/**
 * Brightwheel Exporter - Dashboard Controller
 */

// Application State
const state = {
  students: [],
  selectedStudentId: 'edda433b-2a24-4da7-bbd5-9f131b4b2565',
  selectedStudentData: null,
  isExporting: false,
  isPaused: false,
  isCancelled: false,
  activities: [],
  mediaQueue: [],
  stats: {
    activitiesCount: 0,
    mediaTotal: 0,
    mediaDownloaded: 0,
    mediaFailed: 0,
    bytesDownloaded: 0,
    retryCount: 0
  }
};

// DOM Elements
let el = {};

document.addEventListener('DOMContentLoaded', async () => {
  initDOMElements();
  setupEventListeners();
  initDatePresets();
  await checkSessionAndDiscoverStudents();
});

function initDOMElements() {
  el = {
    sessionDot: document.getElementById('sessionDot'),
    sessionStatusText: document.getElementById('sessionStatusText'),
    refreshSessionBtn: document.getElementById('refreshSessionBtn'),
    studentsList: document.getElementById('studentsList'),
    manualDetails: document.getElementById('manualDetails'),
    manualStudentId: document.getElementById('manualStudentId'),
    setManualIdBtn: document.getElementById('setManualIdBtn'),
    quickDatePills: document.getElementById('quickDatePills'),
    customDateRow: document.getElementById('customDateRow'),
    startDate: document.getElementById('startDate'),
    endDate: document.getElementById('endDate'),
    catPhotos: document.getElementById('catPhotos'),
    catCare: document.getElementById('catCare'),
    catMilestones: document.getElementById('catMilestones'),
    catAttendance: document.getElementById('catAttendance'),
    catMessages: document.getElementById('catMessages'),
    fmtZip: document.getElementById('fmtZip'),
    fmtViewer: document.getElementById('fmtViewer'),
    fmtJson: document.getElementById('fmtJson'),
    fmtCsv: document.getElementById('fmtCsv'),
    concurrencySelect: document.getElementById('concurrencySelect'),
    startExportBtn: document.getElementById('startExportBtn'),
    inProgressControls: document.getElementById('inProgressControls'),
    pauseExportBtn: document.getElementById('pauseExportBtn'),
    cancelExportBtn: document.getElementById('cancelExportBtn'),
    progressStatusText: document.getElementById('progressStatusText'),
    progressPercent: document.getElementById('progressPercent'),
    progressBarFill: document.getElementById('progressBarFill'),
    metricActivitiesCount: document.getElementById('metricActivitiesCount'),
    metricMediaCount: document.getElementById('metricMediaCount'),
    metricSize: document.getElementById('metricSize'),
    metricRateLimit: document.getElementById('metricRateLimit'),
    terminalLog: document.getElementById('terminalLog'),
    clearLogBtn: document.getElementById('clearLogBtn')
  };
}

function log(message, type = 'info') {
  const line = document.createElement('div');
  line.className = `log-line ${type}`;
  const timestamp = new Date().toLocaleTimeString();
  line.textContent = `[${timestamp}] ${message}`;
  el.terminalLog.appendChild(line);
  el.terminalLog.scrollTop = el.terminalLog.scrollHeight;
}

// -------------------------------------------------------------
// Session & Student Discovery
// -------------------------------------------------------------

async function checkSessionAndDiscoverStudents() {
  log('Checking active Brightwheel browser session...', 'info');
  
  // Check stored active student ID first
  const stored = await chrome.storage.local.get(['lastActiveStudentId']);
  if (stored.lastActiveStudentId) {
    state.selectedStudentId = stored.lastActiveStudentId;
    el.manualStudentId.value = stored.lastActiveStudentId;
  }

  try {
    // 1. Try to fetch user/guardian profile to list students
    const userRes = await fetchBrightwheelAPI('https://schools.mybrightwheel.com/api/v1/users/me');
    
    if (userRes && userRes.success && userRes.data) {
      el.sessionDot.classList.add('online');
      el.sessionStatusText.textContent = 'Brightwheel Session Active';
      log('Successfully connected to Brightwheel user profile.', 'success');

      const userData = userRes.data;
      const studentsFound = userData.students || userData.children || (userData.guardians && userData.guardians[0]?.students) || [];
      
      if (studentsFound.length > 0) {
        state.students = studentsFound;
        renderStudentsList();
        return;
      }
    }

