/* ══════════════════════════════════════════════════════════
   SUNO FORGE — app.js
   All logic: channels, API calls, history, CSV export
   ══════════════════════════════════════════════════════════ */

(function () {
  'use strict';

  // ── Constants ──
  const LS_KEY_API = 'sunoforge_apikey';
  const LS_KEY_MODEL = 'sunoforge_model';
  const LS_KEY_CHANNELS = 'sunoforge_channels';
  const LS_KEY_HISTORY = 'sunoforge_history';
  const LS_KEY_MODELS_CACHE = 'sunoforge_models_cache';
  const LS_KEY_SB_URL = 'sunoforge_sb_url';
  const LS_KEY_SB_KEY = 'sunoforge_sb_key';
  const DEFAULT_MODEL = 'google/gemini-flash-1.5';
  const OPENROUTER_URL = 'https://openrouter.ai/api/v1/chat/completions';
  const OPENROUTER_MODELS_URL = 'https://openrouter.ai/api/v1/models';
  const MAX_HISTORY = 50;
  const MODELS_CACHE_TTL = 1000 * 60 * 60; // 1 hour cache

  const SYSTEM_PROMPT = `You are an expert AI music composer and prompt engineer specializing in Suno AI.
Your job is to generate ultra-detailed Suno AI music prompts.
You deeply understand music theory, production techniques, and genre conventions for music channels.

Return ONLY valid JSON with these exact keys — no markdown, no explanation, no backticks:

{
  "style_prompt": "The full detailed Suno AI prompt (1000 characters max, highly specific, rich instrumentation, production details, subgenres, acoustic elements, vocal characteristics, and atmospheric descriptors).",
  "exclude": "Comma-separated list of things Suno should avoid. Under 200 chars.",
  "lyrics": "If requested: structured lyric scaffold with [Verse 1], [Chorus], [Bridge] markers. Under 3000 chars. Empty string if not requested."
}`;

  const GENRES = ['Metal', 'Synthwave', 'Lo-fi', 'Post-Rock', 'Folk', 'EDM', 'Ambient'];
  const MOODS = ['Dark', 'Euphoric', 'Melancholic', 'Aggressive', 'Dreamy', 'Devotional', 'Chill', 'Apocalyptic', 'Nostalgic', 'Ethereal', 'Hype', 'Tense'];
  const INSTRUMENTS = ['Distorted Electric Guitar', 'Analog Synthesizer', 'Heavy 808 Bass', 'Acoustic Cello', 'Grand Piano', 'Saxophone', 'Tribal Percussion', 'Violin Ensemble', 'Vintage Drums', 'Sub Bass & Pad'];
  const TEMPOS = ['Slow', 'Mid', 'Fast', 'Variable'];
  const VOCALS = ['Instrumental', 'Male', 'Female', 'Choir', 'Harsh', 'Soft'];

  // ── State ──
  let channels = [];
  let history = [];
  let activeChannelIndex = -1;
  let lastGeneration = null;
  let freeModels = []; // cached model objects
  let selectedModelPricing = null; // pricing for current model
  let supabaseClient = null;

  // ── DOM refs ──
  const $ = (id) => document.getElementById(id);

  const els = {
    settingsToggle: $('settingsToggle'),
    settingsPanel: $('settingsPanel'),
    apiKeyInput: $('apiKeyInput'),
    apiKeyToggle: $('apiKeyToggle'),
    modelSelect: $('modelSelect'),
    modelMeta: $('modelMeta'),
    btnRefreshModels: $('btnRefreshModels'),
    modelInput: $('modelInput'),
    btnClearHistory: $('btnClearHistory'),
    btnExportAll: $('btnExportAll'),
    importDataInput: $('importDataInput'),
    channelList: $('channelList'),
    btnNewChannel: $('btnNewChannel'),
    newChannelForm: $('newChannelForm'),
    ncName: $('ncName'),
    ncGenre: $('ncGenre'),
    ncMood: $('ncMood'),
    ncLanguage: $('ncLanguage'),
    ncExclude: $('ncExclude'),
    btnSaveChannel: $('btnSaveChannel'),
    btnCancelChannel: $('btnCancelChannel'),
    activeChannelLabel: $('activeChannelLabel'),
    bGenre: $('bGenre'),
    bSubgenre: $('bSubgenre'),
    bMood: $('bMood'),
    bInstruments: $('bInstruments'),
    bScale: $('bScale'),
    bTempo: $('bTempo'),
    bVocal: $('bVocal'),
    bLanguage: $('bLanguage'),
    bExclude: $('bExclude'),
    bConcept: $('bConcept'),
    bLyrics: $('bLyrics'),
    btnForge: $('btnForge'),
    btnSurprise: $('btnSurprise'),
    errorMessage: $('errorMessage'),
    outStyle: $('outStyle'),
    outExclude: $('outExclude'),
    outLyrics: $('outLyrics'),
    styleCounter: $('styleCounter'),
    excludeCounter: $('excludeCounter'),
    lyricsCounter: $('lyricsCounter'),
    lyricsSection: $('lyricsSection'),
    tokenUsage: $('tokenUsage'),
    btnSaveHistory: $('btnSaveHistory'),
    btnCopyStyle: $('btnCopyStyle'),
    btnCopyExclude: $('btnCopyExclude'),
    btnCopyLyrics: $('btnCopyLyrics'),
    historyScroll: $('historyScroll'),
    historyEmpty: $('historyEmpty'),
    btnExportCsv: $('btnExportCsv'),
    sbUrlInput: $('sbUrlInput'),
    sbKeyInput: $('sbKeyInput'),
    sbKeyToggle: $('sbKeyToggle'),
    btnConnectSb: $('btnConnectSb'),
    sbStatus: $('sbStatus'),
    btnShowSqlModal: $('btnShowSqlModal'),
    sqlModal: $('sqlModal'),
    btnCloseSqlModal: $('btnCloseSqlModal'),
    btnCloseSqlModal2: $('btnCloseSqlModal2'),
    btnCopySql: $('btnCopySql'),
    sqlSchemaText: $('sqlSchemaText'),
  };

