use galactica_content::Content;
use galactica_util::constants::{
	OBJECT_SPRITE_INSTANCE_LIMIT, RADIALBAR_SPRITE_INSTANCE_LIMIT, UI_SPRITE_INSTANCE_LIMIT,
};
use glyphon::{FontSystem, SwashCache, TextAtlas, TextRenderer};
use std::{cell::RefCell, rc::Rc};
use wgpu::BufferAddress;
use winit::window::Window;

use crate::{
	globaluniform::GlobalUniform,
	vertexbuffer::{
		consts::{SPRITE_INDICES, SPRITE_VERTICES},
		types::{ObjectInstance, RadialBarInstance, StarfieldInstance, TexturedVertex, UiInstance},
		BufferObject, VertexBuffer,
	},
};

/// Vertex buffers
pub(crate) struct VertexBuffers {
	// Keeps track of length of each buffer
	// Most of these are reset on each frame.
	object_counter: BufferAddress,
	ui_counter: BufferAddress,
	radialbar_counter: BufferAddress,
	starfield_counter: BufferAddress,
	starfield_limit: BufferAddress,

	object: VertexBuffer,
	starfield: VertexBuffer,
	ui: VertexBuffer,
	radialbar: VertexBuffer,
}

impl<'a> VertexBuffers {
	pub fn new(device: &wgpu::Device, ct: &Content) -> Self {
		Self {
			object_counter: 0,
			ui_counter: 0,
			radialbar_counter: 0,
			starfield_counter: 0,
			starfield_limit: ct.config.starfield_instance_limit,

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

			starfield: VertexBuffer::new::<TexturedVertex, StarfieldInstance>(
				"starfield",
				&device,
				Some(SPRITE_VERTICES),
				Some(SPRITE_INDICES),
				ct.config.starfield_instance_limit,
			),

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

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

	pub fn get_ui(&'a self) -> &'a VertexBuffer {
		&self.ui
	}

	pub fn get_object(&'a self) -> &'a VertexBuffer {
		&self.object
	}

	pub fn get_radialbar(&'a self) -> &'a VertexBuffer {
		&self.radialbar
	}

	pub fn get_starfield(&'a self) -> &'a VertexBuffer {
		&self.starfield
	}
}

/// Renderer state. A reference to this struct is often passed to helper functions.
pub(crate) struct RenderState {
	pub window: Window,
	pub window_size: winit::dpi::PhysicalSize<u32>,
	pub window_aspect: f32,

	pub queue: wgpu::Queue,
	pub global_uniform: GlobalUniform,
	pub vertex_buffers: VertexBuffers,

	pub text_font_system: Rc<RefCell<FontSystem>>,
	pub text_renderer: TextRenderer,
	pub text_cache: SwashCache,
	pub text_atlas: TextAtlas,
}

impl RenderState {
	/// Prepare this state for a new frame
	pub fn frame_reset(&mut self) {
		self.vertex_buffers.object_counter = 0;
		self.vertex_buffers.ui_counter = 0;
		self.vertex_buffers.radialbar_counter = 0
	}

	pub fn push_ui_buffer(&mut self, instance: UiInstance) {
		// Enforce buffer limit
		if self.vertex_buffers.ui_counter as u64 > UI_SPRITE_INSTANCE_LIMIT {
			// TODO: no panic, handle this better.
			panic!("UI limit exceeded!")
		}

		self.queue.write_buffer(
			&self.vertex_buffers.ui.instances,
			UiInstance::SIZE * self.vertex_buffers.ui_counter,
			bytemuck::cast_slice(&[instance]),
		);
		self.vertex_buffers.ui_counter += 1;
	}

	pub fn get_ui_counter(&self) -> u32 {
		self.vertex_buffers.ui_counter as u32
	}

	pub fn push_object_buffer(&mut self, instance: ObjectInstance) {
		// Enforce buffer limit
		if self.vertex_buffers.object_counter as u64 > OBJECT_SPRITE_INSTANCE_LIMIT {
			// TODO: no panic, handle this better.
			panic!("Object limit exceeded!")
		}

		self.queue.write_buffer(
			&self.vertex_buffers.object.instances,
			ObjectInstance::SIZE * self.vertex_buffers.object_counter,
			bytemuck::cast_slice(&[instance]),
		);
		self.vertex_buffers.object_counter += 1;
	}

	pub fn get_object_counter(&self) -> u32 {
		self.vertex_buffers.object_counter as u32
	}

	pub fn push_radialbar_buffer(&mut self, instance: RadialBarInstance) {
		// Enforce buffer limit
		if self.vertex_buffers.radialbar_counter as u64 > RADIALBAR_SPRITE_INSTANCE_LIMIT {
			// TODO: no panic, handle this better.
			panic!("Radialbar sprite limit exceeded!")
		}

		self.queue.write_buffer(
			&self.vertex_buffers.radialbar.instances,
			RadialBarInstance::SIZE * self.vertex_buffers.radialbar_counter,
			bytemuck::cast_slice(&[instance]),
		);
		self.vertex_buffers.radialbar_counter += 1;
	}

	pub fn get_radialbar_counter(&self) -> u32 {
		self.vertex_buffers.radialbar_counter as u32
	}

	pub fn reset_starfield_counter(&mut self) {
		self.vertex_buffers.starfield_counter = 0;
	}

	pub fn push_starfield_buffer(&mut self, instance: StarfieldInstance) {
		// Enforce buffer limit
		// This should never happen, since starfield generator checks array size
		if self.vertex_buffers.starfield_counter as u64 > self.vertex_buffers.starfield_limit {
			panic!("Starfield sprite limit exceeded!")
		}

		self.queue.write_buffer(
			&self.vertex_buffers.starfield.instances,
			StarfieldInstance::SIZE * self.vertex_buffers.starfield_counter,
			bytemuck::cast_slice(&[instance]),
		);
		self.vertex_buffers.starfield_counter += 1;
	}

	pub fn get_starfield_counter(&self) -> u32 {
		self.vertex_buffers.starfield_counter as u32
	}
}