use anyhow::Result;
use galactica_content::Content;
use glyphon::{
	Attrs, Buffer, Family, FontSystem, Metrics, Shaping, SwashCache, TextAtlas, TextRenderer,
};
use std::rc::Rc;

use crate::{
	datastructs::{RenderState, VertexBuffers},
	globaluniform::GlobalUniform,
	pipeline::PipelineBuilder,
	shaderprocessor::preprocess_shader,
	starfield::Starfield,
	texturearray::TextureArray,
	ui::UiManager,
	vertexbuffer::{
		consts::{SPRITE_INDICES, SPRITE_VERTICES},
		types::{
			ObjectInstance, ParticleInstance, RadialBarInstance, StarfieldInstance, TexturedVertex,
			UiInstance,
		},
		VertexBuffer,
	},
	GPUState,
};

impl GPUState {
	/// Make a new GPUState that draws on `window`
	pub async fn new(window: winit::window::Window, ct: &Content) -> Result<Self> {
		let window_size = window.inner_size();
		let window_aspect = window_size.width as f32 / window_size.height as f32;

		let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
			backends: wgpu::Backends::all(),
			..Default::default()
		});

		let surface = unsafe { instance.create_surface(&window) }.unwrap();

		// Basic setup
		let device;
		let queue;
		let config;

		{
			let adapter = instance
				.request_adapter(&wgpu::RequestAdapterOptions {
					power_preference: wgpu::PowerPreference::default(),
					compatible_surface: Some(&surface),
					force_fallback_adapter: false,
				})
				.await
				.unwrap();

			(device, queue) = adapter
				.request_device(
					&wgpu::DeviceDescriptor {
						features: wgpu::Features::TEXTURE_BINDING_ARRAY | wgpu::Features::SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING,
						// We may need limits if we compile for wasm
						limits: wgpu::Limits::default(),
						label: Some("gpu device"),
					},
					None,
				)
				.await
				.unwrap();

			// Assume sRGB
			let surface_caps = surface.get_capabilities(&adapter);
			let surface_format = surface_caps
				.formats
				.iter()
				.copied()
				.filter(|f| f.is_srgb())
				.filter(|f| f.has_stencil_aspect())
				.next()
				.unwrap_or(surface_caps.formats[0]);

			config = wgpu::SurfaceConfiguration {
				usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
				format: surface_format,
				width: window_size.width,
				height: window_size.height,
				present_mode: surface_caps.present_modes[0],
				alpha_mode: surface_caps.alpha_modes[0],
				view_formats: vec![],
			};

			surface.configure(&device, &config);
		}

		let vertex_buffers = VertexBuffers {
			object_counter: 0,
			ui_counter: 0,
			particle_counter: 0,
			radialbar_counter: 0,

			object: Rc::new(VertexBuffer::new::<TexturedVertex, ObjectInstance>(
				"object",
				&device,
				Some(SPRITE_VERTICES),
				Some(SPRITE_INDICES),
				galactica_constants::OBJECT_SPRITE_INSTANCE_LIMIT,
			)),

			starfield: Rc::new(VertexBuffer::new::<TexturedVertex, StarfieldInstance>(
				"starfield",
				&device,
				Some(SPRITE_VERTICES),
				Some(SPRITE_INDICES),
				galactica_constants::STARFIELD_SPRITE_INSTANCE_LIMIT,
			)),

			ui: Rc::new(VertexBuffer::new::<TexturedVertex, UiInstance>(
				"ui",
				&device,
				Some(SPRITE_VERTICES),
				Some(SPRITE_INDICES),
				galactica_constants::UI_SPRITE_INSTANCE_LIMIT,
			)),

			particle: Rc::new(VertexBuffer::new::<TexturedVertex, ParticleInstance>(
				"particle",
				&device,
				Some(SPRITE_VERTICES),
				Some(SPRITE_INDICES),
				galactica_constants::PARTICLE_SPRITE_INSTANCE_LIMIT,
			)),

			radialbar: Rc::new(VertexBuffer::new::<TexturedVertex, RadialBarInstance>(
				"radial bar",
				&device,
				Some(SPRITE_VERTICES),
				Some(SPRITE_INDICES),
				10,
			)),
		};

