'use client';

import { useState, useEffect, useMemo, useCallback } from 'react';
import EmailPreview from './EmailPreview';
import ComposeEmail from './ComposeEmail';
import { Loader2 } from 'lucide-react';
import { formatReplyEmail, EmailMessage as FormatterEmailMessage } from '@/lib/utils/email-formatter';
import { useEmailFetch } from '@/hooks/use-email-fetch';
import { debounce } from '@/lib/utils/debounce';
import { formatEmailContent } from '@/lib/utils/email-content';

// Add local EmailMessage interface
interface EmailAddress {
  name: string;
  address: string;
}

interface EmailMessage {
  id: string;
  messageId?: string;
  subject: string;
  from: EmailAddress[];
  to: EmailAddress[];
  cc?: EmailAddress[];
  bcc?: EmailAddress[];
  date: Date | string;
  flags?: {
    seen: boolean;
    flagged: boolean;
    answered: boolean;
    deleted: boolean;
    draft: boolean;
  };
  preview?: string;
  content?: string;
  html?: string;
  text?: string;
  hasAttachments?: boolean;
  attachments?: any[];
  folder?: string;
  size?: number;
  contentFetched?: boolean;
}

interface EmailPanelProps {
  selectedEmail: {
    emailId: string;
    accountId: string;
    folder: string;
  } | null;
  onSendEmail: (email: any) => void;
}

export default function EmailPanel({ 
  selectedEmail, 
  onSendEmail 
}: EmailPanelProps) {
  // Use the new email fetch hook
  const { email, loading, error, fetchEmail } = useEmailFetch({
    onEmailLoaded: (email) => {
      // Handle any post-load actions
      console.log('Email loaded:', email.id);
    },
    onError: (error) => {
      console.error('Error loading email:', error);
    }
  });
  
  // Compose mode state
  const [isComposing, setIsComposing] = useState<boolean>(false);
  const [composeType, setComposeType] = useState<'new' | 'reply' | 'reply-all' | 'forward'>('new');

  // Format the email content
  const formattedEmail = useMemo(() => {
    if (!email) {
      console.log('EmailPanel: No email provided');
      return null;
    }
    
    console.log('EmailPanel: Raw email:', email);
    
    // If content is already an object with html/text, use it directly
    if (email.content && typeof email.content === 'object') {
      console.log('EmailPanel: Using existing content object');
      return {
        ...email,
        content: {
          text: email.content.text || '',
          html: email.content.html || ''
        }
      };
    }
    
    // If content is a string, convert it to object format
    if (typeof email.content === 'string') {
      console.log('EmailPanel: Converting string content to object');
      return {
        ...email,
        content: {
          text: email.text || email.content,
          html: email.html || email.content
        }
      };
    }
    
    // Fallback to html/text properties
    console.log('EmailPanel: Using html/text properties');
    return {
      ...email,
      content: {
        text: email.text || '',
        html: email.html || ''
      }
    };
  }, [email]);

  // Debounced email fetch
  const debouncedFetchEmail = useCallback(
    debounce((emailId: string, accountId: string, folder: string) => {
      fetchEmail(emailId, accountId, folder);
    }, 300),
    [fetchEmail]
  );

  // Load email content when selectedEmail changes
  useEffect(() => {
    if (selectedEmail) {
      // CRITICAL FIX: Store the current account ID to check for changes
      // This helps prevent race conditions during account switching
      const currentAccountId = selectedEmail.accountId;
      console.log(`EmailPanel: Loading email ${selectedEmail.emailId} from account ${currentAccountId}`);
      
      debouncedFetchEmail(selectedEmail.emailId, selectedEmail.accountId, selectedEmail.folder);
      setIsComposing(false);
      
      // Return a cleanup function that can detect and handle account changes
      return () => {
        console.log(`EmailPanel: Cleaning up email fetch for account ${currentAccountId}`);
      };
    }
  }, [selectedEmail, debouncedFetchEmail]);
  
  // Handle reply/forward actions
  const handleReply = (type: 'reply' | 'reply-all' | 'forward') => {
    setComposeType(type);
    setIsComposing(true);
  };
  
  // Handle compose mode close
  const handleComposeClose = () => {
    setIsComposing(false);
    setComposeType('new');
  };

  // If no email is selected and not composing
  if (!selectedEmail && !isComposing) {
    return (
      <div className="h-full flex items-center justify-center">
        <div className="text-center text-muted-foreground">
          <p>Select an email to view or</p>
          <button 
            className="text-primary mt-2 hover:underline"
            onClick={() => {
              setComposeType('new');
              setIsComposing(true);
            }}
          >
            Compose a new message
          </button>
        </div>
      </div>
    );
  }
  
  // Show loading state
  if (loading) {
    return (
      <div className="h-full flex items-center justify-center">
        <div className="text-center">
          <Loader2 className="h-8 w-8 animate-spin mx-auto mb-4 text-primary" />
          <p>Loading email...</p>
        </div>
      </div>
    );
  }
  
  // Show error state
  if (error) {
    return (
      <div className="h-full flex items-center justify-center">
        <div className="text-center text-destructive">
          <p>{error}</p>
          <button 
            className="text-primary mt-2 hover:underline"
            onClick={() => selectedEmail && fetchEmail(selectedEmail.emailId, selectedEmail.accountId, selectedEmail.folder)}
          >
            Try again
          </button>
        </div>
      </div>
    );
  }
  
  // Show compose mode or email preview
  return (
    <div className="h-full">
      {isComposing ? (
        <ComposeEmail
          initialEmail={formattedEmail}
          type={composeType}
          onClose={handleComposeClose}
          onSend={onSendEmail}
        />
      ) : (
        <div className="max-w-4xl mx-auto h-full">
          <EmailPreview 
            email={formattedEmail}
            onReply={handleReply}
          />
        </div>
      )}
    </div>
  );
}