#include "Window.h"

#include <SDL.h>
#include <iostream>

#include "gl.h"
#include "util.h"

namespace Cygnet {

struct WindowState {
	SDL_Window *window;
	SDL_GLContext glctx;
};

Window::Window(const char *name, int w, int h):
		state_(std::make_unique<WindowState>()) {
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_COMPATIBILITY);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
	SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
	SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
	SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 8);

	SDL_GL_SetSwapInterval(1);
	state_->window = SDL_CreateWindow(name,
			SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, w, h,
			SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE |
			SDL_WINDOW_ALLOW_HIGHDPI | SDL_WINDOW_OPENGL);
	sdlCheck(state_->window != NULL);

	state_->glctx = SDL_GL_CreateContext(state_->window);
	glCheck();
	makeCurrent();

	glewInit();

	std::cerr << "OpenGL Version: " << glGetString(GL_VERSION) << '\n';

	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glEnable(GL_BLEND);
	glCheck();

	SDL_GetWindowSize(state_->window, &w, &h);
	onResize(w, h);
}

Window::~Window() {
	SDL_DestroyWindow(state_->window);
}

void Window::makeCurrent() {
	SDL_GL_MakeCurrent(state_->window, state_->glctx);
	glCheck();
}

void Window::clear(Color color) {
	glClearColor(color.r, color.g, color.b, color.a);
	glClear(GL_COLOR_BUFFER_BIT);
	glCheck();
}

void Window::flip() {
	SDL_GL_SwapWindow(state_->window);
	glCheck();
}

void Window::onResize(int w, int h) {
	int dw, dh;
	SDL_GL_GetDrawableSize(state_->window, &dw, &dh);
	glViewport(0, 0, dw, dh);
	glCheck();
	size_ = {dw, dh};

	ratio_ = (double)dw / (double)w;
}

SDL_Window *Window::sdlWindow() {
	return state_->window;
}

}