  // ══════════════════════════════════════
  // LOCAL STORAGE HELPERS
  // ══════════════════════════════════════

  function loadData() {
    try {
      const apiKey = localStorage.getItem(LS_KEY_API) || '';
      const model = localStorage.getItem(LS_KEY_MODEL) || '';
      const sbUrl = localStorage.getItem(LS_KEY_SB_URL) || '';
      const sbKey = localStorage.getItem(LS_KEY_SB_KEY) || '';
      channels = JSON.parse(localStorage.getItem(LS_KEY_CHANNELS) || '[]');
      history = JSON.parse(localStorage.getItem(LS_KEY_HISTORY) || '[]');
      els.apiKeyInput.value = apiKey;
      els.modelInput.value = model;
      if (els.sbUrlInput) els.sbUrlInput.value = sbUrl;
      if (els.sbKeyInput) els.sbKeyInput.value = sbKey;
    } catch (e) {
      console.error('Failed to load data:', e);
      channels = [];
      history = [];
    }
  }

  function saveChannels() {
    localStorage.setItem(LS_KEY_CHANNELS, JSON.stringify(channels));
  }

  function saveHistoryLocally() {
    if (history.length > MAX_HISTORY) {
      history = history.slice(-MAX_HISTORY);
    }
    localStorage.setItem(LS_KEY_HISTORY, JSON.stringify(history));
  }

  function saveHistory() {
    saveHistoryLocally();
    if (lastGeneration && supabaseClient) {
      saveToSupabase(lastGeneration);
    }
  }

  function saveApiKey() {
    localStorage.setItem(LS_KEY_API, els.apiKeyInput.value.trim());
  }

  function saveModel() {
    const custom = els.modelInput.value.trim();
    const selected = els.modelSelect.value;
    localStorage.setItem(LS_KEY_MODEL, custom || selected || DEFAULT_MODEL);
  }

  // ══════════════════════════════════════
  // SETTINGS PANEL
  // ══════════════════════════════════════

  els.settingsToggle.addEventListener('click', (e) => {
    e.stopPropagation();
    els.settingsPanel.classList.toggle('active');
  });

  document.addEventListener('click', (e) => {
    if (!els.settingsPanel.contains(e.target) && e.target !== els.settingsToggle) {
      els.settingsPanel.classList.remove('active');
    }
  });

  els.apiKeyInput.addEventListener('change', saveApiKey);
  els.modelInput.addEventListener('change', saveModel);
  els.modelSelect.addEventListener('change', () => {
    saveModel();
    updateModelMeta();
  });
  els.btnRefreshModels.addEventListener('click', () => fetchFreeModels(true));

  // Password toggle
  els.apiKeyToggle.addEventListener('click', () => {
    const inp = els.apiKeyInput;
    if (inp.type === 'password') {
      inp.type = 'text';
      els.apiKeyToggle.textContent = '🔒';
    } else {
      inp.type = 'password';
      els.apiKeyToggle.textContent = '👁';
    }
  });

  // Supabase password toggle & input listeners
  if (els.sbKeyToggle) {
    els.sbKeyToggle.addEventListener('click', () => {
      const inp = els.sbKeyInput;
      if (inp.type === 'password') {
        inp.type = 'text';
        els.sbKeyToggle.textContent = '🔒';
      } else {
        inp.type = 'password';
        els.sbKeyToggle.textContent = '👁';
      }
    });
  }

  if (els.sbUrlInput) {
    els.sbUrlInput.addEventListener('change', () => {
      localStorage.setItem(LS_KEY_SB_URL, els.sbUrlInput.value.trim());
    });
  }
  if (els.sbKeyInput) {
    els.sbKeyInput.addEventListener('change', () => {
      localStorage.setItem(LS_KEY_SB_KEY, els.sbKeyInput.value.trim());
    });
  }

  if (els.btnConnectSb) {
    els.btnConnectSb.addEventListener('click', () => {
      const url = els.sbUrlInput.value.trim();
      const key = els.sbKeyInput.value.trim();
      localStorage.setItem(LS_KEY_SB_URL, url);
      localStorage.setItem(LS_KEY_SB_KEY, key);
      initSupabase(url, key, true);
    });
  }

