.0),
            target: glam::Vec3::new(0.0, 0.0, 0.0),
            up: glam::Vec3::new(0.0, 1.0, 0.0),
            aspect: config.width as f32 / config.height as f32,
            fovy: 45.0,
            znear: 0.1,
            zfar: 100.0,
        };

        //Camera buffer
        let mut camera_uniform = CameraUniform::new();

        camera_uniform.update_view_proj(&camera);

        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,
            }
        );

        //Camera Bind Group Layout

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

        //Camera Bind Group

        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"),
            }
        );

        //Texture
        let diffuse_bytes = include_bytes!("happy-tree.png");
        let diffuse_texture = texture::Texture::from_bytes(&device, &queue, diffuse_bytes, "happy-tree.png").unwrap();
        //BindGroup

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

        //Creation of the real bind group

        let diffuse_bind_group = device.create_bind_group(
            &wgpu::BindGroupDescriptor {
                layout: &texture_bind_group_layout,
                entries: &[
                    wgpu::BindGroupEntry {
                        binding: 0,
                        resource: wgpu::BindingResource::TextureView(&diffuse_texture.view), // CHANGED!
                    },
                    wgpu::BindGroupEntry {
                        binding: 1,
                        resource: wgpu::BindingResource::Sampler(&diffuse_texture.sampler), // CHANGED!
                    }
                ],
                label: Some("diffuse_bind_group"),
            }
        );
        

        //Shader and Pipeline
        let shader = device.create_shader_module(wgpu::ShaderModuleDescriptor {
            label: Some("Shader"),
            source: wgpu::ShaderSource::Wgsl(include_str!("shader.wgsl").into()),
        });

        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,
                ],
                push_constant_ranges: &[],
            });

        let render_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor{
            label: Some("Render Pipeline"),
            layout: Some(&render_pipeline_layout),
            vertex: wgpu::VertexState{
                module: &shader,
                entry_point: "vs_main",
                buffers: &[
                    Vertex::desc()
                ],
            },
            fragment: Some(wgpu::FragmentState{
                module: &shader,
                entry_point: "fs_main",
                targets: &[Some(wgpu::ColorTargetState{
                    format: config.format,
                    blend: Some(wgpu::BlendState::REPLACE),
                    write_mask: wgpu::ColorWrites::ALL,
                })],
            }),
            primitive: wgpu::PrimitiveState{
                topology: wgpu::PrimitiveTopology::TriangleList,
                strip_index_format: None,
                front_face: wgpu::FrontFace::Ccw,
                cull_mode: Some(wgpu::Face::Back),
                polygon_mode: wgpu::PolygonMode::Fill,
                unclipped_depth: false,
                conservative: false,   
            },
            depth_stencil: None,
            multisample: wgpu::MultisampleState{
                count: 1,
                mask: !0,
                alpha_to_coverage_enabled: false,
            },
            multiview: None,
        });

        //let (vertices, indices) = creer_plan_subdivise(1.0, 1.0, 10);
        //let vert = creer_plan_simple(1.0, 1.0);

        //let vert = generate_simple_plane(0.5, 1);
        //let vert = generate_square();
        let vert = DEBUG_VERT;
        // Create a buffer with the vertex data
        let vertex_buffer = device.create_buffer_init(
            &wgpu::util::BufferInitDescriptor{
                label: Some("Vertex Buffer"),
                contents: bytemuck::cast_slice(&vert),
                usage: wgpu::BufferUsages::VERTEX,
            }
        );

        // let index_buffer = device.create_buffer_init(
        //     &wgpu::util::BufferInitDescriptor{
        //         label: Some("Indice Buffer"),
        //         usage: wgpu::BufferUsages::INDEX,
        //         contents: bytemuck::cast_slice(&indices),
        //     }
        // );

        let num_vertices = vert.len() as u32;
        //let num_indices = indices.len() as u32;
        Self {
            surface,
            device,
            queue,
            config,
            size,
            window,
            render_pipeline,
            vertex_buffer,
            //index_buffer,
            num_vertices,
            //num_indices,
            diffuse_bind_group,
            diffuse_texture,
            //Camera
            camera,
            camera_uniform,
            camera_buffer,
            camera_bind_group,
        }
    }

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

    pub fn resize(&mut self, new_size: winit::dpi::PhysicalSize<u32>) {
        if new_size.width > 0 && new_size.height > 0 {
            self.size = new_size;
            self.config.width = new_size.width;
            self.config.height = new_size.height;
            self.surface.configure(&self.device, &self.config);
        }
    }

    #[allow(unused_variables)]
    fn input(&mut self, event: &WindowEvent) -> bool {
        false
    }

    fn update(&mut self) {}

    fn render(&mut self) -> Result<(), wgpu::SurfaceError> {
        let output = self.surface.get_current_texture()?;
        let view = output
            .texture
            .create_view(&wgpu::TextureViewDescriptor::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: &view,
                    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: None,
                occlusion_query_set: None,
                timestamp_writes: None,
            });
            //Add the pipeline
            render_pass.set_pipeline(&self.render_pipeline);
            //Add the bind group for the texture
            render_pass.set_bind_group(0, &self.diffuse_bind_group, &[]);
            //Add the camera bind group
            render_pass.set_bind_group(1, &self.camera_bind_group, &[]);

            render_pass.set_vertex_buffer(0, self.vertex_buffer.slice(..));
            //render_pass.set_index_buffer(self.index_buffer.slice(..), wgpu::IndexFormat::Uint16);
            //render_pass.draw_indexed(0..self.num_indices,0, 0..1);
            render_pass.draw(0..self.num_vertices, 0..1);
        }

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

        Ok(())
    }
}

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

    let event_loop = EventLoop::new().unwrap();
    let window = WindowBuilder::new().build(&event_loop).unwrap();

    // State::new uses async code, so we're going to wait for it to finish
    let mut state = State::new(&window).await;

    event_loop
        .run(move |event, control_flow| {
            match event {
                Event::WindowEvent {
                    ref event,
                    window_id,
                } if window_id == state.window().id() => {
                    if !state.input(event) {
                        // UPDATED!
                        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 => {
                                // This tells winit that we want another frame after this one
                                state.window().request_redraw();
                                state.update();
                                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) => {
                                        log::error!("OutOfMemory");
                                        control_flow.exit();
                                    }

                                    // This happens when the a frame takes too long to present
                                    Err(wgpu::SurfaceError::Timeout) => {
                                        log::warn!("Surface timeout")
                                    }
                                }
                            }
                            _ => {}
                        }
                    }
                }
                _ => {}
            }
        })
        .unwrap();
}