// Copyright (c) 2016 The vulkano developers
// Licensed under the Apache License, Version 2.0
// <LICENSE-APACHE or
// https://www.apache.org/licenses/LICENSE-2.0> or the MIT
// license <LICENSE-MIT or https://opensource.org/licenses/MIT>,
// at your option. All files in the project carrying such
// notice may not be copied, modified, or distributed except
// according to those terms.

use cgmath::{Matrix3, Matrix4, Rad, Vector2, Vector3, Rotation, Quaternion, Euler, SquareMatrix};
use strafe_client::{Normal, Position, INDICES, NORMALS, POSITIONS};
use std::{sync::Arc, time::Instant};
use vulkano::{
	buffer::{
		allocator::{SubbufferAllocator, SubbufferAllocatorCreateInfo},
		Buffer, BufferCreateInfo, BufferUsage,
	},
	command_buffer::{
		allocator::StandardCommandBufferAllocator, AutoCommandBufferBuilder, CommandBufferUsage,
		RenderPassBeginInfo, SubpassContents,
	},
	descriptor_set::{
		allocator::StandardDescriptorSetAllocator, PersistentDescriptorSet, WriteDescriptorSet,
	},
	device::{
		physical::PhysicalDeviceType, Device, DeviceCreateInfo, DeviceExtensions, DeviceOwned,
		QueueCreateInfo, QueueFlags,
	},
	format::Format,
	image::{view::ImageView, AttachmentImage, ImageAccess, ImageUsage, SwapchainImage},
	instance::{Instance, InstanceCreateInfo},
	memory::allocator::{AllocationCreateInfo, MemoryUsage, StandardMemoryAllocator},
	pipeline::{
		graphics::{
			depth_stencil::DepthStencilState,
			input_assembly::InputAssemblyState,
			vertex_input::Vertex,
			viewport::{Viewport, ViewportState},
		},
		GraphicsPipeline, Pipeline, PipelineBindPoint,
	},
	render_pass::{Framebuffer, FramebufferCreateInfo, RenderPass, Subpass},
	shader::ShaderModule,
	swapchain::{
		acquire_next_image, AcquireError, Swapchain, SwapchainCreateInfo, SwapchainCreationError,
		SwapchainPresentInfo,
	},
	sync::{self, FlushError, GpuFuture},
	VulkanLibrary,
};
use vulkano_win::VkSurfaceBuild;
use winit::{
	event::{ElementState,KeyboardInput,VirtualKeyCode,Event, WindowEvent, DeviceEvent},
	event_loop::{ControlFlow, EventLoop},
	window::{Window, WindowBuilder},
};

const CONTROL_MOVEFORWARD:u32 = 0b00000001;
const CONTROL_MOVEBACK:u32 = 0b00000010;
const CONTROL_MOVERIGHT:u32 = 0b00000100;
const CONTROL_MOVELEFT:u32 = 0b00001000;
const CONTROL_MOVEUP:u32 = 0b00010000;
const CONTROL_MOVEDOWN:u32 = 0b00100000;
//const CONTROL_JUMP:u32 = 0b01000000;
//const CONTROL_ZOOM:u32 = 0b10000000;

const FORWARD_DIR:Vector3<i8> = Vector3::new(0,0,-1);
const RIGHT_DIR:Vector3<i8> = Vector3::new(1,0,0);
const UP_DIR:Vector3<i8> = Vector3::new(0,-1,0);

fn get_control_dir(controls: u32) -> Vector3<f64>{
	//don't get fancy just do it
	let mut control_dir:Vector3<i8> = Vector3::new(0,0,0);
	if controls & CONTROL_MOVEFORWARD == CONTROL_MOVEFORWARD {
		control_dir+=FORWARD_DIR;
	}
	if controls & CONTROL_MOVEBACK == CONTROL_MOVEBACK {
		control_dir+=-FORWARD_DIR;
	}
	if controls & CONTROL_MOVELEFT == CONTROL_MOVELEFT {
		control_dir+=-RIGHT_DIR;
	}
	if controls & CONTROL_MOVERIGHT == CONTROL_MOVERIGHT {
		control_dir+=RIGHT_DIR;
	}
	if controls & CONTROL_MOVEUP == CONTROL_MOVEUP {
		control_dir+=UP_DIR;
	}
	if controls & CONTROL_MOVEDOWN == CONTROL_MOVEDOWN {
		control_dir+=-UP_DIR;
	}
	return control_dir.cast().unwrap()
}

fn main() {
	// The start of this example is exactly the same as `triangle`. You should read the `triangle`
	// example if you haven't done so yet.

