#include <stdio.h>

#include "state/wayland.h"
#include "renderer.h"

Renderer *Renderer::GetInstance() {
	if (!s_instance)
		s_instance = new Renderer;
	return s_instance;
}

const EGLConfig &Renderer::GetConfig() const { return m_config; }

void Renderer::DestroyWindow(const EGLSurface& surface, struct wl_egl_window* window) {
	eglMakeCurrent(m_egl_display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
	eglDestroySurface(m_egl_display, surface);
	wl_egl_window_destroy(window);
}

void Renderer::DestroyContext(const EGLContext& context) {
	eglDestroyContext(m_egl_display, context);
}

EGLContext Renderer::CreateContext() {
	EGLint ctx_attribs[] = {EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE};

	return eglCreateContext(m_egl_display, m_config, EGL_NO_CONTEXT,
			ctx_attribs);
}

EGLSurface Renderer::CreateSurface(struct wl_egl_window *window) {
	PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC createPlatformWindowSurface =
		reinterpret_cast<PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC>(
				eglGetProcAddress("eglCreatePlatformWindowSurfaceEXT"));

	return createPlatformWindowSurface(m_egl_display, m_config, window, NULL);
}

void Renderer::SurfaceSetContext(const EGLSurface &surface, const EGLContext &context) {
	if (!eglMakeCurrent(m_egl_display, surface, surface, context)) {
		fprintf(stderr, "ERROR: could not change current EGL context\n");
		fprintf(stderr, "EGL error: 0x%x\n", eglGetError());
		exit(1);
	}
}

void Renderer::SwapBuffers(const EGLSurface &surface) {
	eglSwapBuffers(m_egl_display, surface);
}

Renderer::Renderer() {
	PFNEGLGETPLATFORMDISPLAYEXTPROC getPlatformDisplay =
		reinterpret_cast<PFNEGLGETPLATFORMDISPLAYEXTPROC>(
				eglGetProcAddress("eglGetPlatformDisplayEXT"));

	m_egl_display = getPlatformDisplay(
			EGL_PLATFORM_WAYLAND_KHR, WaylandState::GetInstance()->m_display, NULL);
	if (m_egl_display == NULL) {
		fprintf(stderr, "ERROR: could not get platform display\n");
		fprintf(stderr, "EGL error: 0x%x\n", eglGetError());
		exit(1);
	}

	if (!eglInitialize(m_egl_display, NULL, NULL)) {
		fprintf(stderr, "ERROR: could not initialize EGL\n");
		fprintf(stderr, "EGL error: 0x%x\n", eglGetError());
		exit(1);
	}

	EGLint config_attribs[] = {EGL_SURFACE_TYPE,
		EGL_WINDOW_BIT,
		EGL_RENDERABLE_TYPE,
		EGL_OPENGL_ES2_BIT,
		EGL_RED_SIZE,
		8,
		EGL_GREEN_SIZE,
		8,
		EGL_BLUE_SIZE,
		8,
		EGL_ALPHA_SIZE,
		8,
		EGL_NONE};

	EGLint num_configs;
	if (!eglChooseConfig(m_egl_display, config_attribs, &m_config, 1,
				&num_configs)) {
		fprintf(stderr, "ERROR: could not choose EGL config\n");
		fprintf(stderr, "EGL error: 0x%x\n", eglGetError());
		exit(1);
	}
}

Renderer::~Renderer() {
	// After all windows are destroyed:
	eglTerminate(m_egl_display);
}

Renderer *Renderer::s_instance = nullptr;