//	TextEditor - A syntax highlighting text editor for ImGui
//	Copyright (c) 2024-2026 Johan A. Goossens. All rights reserved.
//
//	This work is licensed under the terms of the MIT license.
//	For a copy, see <https://opensource.org/licenses/MIT>.


//
//	Include files
//

#include <cstdio>
#include <cstdlib>
#include <cstring>

#include <SDL3/SDL.h>

#include "imgui.h"
#include "imgui_impl_sdl3.h"
#include "imgui_impl_sdlgpu3.h"

#include "editor.h"
#include "dejavu.h"


//
//	main
//

int main(int, char**) {
	// setup SDL
	if (!SDL_Init(SDL_INIT_VIDEO)) {
		printf("Error: SDL_Init(): %s\n", SDL_GetError());
		return -1;
	}

	// create SDL window graphics context
	SDL_Window* window = SDL_CreateWindow("TextEditor Example", 1280, 720, SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIGH_PIXEL_DENSITY);

	if (window == nullptr) {
		printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
		return -1;
	}

	// create GPU device
	SDL_GPUDevice* gpu_device = SDL_CreateGPUDevice(SDL_GPU_SHADERFORMAT_SPIRV | SDL_GPU_SHADERFORMAT_DXIL | SDL_GPU_SHADERFORMAT_METALLIB, true, nullptr);

	if (gpu_device == nullptr) {
		printf("Error: SDL_CreateGPUDevice(): %s\n", SDL_GetError());
		return -1;
	}

	// claim window for GPU device
	if (!SDL_ClaimWindowForGPUDevice(gpu_device, window)) {
		printf("Error: SDL_ClaimWindowForGPUDevice(): %s\n", SDL_GetError());
		return -1;
	}

	// setup Dear ImGui context
	IMGUI_CHECKVERSION();
	ImGui::CreateContext();
	auto& io = ImGui::GetIO();
	io.IniFilename = nullptr;
	ImGui::StyleColorsDark();

	// setup platform/renderer backends
	ImGui_ImplSDL3_InitForSDLGPU(window);
	ImGui_ImplSDLGPU3_InitInfo init_info = {};
	init_info.Device = gpu_device;
	init_info.ColorTargetFormat = SDL_GetGPUSwapchainTextureFormat(gpu_device, window);
	init_info.MSAASamples = SDL_GPU_SAMPLECOUNT_1;
	ImGui_ImplSDLGPU3_Init(&init_info);

	// setup our font
	ImFontConfig config;
	std::memcpy(config.Name, "DejaVu", 7);
	config.FontDataOwnedByAtlas = false;
	config.OversampleH = 1;
	config.OversampleV = 1;
	io.Fonts->Clear();
	io.Fonts->AddFontFromMemoryCompressedTTF((void*) &dejavu, dejavuSize, 15.0f, &config);

	// main loop
	Editor editor;
	SDL_Event event;

	while (!editor.isDone()) {
		// poll and handle events (inputs, window resize, etc.)
		while (SDL_PollEvent(&event)) {
			ImGui_ImplSDL3_ProcessEvent(&event);

			if (event.type == SDL_EVENT_QUIT) {
				editor.tryToQuit();

			} else if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window)) {
				editor.tryToQuit();
			}
		}

		if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED) {
			SDL_Delay(10);
			continue;
		}

		// start the Dear ImGui frame
		ImGui_ImplSDLGPU3_NewFrame();
		ImGui_ImplSDL3_NewFrame();
		ImGui::NewFrame();

		// render editor
		editor.render();

		// render to the screen
		ImGui::Render();
		ImDrawData* draw_data = ImGui::GetDrawData();
		const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);

		// acquire a GPU command buffer and swapchain texture
		SDL_GPUCommandBuffer* command_buffer = SDL_AcquireGPUCommandBuffer(gpu_device);
		SDL_GPUTexture* swapchain_texture;
		SDL_AcquireGPUSwapchainTexture(command_buffer, window, &swapchain_texture, nullptr, nullptr);

		if (swapchain_texture != nullptr && !is_minimized) {
			// setup and start a render pass
			ImGui_ImplSDLGPU3_PrepareDrawData(draw_data, command_buffer);

			SDL_GPUColorTargetInfo target_info = {};
			target_info.texture = swapchain_texture;
			target_info.load_op = SDL_GPU_LOADOP_CLEAR;
			target_info.store_op = SDL_GPU_STOREOP_STORE;
			target_info.mip_level = 0;
			target_info.layer_or_depth_plane = 0;
			target_info.cycle = false;
			SDL_GPURenderPass* render_pass = SDL_BeginGPURenderPass(command_buffer, &target_info, 1, nullptr);

			// render ImGui
			ImGui_ImplSDLGPU3_RenderDrawData(draw_data, command_buffer, render_pass);
			SDL_EndGPURenderPass(render_pass);
		}

		// submit the command buffer
		SDL_SubmitGPUCommandBuffer(command_buffer);
	}

	// cleanup
	SDL_WaitForGPUIdle(gpu_device);
	ImGui_ImplSDL3_Shutdown();
	ImGui_ImplSDLGPU3_Shutdown();
	ImGui::DestroyContext();

	SDL_ReleaseWindowFromGPUDevice(gpu_device, window);
	SDL_DestroyGPUDevice(gpu_device);
	SDL_DestroyWindow(window);
	SDL_Quit();
	return 0;
}