// --- 設定エリア ---
const musicFolderPath = "music/";

// --- ゲーム状態管理 ---
let initialTrackList = []; // 曲ファイル名のリスト
let answerData = {};       // 曲名と歌手名のデータ
let shuffledTrackList = []; 
let currentTrackIndex = 0; 
let currentTimeout; 

// --- DOM要素取得 ---
const audioPlayer = document.getElementById('audio-player');
const quizView = document.getElementById('quiz-view');
const answerView = document.getElementById('answer-view');
const playButtons = document.querySelectorAll('.play-button');
const checkAnswerButton = document.getElementById('checkAnswerButton');
const nextTrackButton = document.getElementById('nextTrackButton');
const currentQuestionEl = document.getElementById('current-question');
const messageAreaEl = document.getElementById('current-track-name');
const answerSongEl = document.getElementById('answer-song');
const answerArtistEl = document.getElementById('answer-artist');

/**
 * 1. list.js 内の csvData 文字列を解析してデータを準備する
 */
function loadDataAndStart() {
    try {
        // list.js で定義した csvData を改行ごとに分ける
        const rows = csvData.trim().split(/\r?\n/);

        // 1行目（ヘッダー）を飛ばして2行目から処理
        for (let i = 1; i < rows.length; i++) {
            const row = rows[i].split(",");
            if (row.length < 3) continue;

            const num = row[0].trim();    // 曲番号 (例: 01)
            const song = row[1].trim();   // 曲名
            const artist = row[2].trim(); // 歌手名

            const fileName = num + ".mp3";
            initialTrackList.push(fileName);
            answerData[fileName] = { song: song, artist: artist };
        }

        // 解析が終わったらゲームを開始
        initializeGame();

    } catch (error) {
        console.error("解析エラー:", error);
        alert("データの読み込みに失敗しました。list.jsの形式を確認してください。");
    }
}

// --- ユーティリティ関数 ---
function shuffleArray(array) {
    for (let i = array.length - 1; i > 0; i--) {
        const j = Math.floor(Math.random() * (i + 1));
        [array[i], array[j]] = [array[j], array[i]];
    }
    return array;
}

// --- イベントリスナー ---
playButtons.forEach(button => {
    button.addEventListener('click', () => {
        const durationType = button.getAttribute('data-duration');
        if (durationType === 'full') {
            playTrackSegment(Infinity);
        } else {
            playTrackSegment(parseInt(durationType));
        }
    });
});

checkAnswerButton.addEventListener('click', showAnswerScreen);
nextTrackButton.addEventListener('click', moveToNextTrack);

audioPlayer.onended = () => {
    enableButtons();
    checkAnswerButton.disabled = false;
    messageAreaEl.textContent = "曲の再生が終了しました。答え合わせへどうぞ。";
};

// --- メインロジック ---

function initializeGame() {
    if (initialTrackList.length === 0) {
        alert("曲データが見つかりません。");
        return;
    }
    shuffledTrackList = shuffleArray([...initialTrackList]);
    currentTrackIndex = 0;
    loadTrack();
}

function loadTrack() {
    if (currentTrackIndex >= shuffledTrackList.length) {
        endGame();
        return;
    }

    const currentTrackName = shuffledTrackList[currentTrackIndex];
    audioPlayer.src = musicFolderPath + currentTrackName;
    audioPlayer.load();

    clearTimeout(currentTimeout);
    audioPlayer.pause();
    audioPlayer.currentTime = 0;

    quizView.classList.remove('hidden');
    answerView.classList.add('hidden');

    currentQuestionEl.textContent = currentTrackIndex + 1;
    messageAreaEl.textContent = "再生ボタンを押してイントロを聴いてみましょう";
    checkAnswerButton.disabled = true;
    enableButtons();
}

function playTrackSegment(duration) {
    if (currentTrackIndex >= shuffledTrackList.length) return;
    
    clearTimeout(currentTimeout);
    audioPlayer.pause();
    audioPlayer.currentTime = 0; 

    disableButtons();
    checkAnswerButton.disabled = true;

    audioPlayer.play().then(() => {
        if (duration !== Infinity) {
            messageAreaEl.textContent = `現在、${duration}秒まで再生中です...`;
            currentTimeout = setTimeout(() => {
                audioPlayer.pause();
                enableButtons(); 
                checkAnswerButton.disabled = false;
                messageAreaEl.textContent = `再生を停止しました。${duration}秒まで聴きました。答え合わせへどうぞ。`;
            }, duration * 1000);
        } else {
            messageAreaEl.textContent = "最後まで再生中です... 曲が終わるまでお待ちください。";
        }
    }).catch(error => {
        console.error("再生エラー:", error);
        alert(`音楽ファイルが見つかりません: music/${shuffledTrackList[currentTrackIndex]}`);
        enableButtons();
        checkAnswerButton.disabled = false;
    });
}

function showAnswerScreen() {
    clearTimeout(currentTimeout);
    audioPlayer.pause();
    
    const currentTrackFile = shuffledTrackList[currentTrackIndex];
    const answer = answerData[currentTrackFile];

    if (answer) {
        answerSongEl.textContent = answer.song;
        answerArtistEl.textContent = answer.artist;
    }

    quizView.classList.add('hidden');
    answerView.classList.remove('hidden');
}

function moveToNextTrack() {
    currentTrackIndex++;
    if (currentTrackIndex < shuffledTrackList.length) {
        loadTrack();
    } else {
        endGame();
    }
}

function endGame() {
    clearTimeout(currentTimeout);
    audioPlayer.pause();
    quizView.classList.add('hidden');
    answerView.classList.remove('hidden');
    answerSongEl.textContent = "全問終了";
    answerArtistEl.textContent = "お疲れ様でした！";
    nextTrackButton.textContent = "ゲーム終了";
    nextTrackButton.disabled = true;
}

function enableButtons() {
    playButtons.forEach(btn => btn.disabled = false);
}

function disableButtons() {
    playButtons.forEach(btn => btn.disabled = true);
}

// 🚀 実行開始
loadDataAndStart();