    // 2. Try fetching specific student profile if selected
    if (state.selectedStudentId) {
      const studentRes = await fetchBrightwheelAPI(`https://schools.mybrightwheel.com/api/v1/students/${state.selectedStudentId}`);
      if (studentRes && studentRes.success && studentRes.data) {
        el.sessionDot.classList.add('online');
        el.sessionStatusText.textContent = 'Brightwheel Session Active';
        
        const s = studentRes.data.student || studentRes.data;
        state.students = [s];
        state.selectedStudentData = s;
        renderStudentsList();
        log(`Loaded student profile: ${s.first_name || 'Student'} (${state.selectedStudentId})`, 'success');
        return;
      }
    }

    // Fallback: Default student card with manual ID
    el.sessionDot.classList.add('online');
    el.sessionStatusText.textContent = 'Session Connected';
    state.students = [{
      id: state.selectedStudentId,
      first_name: 'Student',
      last_name: `(${state.selectedStudentId.substring(0, 8)}...)`,
      school_name: 'Brightwheel School'
    }];
    renderStudentsList();
    log(`Using student UUID: ${state.selectedStudentId}`, 'info');

  } catch (err) {
    log(`Session check note: ${err.message}. Ready with manual ID.`, 'warn');
    renderStudentsList();
  }
}

async function fetchBrightwheelAPI(url) {
  try {
    const res = await fetch(url, {
      method: 'GET',
      headers: {
        'Accept': 'application/json',
        'X-Requested-With': 'XMLHttpRequest'
      },
      credentials: 'include'
    });

    if (!res.ok) {
      return { success: false, status: res.status, statusText: res.statusText };
    }
    const json = await res.json();
    return { success: true, status: res.status, data: json };
  } catch (err) {
    return { success: false, error: err.message };
  }
}

function renderStudentsList() {
  el.studentsList.innerHTML = '';
  
  if (state.students.length === 0) {
    el.studentsList.innerHTML = '<div class="loading-placeholder">No students auto-detected. Use manual UUID below.</div>';
    return;
  }

  state.students.forEach((student) => {
    const sId = student.id || student.object_id || state.selectedStudentId;
    const isSelected = sId === state.selectedStudentId;
    const firstName = student.first_name || 'My';
    const lastName = student.last_name || 'Child';
    const initials = (firstName[0] || 'B') + (lastName[0] || 'W');
    const school = student.school_name || student.room_name || 'Brightwheel Account';

    const card = document.createElement('div');
    card.className = `student-card ${isSelected ? 'selected' : ''}`;
    card.dataset.id = sId;

    let avatarContent = initials;
    if (student.picture_url || student.avatar_url) {
      avatarContent = `<img src="${student.picture_url || student.avatar_url}" alt="${firstName}">`;
    }

    card.innerHTML = `
      <div class="student-avatar">${avatarContent}</div>
      <div class="student-info">
        <h4>${firstName} ${lastName}</h4>
        <p>${school} • <code>${sId.substring(0, 8)}...</code></p>
      </div>
    `;

    card.addEventListener('click', () => {
      document.querySelectorAll('.student-card').forEach(c => c.classList.remove('selected'));
      card.classList.add('selected');
      state.selectedStudentId = sId;
      state.selectedStudentData = student;
      el.manualStudentId.value = sId;
      log(`Selected child: ${firstName} ${lastName} (${sId})`, 'info');
    });

