use std::iter;
use std::path::PathBuf;
use std::sync::Arc;
use std::time::Instant;
use wgpu::BufferUsages;
use wgpu::core::command::DrawKind::Draw;
use wgpu::naga::ShaderStage;
use wgpu::util::DeviceExt;
use winit::dpi::PhysicalSize;
use winit::window::Window;
use comet_colors::Color;
use comet_ecs::{Camera2D, Component, Position2D, Render, Render2D, Transform2D, Scene, Text};
use comet_log::*;
use comet_math::{p2, p3, v2, v3};
use comet_resources::{graphic_resource_manager::GraphicResourceManager, Texture, Vertex};
use comet_resources::texture_atlas::TextureRegion;
use comet_structs::ComponentSet;
use crate::camera::{RenderCamera, CameraUniform};
use crate::draw_info::DrawInfo;
use crate::render_pass::{RenderPassInfo, RenderPassType};
use crate::renderer::Renderer;

pub struct Renderer2D<'a> {
	surface: wgpu::Surface<'a>,
	device: wgpu::Device,
	queue: wgpu::Queue,
	config: wgpu::SurfaceConfiguration,
	size: PhysicalSize<u32>,
	render_pipeline_layout: wgpu::PipelineLayout,
	universal_render_pipeline: wgpu::RenderPipeline,
	texture_bind_group_layout: wgpu::BindGroupLayout,
	dummy_texture_bind_group: wgpu::BindGroup,
	texture_sampler: wgpu::Sampler,
	camera: RenderCamera,
	camera_uniform: CameraUniform,
	camera_buffer: wgpu::Buffer,
	camera_bind_group: wgpu::BindGroup,
	render_pass: Vec<RenderPassInfo>,
	draw_info: Vec<DrawInfo>,
	graphic_resource_manager: GraphicResourceManager,
	delta_time: f32,
	last_frame_time: Instant,
	clear_color: wgpu::Color,
}

impl<'a> Renderer2D<'a> {
	pub fn new(window: Arc<Window>, clear_color: Option<impl Color>) -> Renderer2D<'a> {
		let size = PhysicalSize::<u32>::new(1920, 1080);

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

		let surface = instance.create_surface(window).unwrap();

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

		let (device, queue) = pollster::block_on(adapter
			.request_device(
				&wgpu::DeviceDescriptor {
					label: None,
					required_features: wgpu::Features::empty(),
					required_limits: wgpu::Limits::default(),
					memory_hints: Default::default(),
				},
				None, // Trace path
			))
			.unwrap();

		let surface_caps = surface.get_capabilities(&adapter);
		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],
			view_formats: vec![],
			desired_maximum_frame_latency: 2,
		};

		let shader = device.create_shader_module(wgpu::ShaderModuleDescriptor {
			label: Some("Shader"),
			source: wgpu::ShaderSource::Wgsl(include_str!("base2d.wgsl").into()),
		});

		let graphic_resource_manager = GraphicResourceManager::new();

		let diffuse_bytes = include_bytes!(r"../../../resources/textures/comet_icon.png");
		let diffuse_texture =
			Texture::from_bytes(&device, &queue, diffuse_bytes, "comet_icon.png", false).unwrap();

		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,
							view_dimension: wgpu::TextureViewDimension::D2,
							sample_type: wgpu::TextureSampleType::Float { filterable: true },
						},
						count: None,
					},
					wgpu::BindGroupLayoutEntry {
						binding: 1,
						visibility: wgpu::ShaderStages::FRAGMENT,
						ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
						count: None,
					},
				],
				label: Some("texture_bind_group_layout"),
			});

		let camera = RenderCamera::new(1.0, v2::new(2.0, 2.0), v3::new(0.0, 0.0, 0.0));

		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: BufferUsages::UNIFORM | BufferUsages::COPY_DST,
		});