  // SQL Schema Modal Listeners
  if (els.btnShowSqlModal) {
    els.btnShowSqlModal.addEventListener('click', () => {
      els.sqlModal.style.display = 'flex';
    });
  }
  if (els.btnCloseSqlModal) {
    els.btnCloseSqlModal.addEventListener('click', () => {
      els.sqlModal.style.display = 'none';
    });
  }
  if (els.btnCloseSqlModal2) {
    els.btnCloseSqlModal2.addEventListener('click', () => {
      els.sqlModal.style.display = 'none';
    });
  }
  if (els.btnCopySql) {
    els.btnCopySql.addEventListener('click', () => {
      navigator.clipboard.writeText(els.sqlSchemaText.value).then(() => {
        els.btnCopySql.textContent = 'COPIED!';
        setTimeout(() => { els.btnCopySql.textContent = 'COPY SQL SCHEMA'; }, 1500);
      });
    });
  }

  // Clear history
  els.btnClearHistory.addEventListener('click', () => {
    if (confirm('Clear all history? This cannot be undone.')) {
      history = [];
      saveHistory();
      renderHistory();
    }
  });

  // Export all data
  els.btnExportAll.addEventListener('click', () => {
    const data = {
      sunoforge_apikey: localStorage.getItem(LS_KEY_API) || '',
      sunoforge_model: localStorage.getItem(LS_KEY_MODEL) || DEFAULT_MODEL,
      sunoforge_channels: channels,
      sunoforge_history: history,
    };
    downloadJSON(data, 'sunoforge_backup_' + dateStamp() + '.json');
  });

  // Import data
  els.importDataInput.addEventListener('change', (e) => {
    const file = e.target.files[0];
    if (!file) return;
    const reader = new FileReader();
    reader.onload = function (ev) {
      try {
        const data = JSON.parse(ev.target.result);
        if (data.sunoforge_apikey !== undefined) {
          localStorage.setItem(LS_KEY_API, data.sunoforge_apikey);
          els.apiKeyInput.value = data.sunoforge_apikey;
        }
        if (data.sunoforge_model !== undefined) {
          localStorage.setItem(LS_KEY_MODEL, data.sunoforge_model);
          els.modelInput.value = data.sunoforge_model;
        }
        if (Array.isArray(data.sunoforge_channels)) {
          channels = data.sunoforge_channels;
          saveChannels();
          renderChannels();
        }
        if (Array.isArray(data.sunoforge_history)) {
          history = data.sunoforge_history;
          saveHistory();
          renderHistory();
        }
        alert('Data imported successfully!');
      } catch (err) {
        alert('Invalid JSON file.');
      }
    };
    reader.readAsText(file);
    e.target.value = '';
  });

  // ══════════════════════════════════════
  // CHANNEL MANAGEMENT
  // ══════════════════════════════════════

  function renderChannels() {
    els.channelList.innerHTML = '';
    channels.forEach((ch, i) => {
      const row = document.createElement('div');
      row.className = 'channel-item' + (i === activeChannelIndex ? ' active' : '');
      row.innerHTML = `
        <span class="ch-name" title="${esc(ch.name)}">${esc(ch.name)}</span>
        <span class="ch-badge">${esc(ch.genre || '—')}</span>
        <button class="ch-delete" data-index="${i}" title="Delete channel">✕</button>
      `;
      row.addEventListener('click', (e) => {
        if (e.target.classList.contains('ch-delete')) return;
        selectChannel(i);
      });
      row.querySelector('.ch-delete').addEventListener('click', (e) => {
        e.stopPropagation();
        deleteChannel(i);
      });
      els.channelList.appendChild(row);
    });
  }

  function selectChannel(index) {
    activeChannelIndex = index;
    const ch = channels[index];
    if (!ch) return;

    els.activeChannelLabel.textContent = '▸ ' + ch.name;
    els.bGenre.value = ch.genre || '';
    els.bMood.value = ch.mood || '';
    els.bLanguage.value = ch.language || '';
    els.bExclude.value = ch.exclude || '';
    els.bSubgenre.value = '';
    els.bConcept.value = '';

    renderChannels();
  }

  function deleteChannel(index) {
    if (!confirm('Delete channel "' + channels[index].name + '"?')) return;
    channels.splice(index, 1);
    if (activeChannelIndex === index) {
      activeChannelIndex = -1;
      els.activeChannelLabel.textContent = 'No channel selected';
    } else if (activeChannelIndex > index) {
      activeChannelIndex--;
    }
    saveChannels();
    renderChannels();
  }

  // New Channel Form
  els.btnNewChannel.addEventListener('click', () => {
    els.newChannelForm.classList.add('active');
    els.ncName.value = '';
    els.ncGenre.value = '';
    els.ncMood.value = '';
    els.ncLanguage.value = '';
    els.ncExclude.value = '';
    els.ncName.focus();
  });

  els.btnCancelChannel.addEventListener('click', () => {
    els.newChannelForm.classList.remove('active');
  });

  els.btnSaveChannel.addEventListener('click', () => {
    const name = els.ncName.value.trim();
    if (!name) {
      els.ncName.focus();
      return;
    }
    channels.push({
      name: name,
      genre: els.ncGenre.value.trim(),
      mood: els.ncMood.value.trim(),
      language: els.ncLanguage.value.trim(),
      exclude: els.ncExclude.value.trim(),
    });
    saveChannels();
    renderChannels();
    els.newChannelForm.classList.remove('active');
    // Auto-select the new channel
    selectChannel(channels.length - 1);
  });

