/*
 * Copyright (C) 2017  Kevin Whitaker <eyecreate@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include "GroovePlayer.h"
#include "db/UserAction.h"
#include <Wt/WLogger>
#include <Wt/WServer>
#include <Wt/WApplication>
#include "WebInterface.h"
#include <locale>
#include <Wt/WLogger>
#include <Wt/Dbo/Transaction>
#include <groovefingerprinter/fingerprinter.h>

std::filesystem::path GroovePlayer::musicScanDir = "";

GroovePlayer::GroovePlayer(std::string dbFile) : sqliteConnection(dbFile)
{
    sqlSession.setConnection(this->sqliteConnection);
    sqlSession.mapClass<User>("user");
    sqlSession.mapClass<AudioTrack>("tracks");
    sqlSession.mapClass<UserAction>("actions");
    try
    {
        sqlSession.createTables();
    } catch(Wt::Dbo::Exception e) 
    {
        Wt::log("info") << "Using Existing DB.";
    }
    
    groove_init();
    
    grooveAudioScanner = new std::thread(grooveAudioScannerLoop);
    grooveEvents = new std::thread(grooveEventLoop);
}

std::vector<AudioTrack*> GroovePlayer::getNextVoteBatch()
{
    //TODO
}

void GroovePlayer::grooveEventLoop()
{
    //TODO
}

bool GroovePlayer::addFileToTrackDBIfTagged(std::filesystem::path file)
{
    //Now check if tags exist and put into DB.
    struct GrooveFile* gfile = groove_file_open(file.c_str());
    struct GrooveTag* artist_tag = groove_file_metadata_get(gfile, "artist", nullptr, 0);
    struct GrooveTag* album_tag = groove_file_metadata_get(gfile, "album", nullptr, 0);
    struct GrooveTag* name_tag = groove_file_metadata_get(gfile, "title", nullptr, 0);
    struct GrooveTag* genre_tag = groove_file_metadata_get(gfile, "genre", nullptr, 0);
    if(artist_tag == nullptr || album_tag == nullptr || name_tag == nullptr || genre_tag == nullptr)
    {
        //Only accept song with all metadata for DB.
        groove_file_close(gfile);
        return false;
    }
    
    //Take fingerprint and compare to DB.
    struct GrooveFingerprinter* fingerprinter = groove_fingerprinter_create();
    struct GrooveFingerprinterInfo info;
    struct GroovePlaylist* playlist = groove_playlist_create();
    groove_playlist_insert(playlist,gfile,1.0,1.0,nullptr);
    groove_fingerprinter_attach(fingerprinter, playlist);
    groove_fingerprinter_info_get(fingerprinter, &info, 1);
    double trackLen = info.duration;
    char* encodedFP;
    groove_fingerprinter_encode(info.fingerprint,info.fingerprint_size,&encodedFP);
    std::string fingerprint = std::string(encodedFP);
    groove_fingerprinter_dealloc(encodedFP);
    groove_fingerprinter_free_info(&info);
    groove_fingerprinter_detach(fingerprinter);
    groove_fingerprinter_destroy(fingerprinter);
    groove_playlist_destroy(playlist);
    
    Wt::Dbo::Transaction transaction(getInstance()->sqlSession);
    int existing = getInstance()->sqlSession.query<int>("select count(fingerprint) from tracks").where("fingerprint = ?").bind(fingerprint);
    if(existing >0)
    {
        //This track has a duplicate already.
        groove_file_close(gfile);
        return false;
    }
    
    //Add to DB.
    AudioTrack* newTrack = new AudioTrack();
    newTrack->trackName = groove_tag_value(name_tag);
    newTrack->trackAlbumName = groove_tag_value(album_tag);
    newTrack->trackArtistName = groove_tag_value(artist_tag);
    newTrack->trackGenre = groove_tag_value(genre_tag);
    newTrack->trackLengthSeconds = trackLen;
    newTrack->trackFingerprint = fingerprint;
    newTrack->trackPath = file.string();
    getInstance()->sqlSession.add(newTrack);
    groove_file_close(gfile);
    return true;
}

void GroovePlayer::removeOrphanedTracks()
{
    Wt::Dbo::Transaction transaction(getInstance()->sqlSession);
    Wt::Dbo::collection<Wt::Dbo::ptr<AudioTrack>> tracks = getInstance()->sqlSession.find<AudioTrack>();
    for(Wt::Dbo::collection<Wt::Dbo::ptr<AudioTrack>>::const_iterator i = tracks.begin(); i != tracks.end(); ++i)
    {
        if(!std::filesystem::exists(std::filesystem::path((*i)->trackPath)))
        {
            Wt::Dbo::ptr<AudioTrack> item = getInstance()->sqlSession.find<AudioTrack>().where("fingerprint = ?").bind((*i)->trackFingerprint);
            Wt::log("info") << (*i)->trackPath + " not found in filesystem. Removed from DB.";
            item.remove();
        }
    }
}



void GroovePlayer::grooveAudioScannerLoop()
{
    if(!std::filesystem::exists(musicScanDir))
    {
        std::filesystem::create_directory(musicScanDir);
        Wt::log("info") << "Directory "+std::filesystem::canonical(musicScanDir).string()+" didn't exist, so created.";
    } else 
    {
        Wt::log("info") << "Directory "+std::filesystem::canonical(musicScanDir).string()+" exists.";
    }
    for(std::filesystem::directory_entry p: std::filesystem::directory_iterator(musicScanDir))
    {
        std::string extensionLowered;
        for(auto elem : p.path().extension().string())
        {
            extensionLowered.push_back(std::tolower(elem));
        }
        if(extensionLowered == ".mp3") //TODO:think about supporting more than mp3s.
        {
            if(addFileToTrackDBIfTagged(p.path()))
            {
                Wt::log("info") << p.path().string() << " was added to DB";
            }
        }
        else
        {
            Wt::log("info") << p.path().string() + " was not an accepted audio file.";
        }
    }
    //Now check for tracks in DB without a file.
    removeOrphanedTracks();
}




    //TODO:use this code when sending to UI.
//         Wt::WServer::instance()->postAll([]() {
//             Wt::WApplication* app = Wt::WApplication::instance();
//             if(app != nullptr)
//             {
//                 static_cast<WebInterface*>(app)->updateUIFromServer();
//             }
//         }
//         );