		// Load uniforms
		let global_uniform = GlobalUniform::new(&device);
		let texture_array = TextureArray::new(&device, &queue, ct)?;

		// Make sure these match the indices in each shader
		let bind_group_layouts = &[
			&texture_array.bind_group_layout,
			&global_uniform.bind_group_layout,
		];

		// Text renderer
		let mut text_atlas = TextAtlas::new(&device, &queue, wgpu::TextureFormat::Bgra8UnormSrgb);
		let mut text_font_system = FontSystem::new();

		let text_cache = SwashCache::new();
		let text_renderer = TextRenderer::new(
			&mut text_atlas,
			&device,
			wgpu::MultisampleState::default(),
			None,
		);
		let text_buffer = {
			let mut buffer = Buffer::new(&mut text_font_system, Metrics::new(30.0, 42.0));

			buffer.set_size(
				&mut text_font_system,
				window_size.width as f32,
				window_size.height as f32,
			);
			buffer.set_text(&mut text_font_system, "Hello world! 👋\nThis is rendered with 🦅 glyphon 🦁\nThe text below should be partially clipped.\na b c d e f g h i j k l m n o p q r s t u v w x y z", Attrs::new().family(Family::SansSerif), Shaping::Advanced);
			buffer.shape_until_scroll(&mut text_font_system);
			buffer
		};

		// Create render pipelines
		let object_pipeline = PipelineBuilder::new("object", &device)
			.set_shader(&preprocess_shader(
				&include_str!(concat!(
					env!("CARGO_MANIFEST_DIR"),
					"/shaders/",
					"object.wgsl"
				)),
				&global_uniform,
				1,
			))
			.set_format(config.format)
			.set_triangle(true)
			.set_vertex_buffer(&vertex_buffers.object)
			.set_bind_group_layouts(bind_group_layouts)
			.build();

		let starfield_pipeline = PipelineBuilder::new("starfield", &device)
			.set_shader(&preprocess_shader(
				&include_str!(concat!(
					env!("CARGO_MANIFEST_DIR"),
					"/shaders/",
					"starfield.wgsl"
				)),
				&global_uniform,
				1,
			))
			.set_format(config.format)
			.set_triangle(true)
			.set_vertex_buffer(&vertex_buffers.starfield)
			.set_bind_group_layouts(bind_group_layouts)
			.build();

		let ui_pipeline = PipelineBuilder::new("ui", &device)
			.set_shader(&preprocess_shader(
				&include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/shaders/", "ui.wgsl")),
				&global_uniform,
				1,
			))
			.set_format(config.format)
			.set_triangle(true)
			.set_vertex_buffer(&vertex_buffers.ui)
			.set_bind_group_layouts(bind_group_layouts)
			.build();

		let particle_pipeline = PipelineBuilder::new("particle", &device)
			.set_shader(&preprocess_shader(
				&include_str!(concat!(
					env!("CARGO_MANIFEST_DIR"),
					"/shaders/",
					"particle.wgsl"
				)),
				&global_uniform,
				1,
			))
			.set_format(config.format)
			.set_triangle(true)
			.set_vertex_buffer(&vertex_buffers.particle)
			.set_bind_group_layouts(bind_group_layouts)
			.build();

		let radialbar_pipeline = PipelineBuilder::new("radialbar", &device)
			.set_shader(&preprocess_shader(
				&include_str!(concat!(
					env!("CARGO_MANIFEST_DIR"),
					"/shaders/",
					"radialbar.wgsl"
				)),
				&global_uniform,
				1,
			))
			.set_format(config.format)
			.set_triangle(true)
			.set_vertex_buffer(&vertex_buffers.radialbar)
			.set_bind_group_layouts(bind_group_layouts)
			.build();

		let mut starfield = Starfield::new();
		starfield.regenerate();

		return Ok(Self {
			state: RenderState {
				queue,

				window,
				window_size,
				window_aspect,
				global_uniform,

				vertex_buffers,

				text_atlas,
				text_buffer,
				text_cache,
				text_font_system,
				text_renderer,
			},

			ui: UiManager::new(),
			device,
			config,
			surface,
			starfield,
			texture_array,
			object_pipeline,
			starfield_pipeline,
			ui_pipeline,
			particle_pipeline,
			radialbar_pipeline,
		});
	}
}