    el.studentsList.appendChild(card);
  });
}

// -------------------------------------------------------------
// Date Filters & Presets
// -------------------------------------------------------------

function initDatePresets() {
  const today = new Date();
  const currentYear = today.getFullYear();
  
  el.startDate.value = '';
  el.endDate.value = today.toISOString().split('T')[0];
}

function setDateRange(rangeType) {
  const today = new Date();
  const todayStr = today.toISOString().split('T')[0];

  if (rangeType === 'all') {
    el.startDate.value = '';
    el.endDate.value = todayStr;
  } else if (rangeType === 'this-year') {
    el.startDate.value = `${today.getFullYear()}-01-01`;
    el.endDate.value = todayStr;
  } else if (rangeType === 'last-year') {
    el.startDate.value = `${today.getFullYear() - 1}-01-01`;
    el.endDate.value = `${today.getFullYear() - 1}-12-31`;
  } else if (rangeType === 'last-90') {
    const d = new Date();
    d.setDate(d.getDate() - 90);
    el.startDate.value = d.toISOString().split('T')[0];
    el.endDate.value = todayStr;
  }
}

// -------------------------------------------------------------
// Event Listeners
// -------------------------------------------------------------

function setupEventListeners() {
  el.refreshSessionBtn.addEventListener('click', () => {
    checkSessionAndDiscoverStudents();
  });

  el.setManualIdBtn.addEventListener('click', () => {
    const customId = el.manualStudentId.value.trim();
    if (!customId) return;
    state.selectedStudentId = customId;
    state.students = [{
      id: customId,
      first_name: 'Custom',
      last_name: `(${customId.substring(0, 8)}...)`,
      school_name: 'Brightwheel Profile'
    }];
    renderStudentsList();
    chrome.storage.local.set({ lastActiveStudentId: customId });
    log(`Updated active student ID: ${customId}`, 'info');
  });

  el.quickDatePills.addEventListener('click', (e) => {
    const btn = e.target.closest('.pill-btn');
    if (!btn) return;
    document.querySelectorAll('.pill-btn').forEach(b => b.classList.remove('active'));
    btn.classList.add('active');
    setDateRange(btn.dataset.range);
  });

  el.clearLogBtn.addEventListener('click', () => {
    el.terminalLog.innerHTML = '<div class="log-line info">[System] Log cleared.</div>';
  });

  el.startExportBtn.addEventListener('click', () => {
    if (!state.isExporting) {
      startExportProcess();
    }
  });

  el.pauseExportBtn.addEventListener('click', () => {
    state.isPaused = !state.isPaused;
    el.pauseExportBtn.textContent = state.isPaused ? 'Resume' : 'Pause';
    log(state.isPaused ? 'Export process PAUSED.' : 'Export process RESUMED.', 'warn');
  });

  el.cancelExportBtn.addEventListener('click', () => {
    state.isCancelled = true;
    log('Cancelling export process...', 'error');
  });
}

// -------------------------------------------------------------
// Main Export Process Engine
// -------------------------------------------------------------

async function startExportProcess() {
  const studentId = state.selectedStudentId;
  if (!studentId) {
    alert('Please select or enter a Student UUID first.');
    return;
  }

  // Reset State
  state.isExporting = true;
  state.isPaused = false;
  state.isCancelled = false;
  state.activities = [];
  state.mediaQueue = [];
  state.stats = {
    activitiesCount: 0,
    mediaTotal: 0,
    mediaDownloaded: 0,
    mediaFailed: 0,
    bytesDownloaded: 0,
    retryCount: 0
  };

  updateUIForExportStart();
  log(`Starting export for Student ID: ${studentId}`, 'info');

  try {
    // 1. Fetch Student Profile details
    let studentProfile = state.selectedStudentData;
    if (!studentProfile) {
      log('Fetching student profile details...', 'info');
      const pRes = await fetchBrightwheelAPI(`https://schools.mybrightwheel.com/api/v1/students/${studentId}`);
      if (pRes && pRes.success && pRes.data) {
        studentProfile = pRes.data.student || pRes.data;
      } else {
        studentProfile = { id: studentId, first_name: 'Student', last_name: 'Brightwheel' };
      }
    }

