#include <iostream>
#include <filesystem>
#include <string>
#include <fstream>
#include <regex>

#include <tag.h>
#include <fileref.h>
#include <id3v1tag.h>
#include <id3v2tag.h>

#ifndef VERSION
#define VERSION "0.1"
#endif

void help() {
    std::cout <<
    "mcopy " << VERSION << "\n\n" <<
    "mcopy -f, --format  Specify a format to output files using\n" <<
    "mcopy -a, --ask     Ask the user if metadata cannot be retrieved from file\n" <<
    "mcopy -na, --no-ask Don't ask if metadata cannot be retrieved from file\n" <<
    "mcopy -h, --help    Display help\n" <<
    "mcopy -v, --version Display version\n" <<
    "\n" <<
    "Example: mcopy --format \"/home/anon/Music/Albums/@A/@a/@n. @A - @t.flac\" \"~/Downloads/myflac1.flac\" \"~/Downloads/myflac2.flac\n" <<
    "\n" <<
    "Formats:\n" <<
    "\n" <<
    "@A Artist\n" <<
    "@a Album name\n" <<
    "@t Title\n" <<
    "@n Track number\n";
}

TagLib::FileRef get_file(std::string str) {
    const char *cstr = str.c_str();
    TagLib::FileName fn(cstr);
    TagLib::FileRef file(fn);

    return file;
}

void getMetadataFromFile(std::string format, std::string str) {
    TagLib::FileRef file = get_file(str);
    TagLib::Tag *tag = file.tag();

    if (file.isNull() || !file.audioProperties()) {
        return;
    }

    std::string title = tag->title().to8Bit(true);
    std::string album = tag->album().to8Bit(true);
    std::string artist = tag->artist().to8Bit(true);
    std::string track = std::to_string(tag->track());

    std::string filename = format;

    // TODO: Replace this junk
    filename = std::regex_replace(format, std::regex("@t"), title);
    filename = std::regex_replace(filename, std::regex("@a"), album);
    filename = std::regex_replace(filename, std::regex("@A"), artist);
    filename = std::regex_replace(filename, std::regex("@n"), track);

    std::filesystem::path fs;
    std::string dir = (fs = filename).remove_filename();
    std::filesystem::create_directories(dir);

    if (!std::filesystem::copy_file(str, filename)) {
        std::cout << "mcopy: Failed to copy file " << str << " to " << filename << "\n";
        exit(1);
    } else {
        std::cout << "mcopy: Copied file " << str << " to " << filename << "\n";
    }
}

int main(int argc, char **argv) {
    int ac = argc;
    char **av = argv;

    std::string format = "";

    for (int i{1}; i < argc; i++) {
        std::string arg = argv[i];

        if (!arg.compare("-h")) {
            help();
            exit(0);
        } else if (!arg.compare("-v")) {
            std::cout << "mcopy " << VERSION << '\n';
            exit(0);
        } else if (!arg.compare("-f") && i < argc) {
            format = argv[++i];
            continue;
        }
    }

    if (!format.compare("")) {
        std::cout << "You must specify a format.\n";
        exit(1);
    }

    for (int i{1}; i < ac; i++) {
        std::ifstream f(av[i]);

        if (static_cast<bool>(f.good())) {
            getMetadataFromFile(format, av[i]);
        }
    }
}