/**
 * Gmail Label Cleanup Script
 * Run from https://script.google.com
 *
 * What this does:
 * 1. Merges old labels into inbox-zero categories (relabels all threads)
 * 2. Archives + relabels cvlp threads to Newsletter
 * 3. Merges purchases into Receipt, deletes purchases
 * 4. Moves donations top-level, selling under business
 * 5. Deletes contract label (threads stay under business)
 * 6. Deletes empty/unused labels
 *
 * Safe to run multiple times - skips labels that don't exist.
 */

// ─── STEP 1: Merge old labels into inbox-zero categories ─────────────────────

function mergeLabels() {
  var merges = [
    { from: 'promo',        to: 'Marketing' },
    { from: 'mailing list', to: 'Newsletter' },
    { from: 'twitter',      to: 'Notification' },
    { from: 'facebook',     to: 'Notification' },
    { from: 'tech',         to: 'Newsletter' },
    { from: 'To Reply',     to: 'Awaiting Reply' },
  ];

  merges.forEach(function(m) {
    var fromLabel = GmailApp.getUserLabelByName(m.from);
    if (!fromLabel) {
      Logger.log('Skipping (not found): ' + m.from);
      return;
    }

    var toLabel = GmailApp.getUserLabelByName(m.to);
    if (!toLabel) {
      Logger.log('Creating label: ' + m.to);
      toLabel = GmailApp.createLabel(m.to);
    }

    Logger.log('Merging ' + m.from + ' -> ' + m.to);
    var threads = fromLabel.getThreads(0, 500);
    var total = 0;
    while (threads.length > 0) {
      toLabel.addToThreads(threads);
      fromLabel.removeFromThreads(threads);
      total += threads.length;
      Utilities.sleep(1000);
      threads = fromLabel.getThreads(0, 500);
    }
    Logger.log('Moved ' + total + ' threads: ' + m.from + ' -> ' + m.to);
    fromLabel.deleteLabel();
    Logger.log('Deleted label: ' + m.from);
  });
}

// ─── STEP 2: cvlp → Newsletter + archive ─────────────────────────────────────

function archiveCvlp() {
  var cvlpLabel = GmailApp.getUserLabelByName('cvlp');
  if (!cvlpLabel) {
    Logger.log('cvlp label not found, skipping');
    return;
  }

  var newsletterLabel = GmailApp.getUserLabelByName('Newsletter');
  if (!newsletterLabel) {
    newsletterLabel = GmailApp.createLabel('Newsletter');
  }

  Logger.log('Processing cvlp: relabeling to Newsletter and archiving...');
  var threads = cvlpLabel.getThreads(0, 500);
  var total = 0;
  while (threads.length > 0) {
    newsletterLabel.addToThreads(threads);
    cvlpLabel.removeFromThreads(threads);
    threads.forEach(function(t) { t.moveToArchive(); });
    total += threads.length;
    Utilities.sleep(1000);
    threads = cvlpLabel.getThreads(0, 500);
  }
  Logger.log('Archived ' + total + ' cvlp threads');
  cvlpLabel.deleteLabel();
  Logger.log('Deleted label: cvlp');
}

// ─── STEP 3: Merge purchases into Receipt ────────────────────────────────────

function mergePurchasesIntoReceipt() {
  var purchasesLabel = GmailApp.getUserLabelByName('purchases');
  if (!purchasesLabel) {
    Logger.log('purchases label not found, skipping');
    return;
  }

  var receiptLabel = GmailApp.getUserLabelByName('Receipt');
  if (!receiptLabel) {
    receiptLabel = GmailApp.createLabel('Receipt');
  }

  Logger.log('Merging purchases -> Receipt...');
  var threads = purchasesLabel.getThreads(0, 500);
  var total = 0;
  while (threads.length > 0) {
    receiptLabel.addToThreads(threads);
    purchasesLabel.removeFromThreads(threads);
    total += threads.length;
    Utilities.sleep(1000);
    threads = purchasesLabel.getThreads(0, 500);
  }
  Logger.log('Moved ' + total + ' threads: purchases -> Receipt');
  purchasesLabel.deleteLabel();
  Logger.log('Deleted label: purchases');
}