		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 {
						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 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 universal_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()],
				compilation_options: Default::default(),
			},
			fragment: Some(wgpu::FragmentState {
				module: &shader,
				entry_point: "fs_main",
				targets: &[Some(wgpu::ColorTargetState {
					format: config.format,
					blend: Some(wgpu::BlendState {
						color: wgpu::BlendComponent {
							src_factor: wgpu::BlendFactor::SrcAlpha,
							dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha,
							operation: wgpu::BlendOperation::Add,
						},
						alpha: wgpu::BlendComponent {
							src_factor: wgpu::BlendFactor::One,
							dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha,
							operation: wgpu::BlendOperation::Add,
						},
					}),
					write_mask: wgpu::ColorWrites::ALL,
				})],
				compilation_options: Default::default(),
			}),
			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,
			cache: None,
		});

		let mut render_pass: Vec<RenderPassInfo> = Vec::new();
		/*render_pass.push(RenderPassInfo::new_engine_pass(
			&device,
			"Standard Render Pass".to_string(),
			&texture_bind_group_layout,
			&diffuse_texture,
			vec![],
			vec![],
		));*/

		let clear_color = match clear_color {
			Some(color) => color.to_wgpu(),
			None => wgpu::Color {
				r: 0.0,
				g: 0.0,
				b: 0.0,
				a: 1.0,
			}
		};

		let texture_sampler = device.create_sampler(&wgpu::SamplerDescriptor {
			address_mode_u: wgpu::AddressMode::ClampToEdge,
			address_mode_v: wgpu::AddressMode::ClampToEdge,
			address_mode_w: wgpu::AddressMode::ClampToEdge,
			mag_filter: wgpu::FilterMode::Linear,
			min_filter: wgpu::FilterMode::Linear,
			mipmap_filter: wgpu::FilterMode::Linear,
			lod_min_clamp: 0.0,
			lod_max_clamp: 100.0,
			compare: None,
			anisotropy_clamp: 16,
			border_color: None,
			..Default::default()
		});

		let empty_texture = device.create_texture(&wgpu::TextureDescriptor {
			label: Some("Empty Texture"),
			size: wgpu::Extent3d {
				width: config.width,
				height: config.height,
				depth_or_array_layers: 1,
			},
			mip_level_count: 1,
			sample_count: 1,
			dimension: wgpu::TextureDimension::D2,
			format: wgpu::TextureFormat::Bgra8UnormSrgb,
			usage: wgpu::TextureUsages::COPY_SRC | wgpu::TextureUsages::COPY_DST | wgpu::TextureUsages::TEXTURE_BINDING,
			view_formats: &[wgpu::TextureFormat::Bgra8UnormSrgb],
		});

		let dummy_texture_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
			layout: &texture_bind_group_layout,
			entries: &[
				wgpu::BindGroupEntry {
					binding: 0,
					resource: wgpu::BindingResource::TextureView(&empty_texture.create_view(&wgpu::TextureViewDescriptor::default())),
				},
				wgpu::BindGroupEntry {
					binding: 1,
					resource: wgpu::BindingResource::Sampler(&texture_sampler),
				},
			],
			label: Some("dummy_texture_bind_group"),
		});
		
		let mut draw_info: Vec<DrawInfo> = Vec::new();

		Self {
			surface,
			device,
			queue,
			config,
			size,
			render_pipeline_layout,
			universal_render_pipeline,
			texture_bind_group_layout,
			dummy_texture_bind_group,
			texture_sampler,
			camera,
			camera_uniform,
			camera_buffer,
			camera_bind_group,
			render_pass,
			draw_info,
			graphic_resource_manager,
			delta_time: 0.0,
			last_frame_time: Instant::now(),
			clear_color,
		}
	}

	pub fn dt(&self) -> f32 {
		self.delta_time
	}

	pub fn config(&self) -> &wgpu::SurfaceConfiguration {
		&self.config
	}

	pub fn size(&self) -> PhysicalSize<u32> {
		self.size
	}

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

	pub fn add_render_pass(&mut self, name: String, texture: Texture, shader: String) {
		let render_pass = RenderPassInfo::new_user_pass(
			&self.device,
			name,
			&self.texture_bind_group_layout,
			&texture,
			self.graphic_resource_manager.get_shader(shader.as_str()).unwrap(),
			vec![],
			vec![],
			&self.render_pipeline_layout,
			&self.config
		);
		self.render_pass.push(render_pass);
	}
	
	pub fn add_draw_call(&mut self, draw_call: String, texture: Texture) {
		let draw_info = DrawInfo::new(
			draw_call,
			&self.device,
			&texture,
			&self.texture_bind_group_layout,
			&self.texture_sampler,
			vec![],
			vec![],
		);
		self.draw_info.push(draw_info);
	}

