#include <SDL2/SDL.h>
#include <SDL2/SDL_ttf.h>
#include <SDL2/SDL_image.h>

#include <iostream>
#include <map>
#include <memory>
#include <string>
#include <vector>

#include "json.hpp"

#include "sdl_helpers.h"
#include "Widgets/Widget.h"
#include "Widgets/WidgetImage.h"
#include "Widgets/WidgetRect.h"
#include "Widgets/WidgetText.h"

using std::cout;
using std::endl;
using std::map;
using std::shared_ptr;
using std::string;
using std::unique_ptr;
using std::vector;
using nlohmann::json;

void init_builders(map<string, unique_ptr<Widget>(*)(const json&)>& widget_builders)
{
	widget_builders["image"] = &WidgetImage::builder;
	widget_builders["rect"] = &WidgetRect::builder;
	widget_builders["text"] = &WidgetText::builder;
}

int main(int argc, char **argv)
{
	int result = 0;
	bool ok;

	int screen_width = 800;
	int screen_height = 480;
	string output_filename = "trmnl.png";
	string cfg_filename = "config.json";
	json cfg;

	SDL_Surface* main_surface = nullptr;

	vector<json> widgets_cfg;
	vector<shared_ptr<Widget>> widgets;
	map<string, unique_ptr<Widget>(*)(const json&)> widget_builders;

	ok = init_sdl();
	if (!ok)
	{
		return -1;
	}

	if (argc > 1)
	{
		cfg_filename = argv[1];
	}

	// Read JSON CFG
	ok = read_config_json(cfg, cfg_filename);
	if (!ok)
	{
		result = -1;
		goto cleanup;
	}

	// Change screen size from JSON
	json_extract(cfg, "width", screen_width);
	json_extract(cfg, "height", screen_height);
	json_extract(cfg, "font", default_font_name);

	// Create surface
	main_surface = SDL_CreateRGBSurfaceWithFormat(0, screen_width, screen_height, 32, SDL_PIXELFORMAT_RGBA8888);
	if (nullptr == main_surface)
	{
		cout << "Could not allocate main surface" << endl;
		result = -1;
		goto cleanup;
	}

	init_builders(widget_builders);

	// Add Widgets From JSON
	if (cfg.contains("widgets") && cfg["widgets"].is_array())
	{
		widgets_cfg = cfg["widgets"];
	}

	for (const json& j : widgets_cfg)
	{
		string widget_name;
		json_extract(j, "name", widget_name);
		if (widget_name.empty())
		{
			continue;
		}

		// Check if name exists in known builders
		if (0 == widget_builders.count(widget_name))
		{
			cout << "Unknown widget '" << widget_name << "'. Skipping ..." << endl;
			continue;
		}

		// Construct and add widget to vector
		shared_ptr<Widget> widget = widget_builders[widget_name](j);
		if (nullptr != widget)
		{
			widgets.push_back(widget);
		}
	}

	// Clear screen with white
	SDL_FillRect(main_surface, nullptr, SDL_MapRGBA(main_surface->format, 255, 255, 255, SDL_ALPHA_OPAQUE));

	// Draw and apply all widgets
	for (shared_ptr<Widget>& widget : widgets)
	{
		widget->draw();
		SDL_Rect rect = widget->get_rect();
		SDL_BlitSurface(widget->get_internal_surface(), nullptr, main_surface, &rect);
	}

	// Save image
	json_extract(cfg, "output", output_filename);
	IMG_SavePNG(main_surface, output_filename.c_str());

cleanup:
	widgets.clear();

	clean_sdl();
	return result;
}