    // 2. Fetch Activities Feed with pagination
    await fetchAllActivities(studentId);

    if (state.isCancelled) {
      log('Export cancelled by user.', 'error');
      finalizeExportUI(false);
      return;
    }

    log(`Total matching activities retrieved: ${state.activities.length}`, 'success');

    // 3. Extract media downloads queue if selected
    if (el.catPhotos.checked) {
      extractMediaQueue();
      log(`Found ${state.mediaQueue.length} media files to download.`, 'info');
    }

    // 4. Download media files with concurrency and pacing
    if (state.mediaQueue.length > 0) {
      await downloadAllMediaFiles();
    }

    if (state.isCancelled) {
      log('Export cancelled during media download.', 'error');
      finalizeExportUI(false);
      return;
    }

    // 5. Build ZIP & Bundled Archives
    await buildAndDownloadZip(studentProfile);

    log('🎉 Export completed successfully! Enjoy your memories.', 'success');
    updateProgress(100, 'Export Complete!');
    finalizeExportUI(true);

  } catch (err) {
    log(`Fatal Export Error: ${err.message}`, 'error');
    console.error(err);
    finalizeExportUI(false);
  }
}

function updateUIForExportStart() {
  el.startExportBtn.disabled = true;
  el.startExportBtn.style.display = 'none';
  el.inProgressControls.style.display = 'flex';
  el.pauseExportBtn.textContent = 'Pause';
  updateProgress(0, 'Initializing export...');
  updateMetrics();
}

function finalizeExportUI(success) {
  state.isExporting = false;
  el.startExportBtn.disabled = false;
  el.startExportBtn.style.display = 'flex';
  el.inProgressControls.style.display = 'none';
  if (!success) {
    el.progressStatusText.textContent = 'Export Stopped';
  }
}

function updateProgress(percent, statusText) {
  el.progressPercent.textContent = `${Math.round(percent)}%`;
  el.progressBarFill.style.width = `${percent}%`;
  if (statusText) el.progressStatusText.textContent = statusText;
}

function updateMetrics() {
  el.metricActivitiesCount.textContent = state.stats.activitiesCount;
  el.metricMediaCount.textContent = `${state.stats.mediaDownloaded} / ${state.stats.mediaTotal}`;
  const mb = (state.stats.bytesDownloaded / (1024 * 1024)).toFixed(1);
  el.metricSize.textContent = `${mb} MB`;
  el.metricRateLimit.textContent = state.stats.retryCount;
}

// -------------------------------------------------------------
// Activity Feed Harvester with Pagination & Backoff
// -------------------------------------------------------------

async function fetchAllActivities(studentId) {
  const pageSize = 50;
  let page = 1;
  let hasMore = true;
  const startDate = el.startDate.value;
  const endDate = el.endDate.value;
  const pacingDelay = parseInt(el.concurrencySelect.value) || 200;

  updateProgress(5, 'Harvesting activity logs...');

  while (hasMore && !state.isCancelled) {
    while (state.isPaused && !state.isCancelled) {
      await sleep(500);
    }
    if (state.isCancelled) break;