	/// A function that loads a shader from the resources/shaders folder given the full name of the shader file.
	pub fn load_shader(&mut self, file_name: &str, shader_stage: Option<ShaderStage>) {
		self.graphic_resource_manager.load_shader(shader_stage, ((Self::get_project_root().unwrap().as_os_str().to_str().unwrap().to_string() + "\\resources\\shaders\\").as_str().to_string() + file_name.clone()).as_str(), &self.device).unwrap();
		info!("Shader ({}) loaded successfully", file_name);
	}

	pub fn load_shaders(&mut self, shader_stages: Vec<Option<ShaderStage>>, file_names: Vec<&str>) {
		for (i, file_name) in file_names.iter().enumerate() {
			self.load_shader(file_name, shader_stages[i].clone());
			info!("Shader ({}) loaded successfully", file_name);
		}
	}

	/// A function that applies a shader to the entire surface of the `Renderer2D` if the shader is loaded.
	pub fn apply_shader(&mut self, shader: &str) {
		let module = match self.graphic_resource_manager.get_shader(shader) {
			Some(module) => module,
			None => {
				error!("Shader not found");
				return;
			}
		};

		self.render_pass[0].set_shader(&self.device, &self.config, &self.render_pipeline_layout, module);
	}

	/// A function to revert back to the base shader of the `Renderer2D`
	pub fn apply_base_shader(&mut self) {
		todo!()
	}

	pub fn load_font(&mut self, path: &str, size: f32) {
		self.graphic_resource_manager.load_font(path, size);
		let atlas = self.graphic_resource_manager.fonts().iter().find(|f| f.name() == path).unwrap().glyphs().atlas();
		let font_info = DrawInfo::new(
			format!("{}", path),
			&self.device,
			&Texture::from_image(&self.device, &self.queue, atlas, None, false).unwrap(),
			&self.texture_bind_group_layout,
			&self.texture_sampler,
			vec![],
			vec![],
		);

		self.draw_info.push(font_info);
	}

	/// An interface for getting the location of the texture in the texture atlas.
	pub fn get_texture_region(&self, texture_path: String) -> Option<&TextureRegion> {
		if !self.graphic_resource_manager.texture_atlas().textures().contains_key(&texture_path) {
			error!("Texture {} not found in atlas", &texture_path);
		}
		self.graphic_resource_manager.texture_atlas().textures().get(&texture_path)
	}

	pub fn get_glyph_region(&self, glyph: char, font: String) -> &TextureRegion {
		let font_atlas = self.graphic_resource_manager.fonts().iter().find(|f| f.name() == font).unwrap();
		font_atlas.get_glyph(glyph).unwrap()
	}

	/// A function that allows you to set the texture atlas with a list of paths to the textures.
	/// The old texture atlas will be replaced with the new one.
	pub fn set_texture_atlas_by_paths(&mut self, paths: Vec<String>) {
		self.graphic_resource_manager.create_texture_atlas(paths);
		let universal_draw = DrawInfo::new(
			"Universal Draw".to_string(),
			&self.device,
			&Texture::from_image(&self.device, &self.queue, self.graphic_resource_manager.texture_atlas().atlas(), None, false).unwrap(),
			&self.texture_bind_group_layout,
			&self.texture_sampler,
			vec![],
			vec![],
		);

		self.draw_info.push(universal_draw);
		//self.render_pass[0].set_texture(&self.device, &self.texture_bind_group_layout, &Texture::from_image(&self.device, &self.queue, self.graphic_resource_manager.texture_atlas().atlas(), None, false).unwrap());
	}

	fn set_texture_atlas(&mut self, texture_atlas: Texture) {
		self.draw_info[0].set_texture(
			&self.device,
			&self.texture_bind_group_layout,
			&texture_atlas,
		);
		/*self.render_pass[0].set_texture(
			&self.device,
			&self.texture_bind_group_layout,
			&Texture::from_image(
				&self.device,
				&self.queue,
				&texture_atlas.to_image(&self.device, &self.queue).unwrap(),
				None,
				false
			).unwrap()
		);*/
	}

