'use client';

import { useState, useRef, useEffect, useMemo } from 'react';
import { Loader2, Paperclip, User } from 'lucide-react';
import { Button } from '@/components/ui/button';
import { Badge } from '@/components/ui/badge';
import { ScrollArea } from '@/components/ui/scroll-area';
import { 
  formatReplyEmail, 
  formatForwardedEmail,
  formatEmailForReplyOrForward,
  EmailMessage as FormatterEmailMessage,
  sanitizeHtml
} from '@/lib/utils/email-formatter';
import { formatEmailContent } from '@/lib/utils/email-content';
import { Avatar, AvatarFallback } from '@/components/ui/avatar';
import { AvatarImage } from '@/components/ui/avatar';
import { Card } from '@/components/ui/card';
import { cn } from '@/lib/utils';
import { CalendarIcon, PaperclipIcon } from 'lucide-react';
import Link from 'next/link';
import DOMPurify from 'dompurify';

interface EmailAddress {
  name: string;
  address: string;
}

interface EmailAttachment {
  filename: string;
  contentType: string;
  size: number;
  path?: string;
  content?: string;
}

interface EmailMessage {
  id: string;
  uid: number;
  from: EmailAddress[];
  to: EmailAddress[];
  cc?: EmailAddress[];
  bcc?: EmailAddress[];
  subject: string;
  date: string;
  flags: string[];
  attachments: EmailAttachment[];
  content?: string | {
    text?: string;
    html?: string;
  };
  html?: string;
  text?: string;
  formattedContent?: string;
}

interface EmailPreviewProps {
  email: EmailMessage | null;
  loading?: boolean;
  onReply?: (type: 'reply' | 'reply-all' | 'forward') => void;
}

export default function EmailPreview({ email, loading = false, onReply }: EmailPreviewProps) {
  // Add editorRef to match ComposeEmail exactly
  const editorRef = useRef<HTMLDivElement>(null);
  
  // Format the date
  const formatDate = (date: Date | string) => {
    if (!date) return '';
    
    const dateObj = date instanceof Date ? date : new Date(date);
    return dateObj.toLocaleString('en-US', {
      weekday: 'short',
      year: 'numeric', 
      month: 'short', 
      day: 'numeric',
      hour: '2-digit',
      minute: '2-digit'
    });
  };
  
  // Format email addresses
  const formatEmailAddresses = (addresses: Array<{name: string, address: string}> | undefined) => {
    if (!addresses || addresses.length === 0) return '';
    
    return addresses.map(addr => 
      addr.name && addr.name !== addr.address 
        ? `${addr.name} <${addr.address}>`
        : addr.address
    ).join(', ');
  };
  
  // Get sender initials for avatar
  const getSenderInitials = (name: string) => {
    if (!name) return '';
    return name
      .split(" ")
      .map((n) => n?.[0] || '')
      .join("")
      .toUpperCase()
      .slice(0, 2);
  };
  
  // Format the email content
  const formattedContent = useMemo(() => {
    if (!email) {
      return '';
    }
    
    // Use the improved, standardized email content formatter
    return formatEmailContent(email);
  }, [email]);
  
  // Display loading state
  if (loading) {
    return (
      <div className="flex items-center justify-center h-full p-6">
        <div className="text-center">
          <Loader2 className="h-8 w-8 animate-spin mx-auto mb-4 text-primary" />
          <p>Loading email...</p>
        </div>
      </div>
    );
  }
  
  // No email selected
  if (!email) {
    return (
      <div className="flex items-center justify-center h-full p-6">
        <div className="text-center text-muted-foreground">
          <p>Select an email to view</p>
        </div>
      </div>
    );
  }
  
  const sender = email.from && email.from.length > 0 ? email.from[0] : undefined;
  
  // Update the array access to use proper type checking
  const hasAttachments = email.attachments && email.attachments.length > 0;
  
  return (
    <Card className="flex flex-col h-full overflow-hidden border-0 shadow-none">
      {/* Email header */}
      <div className="p-6 border-b">
        <div className="mb-4">
          <h2 className="text-xl font-semibold mb-4">{email.subject}</h2>
          
          <div className="flex items-start gap-3 mb-4">
            <Avatar className="h-10 w-10">
              <AvatarFallback>{getSenderInitials(sender?.name || '')}</AvatarFallback>
            </Avatar>
            
            <div className="flex-1 min-w-0">
              <div className="flex items-center justify-between">
                <div className="font-medium">{sender?.name || sender?.address}</div>
                <span className="text-sm text-muted-foreground">{formatDate(email.date)}</span>
              </div>
              
              <div className="text-sm text-muted-foreground truncate mt-1">
                To: {formatEmailAddresses(email.to)}
              </div>
              
              {email.cc && email.cc.length > 0 && (
                <div className="text-sm text-muted-foreground truncate mt-1">
                  Cc: {formatEmailAddresses(email.cc)}
                </div>
              )}
            </div>
          </div>
        
          {/* Action buttons */}
          {onReply && (
            <div className="flex gap-2 mt-4">
              <Button
                size="sm"
                variant="outline"
                onClick={() => onReply('reply')}
              >
                Reply
              </Button>
              <Button
                size="sm"
                variant="outline"
                onClick={() => onReply('reply-all')}
              >
                Reply All
              </Button>
              <Button
                size="sm"
                variant="outline"
                onClick={() => onReply('forward')}
              >
                Forward
              </Button>
            </div>
          )}
        </div>
        
        {/* Attachments */}
        {hasAttachments && (
          <div className="px-6 py-3 border-b bg-muted/30">
            <div className="text-sm font-medium mb-2">Attachments</div>
            <div className="flex flex-wrap gap-2">
              {email.attachments.map((attachment, index) => (
                <Badge key={index} variant="outline" className="flex items-center gap-1 px-2 py-1">
                  <Paperclip className="h-3.5 w-3.5" />
                  <span>{attachment.filename}</span>
                  <span className="text-xs text-muted-foreground ml-1">
                    ({Math.round(attachment.size / 1024)}KB)
                  </span>
                </Badge>
              ))}
            </div>
          </div>
        )}
      </div>
      
      {/* Email content */}
      <ScrollArea className="flex-1">
        <div className="p-6">
          <div 
            ref={editorRef}
            contentEditable={false}
            className="w-full email-content-container"
            style={{
              backgroundColor: '#ffffff',
              borderRadius: '4px',
              border: '1px solid #e2e8f0',
              boxShadow: '0 1px 3px rgba(0,0,0,0.05)',
              overflow: 'hidden',
              minHeight: '300px'
            }}
          >
            <div 
              className="email-content-body p-6"
              style={{
                fontFamily: '-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif',
                fontSize: '15px',
                lineHeight: '1.6',
                color: '#1A202C'
              }}
              dangerouslySetInnerHTML={{ __html: formattedContent }}
            />
          </div>
        </div>
      </ScrollArea>
    </Card>
  );
}