const sodium = require('libsodium-wrappers');
const { Client, GatewayIntentBits } = require('discord.js');
const { joinVoiceChannel, getVoiceConnection, VoiceConnectionStatus, EndBehaviorType } = require('@discordjs/voice');
const fs = require('fs');
const { OpusEncoder } = require('@discordjs/opus');
const { exec } = require('child_process');
const OpenAI = require('openai');

// OpenAI APIキーの確認
const apiKey = process.env.OPENAI_API_KEY || 'your-openai-api-key';
if (!apiKey || apiKey === 'your-openai-api-key') {
    console.error('Error: OpenAI API key is missing or invalid. Set the API key in the environment variables.');
    process.exit(1); // エラーコード1で終了
}

// OpenAI APIクライアントの作成
const openai = new OpenAI({
    apiKey: apiKey,
});

sodium.ready.then(() => {
    console.log('Sodium library loaded!');
});

const client = new Client({
    intents: [
        GatewayIntentBits.Guilds,
        GatewayIntentBits.GuildVoiceStates,
        GatewayIntentBits.GuildMessages,
        GatewayIntentBits.MessageContent,
    ],
});

client.once('ready', () => {
    console.log('Bot is ready!');
});

client.on('messageCreate', async message => {
    if (message.content === '!join') {
        if (message.member.voice.channel) {
            const connection = joinVoiceChannel({
                channelId: message.member.voice.channel.id,
                guildId: message.guild.id,
                adapterCreator: message.guild.voiceAdapterCreator,
                selfDeaf: false,
                selfMute: false,
            });

            connection.on(VoiceConnectionStatus.Ready, () => {
                console.log('Bot has connected to the channel!');
                startRecording(connection, message.member.voice.channel);
            });
        } else {
            message.reply('ボイスチャンネルに接続してください。');
        }
    }

    if (message.content === '!leave') {
        const connection = getVoiceConnection(message.guild.id);
        if (connection) {
            connection.destroy();
            message.reply('ボイスチャンネルを離れました。');
        } else {
            message.reply('ボイスチャンネルに接続していません。');
        }
    }
});

function startRecording(connection, voiceChannel) {
    const receiver = connection.receiver;
    const activeStreams = new Map(); // ユーザーごとの音声ストリーム管理

    receiver.speaking.on('start', (userId) => {
        const user = voiceChannel.members.get(userId);
        if (!user) {
            console.error('User is undefined');
            return;
        }

        console.log(`Started receiving audio from user: ${user.id}`);

        if (activeStreams.has(user.id)) {
            return;
        }

        const audioStream = receiver.subscribe(user.id, {
            end: EndBehaviorType.Manual
        });

        const filePath = `./recordings/${user.id}-${Date.now()}.pcm`;
        const writableStream = fs.createWriteStream(filePath);
        activeStreams.set(user.id, { audioStream, writableStream, filePath });

        const opusDecoder = new OpusEncoder(48000, 2); // Opusデコーダーを使用
        audioStream.on('data', (chunk) => {
            try {
                const pcmData = opusDecoder.decode(chunk);
                writableStream.write(pcmData);
                console.log(`Received ${chunk.length} bytes of audio data from user ${user.id}`);
            } catch (err) {
                console.error('Error decoding audio chunk:', err);
            }
        });

        audioStream.on('error', (err) => {
            console.error('Error in the audio stream:', err);
        });
    });

    receiver.speaking.on('end', (userId) => {
        const streamData = activeStreams.get(userId);
        if (!streamData) {
            return;
        }

        const { writableStream, filePath } = streamData;

        writableStream.end(() => {
            console.log(`Recording saved to ${filePath}`);
            activeStreams.delete(userId);

            fs.stat(filePath, (err, stats) => {
                if (err) {
                    console.error('Error checking file:', err);
                    return;
                }
                if (stats.size > 0) {
                    convertToWavAndTranscribe(filePath);  // バックグラウンドで変換と文字起こしを実行
                } else {
                    console.log(`File ${filePath} is empty, skipping conversion.`);
                    fs.unlinkSync(filePath); // 空のファイルを削除
                }
            });
        });
    });
}

function convertToWavAndTranscribe(pcmPath) {
    const wavPath = pcmPath.replace('.pcm', '.wav');
    console.log(`Converting ${pcmPath} to ${wavPath} and transcribing in the background`);

    const ffmpeg = exec(`ffmpeg -f s16le -ar 48000 -ac 2 -i ${pcmPath} ${wavPath}`, (error, stdout, stderr) => {
        if (error) {
            console.error(`Error during conversion: ${error.message}`);
            return;
        }
        if (stderr) {
            console.error(`FFmpeg stderr: ${stderr}`);
            return;
        }
    });

    ffmpeg.on('close', (code) => {
        if (code === 0) {
            console.log(`Successfully converted ${pcmPath} to ${wavPath}`);
            fs.unlinkSync(pcmPath); // PCMファイルを削除

            // Whisper APIを使って文字起こしを実行
            transcribeAudio(wavPath);
        } else {
            console.error(`FFmpeg exited with code ${code}, conversion failed.`);
        }
    });
}

// Whisper APIを使って音声ファイルを文字起こしする関数
async function transcribeAudio(filePath) {
    try {
        console.log(`Transcribing file: ${filePath}`);

        const response = await openai.audio.transcriptions.create({
            file: fs.createReadStream(filePath),
            model: 'whisper-1',
            response_format: 'json' // レスポンス形式をJSONに指定
        });

        // 文字起こし結果を表示
        if (response && response.text) {
            console.log('Transcription:', response.text);
        } else {
            console.error('Error: Transcription response is missing "text" field.');
        }
    } catch (error) {
        console.error('Error during transcription:', error.response ? error.response.data : error.message);
    }
}

client.login(process.env.BOT_TOKEN);