#include <iostream>

// imgui includes
#include <imgui/imgui.h>
#include <imgui/backends/imgui_impl_sdl2.h>
#include <imgui/backends/imgui_impl_opengl3.h>
#include <SDL2/SDL.h>
#if defined(IMGUI_IMPL_OPENGL_ES2)
#include <SDL2/SDL_opengles2.h>
#else
#include <SDL2/SDL_opengl.h>
#endif


int
main()
{
	// Should this use the SDL_EVENTS subsystem?
	if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER) != 0) {
		std::cerr << "kge: failed to initialize SDL" << std::endl;
		std::cerr << "\t" << SDL_GetError() << std::endl;
		return -1;
	}

	// Decide GL+GLSL versions. Taken from the imgui examples.
#if defined(IMGUI_IMPL_OPENGL_ES2)
	// GL ES 2.0 + GLSL 100
	const char* glsl_version = "#version 100";
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
#elif defined(__APPLE__)
	// GL 3.2 Core + GLSL 150
	const char* glsl_version = "#version 150";
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_FORWARD_COMPATIBLE_FLAG); // Always required on Mac
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
#else
	// GL 3.0 + GLSL 130
	const char* glsl_version = "#version 130";
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
#endif

	// From 2.0.18: Enable native IME.
#ifdef SDL_HINT_IME_SHOW_UI
	SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
#endif

	// Create window with graphics context
	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
	SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
	SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
	SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
	SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
	SDL_GLContext gl_context = SDL_GL_CreateContext(window);
	SDL_GL_MakeCurrent(window, gl_context);
	SDL_GL_SetSwapInterval(1); // Enable vsync

	return 0;
}