/**
 * Change the current folder and load emails from that folder
 */
const changeFolder = async (folder: string, accountId?: string) => {
  console.log(`Changing folder to ${folder} for account ${accountId || 'default'}`);
  try {
    // Reset selected email
    setSelectedEmail(null);
    setSelectedEmailIds([]);
    
    // Record the new folder
    setCurrentFolder(folder);
    
    // Reset search query when changing folders
    setSearchQuery('');
    
    // Reset to page 1
    setPage(1);
    
    // Clear existing emails before loading new ones to prevent UI flicker
    setEmails([]);
    
    // Show loading state
    setIsLoading(true);
    
    // Load emails for the new folder with a deliberate delay to allow state to update
    await new Promise(resolve => setTimeout(resolve, 100));
    await loadEmails(folder, 1, 20, accountId);
  } catch (error) {
    console.error(`Error changing to folder ${folder}:`, error);
    setError(`Failed to load emails from ${folder}: ${error instanceof Error ? error.message : 'Unknown error'}`);
  } finally {
    setIsLoading(false);
  }
};

/**
 * Load emails for the current folder
 */
const loadEmails = async (
  folderOverride?: string, 
  pageOverride?: number,
  perPageOverride?: number,
  accountIdOverride?: string
) => {
  const folderToUse = folderOverride || currentFolder;
  
  // Enhanced folder and account handling
  let normalizedFolder = folderToUse;
  let normalizedAccountId = accountIdOverride;
  
  // Extract account ID from folder if it has a prefix and no explicit account ID was provided
  if (folderToUse.includes(':')) {
    const [folderAccountId, baseFolderName] = folderToUse.split(':');
    console.log(`Folder has prefix: accountId=${folderAccountId}, baseName=${baseFolderName}`);
    
    // If no explicit account ID was provided, use the one from the folder name
    if (!normalizedAccountId) {
      normalizedAccountId = folderAccountId;
      console.log(`Using account ID from folder prefix: ${normalizedAccountId}`);
    } 
    // If both exist but don't match, log a warning
    else if (normalizedAccountId !== folderAccountId) {
      console.warn(`⚠️ Mismatch between folder account prefix (${folderAccountId}) and provided accountId (${normalizedAccountId})`);
      console.warn(`Using provided accountId (${normalizedAccountId}) but this may cause unexpected behavior`);
    }
  }
  
  const pageToUse = pageOverride || page;
  const perPageToUse = perPageOverride || perPage;
  
  console.log(`Loading emails: folder=${folderToUse}, page=${pageToUse}, accountId=${normalizedAccountId || 'default'}`);
  
  try {
    setIsLoading(true);
    setError('');
    
    // Construct the API URL with a unique timestamp to prevent caching
    let url = `/api/courrier/emails?folder=${encodeURIComponent(folderToUse)}&page=${pageToUse}&perPage=${perPageToUse}`;
    
    // Add accountId parameter if specified
    if (normalizedAccountId) {
      url += `&accountId=${encodeURIComponent(normalizedAccountId)}`;
    }
    
    // Add cache-busting timestamp
    url += `&_t=${Date.now()}`;
    
    console.log(`Fetching emails from API: ${url}`);
    const response = await fetch(url);
    
    if (!response.ok) {
      let errorText;
      try {
        const errorData = await response.json();
        errorText = errorData.error || `Server error: ${response.status}`;
      } catch {
        errorText = `HTTP error: ${response.status}`;
      }
      console.error(`API error: ${errorText}`);
      throw new Error(errorText);
    }
    
    const data = await response.json();
    console.log(`Received ${data.emails?.length || 0} emails from API`);
    
    if (pageToUse === 1 || !pageOverride) {
      // Replace emails when loading first page
      console.log(`Setting ${data.emails?.length || 0} emails (replacing existing)`);
      setEmails(data.emails || []);
    } else {
      // Append emails when loading subsequent pages
      console.log(`Appending ${data.emails?.length || 0} emails to existing list`);
      setEmails(prev => [...prev, ...(data.emails || [])]);
    }
    
    // Update pagination info
    setTotalPages(data.totalPages || 0);
    if (data.mailboxes && data.mailboxes.length > 0) {
      console.log(`Received ${data.mailboxes.length} mailboxes from API`);
      setMailboxes(data.mailboxes);
    }
    
    return data;
  } catch (error) {
    console.error('Error loading emails:', error);
    setError(`Failed to load emails: ${error instanceof Error ? error.message : 'Unknown error'}`);
    // Set empty emails array on error to prevent UI issues
    if (pageToUse === 1) {
      setEmails([]);
    }
    return null;
  } finally {
    setIsLoading(false);
  }
};