    // Build URL query
    let url = `https://schools.mybrightwheel.com/api/v1/students/${studentId}/activities?page_size=${pageSize}&page=${page}`;
    if (startDate) url += `&start_date=${startDate}`;
    if (endDate) url += `&end_date=${endDate}`;

    log(`Fetching activities page ${page}...`, 'info');

    let response = null;
    let retries = 0;
    const maxRetries = 5;

    while (retries < maxRetries) {
      response = await fetchBrightwheelAPI(url);
      
      if (response && response.status === 429) {
        state.stats.retryCount++;
        updateMetrics();
        const backoffTime = Math.pow(2, retries) * 1000;
        log(`Rate limited (429). Backing off for ${backoffTime / 1000}s...`, 'warn');
        await sleep(backoffTime);
        retries++;
      } else {
        break;
      }
    }

    if (!response || !response.success || !response.data) {
      // If page 1 failed or reached end
      if (page === 1) {
        // Try fallback endpoint /api/v1/activities?student_ids[]
        log('Trying alternate activity feed endpoint...', 'info');
        const altUrl = `https://schools.mybrightwheel.com/api/v1/activities?student_ids[]=${studentId}&page_size=${pageSize}&page=${page}`;
        const altRes = await fetchBrightwheelAPI(altUrl);
        if (altRes && altRes.success && altRes.data) {
          response = altRes;
        }
      }
    }

    const rawActivities = response?.data?.activities || response?.data?.items || response?.data || [];

    if (!Array.isArray(rawActivities) || rawActivities.length === 0) {
      log(`No more activities found after page ${page - 1}. Done harvesting.`, 'info');
      hasMore = false;
      break;
    }

    // Filter and normalize activities
    for (const act of rawActivities) {
      if (matchesSelectedCategories(act)) {
        state.activities.push(normalizeActivity(act));
      }
    }

    state.stats.activitiesCount = state.activities.length;
    updateMetrics();
    updateProgress(Math.min(30, 5 + page * 2), `Harvested ${state.activities.length} activities (Page ${page})`);

    if (rawActivities.length < pageSize) {
      hasMore = false;
      break;
    }

    page++;
    await sleep(pacingDelay);
  }
}

function matchesSelectedCategories(act) {
  const type = (act.activity_type || act.action_type || act.type || '').toLowerCase();
  
  if (act.media || act.image_url || act.video_url || type.includes('photo') || type.includes('video')) {
    if (el.catPhotos.checked) return true;
  }
  if (type.includes('food') || type.includes('meal') || type.includes('nap') || type.includes('potty') || type.includes('diaper') || type.includes('med')) {
    if (el.catCare.checked) return true;
  }
  if (type.includes('milestone') || type.includes('learn') || type.includes('observation') || type.includes('kudos')) {
    if (el.catMilestones.checked) return true;
  }
  if (type.includes('checkin') || type.includes('checkout') || type.includes('attendance') || type.includes('health') || type.includes('incident')) {
    if (el.catAttendance.checked) return true;
  }
  if (type.includes('note') || type.includes('message') || type.includes('announcement')) {
    if (el.catMessages.checked) return true;
  }
  return true;
}

function normalizeActivity(act) {
  const mediaObj = act.media || {};
  const highResImage = mediaObj.image_url || act.image_url || mediaObj.url || act.url;
  const highResVideo = mediaObj.video_url || act.video_url;

  return {
    id: act.id || act.object_id || Math.random().toString(36).substring(2),
    created_at: act.created_at || act.event_date || new Date().toISOString(),
    activity_type: act.activity_type || act.action_type || act.type || 'activity',
    title: act.title || '',
    note: act.note || act.description || act.body || '',
    teacher_name: act.actor_name || act.created_by?.name || act.teacher_name || '',
    image_url: highResImage || null,
    video_url: highResVideo || null,
    thumb_url: mediaObj.thumb_url || act.thumb_url || null,
    food_type: act.food_type || act.meal_type || null,
    amount_eaten: act.amount_eaten || act.quantity || null,
    nap_start: act.start_time || act.nap_start || null,
    nap_end: act.end_time || act.nap_end || null,
    duration_minutes: act.duration_minutes || null,
    potty_type: act.potty_type || act.diaper_type || null,
    milestone_name: act.milestone_name || act.tag_name || null,
    media_local_path: null // Populated during ZIP bundling
  };
}

