/*
 * Copyright 2016 - 2022 Gary Talent (gary@drinkingtea.net). All rights reserved.
 */

#include <GLFW/glfw3.h>
#include <imgui_impl_opengl3.h>
#include <imgui_impl_glfw.h>

#include <nostalgia/core/config.hpp>
#include <nostalgia/core/userland/gfx.hpp>

#include "core.hpp"

namespace nostalgia::core {

constexpr auto Scale = 5;

static void handleGlfwError(int err, const char *desc) noexcept {
    oxErrf("GLFW error ({}): {}\n", err, desc);
}

void ImGui_Impl_NewFrame() noexcept {
	ImGui_ImplGlfw_NewFrame();
}

static void handleKeyPress(Context *ctx, int key) noexcept {
	switch (key) {
		case GLFW_KEY_ESCAPE:
		case GLFW_KEY_Q:
			shutdown(ctx);
			break;
		default:
			break;
	}
}

static void handleGlfwKeyEvent(GLFWwindow *window, int key, int, int action, int) noexcept {
	const auto ctx = static_cast<Context *>(glfwGetWindowUserPointer(window));
	if (action == GLFW_PRESS) {
		handleKeyPress(ctx, key);
	}
}

ox::Error initGfx(Context *ctx) noexcept {
	auto id = ctx->windowerData<GlfwImplData>();
	glfwSetErrorCallback(handleGlfwError);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
	if constexpr(ox::defines::OS == ox::defines::OS::Darwin) {
		glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
	}
	glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);
	id->window = glfwCreateWindow(240 * Scale, 160 * Scale, "nostalgia", nullptr, nullptr);
	if (id->window == nullptr) {
		return OxError(1, "Could not open GLFW window");
	}
	glfwSetKeyCallback(id->window, handleGlfwKeyEvent);
	glfwSetWindowUserPointer(id->window, ctx);
	glfwMakeContextCurrent(id->window);
	if constexpr(config::ImGuiEnabled) {
		IMGUI_CHECKVERSION();
		ImGui::CreateContext();
		auto &io = ImGui::GetIO();
		io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
		//io.MouseDrawCursor = true;
		ImGui_ImplGlfw_InitForOpenGL(id->window, true);
	}
	return renderer::init(ctx);
}

void setWindowTitle(Context *ctx, const char *title) noexcept {
	const auto id = ctx->windowerData<GlfwImplData>();
	glfwSetWindowTitle(id->window, title);
}

void focusWindow(Context *ctx) noexcept {
	const auto id = ctx->windowerData<GlfwImplData>();
	glfwFocusWindow(id->window);
}

int getScreenWidth(Context *ctx) noexcept {
	auto id = ctx->windowerData<GlfwImplData>();
	int w = 0, h = 0;
	glfwGetFramebufferSize(id->window, &w, &h);
	return w;
}

int getScreenHeight(Context *ctx) noexcept {
	auto id = ctx->windowerData<GlfwImplData>();
	int w = 0, h = 0;
	glfwGetFramebufferSize(id->window, &w, &h);
	return h;
}

common::Size getScreenSize(Context *ctx) noexcept {
	auto id = ctx->windowerData<GlfwImplData>();
	int w = 0, h = 0;
	glfwGetFramebufferSize(id->window, &w, &h);
	return {w, h};
}

}