	fn get_project_root() -> std::io::Result<PathBuf> {
		let path = std::env::current_dir()?;
		let mut path_ancestors = path.as_path().ancestors();

		while let Some(p) = path_ancestors.next() {
			let has_cargo =
				std::fs::read_dir(p)?
					.into_iter()
					.any(|p| p.unwrap().file_name() == std::ffi::OsString::from("Cargo.lock"));
			if has_cargo {
				return Ok(PathBuf::from(p))
			}
		}
		Err(std::io::Error::new(std::io::ErrorKind::NotFound, "Ran out of places to find Cargo.toml"))
	}

	/// A function that takes all the textures inside the resources/textures folder and creates a texture atlas from them.
	pub fn initialize_atlas(&mut self) {
		let texture_path = "resources/textures/".to_string();
		let mut paths: Vec<String> = Vec::new();

		for path in std::fs::read_dir(Self::get_project_root().unwrap().as_os_str().to_str().unwrap().to_string() + "/resources/textures").unwrap() {
			paths.push(texture_path.clone() + path.unwrap().file_name().to_str().unwrap());
		}

		self.set_texture_atlas_by_paths(paths);
	}

	/// A function that writes on the buffers and sets the geometry and index buffer of the `Renderer2D` with the given data.
	fn set_buffers(&mut self, new_geometry_buffer: Vec<Vertex>, new_index_buffer: Vec<u16>) {
		self.draw_info[0].update_vertex_buffer(&self.device, &self.queue, new_geometry_buffer);
		self.draw_info[0].update_index_buffer(&self.device, &self.queue, new_index_buffer);
		//self.render_pass[0].set_vertex_buffer(&self.device, &self.queue, new_geometry_buffer);
		//self.render_pass[0].set_index_buffer(&self.device, &self.queue, new_index_buffer);
	}

	/// A function that adds data to the already existing geometry and index buffers of the `Renderer2D`.
	fn push_to_buffers(&mut self, new_geometry_data: &mut Vec<Vertex>, new_index_buffer: &mut Vec<u16>) {
		self.render_pass[0].push_to_vertex_buffer(&self.device, new_geometry_data);
		self.render_pass[0].push_to_index_buffer(&self.device, new_index_buffer);
	}

	/// A function that clears the geometry and index buffers of the `Renderer2D`.
	fn clear_buffers(&mut self) {
		todo!()
	}

	/// A function to just draw a textured quad at a given position.
	pub fn draw_texture_at(&mut self, texture_path: String, position: p3) {
		let region = self.graphic_resource_manager.texture_locations().get(&texture_path).unwrap();
		let (dim_x, dim_y) = region.dimensions();

		let (bound_x, bound_y) =
			((dim_x as f32/ self.config.width as f32) * 0.5, (dim_y as f32/ self.config.height as f32) * 0.5);

		let vertices: &mut Vec<Vertex> = &mut vec![
			Vertex :: new ( [-bound_x + position.x(),  bound_y + position.y(), 0.0 + position.z()], [region.u0(), region.v0()], [0.0, 0.0, 0.0, 0.0] ),
			Vertex :: new ( [-bound_x + position.x(), -bound_y + position.y(), 0.0 + position.z()], [region.u0(), region.v1()], [0.0, 0.0, 0.0, 0.0] ),
			Vertex :: new ( [ bound_x + position.x(), -bound_y + position.y(), 0.0 + position.z()], [region.u1(), region.v1()], [0.0, 0.0, 0.0, 0.0] ) ,
			Vertex :: new ( [ bound_x + position.x(),  bound_y + position.y(), 0.0 + position.z()], [region.u1(), region.v0()], [0.0, 0.0, 0.0, 0.0] )
		];

		let buffer_size = self.render_pass[0].vertex_data().len() as u16;

		let indices: &mut Vec<u16> = &mut vec![
			0 + buffer_size, 1 + buffer_size, 3 + buffer_size,
			1 + buffer_size, 2 + buffer_size, 3 + buffer_size
		];