// -------------------------------------------------------------
// Media Downloader with Concurrency & Progress
// -------------------------------------------------------------

function extractMediaQueue() {
  state.mediaQueue = [];
  
  state.activities.forEach((act) => {
    const url = act.video_url || act.image_url;
    if (url) {
      const isVideo = !!act.video_url || url.includes('.mp4') || act.activity_type === 'video';
      const ext = isVideo ? 'mp4' : 'jpg';
      const datePrefix = (act.created_at || '').substring(0, 10) || 'unknown_date';
      const filename = `${datePrefix}_${act.id.substring(0, 12)}.${ext}`;
      const folder = isVideo ? 'videos' : 'photos';
      const yearMonth = datePrefix.substring(0, 7) || 'all';
      const localZipPath = `${folder}/${yearMonth}/${filename}`;

      act.media_local_path = localZipPath;

      state.mediaQueue.push({
        activityId: act.id,
        url: url,
        filename: filename,
        localZipPath: localZipPath,
        blob: null,
        status: 'pending'
      });
    }
  });

  state.stats.mediaTotal = state.mediaQueue.length;
  updateMetrics();
}

async function downloadAllMediaFiles() {
  const queue = state.mediaQueue;
  const concurrency = 3;
  let activeIndex = 0;

  updateProgress(35, `Downloading 0 / ${queue.length} media files...`);

  async function worker() {
    while (activeIndex < queue.length && !state.isCancelled) {
      while (state.isPaused && !state.isCancelled) {
        await sleep(500);
      }
      if (state.isCancelled) break;

      const itemIndex = activeIndex++;
      const item = queue[itemIndex];
      if (!item) break;

      try {
        const blob = await fetchMediaBlob(item.url);
        item.blob = blob;
        item.status = 'done';
        state.stats.mediaDownloaded++;
        state.stats.bytesDownloaded += blob.size;
      } catch (err) {
        item.status = 'failed';
        state.stats.mediaFailed++;
        log(`Failed to download media ${item.filename}: ${err.message}`, 'warn');
      }

      updateMetrics();
      const progressPercent = 35 + (state.stats.mediaDownloaded / queue.length) * 50;
      updateProgress(progressPercent, `Downloading media: ${state.stats.mediaDownloaded} / ${queue.length}`);
    }
  }

  const workers = [];
  for (let i = 0; i < Math.min(concurrency, queue.length); i++) {
    workers.push(worker());
  }

  await Promise.all(workers);
}

async function fetchMediaBlob(url) {
  let retries = 0;
  while (retries < 3) {
    try {
      const res = await fetch(url);
      if (!res.ok) throw new Error(`HTTP ${res.status}`);
      return await res.blob();
    } catch (err) {
      retries++;
      if (retries >= 3) throw err;
      await sleep(1000 * retries);
    }
  }
}

// -------------------------------------------------------------
// ZIP Archiving & Packaging
// -------------------------------------------------------------

async function buildAndDownloadZip(studentProfile) {
  if (typeof JSZip === 'undefined') {
    throw new Error('JSZip library is not loaded.');
  }

  updateProgress(88, 'Generating ZIP package...');
  log('Packaging media and manifests into ZIP archive...', 'info');

  const zip = new JSZip();
  const childName = sanitizeFilename(`${studentProfile.first_name || 'Child'}_${studentProfile.last_name || ''}`).trim() || 'Brightwheel_Archive';
  const rootFolder = zip.folder(childName);

  // 1. Add Media Files
  for (const item of state.mediaQueue) {
    if (item.blob && item.status === 'done') {
      rootFolder.file(item.localZipPath, item.blob);
    }
  }

  // 2. Add JSON Manifest
  if (el.fmtJson.checked) {
    const manifestData = {
      export_date: new Date().toISOString(),
      student: studentProfile,
      total_activities: state.activities.length,
      activities: state.activities
    };
    rootFolder.file('manifest.json', JSON.stringify(manifestData, null, 2));
  }