  // ══════════════════════════════════════
  // LYRICS TOGGLE
  // ══════════════════════════════════════

  els.bLyrics.addEventListener('change', () => {
    els.lyricsSection.classList.toggle('active', els.bLyrics.checked);
  });

  // ══════════════════════════════════════
  // CHAR COUNTERS
  // ══════════════════════════════════════

  function updateCharCounter(textarea, counterEl, limit) {
    const len = textarea.value.length;
    counterEl.textContent = len + ' / ' + limit;
    counterEl.className = 'char-counter';
    if (limit === 1000) {
      if (len <= 800) counterEl.classList.add('green');
      else if (len <= 1000) counterEl.classList.add('amber');
      else counterEl.classList.add('red');
    } else {
      if (len <= limit * 0.8) counterEl.classList.add('green');
      else if (len <= limit) counterEl.classList.add('amber');
      else counterEl.classList.add('red');
    }
  }

  els.outStyle.addEventListener('input', () => updateCharCounter(els.outStyle, els.styleCounter, 1000));
  els.outExclude.addEventListener('input', () => updateCharCounter(els.outExclude, els.excludeCounter, 200));
  els.outLyrics.addEventListener('input', () => updateCharCounter(els.outLyrics, els.lyricsCounter, 3000));

  // ══════════════════════════════════════
  // COPY BUTTONS
  // ══════════════════════════════════════

  function setupCopy(btn, targetId) {
    btn.addEventListener('click', () => {
      const text = $(targetId).value;
      if (!text) return;
      navigator.clipboard.writeText(text).then(() => {
        btn.textContent = 'COPIED!';
        btn.classList.add('copied');
        setTimeout(() => {
          btn.textContent = 'COPY';
          btn.classList.remove('copied');
        }, 1500);
      }).catch(() => {
        // Fallback
        const ta = document.createElement('textarea');
        ta.value = text;
        document.body.appendChild(ta);
        ta.select();
        document.execCommand('copy');
        document.body.removeChild(ta);
        btn.textContent = 'COPIED!';
        btn.classList.add('copied');
        setTimeout(() => {
          btn.textContent = 'COPY';
          btn.classList.remove('copied');
        }, 1500);
      });
    });
  }

  setupCopy(els.btnCopyStyle, 'outStyle');
  setupCopy(els.btnCopyExclude, 'outExclude');
  setupCopy(els.btnCopyLyrics, 'outLyrics');

  // ══════════════════════════════════════
  // FORGE PROMPT (API CALL)
  // ══════════════════════════════════════

  els.btnForge.addEventListener('click', () => forgePrompt());

  async function forgePrompt() {
    const apiKey = (localStorage.getItem(LS_KEY_API) || '').trim();
    if (!apiKey) {
      showError('No API key set. Open Settings (⚙) and paste your OpenRouter API key.');
      return;
    }

    const genre = els.bGenre.value;
    const subgenre = els.bSubgenre.value.trim();
    const mood = els.bMood.value.trim();
    const instruments = els.bInstruments ? els.bInstruments.value.trim() : '';
    const scale = els.bScale ? els.bScale.value.trim() : '';
    const tempo = els.bTempo.value;
    const vocal = els.bVocal.value;
    const language = els.bLanguage.value;
    const exclude = els.bExclude.value.trim();
    const concept = els.bConcept.value.trim();
    const wantLyrics = els.bLyrics.checked;

    if (!genre && !subgenre && !concept && !instruments) {
      showError('Provide at least a genre, subgenre, instruments, or song concept.');
      return;
    }

    hideError();
    setLoading(true);

    // Build user prompt
    let userMsg = 'Generate a Suno AI prompt with these parameters:\n';
    if (genre) userMsg += `- Genre: ${genre}\n`;
    if (subgenre) userMsg += `- Subgenre: ${subgenre}\n`;
    if (mood) userMsg += `- Mood: ${mood}\n`;
    if (instruments) userMsg += `- Instruments: ${instruments}\n`;
    if (scale) userMsg += `- Scale/Key: ${scale}\n`;
    if (tempo) userMsg += `- Tempo: ${tempo}\n`;
    if (vocal) userMsg += `- Vocal Style: ${vocal}\n`;
    if (language) userMsg += `- Language: ${language}\n`;
    if (exclude) userMsg += `- Exclude: ${exclude}\n`;
    if (concept) userMsg += `- Song Concept: ${concept}\n`;
    userMsg += `- Include lyrics scaffold: ${wantLyrics ? 'YES' : 'NO'}\n`;

    const model = getActiveModel();

    const body = {
      model: model,
      messages: [
        { role: 'system', content: SYSTEM_PROMPT },
        { role: 'user', content: userMsg },
      ],
      temperature: 0.8,
      max_tokens: 2000,
    };

    try {
      const response = await fetch(OPENROUTER_URL, {
        method: 'POST',
        headers: {
          'Authorization': 'Bearer ' + apiKey,
          'HTTP-Referer': 'https://huggingface.co/spaces/',
          'X-Title': 'SUNO FORGE',
          'Content-Type': 'application/json',
        },
        body: JSON.stringify(body),
      });

      if (!response.ok) {
        const errData = await response.json().catch(() => ({}));
        throw new Error(errData.error?.message || `API error: ${response.status} ${response.statusText}`);
      }

      const data = await response.json();