		self.push_to_buffers(vertices, indices)
	}

	/// A function to draw text at a given position.
	pub fn draw_text_at(&mut self, text: &str, font: String, size: f32, position: p2, color: impl Color) {
		//self.set_font_atlas(font.clone());

		let wgpu_color = color.to_wgpu();
		let vert_color = [wgpu_color.r as f32, wgpu_color.g as f32, wgpu_color.b as f32, wgpu_color.a as f32];

		let screen_position = p2::new(position.x()/self.config.width as f32, position.y()/self.config.height as f32);
		let scale_factor = size / self.graphic_resource_manager.fonts().iter().find(|f| f.name() == font).unwrap().size();

		let line_height = (self.graphic_resource_manager.fonts().iter().find(|f| f.name() == font).unwrap().line_height() / self.config.height as f32) * scale_factor;
		let lines = text.split("\n").collect::<Vec<&str>>();

		let mut x_offset = 0.0;
		let mut y_offset = 0.0;

		for line in lines {
			for c in line.chars() {
				let region = self.get_glyph_region(c, font.clone());
				let (dim_x, dim_y) = region.dimensions();

				let w = (dim_x as f32 / self.config.width as f32) * scale_factor;
				let h = (dim_y as f32 / self.config.height as f32) * scale_factor;

				let offset_x_px = (region.offset_x() / self.config.width as f32) * scale_factor;
				let offset_y_px = (region.offset_y() / self.config.height as f32) * scale_factor;

				let glyph_left   = screen_position.x() + x_offset + offset_x_px;
				let glyph_top    = screen_position.y() - offset_y_px - y_offset;
				let glyph_right  = glyph_left + w;
				let glyph_bottom = glyph_top - h;

				let vertices: &mut Vec<Vertex> = &mut vec![
					Vertex::new([ glyph_left,  glyph_top,    0.0 ], [region.u0(), region.v0()], vert_color),
					Vertex::new([ glyph_left,  glyph_bottom, 0.0 ], [region.u0(), region.v1()], vert_color),
					Vertex::new([ glyph_right, glyph_bottom, 0.0 ], [region.u1(), region.v1()], vert_color),
					Vertex::new([ glyph_right, glyph_top,    0.0 ], [region.u1(), region.v0()], vert_color),
				];

				let buffer_size = self.render_pass[1].vertex_data().len() as u16;
				let indices: &mut Vec<u16> = &mut vec![
					buffer_size,     buffer_size + 1, buffer_size + 3,
					buffer_size + 1, buffer_size + 2, buffer_size + 3,
				];

				x_offset += (region.advance() / self.config.width as f32) * scale_factor;

				self.push_to_buffers(vertices, indices);
			}

			y_offset += line_height;
			x_offset = 0.0;
		}
	}

	fn add_text_to_buffers(&self, draw_index: usize, text: String, font: String, size: f32, position: p2, color: wgpu::Color) -> (Vec<Vertex>, Vec<u16>) {
		let vert_color = [color.r as f32, color.g as f32, color.b as f32, color.a as f32];

		let screen_position = p2::new(position.x()/self.config.width as f32, position.y()/self.config.height as f32);
		let scale_factor = size / self.graphic_resource_manager.fonts().iter().find(|f| f.name() == font).unwrap().size();

		let line_height = (self.graphic_resource_manager.fonts().iter().find(|f| f.name() == font).unwrap().line_height() / self.config.height as f32) * scale_factor;
		let lines = text.split("\n").collect::<Vec<&str>>();

		let mut x_offset = 0.0;
		let mut y_offset = 0.0;

		let mut vertex_data = Vec::new();
		let mut index_data = Vec::new();

		for line in lines {
			for c in line.chars() {
				let region = self.get_glyph_region(c, font.clone());
				let (dim_x, dim_y) = region.dimensions();

				let w = (dim_x as f32 / self.config.width as f32) * scale_factor;
				let h = (dim_y as f32 / self.config.height as f32) * scale_factor;

				let offset_x_px = (region.offset_x() / self.config.width as f32) * scale_factor;
				let offset_y_px = (region.offset_y() / self.config.height as f32) * scale_factor;

