'use client';

import { useState, useEffect, useMemo } 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';

// 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 {
  selectedEmailId: string | null;
  folder?: string;
  onSendEmail: (emailData: {
    to: string;
    cc?: string;
    bcc?: string;
    subject: string;
    body: string;
    attachments?: Array<{
      name: string;
      content: string;
      type: string;
    }>;
  }) => Promise<void>;
}

export default function EmailPanel({ 
  selectedEmailId, 
  folder = 'INBOX',
  onSendEmail 
}: EmailPanelProps) {
  const [email, setEmail] = useState<EmailMessage | null>(null);
  const [loading, setLoading] = useState<boolean>(false);
  const [error, setError] = useState<string | null>(null);
  
  // Compose mode state
  const [isComposing, setIsComposing] = useState<boolean>(false);
  const [composeType, setComposeType] = useState<'new' | 'reply' | 'reply-all' | 'forward'>('new');

  // Create a formatted version of the email content using the same formatter as ComposeEmail
  const formattedEmail = useMemo(() => {
    if (!email) return null;
    
    try {
      // Convert to the formatter message format - this is what ComposeEmail does
      const formatterEmail: FormatterEmailMessage = {
        id: email.id,
        messageId: email.messageId,
        subject: email.subject,
        from: email.from || [],
        to: email.to || [],
        cc: email.cc || [],
        bcc: email.bcc || [],
        date: email.date,
        content: email.content,
        html: email.html,
        text: email.text,
        hasAttachments: email.hasAttachments || false
      };
      
      // Try both formatting approaches to match what ComposeEmail would display
      // This handles preview, reply and forward cases
      let formattedContent: string;
      
      // ComposeEmail switches based on type - we need to do the same
      const { content: replyContent } = formatReplyEmail(formatterEmail, 'reply');
      
      // Set the formatted content
      formattedContent = replyContent;
      
      console.log("Generated formatted content for email preview");
      
      // Return a new email object with the formatted content
      return {
        ...email,
        formattedContent
      };
    } catch (error) {
      console.error('Error formatting email content:', error);
      return email;
    }
  }, [email]);

  // Load email content when selectedEmailId changes
  useEffect(() => {
    if (selectedEmailId) {
      fetchEmail(selectedEmailId);
      // Close compose mode when selecting a different email
      setIsComposing(false);
    } else {
      setEmail(null);
    }
  }, [selectedEmailId, folder]);

  // Fetch the email content
  const fetchEmail = async (id: string) => {
    setLoading(true);
    setError(null);
    
    try {
      const response = await fetch(`/api/courrier/${id}?folder=${encodeURIComponent(folder)}`);
      
      if (!response.ok) {
        const errorData = await response.json();
        throw new Error(errorData.error || 'Failed to fetch email');
      }
      
      const data = await response.json();
      
      if (!data) {
        throw new Error('Email not found');
      }
      
      // Mark as read if not already
      if (!data.flags?.seen) {
        markAsRead(id);
      }
      
      setEmail(data);
    } catch (err) {
      console.error('Error fetching email:', err);
      setError(err instanceof Error ? err.message : 'Failed to load email');
    } finally {
      setLoading(false);
    }
  };
  
  // Mark email as read
  const markAsRead = async (id: string) => {
    try {
      await fetch(`/api/courrier/${id}/mark-read`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({ action: 'mark-read' }),
      });
    } catch (err) {
      console.error('Error marking email as read:', err);
    }
  };
  
  // 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 (!selectedEmailId && !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={() => selectedEmailId && fetchEmail(selectedEmailId)}
          >
            Try again
          </button>
        </div>
      </div>
    );
  }
  
  // Show compose mode or email preview
  return (
    <div className="h-full">
      {/* Remove ComposeEmail overlay/modal logic. Only show preview or a button to trigger compose in parent. */}
      {isComposing ? (
        <div className="h-full flex items-center justify-center">
          <div className="text-center text-muted-foreground">
            <p>Compose mode is now handled by the main modal.</p>
            <button 
              className="text-primary mt-2 hover:underline"
              onClick={handleComposeClose}
            >
              Close
            </button>
          </div>
        </div>
      ) : (
        <div className="max-w-4xl mx-auto h-full">
          <EmailPreview 
            email={formattedEmail}
            onReply={handleReply}
          />
        </div>
      )}
    </div>
  );
}