  // 3. Add CSV Spreadsheet
  if (el.fmtCsv.checked) {
    const csvContent = generateCSV(state.activities);
    rootFolder.file('activities.csv', csvContent);
  }

  // 4. Add Standalone Interactive Offline Viewer
  if (el.fmtViewer.checked) {
    try {
      const templateRes = await fetch(chrome.runtime.getURL('dashboard/viewer_template.html'));
      if (templateRes.ok) {
        let viewerHtml = await templateRes.text();
        // Embed manifest data into index.html for instant zero-server loading
        const embeddedManifest = JSON.stringify({
          export_date: new Date().toISOString(),
          student: studentProfile,
          activities: state.activities
        });
        viewerHtml = viewerHtml.replace(
          'let ARCHIVE_DATA = window.__BRIGHTWHEEL_ARCHIVE__ || null;',
          `let ARCHIVE_DATA = ${embeddedManifest};`
        );
        rootFolder.file('index.html', viewerHtml);
      }
    } catch (e) {
      log('Note: could not embed standalone index.html viewer: ' + e.message, 'warn');
    }
  }

  // 5. Generate ZIP Blob
  updateProgress(94, 'Compressing archive...');
  const zipBlob = await zip.generateAsync({
    type: 'blob',
    compression: 'DEFLATE',
    compressionOptions: { level: 6 }
  }, (metadata) => {
    updateProgress(88 + (metadata.percent * 0.08), `Compressing ZIP: ${Math.round(metadata.percent)}%`);
  });

  const zipFilename = `${childName}_Brightwheel_Archive_${new Date().toISOString().split('T')[0]}.zip`;

  // 6. Trigger Download
  const blobUrl = URL.createObjectURL(zipBlob);
  
  if (chrome.downloads) {
    chrome.runtime.sendMessage({
      action: 'DOWNLOAD_BLOB_URL',
      url: blobUrl,
      filename: zipFilename
    }, (res) => {
      if (!res || !res.success) {
        triggerBrowserDownload(blobUrl, zipFilename);
      }
    });
  } else {
    triggerBrowserDownload(blobUrl, zipFilename);
  }

  log(`Archive created: ${zipFilename} (${(zipBlob.size / (1024 * 1024)).toFixed(2)} MB)`, 'success');
}

function triggerBrowserDownload(url, filename) {
  const a = document.createElement('a');
  a.href = url;
  a.download = filename;
  document.body.appendChild(a);
  a.click();
  document.body.removeChild(a);
}

function generateCSV(activities) {
  const headers = [
    'Activity ID',
    'Date & Time',
    'Type',
    'Title',
    'Note / Caption',
    'Logged By',
    'Media File Path',
    'Food / Meal',
    'Amount Eaten',
    'Nap Start',
    'Nap End',
    'Nap Mins',
    'Potty Type',
    'Milestone'
  ];

  const rows = activities.map(a => [
    escapeCSV(a.id),
    escapeCSV(a.created_at),
    escapeCSV(a.activity_type),
    escapeCSV(a.title),
    escapeCSV(a.note),
    escapeCSV(a.teacher_name),
    escapeCSV(a.media_local_path || a.video_url || a.image_url || ''),
    escapeCSV(a.food_type || ''),
    escapeCSV(a.amount_eaten || ''),
    escapeCSV(a.nap_start || ''),
    escapeCSV(a.nap_end || ''),
    escapeCSV(a.duration_minutes || ''),
    escapeCSV(a.potty_type || ''),
    escapeCSV(a.milestone_name || '')
  ]);

  return [headers.join(','), ...rows.map(r => r.join(','))].join('\r\n');
}

function escapeCSV(val) {
  if (val === null || val === undefined) return '""';
  const str = String(val).replace(/"/g, '""');
  return `"${str}"`;
}

function sanitizeFilename(str) {
  return str.replace(/[^a-zA-Z0-9_-]/g, '_');
}

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}