#include "functions.hpp"
#include "filesystem.hpp"
#include <algorithm>
#include <iomanip>
#include <sstream>

#ifndef GUI

#include <iostream>
#include <curl/curl.h>
#include <stdlib.h>
#include <vector>

#else

#include <unistd.h>
#include <pwd.h>

#endif

#ifndef GUI

constexpr std::array<const char *, 46> languages{
    "en", "English", "sv", "Svenska", "no", "Norsk", "da", "Dansk", "fi", "Suomeksi",
    "nl", "Nederlands", "de", "Deutsch", "it", "Italiano", "es", "Español", "fr", "Français",
    "pl", "Polski", "hu", "Magyar", "el", "Greek", "tr", "Turkish", "ru", "Russian",
    "he", "Hebrew", "ja", "Japanese", "pt", "Portuguese", "zh", "Chinese", "cs", "Czech",
    "sl", "Slovenian", "hr", "Croatian", "ko","Korea"
};

#endif

// encode url so it's valid even with UTF-8 characters
std::string encodeUrl( const std::string &url ) {
    //stolen from here - https://stackoverflow.com/questions/154536/encode-decode-urls-in-c
    std::ostringstream encoded;
    encoded.fill('0');
    encoded << std::hex;
    for( auto &x : url ) {
        if( std::isalnum(x) || x == '-' || x == '_' || x == '.' || x == '~' ) {
            encoded << x;
            continue;
        }
        encoded << std::uppercase << '%' << std::setw(2);
        encoded << int(static_cast<unsigned char>(x)) << std::nouppercase;
    }
    return encoded.str();
}

// return true if filename has specified season
// set ep_pos to position where episode number starts
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 iterateFS(std::map<int, std::set<std::string>> &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[atoi(p+season_pos)].insert(path + "/" + p);
    }
}

#ifndef GUI

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 findSeasons(std::map<int, std::set<std::string>> &seasons, const std::string &path, const std::set<int> &season_numbers) {
    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)) {
            findSeasons(seasons, path + "/" + p, season_numbers);
            continue;
        }

        if( searchSeason(p, season_pos) ) {
            auto num = atoi(p+season_pos);
            if( season_numbers.find(num) != season_numbers.end() )
                seasons[num].insert(path + "/" + p);
        }
    }
}

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=" + encodeUrl(show) + "&l=" + language);
    size_t order{}, pos{};
    std::vector<std::pair<std::string, std::string>> urls;
    while( true ) {
        pos = source_code.find("/ser", pos);
        if( pos != std::string::npos ) {
            auto end = source_code.find(">", pos);
            end--;
            auto end2 = source_code.find("<", end + 2);
            urls.emplace_back(source_code.substr(end + 2, end2 - end - 2), source_code.substr(pos, end - pos));
            std::cout << ++order << ". " << urls.back().first << std::endl;
            pos = end2;
        } else {
            break;
        }
    }
    std::cout << "Which TV Show is the right one? ";
    std::cin >> pos;
    std::cin.clear();
    std::cin.ignore(1, '\n');
    show = urls[pos-1].first;
    return "https://www.thetvdb.com" + urls[pos-1].second;
}

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 << "  --show-path show path, -p show path" << std::endl;
    std::cout << "\t\t\tPath of the directory with episodes" << std::endl;
    std::cout << "  --correct-path, -c\tThis is the correct path, stop asking me!" << std::endl;
    std::cout << "  --name-pattern pattern" << std::endl;
    std::cout << "\t\t\tPattern to which change the file name. Possible sequences are:" << std::endl;
    std::cout << "\t\t\t\t\%filename - original filename (without filetype extension)" << std::endl;
    std::cout << "\t\t\t\t\%show - show name from thetvdb" << std::endl;
    std::cout << "\t\t\t\t\%epname - episode name from thetvdb" << std::endl;
    std::cout << "\t\t\t\t\%season - season number" << std::endl;
    std::cout << "\t\t\t\t\tpossible to specify leading 0 like this: \%2season (number means how many leading zeros)" << std::endl;
    std::cout << "\t\t\t\t\%episode - episode number" << std::endl;
    std::cout << "\t\t\t\t\tpossible to specify leading 0 like this: \%2episode (number means how many leading zeros)" << std::endl;
    std::cout << "\t\t\tDefault pattern is \"$filename - $epname\"" << 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;
}