      // Extract content
      const content = data.choices?.[0]?.message?.content || '';
      const parsed = parseAIResponse(content);

      if (!parsed) {
        throw new Error('Failed to parse AI response. Raw: ' + content.substring(0, 200));
      }

      // Populate output
      els.outStyle.value = parsed.style_prompt || '';
      els.outExclude.value = parsed.exclude || '';
      els.outLyrics.value = parsed.lyrics || '';

      // Update char counters
      updateCharCounter(els.outStyle, els.styleCounter, 1000);
      updateCharCounter(els.outExclude, els.excludeCounter, 200);
      updateCharCounter(els.outLyrics, els.lyricsCounter, 3000);

      // Show lyrics section if there are lyrics
      if (parsed.lyrics && wantLyrics) {
        els.lyricsSection.classList.add('active');
        els.bLyrics.checked = true;
      }

      // Token usage — use actual pricing from model data if available
      const usage = data.usage || {};
      const totalTokens = usage.total_tokens || (usage.prompt_tokens || 0) + (usage.completion_tokens || 0) || 0;
      const pricing = getModelPricing(model);
      const promptCost = (usage.prompt_tokens || 0) * pricing.prompt;
      const completionCost = (usage.completion_tokens || 0) * pricing.completion;
      const estCost = promptCost + completionCost;
      const costLabel = estCost === 0 ? 'FREE' : '$' + estCost.toFixed(6);
      els.tokenUsage.textContent = `Model: ${model} | Tokens: ${totalTokens} | Cost: ${costLabel}`;

      // Store last generation
      const channelName = activeChannelIndex >= 0 ? channels[activeChannelIndex].name : 'No Channel';
      lastGeneration = {
        timestamp: new Date().toISOString(),
        channel: channelName,
        genre: genre,
        mood: mood,
        instruments: instruments,
        scale: scale,
        tempo: tempo,
        vocal: vocal,
        language: language,
        concept: concept,
        subgenre: subgenre,
        exclude: exclude,
        style_prompt: parsed.style_prompt || '',
        exclude_output: parsed.exclude || '',
        lyrics: parsed.lyrics || '',
      };

    } catch (err) {
      showError(err.message);
    } finally {
      setLoading(false);
    }
  }

  function parseAIResponse(raw) {
    // Strip markdown fences if present
    let cleaned = raw.trim();
    cleaned = cleaned.replace(/^```json\s*/i, '');
    cleaned = cleaned.replace(/^```\s*/i, '');
    cleaned = cleaned.replace(/\s*```$/i, '');
    cleaned = cleaned.trim();

    try {
      const obj = JSON.parse(cleaned);
      return {
        style_prompt: String(obj.style_prompt || ''),
        exclude: String(obj.exclude || ''),
        lyrics: String(obj.lyrics || ''),
      };
    } catch (e) {
      // Try to extract JSON from the response
      const jsonMatch = cleaned.match(/\{[\s\S]*\}/);
      if (jsonMatch) {
        try {
          const obj = JSON.parse(jsonMatch[0]);
          return {
            style_prompt: String(obj.style_prompt || ''),
            exclude: String(obj.exclude || ''),
            lyrics: String(obj.lyrics || ''),
          };
        } catch (e2) {
          return null;
        }
      }
      return null;
    }
  }

  function setLoading(on) {
    if (on) {
      els.btnForge.classList.add('loading');
      els.btnForge.innerHTML = '<span class="spinner"></span> FORGING...';
      els.btnSurprise.disabled = true;
    } else {
      els.btnForge.classList.remove('loading');
      els.btnForge.innerHTML = '⚡ FORGE PROMPT';
      els.btnSurprise.disabled = false;
    }
  }

  function showError(msg) {
    els.errorMessage.textContent = '⚠ ' + msg;
    els.errorMessage.classList.add('active');
  }

  function hideError() {
    els.errorMessage.classList.remove('active');
    els.errorMessage.textContent = '';
  }

  // ══════════════════════════════════════
  // SURPRISE ME
  // ══════════════════════════════════════

  els.btnSurprise.addEventListener('click', () => {
    els.bGenre.value = pick(GENRES);
    els.bMood.value = pick(MOODS);
    if (els.bInstruments) els.bInstruments.value = pick(INSTRUMENTS);
    els.bTempo.value = pick(TEMPOS);
    els.bVocal.value = pick(VOCALS);
    els.bSubgenre.value = '';
    els.bConcept.value = '';
    forgePrompt();
  });

  function pick(arr) {
    return arr[Math.floor(Math.random() * arr.length)];
  }

  // ══════════════════════════════════════
  // SAVE TO HISTORY
  // ══════════════════════════════════════

  els.btnSaveHistory.addEventListener('click', () => {
    if (!lastGeneration) {
      showError('Nothing to save. Forge a prompt first.');
      return;
    }
    history.push(lastGeneration);
    saveHistory();
    renderHistory();
    // Brief visual feedback
    els.btnSaveHistory.textContent = '✓ SAVED!';
    setTimeout(() => {
      els.btnSaveHistory.textContent = '💾 SAVE TO HISTORY';
    }, 1500);
  });