// ─── STEP 4: Restructure business nested labels ───────────────────────────────

function restructureBusinessLabels() {
  // Move donations top-level: rename business/donations -> donations
  var bizDonations = GmailApp.getUserLabelByName('business/donations');
  if (bizDonations) {
    var donationsLabel = GmailApp.getUserLabelByName('donations');
    if (!donationsLabel) {
      donationsLabel = GmailApp.createLabel('donations');
    }
    Logger.log('Moving business/donations -> donations (top-level)');
    var threads = bizDonations.getThreads(0, 500);
    var total = 0;
    while (threads.length > 0) {
      donationsLabel.addToThreads(threads);
      bizDonations.removeFromThreads(threads);
      total += threads.length;
      Utilities.sleep(1000);
      threads = bizDonations.getThreads(0, 500);
    }
    Logger.log('Moved ' + total + ' threads to top-level donations');
    bizDonations.deleteLabel();
  } else {
    Logger.log('business/donations not found - skipping');
  }

  // Move selling under business: rename selling -> business/selling
  var sellingLabel = GmailApp.getUserLabelByName('selling');
  if (sellingLabel) {
    var bizSelling = GmailApp.getUserLabelByName('business/selling');
    if (!bizSelling) {
      bizSelling = GmailApp.createLabel('business/selling');
    }
    Logger.log('Moving selling -> business/selling');
    var threads = sellingLabel.getThreads(0, 500);
    var total = 0;
    while (threads.length > 0) {
      bizSelling.addToThreads(threads);
      sellingLabel.removeFromThreads(threads);
      total += threads.length;
      Utilities.sleep(1000);
      threads = sellingLabel.getThreads(0, 500);
    }
    Logger.log('Moved ' + total + ' threads to business/selling');
    sellingLabel.deleteLabel();
  }

  // Delete contract label (threads already have business label)
  var contractLabel = GmailApp.getUserLabelByName('business/contract');
  if (!contractLabel) {
    contractLabel = GmailApp.getUserLabelByName('contract');
  }
  if (contractLabel) {
    Logger.log('Removing contract label from all threads...');
    var threads = contractLabel.getThreads(0, 500);
    var total = 0;
    while (threads.length > 0) {
      contractLabel.removeFromThreads(threads);
      total += threads.length;
      Utilities.sleep(1000);
      threads = contractLabel.getThreads(0, 500);
    }
    contractLabel.deleteLabel();
    Logger.log('Deleted contract label (' + total + ' threads unaffected)');
  }
}

// ─── STEP 5: Delete unused labels ────────────────────────────────────────────

function deleteUnusedLabels() {
  var toDelete = [
    'Notes',
    '[Mailbox]',
    'Later',
    'To Buy',
    'To Read',
    'To Watch',
    'Cold Email',
    'Oak Ridge Moms',
    'music',
  ];

  toDelete.forEach(function(name) {
    var label = GmailApp.getUserLabelByName(name);
    if (!label) {
      Logger.log('Not found (already gone?): ' + name);
      return;
    }
    var threads = label.getThreads(0, 500);
    var total = 0;
    while (threads.length > 0) {
      label.removeFromThreads(threads);
      total += threads.length;
      Utilities.sleep(500);
      threads = label.getThreads(0, 500);
    }
    if (total > 0) {
      Logger.log('Removed label from ' + total + ' threads: ' + name);
    }
    label.deleteLabel();
    Logger.log('Deleted: ' + name);
  });
}

// ─── RUN ALL ──────────────────────────────────────────────────────────────────

function runAll() {
  Logger.log('=== Starting Gmail label cleanup ===');
  Logger.log('--- Step 1: Merging labels ---');
  mergeLabels();
  Logger.log('--- Step 2: Archiving cvlp ---');
  archiveCvlp();
  Logger.log('--- Step 3: Merging purchases into Receipt ---');
  mergePurchasesIntoReceipt();
  Logger.log('--- Step 4: Restructuring business labels ---');
  restructureBusinessLabels();
  Logger.log('--- Step 5: Deleting unused labels ---');
  deleteUnusedLabels();
  Logger.log('=== Done! ===');
}