// 核心生成 API
// POST /api/generate { audioUrl, style, lyrics, author, title, instr, voice }

const SUNO_KEY = '84e3182b1bbeb540164ff543d7749cef';
const BASE = 'https://api.sunoapi.org/api/v1';

// 乐器名 → Suno 英文关键词
const INSTR_EN = {
  '钢琴':'piano', '古筝':'guzheng', '琵琶':'pipa', '效果器':'effects', '提琴':'violin',
  '竖笛':'recorder', '吉他':'guitar', '架子鼓':'drums', '电子鼓':'electronic drums',
  '二胡':'erhu', '弦乐':'strings', '贝斯':'bass', '竹笛':'bamboo flute', '南箫':'nanxiao',
  '口琴':'harmonica', '萨克斯':'saxophone', '合成器':'synthesizer'
};

// 各风格的 Suno 提示词
const STYLE_PROMPTS = {
  '国风': 'Chinese pentatonic scale, traditional Chinese instruments blended with modern pop',
  '流行': 'modern K-pop influenced Chinese pop, piano guitar, polished catchy melodic',
  '民谣': 'Chinese indie folk ballad, acoustic guitar fingerpicking, storytelling vocal',
  '摇滚': 'Chinese rock, distorted electric guitar, powerful drums, high energy',
  '电子': 'Chinese EDM, synth leads, electronic drum beats, build-up drop, futuristic',
  'R&B': 'Chinese R&B soul, smooth vocal runs, electric piano, groovy drum patterns',
  '爵士': 'modern Chinese jazz, piano saxophone, walking bass, swing rhythm'
};

async function pollTask(taskId, env) {
  // 快速检查3次（每次3秒），不超过30秒
  for (let i = 0; i < 3; i++) {
    await new Promise(r => setTimeout(r, 3000));
    try {
      const cbData = await env.AUDIO_KV.get('suno:task:' + taskId, { type: 'text' });
      if (cbData) { const s = JSON.parse(cbData); return { id: s.id, title: s.title, audio_url: s.audio_url, image_url: s.image_url, duration: s.duration }; }
    } catch(e) {}
    const resp = await fetch(BASE + '/generate/record-info?taskId=' + taskId, {
      headers: { 'Authorization': 'Bearer ' + SUNO_KEY }
    });
    const data = await resp.json();
    const songs = data.data?.response?.sunoData || data.data?.sunoData;
    if (data.code === 200 && songs?.length > 0) {
      const s = songs[0];
      const audioUrl = s.audioUrl || s.sourceAudioUrl || s.audio_url;
      if (audioUrl) return { id: s.id, title: s.title, audio_url: audioUrl, image_url: s.image_url || s.sourceImageUrl, duration: s.duration };
    }
  }
  return null;
}

export async function onRequest(context) {
  const { request, env } = context;
  if (request.method === 'OPTIONS') {
    return new Response(null, { headers: { 'Access-Control-Allow-Origin': '*', 'Access-Control-Allow-Methods': 'POST', 'Access-Control-Allow-Headers': 'Content-Type' } });
  }
  try {
    const { audioUrl, style, lyrics: userLyrics, author, title, instr, voice } = await request.json();
    if (!audioUrl) return new Response(JSON.stringify({ ok: false, error: 'no audioUrl' }), { status: 400, headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' } });

    const SENSITIVE = ['色情','赌博','毒品','暴力','枪支','血腥','反动','分裂','恐怖','邪教'];
    function isSafe(t) { for (const w of SENSITIVE) { if (t.includes(w)) return false; } return true; }
    let lyrics = (userLyrics || '').trim();
    if (lyrics && !isSafe(lyrics)) return new Response(JSON.stringify({ ok: false, error: '歌词不合适' }), { status: 400, headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' } });
    if (lyrics.length > 800) lyrics = lyrics.slice(0, 800);
    if (!lyrics) return new Response(JSON.stringify({ ok: false, error: 'no lyrics' }), { status: 400, headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' } });

