/**
 * User Email Lookup Tool
 * Provides hover tooltips showing email addresses when hovering over user names
 * 
 * @module UserEmailLookup
 * @description Standalone utility for looking up email addresses from the Associations
 *   collection and displaying them as hover tooltips. Integrates with note/conversation
 *   sharing UI to enhance user experience when managing shared access.
 * @usage Call window.setupUserEmailLookup(pbInstance, containerSelector) after page load.
 *   Pass PocketBase instance and CSS selector for user capsule container.
 * @dependencies PocketBase instance (passed in). Browser APIs: DOM, tooltips via title attribute.
 * @integration Used in index.html note/conversation sharing forms to show email on hover
 * @gotchas Associations collection must have first_name field for lookups. Lookups are
 *   performed on hover, so network latency may cause brief delay before tooltip appears.
 *   Cache email lookups to minimize PocketBase queries.
 */

// Cache for email lookups to minimize queries
const emailLookupCache = {};
let associationsCollectionAvailable = true;
let associationsWarningShown = false;

function getAssociationEmail(record) {
  return record?.emailtext || record?.email || 'Email not found';
}

function handleAssociationsError(error) {
  const statusCode = Number(error?.status || error?.response?.status || 0);
  if (statusCode === 404) {
    associationsCollectionAvailable = false;
    if (!associationsWarningShown) {
      associationsWarningShown = true;
      console.warn("'Associations' collection not found. Email hover lookup disabled.");
    }
    return;
  }
  console.error('Associations lookup failed:', error);
}

/**
 * Fetch email from Associations collection by first name
 * Uses cache to avoid duplicate queries
 * 
 * @param {PocketBase} pb - PocketBase instance
 * @param {string} firstName - First name to look up
 * @returns {Promise<string>} Email address or fallback message
 * @example
 * const email = await getEmailByFirstName(pb, 'John');
 * console.log(email); // 'john@example.com' or 'Email not found'
 */
async function getEmailByFirstName(pb, firstName) {
  if (!firstName) return 'Email not found';
  if (!associationsCollectionAvailable) return 'Email lookup unavailable';
  
  // Check cache first
  if (emailLookupCache[firstName]) {
    return emailLookupCache[firstName];
  }
  
  try {
    const records = await pb.collection('Associations').getList(1, 50, {
      filter: `first_name = "${firstName}"`,
    });

    if (records.items.length === 0) {
      emailLookupCache[firstName] = 'Email not found';
      return 'Email not found';
    }
    
    // Use first match's emailtext field
    const firstRecord = records.items[0];
    const email = getAssociationEmail(firstRecord);
    emailLookupCache[firstName] = email;
    return email;
  } catch (error) {
    handleAssociationsError(error);
    return 'Error loading email';
  }
}

/**
 * Setup email lookups for user capsules in a container
 * Attaches hover event listeners to show email in tooltip
 * 
 * @param {PocketBase} pb - PocketBase instance
 * @param {string} containerSelector - CSS selector for container with user capsules
 * @example
 * window.setupUserEmailLookup(pb, '#selectedUsersContainer');
 */
window.setupUserEmailLookup = function(pb, containerSelector) {
  const container = document.querySelector(containerSelector);
  if (!container) {
    console.warn(`setupUserEmailLookup: Container not found: ${containerSelector}`);
    return;
  }
  
  console.log(`✓ User Email Lookup initialized for: ${containerSelector}`);
  const observer = new MutationObserver((mutations) => {
    mutations.forEach((mutation) => {
      mutation.addedNodes.forEach((node) => {
        if (node.nodeType === 1 && node.classList?.contains('inline-flex')) {
          attachEmailLookupTooltip(pb, node);
        }
      });
    });
  });
  
  observer.observe(container, {
    childList: true,
    subtree: true
  });
  
  // Also process any existing capsules
  container.querySelectorAll('.inline-flex.items-center.gap-2').forEach((capsule) => {
    attachEmailLookupTooltip(pb, capsule);
  });
};

/**
 * Attach email lookup tooltip to a single user capsule
 * Shows email on hover (with caching to prevent redundant queries)
 * 
 * @param {PocketBase} pb - PocketBase instance
 * @param {HTMLElement} capsuleEl - The user capsule element
 * @private
 */
function attachEmailLookupTooltip(pb, capsuleEl) {
  // Extract first name from capsule text
  const nameSpan = capsuleEl.querySelector('span:not([data-email-loaded])');
  if (!nameSpan || nameSpan.hasAttribute('data-email-loaded')) {
    return;
  }
  
  const firstName = nameSpan.textContent.trim();
  if (!firstName) return;
  
  console.log(`[Email Lookup] Attached to user: ${firstName}`);
  
  // Mark as processed
  nameSpan.setAttribute('data-email-loaded', 'true');
  
  // Attach hover listener
  capsuleEl.addEventListener('mouseenter', async () => {
    console.log(`[Email Lookup] Hover on: ${firstName}`);
    // If email already in title, don't query again
    if (capsuleEl.title && !capsuleEl.title.startsWith('Loading')) {
      return;
    }
    
    capsuleEl.title = 'Loading email...';
    const email = await getEmailByFirstName(pb, firstName);
    capsuleEl.title = email;
    capsuleEl.classList.add('cursor-help');
  });
  
  capsuleEl.addEventListener('mouseleave', () => {
    // Title persists so user can still see it if they hover back quickly
  });
}

/**
 * Clear the email lookup cache
 * Useful if Associations collection is updated and you need fresh data
 * 
 * @example
 * window.clearEmailLookupCache();
 */
window.clearEmailLookupCache = function() {
  Object.keys(emailLookupCache).forEach(key => delete emailLookupCache[key]);
  associationsCollectionAvailable = true;
  associationsWarningShown = false;
  console.log('✓ Email lookup cache cleared');
};

console.log('✓ User Email Lookup tool loaded - call window.setupUserEmailLookup(pb, containerSelector)');