#include "app/app.hpp"
#include "conversion.hpp"
#include "engine/vector2.hpp"
#include "random_generator.hpp"

#include <getopt.h>
#include <iostream>
#include <memory>
#include <string_view>
#include <vector>

constexpr unsigned int DEFAULT_MAZE_WIDTH = 40U;
constexpr unsigned int DEFAULT_MAZE_HEIGHT = 20U;

constexpr std::string_view DEFAULT_MAZE_WALL = "█";

namespace
{
void optarg_error(char arg, const std::string_view &error)
{
	std::cout << "Error: Invalid option argument for -" << arg << ". " << error
			  << std::endl;
	exit(EXIT_FAILURE);
}

/**
 * Returns the current optarg as a string view.
 */
std::string_view get_str_optarg()
{
	return std::string_view(optarg);
}

/**
 * Returns the current optarg as a unsigned integer.
 *
 * @param arg The current command-line argument character
 * @param check_zero Whether or not to make sure that the result is not zero
 */
unsigned int get_uint_optarg(char arg, bool check_zero = false)
{
	unsigned int num = 0;

	try
	{
		num = str_to_uint(get_str_optarg());

		if (check_zero && num == 0)
		{
			throw "It should not be 0";
		}
	}
	catch (const char *error)
	{
		optarg_error(arg, std::string_view(error));
	}

	return num;
}
} // namespace

constexpr std::array<option, 8> options = {
	option({"width", required_argument, nullptr, 'w'}),
	option({"height", required_argument, nullptr, 'h'}),
	option({"wall", required_argument, nullptr, 'W'}),
	option({"seed", required_argument, nullptr, 's'}),
	option({"start-x", required_argument, nullptr, 'x'}),
	option({"start-y", required_argument, nullptr, 'y'}),
	option({"help", no_argument, nullptr, 0}),
	option({nullptr, 0, nullptr, 0})};

int main(int argc, char *argv[])
{
	auto args = std::vector<std::string_view>(argv, argv + argc);

	AppOptions app_options;

	BoundsOptions default_maze_bounds = {DEFAULT_MAZE_WIDTH, DEFAULT_MAZE_HEIGHT};

	app_options.maze_bounds = std::make_shared<Bounds>(default_maze_bounds);

	app_options.wall = DEFAULT_MAZE_WALL;

	std::unique_ptr<unsigned int> start_x = nullptr;
	std::unique_ptr<unsigned int> start_y = nullptr;

	char arg = 0;
	while ((arg = static_cast<char>(
				getopt_long(argc, argv, "w:h:W:s:x:y:", options.data(), nullptr))) != -1)
	{
		switch (arg)
		{
		case 'w':
		{
			app_options.maze_bounds->width(get_uint_optarg(arg, true));
			break;
		}
		case 'h':
		{
			app_options.maze_bounds->height(get_uint_optarg(arg, true));
			break;
		}
		case 'x':
		{
			start_x = std::make_unique<unsigned int>(get_uint_optarg(arg));
			break;
		}
		case 'y':
		{
			start_y = std::make_unique<unsigned int>(get_uint_optarg(arg));
			break;
		}
		case 'W':
		{
			app_options.wall = get_str_optarg();
			break;
		}
		case 's':
		{
			auto seed = get_uint_optarg(arg, true);

			app_options.random_gen = std::make_shared<RandomNumberGenerator>(seed);
			break;
		}
		case 0:
		{
			std::cout << "Usage: " << args[0]
					  << " [OPTION]...\n\n"
						 "Options:\n"
						 "  -w, --width WIDTH       The width of the maze (Default: "
					  << DEFAULT_MAZE_WIDTH
					  << ")\n"
						 "  -h, --height HEIGHT     The height of the maze (Default: "
					  << DEFAULT_MAZE_HEIGHT
					  << ")\n"
						 "  -x, --start-x X         The x coordinate for the start "
						 "position "
						 "(Default: random)\n"
						 "  -y, --start-y Y         The y coordinate for the start "
						 "position "
						 "(Default: random)\n"
						 "  -W, --wall WALL         Single character used as maze walls "
						 "(Default: '"
					  << DEFAULT_MAZE_WALL
					  << "')\n"
						 "  -s, --seed SEED         The randomization seed used for maze "
						 "generation\n"
						 "  --help                  Displays usage information"
					  << std::endl;
			return EXIT_SUCCESS;
		}
		case '?':
		{
			std::cout << "\nTry '" << args[0] << " --help' for more information"
					  << std::endl;
			return EXIT_FAILURE;
		}
		default:
			abort();
		}
	}

	if (app_options.random_gen == nullptr)
	{
		app_options.random_gen = std::make_shared<RandomNumberGenerator>();
	}

	if (start_x == nullptr)
	{
		start_x = std::make_unique<unsigned int>(
			app_options.random_gen->in_range(0, app_options.maze_bounds->width() - 1U));
	}

	if (start_y == nullptr)
	{
		start_y = std::make_unique<unsigned int>(
			app_options.random_gen->in_range(0, app_options.maze_bounds->height() - 1U));
	}

	Vector2Options start_coords = {.x = *start_x, .y = *start_y};

	app_options.start_coords = std::make_shared<Vector2>(start_coords);

	try
	{
		app_options.maze_bounds->verify_coords(*app_options.start_coords);
	}
	catch (const char *error)
	{
		std::cout << "Error: " << error << std::endl;
		return EXIT_FAILURE;
	}

	auto app = App(app_options);

	app.run();
}