	let library = VulkanLibrary::new().unwrap();
	let required_extensions = vulkano_win::required_extensions(&library);
	let instance = Instance::new(
		library,
		InstanceCreateInfo {
			enabled_extensions: required_extensions,
			enumerate_portability: true,
			..Default::default()
		},
	)
	.unwrap();

	let event_loop = EventLoop::new();
	let surface = WindowBuilder::new()
		.build_vk_surface(&event_loop, instance.clone())
		.unwrap();

	let device_extensions = DeviceExtensions {
		khr_swapchain: true,
		..DeviceExtensions::empty()
	};
	let (physical_device, queue_family_index) = instance
		.enumerate_physical_devices()
		.unwrap()
		.filter(|p| p.supported_extensions().contains(&device_extensions))
		.filter_map(|p| {
			p.queue_family_properties()
				.iter()
				.enumerate()
				.position(|(i, q)| {
					q.queue_flags.intersects(QueueFlags::GRAPHICS)
						&& p.surface_support(i as u32, &surface).unwrap_or(false)
				})
				.map(|i| (p, i as u32))
		})
		.min_by_key(|(p, _)| match p.properties().device_type {
			PhysicalDeviceType::DiscreteGpu => 0,
			PhysicalDeviceType::IntegratedGpu => 1,
			PhysicalDeviceType::VirtualGpu => 2,
			PhysicalDeviceType::Cpu => 3,
			PhysicalDeviceType::Other => 4,
			_ => 5,
		})
		.unwrap();

	println!(
		"Using device: {} (type: {:?})",
		physical_device.properties().device_name,
		physical_device.properties().device_type,
	);

	let (device, mut queues) = Device::new(
		physical_device,
		DeviceCreateInfo {
			enabled_extensions: device_extensions,
			queue_create_infos: vec![QueueCreateInfo {
				queue_family_index,
				..Default::default()
			}],
			..Default::default()
		},
	)
	.unwrap();

	let queue = queues.next().unwrap();

	let (mut swapchain, images) = {
		let surface_capabilities = device
			.physical_device()
			.surface_capabilities(&surface, Default::default())
			.unwrap();
		let image_format = Some(
			device
				.physical_device()
				.surface_formats(&surface, Default::default())
				.unwrap()[0]
				.0,
		);
		let window = surface.object().unwrap().downcast_ref::<Window>().unwrap();

		Swapchain::new(
			device.clone(),
			surface.clone(),
			SwapchainCreateInfo {
				min_image_count: surface_capabilities.min_image_count,
				image_format,
				image_extent: window.inner_size().into(),
				image_usage: ImageUsage::COLOR_ATTACHMENT,
				composite_alpha: surface_capabilities
					.supported_composite_alpha
					.into_iter()
					.next()
					.unwrap(),
				..Default::default()
			},
		)
		.unwrap()
	};

	let memory_allocator = Arc::new(StandardMemoryAllocator::new_default(device.clone()));