  // ══════════════════════════════════════
  // HISTORY RENDERING
  // ══════════════════════════════════════

  function renderHistory() {
    const last10 = history.slice(-10).reverse();
    if (last10.length === 0) {
      els.historyScroll.innerHTML = '<div class="history-empty">No generations yet. Forge something!</div>';
      return;
    }
    els.historyScroll.innerHTML = '';
    last10.forEach((item, i) => {
      const tile = document.createElement('div');
      tile.className = 'history-tile fade-in';
      const date = new Date(item.timestamp);
      const timeStr = date.toLocaleDateString() + ' ' + date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
      tile.innerHTML = `
        <div class="ht-channel">${esc(item.channel)}</div>
        <div class="ht-genre">${esc(item.genre || item.subgenre || '—')}</div>
        <div class="ht-time">${timeStr}</div>
      `;
      tile.addEventListener('click', () => restoreFromHistory(item));
      els.historyScroll.appendChild(tile);
    });
  }

  function restoreFromHistory(item) {
    els.bGenre.value = item.genre || '';
    els.bSubgenre.value = item.subgenre || '';
    els.bMood.value = item.mood || '';
    if (els.bInstruments) els.bInstruments.value = item.instruments || '';
    if (els.bScale) els.bScale.value = item.scale || '';
    els.bTempo.value = item.tempo || '';
    els.bVocal.value = item.vocal || '';
    els.bLanguage.value = item.language || '';
    els.bExclude.value = item.exclude || '';
    els.bConcept.value = item.concept || '';

    els.outStyle.value = item.style_prompt || '';
    els.outExclude.value = item.exclude_output || '';
    els.outLyrics.value = item.lyrics || '';

    updateCharCounter(els.outStyle, els.styleCounter, 1000);
    updateCharCounter(els.outExclude, els.excludeCounter, 200);
    updateCharCounter(els.outLyrics, els.lyricsCounter, 3000);

    if (item.lyrics) {
      els.lyricsSection.classList.add('active');
      els.bLyrics.checked = true;
    }

    lastGeneration = item;

    // Scroll to builder
    els.bGenre.scrollIntoView({ behavior: 'smooth', block: 'start' });
  }

  // ══════════════════════════════════════
  // CSV EXPORT
  // ══════════════════════════════════════

  els.btnExportCsv.addEventListener('click', () => {
    if (history.length === 0) {
      showError('No history to export.');
      return;
    }
    const headers = ['timestamp', 'channel', 'genre', 'mood', 'instruments', 'scale', 'tempo', 'vocal', 'language', 'concept', 'style_prompt', 'exclude', 'lyrics'];
    const rows = [headers.join(',')];
    history.forEach((item) => {
      const row = headers.map((h) => {
        let val = '';
        if (h === 'exclude') val = item.exclude_output || '';
        else val = item[h] || '';
        // Escape CSV
        val = String(val).replace(/"/g, '""');
        if (val.includes(',') || val.includes('"') || val.includes('\n')) {
          val = '"' + val + '"';
        }
        return val;
      });
      rows.push(row.join(','));
    });
    const csv = rows.join('\n');
    const blob = new Blob([csv], { type: 'text/csv;charset=utf-8;' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = 'sunoforge_history_' + dateStamp() + '.csv';
    a.click();
    URL.revokeObjectURL(url);
  });

  // ══════════════════════════════════════
  // UTILITIES
  // ══════════════════════════════════════

  function esc(str) {
    const div = document.createElement('div');
    div.textContent = str || '';
    return div.innerHTML;
  }

  function dateStamp() {
    return new Date().toISOString().slice(0, 10).replace(/-/g, '');
  }

  function downloadJSON(data, filename) {
    const blob = new Blob([JSON.stringify(data, null, 2)], { type: 'application/json' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = filename;
    a.click();
    URL.revokeObjectURL(url);
  }

  // ══════════════════════════════════════
  // MODEL FETCHING (OpenRouter /api/v1/models)
  // ══════════════════════════════════════

  function getActiveModel() {
    const custom = els.modelInput.value.trim();
    if (custom) return custom;
    const selected = els.modelSelect.value;
    if (selected) return selected;
    return DEFAULT_MODEL;
  }

  function getModelPricing(modelId) {
    const m = freeModels.find((x) => x.id === modelId);
    if (m && m.pricing) {
      return {
        prompt: parseFloat(m.pricing.prompt) || 0,
        completion: parseFloat(m.pricing.completion) || 0,
      };
    }
    // Fallback rough estimate
    return { prompt: 0.000000075, completion: 0.0000003 };
  }

  function updateModelMeta() {
    const modelId = els.modelSelect.value;
    const m = freeModels.find((x) => x.id === modelId);
    if (!m) {
      els.modelMeta.innerHTML = '';
      return;
    }
    const ctx = m.context_length ? (m.context_length / 1000).toFixed(0) + 'k' : '?';
    const isFree = m.pricing && parseFloat(m.pricing.prompt) === 0 && parseFloat(m.pricing.completion) === 0;
    const freeTag = isFree ? '<span class="model-free">FREE</span>' : '';
    els.modelMeta.innerHTML = `<span class="model-context">Context: ${ctx}</span> ${freeTag}`;
  }

