#include "functions.hpp"
#include "filesystem.hpp"
#include <algorithm>
#include <iostream>
#include <curl/curl.h>
#include <stdlib.h>
#include <vector>

size_t writeCallback( void *contents, size_t size, size_t nmemb, void *target ) {
    *static_cast<std::string*>(target) += std::string(static_cast<char*>(contents), size*nmemb);
    return size * nmemb;
}

Curl::Curl() {
    curl_global_init(CURL_GLOBAL_ALL);
    curl_handle = curl_easy_init();
    curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, writeCallback);
    curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");
}

Curl::~Curl() {
    curl_easy_cleanup(curl_handle);
    curl_global_cleanup();
}

std::string Curl::execute(const std::string &url) {
    std::string source;
    source.reserve(100000);
    curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, static_cast<void*>(&source));
    curl_easy_setopt(curl_handle, CURLOPT_URL, url.c_str());
    auto res = curl_easy_perform(curl_handle);
    if(res != CURLE_OK) {
        std::cerr << "curl_easy_perform() failed: " << curl_easy_strerror(res) << std::endl;
        return "";
    }
    return source;
}

bool searchSpecificSeason(const char *const p, size_t &ep_pos, const std::string &number) {
    size_t cur_pos{};
    bool found_season{false};
    while( p[cur_pos] != '\0' ) {
        if( (p[cur_pos] == 's' || p[cur_pos] == 'S') && isdigit(p[cur_pos+1]) ) {
            cur_pos++;
            while( p[cur_pos] == '0' )
                cur_pos++;
            size_t offset{};
            while( offset < number.size() && p[cur_pos + offset] == number[offset] )
                offset++;
            cur_pos += offset;
            if( offset != number.size() )
                continue;
            if( (p[cur_pos] == 'e' || p[cur_pos] == 'E') && isdigit(p[cur_pos+1]) ) {
                found_season = true;
                ep_pos = cur_pos + 1;
                break;
            }
        }
        cur_pos++;
    }
    return found_season;
}

bool searchSpecificSeason(const char *const p, const std::string &number) {
    size_t tmp;
    return searchSpecificSeason(p, tmp, number);
}

bool searchSeason(const char *const p, size_t &season_pos) {
    size_t cur_pos{};
    bool found_season{false};
    while( p[cur_pos] != '\0' ) {
        if( (p[cur_pos] == 's' || p[cur_pos] == 'S') && isdigit(p[cur_pos+1]) ) {
            cur_pos++;
            season_pos = cur_pos; // after ++ because we want the first pos to point to season's number
            while( isdigit(p[cur_pos]) )
                cur_pos++;
            if( (p[cur_pos] == 'e' || p[cur_pos] == 'E') && isdigit(p[cur_pos+1]) ) {
                found_season = true;
                break;
            }
        }
        cur_pos++;
    }
    return found_season;
}

bool searchSeason(const char *const p) {
    size_t tmp{};
    return searchSeason(p, tmp);
}

void findSeason(std::set<std::string> &files, int season, const std::string &path) {
    auto number = std::to_string(season);

    for( const auto p: FSLib::Directory(path) ) {
        if(FSLib::isDirectory(path + "/" + p)) {
            findSeason(files, season, path + "/" + p);
            continue;
        }

        if( searchSpecificSeason(p, number) )
            files.insert(path + "/" + p);
    }
}

void iterateFS(std::set<int> &seasons, const std::string &path) {
    size_t season_pos{std::string::npos}; // season_pos - position of first digit of the season
    for( const auto p: FSLib::Directory(path) ) {
        if(FSLib::isDirectory(path + "/" + p)) {
            iterateFS(seasons, path + "/" + p);
            continue;
        }

        if( searchSeason(p, season_pos) )
            seasons.insert(atoi(p+season_pos));
    }
}

std::string getDefUrl( std::string show, const std::string &language, Curl &c ) {
    std::replace(show.begin(), show.end(), ' ', '+');
    auto source_code = c.execute("https://www.thetvdb.com/search?q=" + show + "&l=" + language);
    size_t order{}, pos{};
    std::vector<std::string> urls;
    while( true ) {
        pos = source_code.find("/ser", pos);
        if( pos != std::string::npos ) {
            auto end = source_code.find(">", pos);
            end--;
            urls.push_back(source_code.substr(pos, end - pos));
            pos = end + 2;
            end = source_code.find("<", pos);
            std::cout << ++order << ". " << source_code.substr(pos, end - pos) << std::endl;
        } else {
            break;
        }
    }
    std::cout << "Which TV Show is the right one? ";
    std::cin >> pos;
    std::cin.clear();
    std::cin.ignore(1, '\n');
    return "https://www.thetvdb.com" + urls[pos-1];
}

void printHelp() {
    std::cout << "usage: tv_rename [--help] [--show show name] [--season season number]" << std::endl;
    std::cout << "                 [--correct-path] [--show-path show path] [--trust]" << std::endl;
    std::cout << "                 [--linux] [--lang language] [--print-langs]" << std::endl;
    std::cout << std::endl << "Rename TV episodes" << std::endl << std::endl << "optional arguments:" << std::endl;
    std::cout << "  -h, --help\t\tshow this help message and exit" << std::endl;
    std::cout << "  --show show name, -s show name" << std::endl;
    std::cout << "\t\t\tTV show from which you want episode names (needs to be" << std::endl;
    std::cout << "\t\t\tin quotation marks if it has more than one word)" << std::endl;
    std::cout << "  --season season number, -n season number" << std::endl;
    std::cout << "\t\t\tSeason number/s (if multiple seasons, put them in" << std::endl;
    std::cout << "\t\t\tquotation marks and seperate by one space)" << std::endl;
    std::cout << "\t\t\tor 'all' for all seasons in selected subdirectory" << std::endl;
    std::cout << "  --correct-path, -c\tThis is the correct path, stop asking me!" << std::endl;
    std::cout << "  --show-path show path, -p show path" << std::endl;
    std::cout << "\t\t\tPath of the directory with episodes" << std::endl;
    std::cout << "  --trust, -t\t\tDon't ask whether the names are correct" << std::endl;
    std::cout << "  --linux, -x\t\tDon't replace characters characters that are illegal in Windows" << std::endl;
    std::cout << "  --lang language, -l language" << std::endl;
    std::cout << "\t\t\tSelect which language the episode names shoud be in" << std::endl;
    std::cout << "  --print-langs\t\tPring available language" << std::endl;
}