	let vertex_buffer = Buffer::from_iter(
		&memory_allocator,
		BufferCreateInfo {
			usage: BufferUsage::VERTEX_BUFFER,
			..Default::default()
		},
		AllocationCreateInfo {
			usage: MemoryUsage::Upload,
			..Default::default()
		},
		POSITIONS,
	)
	.unwrap();
	let normals_buffer = Buffer::from_iter(
		&memory_allocator,
		BufferCreateInfo {
			usage: BufferUsage::VERTEX_BUFFER,
			..Default::default()
		},
		AllocationCreateInfo {
			usage: MemoryUsage::Upload,
			..Default::default()
		},
		NORMALS,
	)
	.unwrap();
	let index_buffer = Buffer::from_iter(
		&memory_allocator,
		BufferCreateInfo {
			usage: BufferUsage::INDEX_BUFFER,
			..Default::default()
		},
		AllocationCreateInfo {
			usage: MemoryUsage::Upload,
			..Default::default()
		},
		INDICES,
	)
	.unwrap();

	let uniform_buffer = SubbufferAllocator::new(
		memory_allocator.clone(),
		SubbufferAllocatorCreateInfo {
			buffer_usage: BufferUsage::UNIFORM_BUFFER,
			..Default::default()
		},
	);

	let vs = vs::load(device.clone()).unwrap();
	let fs = fs::load(device.clone()).unwrap();

	let render_pass = vulkano::single_pass_renderpass!(
		device.clone(),
		attachments: {
			color: {
				load: Clear,
				store: Store,
				format: swapchain.image_format(),
				samples: 1,
			},
			depth: {
				load: Clear,
				store: DontCare,
				format: Format::D16_UNORM,
				samples: 1,
			},
		},
		pass: {
			color: [color],
			depth_stencil: {depth},
		},
	)
	.unwrap();

	let (mut pipeline, mut framebuffers) =
		window_size_dependent_setup(&memory_allocator, &vs, &fs, &images, render_pass.clone());
	let mut recreate_swapchain = false;

	let mut previous_frame_end = Some(sync::now(device.clone()).boxed());
	let rotation_start = Instant::now();

	let descriptor_set_allocator = StandardDescriptorSetAllocator::new(device.clone());
	let command_buffer_allocator =
		StandardCommandBufferAllocator::new(device.clone(), Default::default());


	let mut time = Instant::now();
	//polution
	let mut mouse = Vector2::new(0.0,0.0);
	let mut pos = Vector3::new(0.0,0.0,0.0);
	let mut controls:u32 = 0;
	let fly_speed = 0.05;
	event_loop.run(move |event, _, control_flow| {
		match event {
			Event::WindowEvent {
				event: WindowEvent::CloseRequested,
				..
			} => {
				*control_flow = ControlFlow::Exit;
			}
			Event::WindowEvent {
				event: WindowEvent::Resized(_),
				..
			} => {
				recreate_swapchain = true;
			}
			Event::DeviceEvent {
				event:
					DeviceEvent::MouseMotion {
						delta,
					},
				..
			} => {
				mouse+=Vector2::from(delta);
			}
			Event::WindowEvent {
				event:
					WindowEvent::KeyboardInput {
						input:
							KeyboardInput {
								state,
								virtual_keycode: Some(keycode),
								..
							},
						..
					},
				..
			} => {
				match (state,keycode) {
					(k,VirtualKeyCode::W) => match k {
						ElementState::Pressed => controls|=CONTROL_MOVEFORWARD,
						ElementState::Released => controls&=!CONTROL_MOVEFORWARD,
					}
					(k,VirtualKeyCode::A) => match k {
						ElementState::Pressed => controls|=CONTROL_MOVELEFT,
						ElementState::Released => controls&=!CONTROL_MOVELEFT,
					}
					(k,VirtualKeyCode::S) => match k {
						ElementState::Pressed => controls|=CONTROL_MOVEBACK,
						ElementState::Released => controls&=!CONTROL_MOVEBACK,
					}
					(k,VirtualKeyCode::D) => match k {
						ElementState::Pressed => controls|=CONTROL_MOVERIGHT,
						ElementState::Released => controls&=!CONTROL_MOVERIGHT,
					}
					(k,VirtualKeyCode::E) => match k {
						ElementState::Pressed => controls|=CONTROL_MOVEUP,
						ElementState::Released => controls&=!CONTROL_MOVEUP,
					}
					(k,VirtualKeyCode::Q) => match k {
						ElementState::Pressed => controls|=CONTROL_MOVEDOWN,
						ElementState::Released => controls&=!CONTROL_MOVEDOWN,
					}
					_ => (),
				}
			}
			_ => (),
		}
		let time_now = Instant::now();
		let dt = (time_now-time).as_secs_f64();
		if dt > 1.0 / 120.0 {
			time = time_now;
				let angles = Euler{x:Rad(mouse.y/256.),y:Rad(mouse.x/-256.),z:Rad(0.0)};
				let orientation=Quaternion::from(angles);
				pos += orientation.rotate_vector(get_control_dir(controls))*fly_speed;