				let glyph_left   = screen_position.x() + x_offset + offset_x_px;
				let glyph_top    = screen_position.y() - offset_y_px - y_offset;
				let glyph_right  = glyph_left + w;
				let glyph_bottom = glyph_top - h;

				let vertices: &mut Vec<Vertex> = &mut vec![
					Vertex::new([ glyph_left,  glyph_top,    0.0 ], [region.u0(), region.v0()], vert_color),
					Vertex::new([ glyph_left,  glyph_bottom, 0.0 ], [region.u0(), region.v1()], vert_color),
					Vertex::new([ glyph_right, glyph_bottom, 0.0 ], [region.u1(), region.v1()], vert_color),
					Vertex::new([ glyph_right, glyph_top,    0.0 ], [region.u1(), region.v0()], vert_color),
				];

				let buffer_size = vertex_data.len() as u16;
				let indices: &mut Vec<u16> = &mut vec![
					buffer_size,     buffer_size + 1, buffer_size + 3,
					buffer_size + 1, buffer_size + 2, buffer_size + 3,
				];

				x_offset += (region.advance() / self.config.width as f32) * scale_factor;

				vertex_data.append(vertices);
				index_data.append(indices);
			}

			y_offset += line_height;
			x_offset = 0.0;
		}

		(vertex_data, index_data)
	}

	fn find_priority_camera(&self, cameras: Vec<Camera2D>) -> usize {
		let mut priority = 0;
		let mut position = 0;
		for (i, camera) in cameras.iter().enumerate() {
			if camera.priority() < priority {
				priority = camera.priority();
				position = i;
			}
		}
		position
	}

	fn setup_camera<'b>(&mut self, cameras: Vec<usize>, scene: &'b Scene) -> (&'b Position2D, &'b Camera2D){
		let cam = cameras.get(
			self.find_priority_camera(
				cameras.iter().map(|e| *scene.get_component::<Camera2D>(*e).unwrap()
				).collect::<Vec<Camera2D>>())
		).unwrap();

		let camera_component = scene.get_component::<Camera2D>(*cam).unwrap();
		let camera_position = scene.get_component::<Transform2D>(*cam).unwrap().position();

		let camera = RenderCamera::new(
			camera_component.zoom(),
			camera_component.dimensions(),
			v3::new(camera_position.as_vec().x(),
					camera_position.as_vec().y(),
					0.0));
		let mut camera_uniform = CameraUniform::new();
		camera_uniform.update_view_proj(&camera);

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

		let camera_bind_group_layout =
			self.device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
				entries: &[wgpu::BindGroupLayoutEntry {
					binding: 0,
					visibility: wgpu::ShaderStages::VERTEX,
					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 = self.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"),
		});

		self.camera = camera;
		self.camera_buffer = camera_buffer;
		self.camera_uniform = camera_uniform;
		self.camera_bind_group = camera_bind_group;

		(camera_position, camera_component)
	}

	/// A function to automatically render all the entities of the `Scene` struct.
	/// The entities must have the `Render2D` and `Transform2D` components to be rendered as well as set visible.
	pub fn render_scene_2d(&mut self, scene: &Scene) {
		let cameras = scene.get_entities_with(ComponentSet::from_ids(vec![Transform2D::type_id(), Camera2D::type_id()]));

		if cameras.is_empty() {
			return;
		}

		let entities =  scene.get_entities_with(ComponentSet::from_ids(vec![Transform2D::type_id(), Render2D::type_id()]));
		let texts = scene.get_entities_with(ComponentSet::from_ids(vec![Transform2D::type_id(), comet_ecs::Text::type_id()]));

		self.setup_camera(cameras, scene);

		let mut vertex_buffer: Vec<Vertex> = Vec::new();
		let mut index_buffer: Vec<u16> = Vec::new();

		for entity in entities {
			let renderer_component =  scene.get_component::<Render2D>(entity).unwrap();
			let transform_component = scene.get_component::<Transform2D>(entity).unwrap();