  async function fetchFreeModels(forceRefresh = false) {
    // Try cache first
    if (!forceRefresh) {
      try {
        const cached = JSON.parse(localStorage.getItem(LS_KEY_MODELS_CACHE) || '{}');
        if (cached.data && cached.ts && (Date.now() - cached.ts < MODELS_CACHE_TTL)) {
          freeModels = cached.data;
          populateModelDropdown();
          return;
        }
      } catch (e) { /* ignore cache errors */ }
    }

    els.modelSelect.innerHTML = '<option value="">⟳ Fetching models...</option>';
    els.btnRefreshModels.disabled = true;

    try {
      const response = await fetch(OPENROUTER_MODELS_URL);
      if (!response.ok) throw new Error('Failed to fetch models');
      const json = await response.json();
      const allModels = json.data || [];

      // Filter: free models (prompt and completion pricing both "0")
      freeModels = allModels.filter((m) => {
        if (!m.pricing) return false;
        return parseFloat(m.pricing.prompt) === 0 && parseFloat(m.pricing.completion) === 0;
      });

      // Sort alphabetically by name
      freeModels.sort((a, b) => (a.name || a.id).localeCompare(b.name || b.id));

      // Cache
      try {
        localStorage.setItem(LS_KEY_MODELS_CACHE, JSON.stringify({
          data: freeModels,
          ts: Date.now(),
        }));
      } catch (e) { /* storage full, ignore */ }

      populateModelDropdown();
    } catch (err) {
      console.error('Model fetch error:', err);
      els.modelSelect.innerHTML = '<option value="">Failed to load — use custom slug below</option>';
      // Add default as fallback
      const opt = document.createElement('option');
      opt.value = DEFAULT_MODEL;
      opt.textContent = 'google/gemini-flash-1.5 (default)';
      els.modelSelect.appendChild(opt);
    } finally {
      els.btnRefreshModels.disabled = false;
    }
  }

  function populateModelDropdown() {
    els.modelSelect.innerHTML = '';

    if (freeModels.length === 0) {
      els.modelSelect.innerHTML = '<option value="">No free models found</option>';
      return;
    }

    // Group by provider
    const groups = {};
    freeModels.forEach((m) => {
      const provider = m.id.split('/')[0] || 'other';
      if (!groups[provider]) groups[provider] = [];
      groups[provider].push(m);
    });

    // Sort provider names
    const sortedProviders = Object.keys(groups).sort();

    // Add a default option
    const defaultOpt = document.createElement('option');
    defaultOpt.value = '';
    defaultOpt.textContent = `— Select from ${freeModels.length} free models —`;
    els.modelSelect.appendChild(defaultOpt);

    sortedProviders.forEach((provider) => {
      const optgroup = document.createElement('optgroup');
      optgroup.label = provider.toUpperCase();
      groups[provider].forEach((m) => {
        const opt = document.createElement('option');
        opt.value = m.id;
        const ctx = m.context_length ? ` [${(m.context_length / 1000).toFixed(0)}k]` : '';
        opt.textContent = (m.name || m.id) + ctx;
        optgroup.appendChild(opt);
      });
      els.modelSelect.appendChild(optgroup);
    });

    // Restore saved selection
    const saved = localStorage.getItem(LS_KEY_MODEL) || '';
    if (saved && !els.modelInput.value.trim()) {
      // Try to select it in dropdown
      const exists = freeModels.some((m) => m.id === saved);
      if (exists) {
        els.modelSelect.value = saved;
      }
    }

    updateModelMeta();
  }

  // ══════════════════════════════════════
  // IFRAME DETECTION & STORAGE ACCESS
  // ══════════════════════════════════════

  function isInIframe() {
    try {
      return window.self !== window.top;
    } catch (e) {
      return true; // cross-origin iframe blocks access to window.top
    }
  }

  function getDirectUrl() {
    // When on HF Spaces, the iframe src is like https://username-spacename.hf.space
    // The parent page is https://huggingface.co/spaces/username/spacename
    // We want to link to the direct .hf.space URL
    const loc = window.location;
    if (loc.hostname.endsWith('.hf.space')) {
      return loc.href;
    }
    // Fallback: try to construct from current URL
    return loc.href;
  }

  async function requestStorageAccess() {
    // Try the Storage Access API to get unpartitioned storage in iframe
    if (document.hasStorageAccess) {
      try {
        const hasAccess = await document.hasStorageAccess();
        if (!hasAccess && document.requestStorageAccess) {
          await document.requestStorageAccess();
          // Reload data after getting access
          loadData();
          renderChannels();
          renderHistory();
        }
      } catch (e) {
        console.log('Storage Access API not available or denied:', e);
      }
    }
  }

  function setupIframeBanner() {
    if (!isInIframe()) return;

    const banner = document.getElementById('iframeBanner');
    const notice = document.getElementById('iframeNotice');
    const btnOpen = document.getElementById('btnOpenFull');
    const btnOpenSettings = document.getElementById('settingsOpenFull');
    const btnDismiss = document.getElementById('btnDismissBanner');