    // 解析用户选择的乐器 → 英文关键词
    var instrEnList = [];
    if (instr) {
      try {
        var instrSel = typeof instr === 'string' ? JSON.parse(instr) : instr;
        ['intro','verse','bridge','chorus','outro'].forEach(function(k) {
          var v = instrSel[k] || '';
          if (v) {
            v.split(',').forEach(function(item) {
              var trimmed = item.trim();
              var en = INSTR_EN[trimmed] || trimmed;
              if (en && instrEnList.indexOf(en) < 0) instrEnList.push(en);
            });
          }
        });
      } catch(e) {}
    }

    // 构建 style（详细乐器和风格）
    var stylePrompt = STYLE_PROMPTS[style] || STYLE_PROMPTS['流行'];
    var vocalText = voice === '女声' ? 'female vocal' : 'male vocal';
    var instrText = instrEnList.length > 0 ? instrEnList.join(', ') : '';
    var sunoStyle = [stylePrompt, instrText, vocalText].filter(Boolean).join(', ');
    var sunoStyleText = sunoStyle.slice(0, 1000);

    // 清洗歌词：去掉 [xxx前奏] [xxx主歌] 等乐器标注，保留标准 [Verse], [Chorus] 格式
    var cleanLyrics = lyrics
      .replace(/\[[^\]]*?前奏[^\]]*\]/g, '[Intro]')
      .replace(/\[[^\]]*?主歌[^\]]*\]/g, '[Verse]')
      .replace(/\[[^\]]*?间奏[^\]]*\]/g, '[Interlude]')
      .replace(/\[[^\]]*?副歌[^\]]*\]/g, '[Chorus]')
      .replace(/\[[^\]]*?结尾[^\]]*\]/g, '[Outro]')
      .replace(/\[[^\]]*?桥段[^\]]*\]/g, '[Bridge]')
      .replace(/\[[^\]]*?过渡[^\]]*\]/g, '[Interlude]')
      .replace(/（纯音乐）\s*/g, '').trim();

    var sunoLyrics = cleanLyrics.slice(0, 5000);
    if (instrEnList.length > 0) sunoLyrics += '\n[Instrument: ' + instrEnList.join(', ') + ']';
    var songTitle = (title || (author ? author + '的灵感创作' : '灵感创作')).slice(0, 100);

    const sunoPayload = {
      uploadUrl: audioUrl,
      customMode: true, instrumental: false,
      prompt: sunoLyrics,
      style: sunoStyleText,
      title: songTitle,
      model: 'V5',
      callBackUrl: 'https://inspiration-rnp.pages.dev/api/callback'
    };

    const sunoResp = await fetch(BASE + '/generate/upload-cover', {
      method: 'POST',
      headers: { 'Authorization': 'Bearer ' + SUNO_KEY, 'Content-Type': 'application/json' },
      body: JSON.stringify(sunoPayload)
    });
    const sunoData = await sunoResp.json();

    if (sunoData.code === 200 && sunoData.data?.taskId) {
      const result = await pollTask(sunoData.data.taskId, env);
      if (result) {
        try {
          const songId = 'song_' + Date.now().toString(36) + Math.random().toString(36).substring(2,6);
          await env.AUDIO_KV.put('song:' + songId, JSON.stringify({ id: songId, title: result.title || title, audio_url: result.audio_url, image_url: result.image_url || '', nickname: author ? '词曲：' + author : '匿名', occasion: style, lyrics, created_at: new Date().toISOString(), likes: 0, plays: 0 }));
          var listStr = await env.AUDIO_KV.get('songs:recent') || '[]';
          var ids = JSON.parse(listStr);
          ids.unshift(songId);
          if (ids.length > 20) ids.length = 20;
          await env.AUDIO_KV.put('songs:recent', JSON.stringify(ids));
        } catch(e) { console.log('save error:', e); }
        return new Response(JSON.stringify({ ok: true, data: { ...result, lyrics } }), { headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' } });
      }
    }
    if (sunoData.code === 200 && sunoData.data?.taskId) {
      return new Response(JSON.stringify({ ok: true, taskId: sunoData.data.taskId, data: { taskId: sunoData.data.taskId, lyrics } }), {
        headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' }
      });
    }
    return new Response(JSON.stringify({ ok: false, error: 'Suno failed', data: sunoData }), { headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' } });
  } catch(e) {
    return new Response(JSON.stringify({ ok: false, error: e.message }), { headers: { 'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' } });
  }
}