#include "application.h"
#include "output_util.h"
#include "filepath_util.h"
#include <iostream>
#include <cstring>
#include <cctype>
#include <set>

/////////////////////////////////////////////////////////////////////////

static constexpr int NO_ARGC  = 1;
static constexpr int MIN_ARGC = 2;
static constexpr int MAX_ARGC = 4;
static constexpr int DEFAULT_SPLITTING = 5;
static const std::string DEFAULT_PATH = "."; // current folder, I guess

/////////////////////////////////////////////////////////////////////////

static std::tuple<int, int, std::string> error(const char* msg)
{
    std::cout << msg;
    return {EXIT_FAILURE, -1, {}};
}

static std::tuple<int, std::string> parsePath(const std::string &argv)
{
    std::filesystem::path path(argv);
    if (!std::filesystem::exists(path))
    {
        std::cout << "Path " << path << " does not exist.\n";
        return {EXIT_FAILURE, {}};
    }

    // Maybe user chose a specific image, not a folder
    if (std::filesystem::is_regular_file(path))
        return {EXIT_SUCCESS, path.string()};

    // So... it is a folder
    // Creating a vector of everything in the given directory
    std::vector<std::tuple<std::filesystem::path, std::filesystem::file_status>> dir_items;
    std::transform(std::filesystem::directory_iterator(path), {}, std::back_inserter(dir_items), filepath::getFileInfo);

    std::set<std::string> allowed_ext = {".bmp", ".dds", ".jpg", ".png", ".tga", ".psd"};

    // Now getting images
    std::vector<std::string> dir_image_items;
    for (const auto &[local_path, status] : dir_items)
    {
        const std::string str_path = local_path.string();
        if (std::filesystem::is_regular_file(local_path) &&
                std::any_of(allowed_ext.begin(), allowed_ext.end(), [&](const std::string& e) { return filepath::endsWith(str_path, e); }))
        {
            dir_image_items.emplace_back(str_path);
        }
    }

    if (dir_image_items.empty())
    {
        std::cout << "No images found at " << path << "\n --help for more information.\n";
        return {EXIT_FAILURE, {}};
    }

    std::cout << "Loading random image file from " << path << "\n";
    srand(static_cast<unsigned int>(time(nullptr)));
    return {EXIT_SUCCESS, dir_image_items[rand() & (dir_image_items.size() - 1)]};
}

static std::tuple<int, int, std::string> parseInput(int argc, char **argv)
{
    int splitting = DEFAULT_SPLITTING;
    std::string path = DEFAULT_PATH;

    switch (argc)
    {
    default:
        return error(output::NO_ARG_MSG);

    case NO_ARGC:
    {
        // Just launch the application with default parameters
        std::cout << "No arguments given. Launching at \"" + DEFAULT_PATH + "\" with splitting " + std::to_string(DEFAULT_SPLITTING) + "\n";
        const auto &[ret_code, ret_path] = parsePath(DEFAULT_PATH);

        if (ret_code)
            return error(output::IMG_FAIL_MSG);

        path = ret_path;
        break;
    }

    case MIN_ARGC:
    {
        // maybe --help
        if (strcmp(argv[1], output::HELP_FLAG) == 0)
            return error(output::HELP_MSG);

        const auto &[ret_code, ret_path] = parsePath(argv[1]);

        if (ret_code)
            return error(output::IMG_FAIL_MSG);

        path = ret_path;
        break;
    }

    case (MAX_ARGC - 1):
    case MAX_ARGC:
    {
        // full stack
        if (strcmp(argv[1], output::SPLITTING_FLAG) == 0)
        {
            if (std::isdigit(*argv[2]))
                splitting = std::stoi(argv[2]);

            if (splitting < 1)
                return error(output::SPLITTING_MSG);

            const auto &[ret_code, ret_path] = parsePath(argv[3]);

            if (ret_code)
                return error(output::IMG_FAIL_MSG);

            path = ret_path;
        }
        break;
    }
    }

    return {EXIT_SUCCESS, splitting, path};
}

/////////////////////////////////////////////////////////////////////////

int main(int argc, char **argv)
{
    const auto&[ret_code, splitting, path] = parseInput(argc, argv);

    if (ret_code) // Error code is EXIT_FAILURE
        return ret_code;

    Application app;
    if (app.init(path, splitting))
    {
        app.run();
        return EXIT_SUCCESS;
    }

    return EXIT_FAILURE;
}