    // Check if user previously dismissed (session-only)
    const dismissed = sessionStorage.getItem('sunoforge_banner_dismissed');

    const directUrl = getDirectUrl();
    btnOpen.href = directUrl;
    if (btnOpenSettings) btnOpenSettings.href = directUrl;

    if (!dismissed) {
      banner.style.display = 'flex';
    }
    if (notice) {
      notice.style.display = 'block';
    }

    btnDismiss.addEventListener('click', () => {
      banner.style.display = 'none';
      sessionStorage.setItem('sunoforge_banner_dismissed', '1');
    });

    // Try to request storage access
    requestStorageAccess();
  }

  // ══════════════════════════════════════
  // SUPABASE CLOUD HISTORY SYNC
  // ══════════════════════════════════════

  function initSupabase(url, key, isUserAction = false) {
    if (!url || !key) {
      if (els.sbStatus) {
        els.sbStatus.textContent = 'Status: Local storage only';
        els.sbStatus.style.color = 'var(--dim)';
      }
      supabaseClient = null;
      return;
    }

    if (typeof window.supabase === 'undefined' || !window.supabase.createClient) {
      if (els.sbStatus) {
        els.sbStatus.textContent = 'Status: Supabase SDK loading...';
        els.sbStatus.style.color = 'var(--amber)';
      }
      setTimeout(() => initSupabase(url, key, isUserAction), 500);
      return;
    }

    try {
      supabaseClient = window.supabase.createClient(url, key);
      syncHistoryFromSupabase(isUserAction);
    } catch (e) {
      console.error('Supabase init error:', e);
      if (els.sbStatus) {
        els.sbStatus.textContent = 'Status: Invalid URL/Key format';
        els.sbStatus.style.color = 'var(--red)';
      }
    }
  }

  async function syncHistoryFromSupabase(isUserAction = false) {
    if (!supabaseClient) return;

    if (els.sbStatus) {
      els.sbStatus.textContent = 'Status: Connecting...';
      els.sbStatus.style.color = 'var(--amber)';
    }

    try {
      const { data, error } = await supabaseClient
        .from('suno_history')
        .select('*')
        .order('created_at', { ascending: false })
        .limit(50);

      if (error) {
        console.warn('Supabase query error:', error);
        if (els.sbStatus) {
          els.sbStatus.textContent = `Status: Error (${error.message || 'Check RLS/Table'})`;
          els.sbStatus.style.color = 'var(--red)';
        }
        return;
      }

      if (Array.isArray(data)) {
        if (els.sbStatus) {
          els.sbStatus.textContent = `Status: Connected ✓ (${data.length} cloud records)`;
          els.sbStatus.style.color = 'var(--green)';
        }

        if (data.length > 0) {
          const cloudItems = data.map((row) => ({
            timestamp: row.created_at || new Date().toISOString(),
            channel: row.channel || '',
            genre: row.genre || '',
            subgenre: row.subgenre || '',
            mood: row.mood || '',
            instruments: row.instruments || '',
            scale: row.scale || '',
            tempo: row.tempo || '',
            vocal: row.vocal || '',
            language: row.language || '',
            exclude: row.exclude || '',
            concept: row.concept || '',
            style_prompt: row.style_prompt || '',
            exclude_output: row.exclude_output || '',
            lyrics: row.lyrics || '',
          })).reverse();

          history = cloudItems;
          saveHistoryLocally();
          renderHistory();
        }

        if (isUserAction) {
          alert(`Successfully connected to Supabase! Syncing ${data.length} records.`);
        }
      }
    } catch (err) {
      console.error('Supabase sync error:', err);
      if (els.sbStatus) {
        els.sbStatus.textContent = 'Status: Connection failed';
        els.sbStatus.style.color = 'var(--red)';
      }
    }
  }

  async function saveToSupabase(genItem) {
    if (!supabaseClient) return;

    try {
      const { error } = await supabaseClient
        .from('suno_history')
        .insert([{
          channel: genItem.channel || '',
          genre: genItem.genre || '',
          subgenre: genItem.subgenre || '',
          mood: genItem.mood || '',
          instruments: genItem.instruments || '',
          scale: genItem.scale || '',
          tempo: genItem.tempo || '',
          vocal: genItem.vocal || '',
          language: genItem.language || '',
          exclude: genItem.exclude || '',
          concept: genItem.concept || '',
          style_prompt: genItem.style_prompt || '',
          exclude_output: genItem.exclude_output || '',
          lyrics: genItem.lyrics || '',
          created_at: genItem.timestamp || new Date().toISOString()
        }]);

      if (error) {
        console.warn('Supabase insert error:', error);
      } else {
        if (els.sbStatus) {
          els.sbStatus.textContent = 'Status: Connected ✓ (Saved row)';
          els.sbStatus.style.color = 'var(--green)';
        }
      }
    } catch (e) {
      console.error('Failed to insert into Supabase:', e);
    }
  }

  // ══════════════════════════════════════
  // INIT
  // ══════════════════════════════════════

  function init() {
    loadData();
    renderChannels();
    renderHistory();
    fetchFreeModels();
    setupIframeBanner();

    // Auto-connect Supabase if credentials are in localStorage
    const sbUrl = localStorage.getItem(LS_KEY_SB_URL);
    const sbKey = localStorage.getItem(LS_KEY_SB_KEY);
    if (sbUrl && sbKey) {
      initSupabase(sbUrl, sbKey, false);
    }
  }

  init();

})();