			if renderer_component.is_visible() {
				let mut position = transform_component.position().clone();
				position.set_x(position.x() / self.config().width as f32);
				position.set_y(position.y() / self.config().height as f32);
				let mut t_region: Option<&TextureRegion> = None;
				match self.get_texture_region(renderer_component.get_texture().to_string()) {
					Some(texture_region) => {
						t_region = Some(texture_region);
					},
					None => continue,
				}
				let region = t_region.unwrap();
				let (dim_x, dim_y) = region.dimensions();

				let (bound_x, bound_y) =
					((dim_x as f32/ self.config().width as f32) * 0.5, (dim_y as f32/ self.config().height as f32) * 0.5);

				let buffer_size = vertex_buffer.len() as u16;

				vertex_buffer.append(&mut vec![
					Vertex :: new ( [-bound_x + position.x(),  bound_y + position.y(), 0.0], [region.u0(), region.v0()], [1.0, 1.0, 1.0, 1.0] ),
					Vertex :: new ( [-bound_x + position.x(), -bound_y + position.y(), 0.0], [region.u0(), region.v1()], [1.0, 1.0, 1.0, 1.0] ),
					Vertex :: new ( [ bound_x + position.x(), -bound_y + position.y(), 0.0], [region.u1(), region.v1()], [1.0, 1.0, 1.0, 1.0] ) ,
					Vertex :: new ( [ bound_x + position.x(),  bound_y + position.y(), 0.0], [region.u1(), region.v0()], [1.0, 1.0, 1.0, 1.0] )
				]);

				index_buffer.append(&mut vec![
					0 + buffer_size, 1 + buffer_size, 3 + buffer_size,
					1 + buffer_size, 2 + buffer_size, 3 + buffer_size
				]);
			}
		}

		for text in texts {
			let component = scene.get_component::<Text>(text).unwrap();
			let transform = scene.get_component::<Transform2D>(text).unwrap();

			if component.is_visible() {
				let draw_index = self.draw_info.iter().enumerate().find(|(_, d)| d.name() == &format!("{}", component.font())).unwrap().0;
				let (vertices, indices) = self.add_text_to_buffers(draw_index, component.content().to_string(), component.font().to_string(), component.font_size(), p2::from_vec(transform.position().as_vec()), component.color().to_wgpu());
				let draw = self.draw_info.iter_mut().find(|d| d.name() == &format!("{}", component.font())).unwrap();
				draw.update_vertex_buffer(&self.device, &self.queue, vertices);
				draw.update_index_buffer(&self.device, &self.queue, indices);
			}
		}

		self.set_buffers(vertex_buffer, index_buffer);
	}

	fn sort_entities_by_position(&self, entity_data: Vec<(usize, Position2D)>) -> Vec<usize> {
		let mut sorted_entities: Vec<usize> = vec![];

		let mut entity_data = entity_data.clone();
		entity_data.sort_by(|a, b| a.1.x().partial_cmp(&b.1.x()).unwrap());

		for (i, _) in entity_data {
			sorted_entities.push(i);
		}

		sorted_entities
	}

	/// A function to render the screen from top to bottom.
	/// Generally useful in top-down games to render trees in front of players for example.
	pub fn render_layered_scene_2d(&mut self, world: &Scene) {
		let cameras = world.get_entities_with(ComponentSet::from_ids(vec![Camera2D::type_id()]));

		if cameras == vec![] {
			return;
		}

		let (camera_position, camera_component) = self.setup_camera(cameras, world);

		let mut visible_entities: Vec<usize> = vec![];

		for entity in world.get_entities_with(ComponentSet::from_ids(vec![Transform2D::type_id(), Render2D::type_id()])) {
			let entity_id = entity as usize;

			if !camera_component
				.in_view_frustum(*camera_position, *world.get_component::<Transform2D>(entity_id).unwrap().position())
			{
				continue;
			}

			match world.get_component::<Render2D>(entity_id) {
				Some(render) => {
					if !render.is_visible() {
						continue;
					}
					if let Some(cam) = world.get_component::<Camera2D>(entity_id) {
						continue;
					}
					visible_entities.push(entity_id);
				}
				None => {
					continue;
				}
			}
		}