void parseSeasonNumbers(std::set<int> &seasons_num, const char *argument) {
    size_t pos{0};

    while(!isdigit(argument[pos]) && argument[pos] != '\0')
        pos++;

    if( argument[pos] == '\0' ) {
        seasons_num.clear();
        return;
    }

    int temp;
    std::istringstream iss(argument + pos);
    while(iss >> temp) {
        seasons_num.insert(temp);
    }
}

void printLangs() {
    for( size_t i = 0; i < languages.size(); i += 2 ) {
        std::cout << languages[i] << " - " << languages[i+1] << std::endl;
    }
}

bool findLanguage( const char *language ) {
    for( size_t i = 0; i < languages.size(); i += 2 ) {
        if( !strcmp(language, languages[i]) )
            return true;
    }
    return false;
}

#else

std::vector<std::pair<std::string, std::string>> getPossibleShows( 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=" + encodeUrl(show) + "&l=" + language);
    size_t pos{};
    std::vector<std::pair<std::string, std::string>> urls;
    while( true ) {
        pos = source_code.find("/ser", pos);
        if( pos != std::string::npos ) {
            auto end = source_code.find(">", pos);
            auto end2 = source_code.find("<", end+1);
            end--;
            urls.emplace_back(source_code.substr(end+2, end2 - (end+2)), source_code.substr(pos, end - pos));
            pos = end + 2;
        } else {
            break;
        }
    }
    return urls;
}

std::string userHome() {
    uid_t user_uid;
    {
        uid_t eid;
        uid_t sid;
        getresuid( &user_uid, &eid, &sid ); // don't need eid and sid
    }
    auto user_passwd = getpwuid( user_uid );

    if ( user_passwd == nullptr )
        throw std::runtime_error(
            "User with uid " + std::to_string( user_uid ) + " doesn't exist!" );
    return user_passwd->pw_dir;
}

#endif

std::string compilePattern(const std::string &pattern, int season, int episode, const std::string &filename, const std::string &episodeName, const std::string &showName) {
    std::string output;

    for( size_t i = 0; i < pattern.size(); i++ ) {
        if( pattern[i] == '%' ) {
            // if current character is % check if a pattern follows, otherwise put %
            // check for numbers right after % indicating size of zero padding for numbers
            auto pos = pattern.find_first_not_of("0123456789", i+1);

            if( pattern.find( "season", pos - 1 ) == pos ) {
                // if season is AFTER numbers, put season number padded
                // with zeros

                // get number of leading zeros
                auto leading = std::atoi( pattern.c_str() + i + 1 );
                // move i to the last char of 'season'
                i = pos + 5;
                auto season_num =  std::to_string(season);

                // get number of zeros to be put before the season number
                leading -= season_num.size();
                if( leading < 0 )
                    leading = 0;

                // add padded season to output
                output += std::string(leading, '0') + season_num;
            } else if ( pattern.find( "season", i ) == i + 1 ) {
                // if season isn't after numbers, just put season number to output
                i += 6;
                output += std::to_string(season);
            } else if ( pattern.find( "episode", pos - 1 ) == pos ) {
                // same principle as with season after number
                auto leading = std::atoi( pattern.c_str() + i + 1 );

                i = pos + 6;
                auto ep_num =  std::to_string(episode);

                leading -= ep_num.size();
                if( leading < 0 )
                    leading = 0;

                output += std::string(leading, '0') + ep_num;
            } else if ( pattern.find( "episode", i ) == i + 1 ) {
                // if episode isn't after number, just put the episode number to output
                i += 7;
                output += std::to_string(episode);
            } else if ( pattern.find( "epname", i ) == i + 1 ) {
                // episode name from thetvdb
                i += 6;
                output += episodeName;
            } else if ( pattern.find( "show", i ) == i + 1 ) {
                // show name from thetvdb
                i += 4;
                output += showName;
            } else if ( pattern.find( "filename", i ) == i + 1 ) {
                // original file name
                i += 8;
                output += filename;
            } else {
                // output % if no escape sequence was found
                output += '%';
            }
        } else if ( pattern[i] == '\\' ) {
            // possibility to escape %
            if( pattern[i+1] == '%' ) {
                output += '%';
                i++;
            } else if ( pattern[i+1] == '\\' ) {
                output += '\\';
                i++;
            } else {
                output += '\\';
            }
        } else {
            // if char isn't % or / just add it to the output string
            output += pattern[i];
        }
    }

    return output;
}