				let window = surface.object().unwrap().downcast_ref::<Window>().unwrap();
				let dimensions = window.inner_size();
				if dimensions.width == 0 || dimensions.height == 0 {
					return;
				}

				previous_frame_end.as_mut().unwrap().cleanup_finished();

				if recreate_swapchain {
					let (new_swapchain, new_images) =
						match swapchain.recreate(SwapchainCreateInfo {
							image_extent: dimensions.into(),
							..swapchain.create_info()
						}) {
							Ok(r) => r,
							Err(SwapchainCreationError::ImageExtentNotSupported { .. }) => return,
							Err(e) => panic!("failed to recreate swapchain: {e}"),
						};

					swapchain = new_swapchain;
					let (new_pipeline, new_framebuffers) = window_size_dependent_setup(
						&memory_allocator,
						&vs,
						&fs,
						&new_images,
						render_pass.clone(),
					);
					pipeline = new_pipeline;
					framebuffers = new_framebuffers;
					recreate_swapchain = false;
				}

				let uniform_buffer_subbuffer = {
					let elapsed = rotation_start.elapsed();
					let rotation =
						elapsed.as_secs() as f64 + elapsed.subsec_nanos() as f64 / 1_000_000_000.0;
					let rotation = Matrix3::from_angle_y(Rad(rotation as f32));

					// note: this teapot was meant for OpenGL where the origin is at the lower left
					//       instead the origin is at the upper left in Vulkan, so we reverse the Y axis
					let aspect_ratio =
						swapchain.image_extent()[0] as f32 / swapchain.image_extent()[1] as f32;
					let proj = cgmath::perspective(
						Rad(std::f32::consts::FRAC_PI_2),
						aspect_ratio,
						0.01,
						100.0,
					);
					let view = Matrix4::from_translation(pos)*Matrix4::from(angles);
					let scale = Matrix4::from_scale(-0.01);

					let uniform_data = vs::Data {
						world: (Matrix4::from_translation(Vector3 { x: 0.0, y: 0.0, z: 0.0 }) * Matrix4::from(rotation) * scale).into(),
						view: view.invert().unwrap().cast::<f32>().unwrap().into(),
						proj: proj.into(),
					};

					let subbuffer = uniform_buffer.allocate_sized().unwrap();
					*subbuffer.write().unwrap() = uniform_data;

					subbuffer
				};

				let layout = pipeline.layout().set_layouts().get(0).unwrap();
				let set = PersistentDescriptorSet::new(
					&descriptor_set_allocator,
					layout.clone(),
					[WriteDescriptorSet::buffer(0, uniform_buffer_subbuffer)],
				)
				.unwrap();

				let (image_index, suboptimal, acquire_future) =
					match acquire_next_image(swapchain.clone(), None) {
						Ok(r) => r,
						Err(AcquireError::OutOfDate) => {
							recreate_swapchain = true;
							return;
						}
						Err(e) => panic!("failed to acquire next image: {e}"),
					};