		let entity_data = {
			let mut data: Vec<(usize, Position2D)> = vec![];
			for entity in visible_entities {
				data.push((entity, *world.get_component::<Transform2D>(entity).unwrap().position()));
			}
			data
		};

		let visible_entities = self.sort_entities_by_position(entity_data);

		let mut vertex_buffer: Vec<Vertex> = Vec::new();
		let mut index_buffer: Vec<u16> = Vec::new();

		for entity in visible_entities {
			let renderer_component = world.get_component::<Render2D>(entity);
			let transform_component = world.get_component::<Transform2D>(entity);

			if renderer_component.unwrap().is_visible() {
				let mut position = transform_component.unwrap().position().clone();
				position.set_x(position.x() / self.config().width as f32);
				position.set_y(position.y() / self.config().height as f32);
				let region = self.get_texture_region(renderer_component.unwrap().get_texture().to_string()).unwrap();
				let (dim_x, dim_y) = region.dimensions();

				let (bound_x, bound_y) =
					((dim_x as f32 / self.config().width as f32) * 0.5, (dim_y as f32 / self.config().height as f32) * 0.5);

				let buffer_size = vertex_buffer.len() as u16;

				vertex_buffer.append(&mut vec![
					Vertex::new([-bound_x + position.x(), bound_y + position.y(), 0.0], [region.u0(), region.v0()], [0.0, 0.0, 0.0, 0.0]),
					Vertex::new([-bound_x + position.x(), -bound_y + position.y(), 0.0], [region.u0(), region.v1()], [0.0, 0.0, 0.0, 0.0]),
					Vertex::new([bound_x + position.x(), -bound_y + position.y(), 0.0], [region.u1(), region.v1()], [0.0, 0.0, 0.0, 0.0]),
					Vertex::new([bound_x + position.x(), bound_y + position.y(), 0.0], [region.u1(), region.v0()], [0.0, 0.0, 0.0, 0.0])
				]);

				index_buffer.append(&mut vec![
					0 + buffer_size, 1 + buffer_size, 3 + buffer_size,
					1 + buffer_size, 2 + buffer_size, 3 + buffer_size
				]);
			}
		}

		self.set_buffers(vertex_buffer, index_buffer);
	}

	pub fn update(&mut self) -> f32 {
		let now = Instant::now();
		self.delta_time = now.duration_since(self.last_frame_time).as_secs_f32();  // Time delta in seconds
		self.last_frame_time = now;
		self.delta_time
	}

	pub fn render(&mut self) -> Result<(), wgpu::SurfaceError> {
		let output = self.surface.get_current_texture()?;
		let output_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: &output_view,
					resolve_target: None,
					ops: wgpu::Operations {
						load: wgpu::LoadOp::Clear(self.clear_color),
						store: wgpu::StoreOp::Store,
					},
				})],
				depth_stencil_attachment: None,
				occlusion_query_set: None,
				timestamp_writes: None,
			});

			for i in 0..self.draw_info.len() {
				render_pass.set_pipeline(&self.universal_render_pipeline);
				render_pass.set_bind_group(0, self.draw_info[i].texture(), &[]);
				render_pass.set_bind_group(1, &self.camera_bind_group, &[]);
				render_pass.set_vertex_buffer(0, self.draw_info[i].vertex_buffer().slice(..));
				render_pass.set_index_buffer(self.draw_info[i].index_buffer().slice(..), wgpu::IndexFormat::Uint16);
				render_pass.draw_indexed(0..self.draw_info[i].num_indices(), 0, 0..1);
			}
		}
		
		self.queue.submit(iter::once(encoder.finish()));
		output.present();
		Ok(())
	}
}

impl<'a> Renderer for Renderer2D<'a> {
	fn new(window: Arc<Window>, clear_color: Option<impl Color>) -> Renderer2D<'a> {
		Self::new(window, clear_color)
	}

	fn size(&self) -> PhysicalSize<u32> {
		self.size()
	}

	fn resize(&mut self, new_size: PhysicalSize<u32>) {
		self.resize(new_size)
	}

	fn update(&mut self) -> f32 {
		self.update()
	}

	fn render(&mut self) -> Result<(), wgpu::SurfaceError> {
		self.render()
	}
}