				if suboptimal {
					recreate_swapchain = true;
				}

				let mut builder = AutoCommandBufferBuilder::primary(
					&command_buffer_allocator,
					queue.queue_family_index(),
					CommandBufferUsage::OneTimeSubmit,
				)
				.unwrap();
				builder
					.begin_render_pass(
						RenderPassBeginInfo {
							clear_values: vec![
								Some([0.0, 0.0, 1.0, 1.0].into()),
								Some(1f32.into()),
							],
							..RenderPassBeginInfo::framebuffer(
								framebuffers[image_index as usize].clone(),
							)
						},
						SubpassContents::Inline,
					)
					.unwrap()
					.bind_pipeline_graphics(pipeline.clone())
					.bind_descriptor_sets(
						PipelineBindPoint::Graphics,
						pipeline.layout().clone(),
						0,
						set,
					)
					.bind_vertex_buffers(0, (vertex_buffer.clone(), normals_buffer.clone()))
					.bind_index_buffer(index_buffer.clone())
					.draw_indexed(index_buffer.len() as u32, 1, 0, 0, 0)
					.unwrap()
					.end_render_pass()
					.unwrap();
				let command_buffer = builder.build().unwrap();

				let future = previous_frame_end
					.take()
					.unwrap()
					.join(acquire_future)
					.then_execute(queue.clone(), command_buffer)
					.unwrap()
					.then_swapchain_present(
						queue.clone(),
						SwapchainPresentInfo::swapchain_image_index(swapchain.clone(), image_index),
					)
					.then_signal_fence_and_flush();

				match future {
					Ok(future) => {
						previous_frame_end = Some(future.boxed());
					}
					Err(FlushError::OutOfDate) => {
						recreate_swapchain = true;
						previous_frame_end = Some(sync::now(device.clone()).boxed());
					}
					Err(e) => {
						println!("failed to flush future: {e}");
						previous_frame_end = Some(sync::now(device.clone()).boxed());
					}
				}
			}
	});
}

/// This function is called once during initialization, then again whenever the window is resized.
fn window_size_dependent_setup(
	memory_allocator: &StandardMemoryAllocator,
	vs: &ShaderModule,
	fs: &ShaderModule,
	images: &[Arc<SwapchainImage>],
	render_pass: Arc<RenderPass>,
) -> (Arc<GraphicsPipeline>, Vec<Arc<Framebuffer>>) {
	let dimensions = images[0].dimensions().width_height();

	let depth_buffer = ImageView::new_default(
		AttachmentImage::transient(memory_allocator, dimensions, Format::D16_UNORM).unwrap(),
	)
	.unwrap();

	let framebuffers = images
		.iter()
		.map(|image| {
			let view = ImageView::new_default(image.clone()).unwrap();
			Framebuffer::new(
				render_pass.clone(),
				FramebufferCreateInfo {
					attachments: vec![view, depth_buffer.clone()],
					..Default::default()
				},
			)
			.unwrap()
		})
		.collect::<Vec<_>>();

	// In the triangle example we use a dynamic viewport, as its a simple example. However in the
	// teapot example, we recreate the pipelines with a hardcoded viewport instead. This allows the
	// driver to optimize things, at the cost of slower window resizes.
	// https://computergraphics.stackexchange.com/questions/5742/vulkan-best-way-of-updating-pipeline-viewport
	let pipeline = GraphicsPipeline::start()
		.vertex_input_state([Position::per_vertex(), Normal::per_vertex()])
		.vertex_shader(vs.entry_point("main").unwrap(), ())
		.input_assembly_state(InputAssemblyState::new())
		.viewport_state(ViewportState::viewport_fixed_scissor_irrelevant([
			Viewport {
				origin: [0.0, 0.0],
				dimensions: [dimensions[0] as f32, dimensions[1] as f32],
				depth_range: 0.0..1.0,
			},
		]))
		.fragment_shader(fs.entry_point("main").unwrap(), ())
		.depth_stencil_state(DepthStencilState::simple_depth_test())
		.render_pass(Subpass::from(render_pass, 0).unwrap())
		.build(memory_allocator.device().clone())
		.unwrap();

	(pipeline, framebuffers)
}

mod vs {
	vulkano_shaders::shader! {
		ty: "vertex",
		path: "src/vert.glsl",
	}
}

mod fs {
	vulkano_shaders::shader! {
		ty: "fragment",
		path: "src/frag.glsl",
	}
}