'use client';

import { useState, useRef, useEffect } from 'react';
import { formatEmailForReplyOrForward, EmailMessage } from '@/lib/services/email-service';
import { X, Paperclip, ChevronDown, ChevronUp, SendHorizontal, Loader2 } from 'lucide-react';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Card, CardContent, CardHeader, CardTitle, CardFooter } from '@/components/ui/card';
import { decodeEmail } from '@/lib/mail-parser-wrapper';
import DOMPurify from 'isomorphic-dompurify';

interface ComposeEmailProps {
  initialEmail?: EmailMessage | null;
  type?: 'new' | 'reply' | 'reply-all' | 'forward';
  onClose: () => void;
  onSend: (emailData: {
    to: string;
    cc?: string;
    bcc?: string;
    subject: string;
    body: string;
    attachments?: Array<{
      name: string;
      content: string;
      type: string;
    }>;
  }) => Promise<void>;
}

export default function ComposeEmail({ 
  initialEmail, 
  type = 'new', 
  onClose, 
  onSend 
}: ComposeEmailProps) {
  // Email form state
  const [to, setTo] = useState<string>('');
  const [cc, setCc] = useState<string>('');
  const [bcc, setBcc] = useState<string>('');
  const [subject, setSubject] = useState<string>('');
  const [body, setBody] = useState<string>('');
  
  // UI state
  const [showCc, setShowCc] = useState<boolean>(false);
  const [showBcc, setShowBcc] = useState<boolean>(false);
  const [sending, setSending] = useState<boolean>(false);
  const [attachments, setAttachments] = useState<Array<{
    name: string;
    content: string;
    type: string;
  }>>([]);
  
  const editorRef = useRef<HTMLDivElement | null>(null);
  const attachmentInputRef = useRef<HTMLInputElement | null>(null);

  // Initialize the form when replying to or forwarding an email
  useEffect(() => {
    if (initialEmail && type !== 'new') {
      // If it's a forward, use the same approach as Panel 3
      if (type === 'forward') {
        initializeForwardedEmail();
      } else {
        // For reply/reply-all, continue using formatEmailForReplyOrForward
        const formattedEmail = formatEmailForReplyOrForward(initialEmail, type as 'reply' | 'reply-all');
        
        setTo(formattedEmail.to);
        
        if (formattedEmail.cc) {
          setCc(formattedEmail.cc);
          setShowCc(true);
        }
        
        setSubject(formattedEmail.subject);
        setBody(formattedEmail.body);
      }
      
      // Focus editor after initializing
      setTimeout(() => {
        if (editorRef.current) {
          editorRef.current.focus();
          
          // Place cursor at the beginning of the content
          const selection = window.getSelection();
          const range = document.createRange();
          
          range.setStart(editorRef.current, 0);
          range.collapse(true);
          
          selection?.removeAllRanges();
          selection?.addRange(range);
        }
      }, 100);
    }
  }, [initialEmail, type]);

  // Helper functions for formatting the forwarded message - moved outside try block
  
  // Format date for the forwarded message header
  const formatDate = (date: Date | null): string => {
    if (!date) return '';
    try {
      return date.toLocaleString('en-US', {
        weekday: 'short',
        year: 'numeric', 
        month: 'short', 
        day: 'numeric',
        hour: '2-digit',
        minute: '2-digit'
      });
    } catch (e) {
      return date.toString();
    }
  };
  
  // Format sender address in a readable format
  const formatSender = (from: Array<{name?: string, address: string}> | undefined): string => {
    if (!from || from.length === 0) return 'Unknown';
    return from.map(sender => 
      sender.name && sender.name !== sender.address 
        ? `${sender.name} <${sender.address}>`
        : sender.address
    ).join(', ');
  };
  
  // Format recipient addresses in a readable format
  const formatRecipients = (recipients: Array<{name?: string, address: string}> | undefined): string => {
    if (!recipients || recipients.length === 0) return '';
    return recipients.map(recipient => 
      recipient.name && recipient.name !== recipient.address 
        ? `${recipient.name} <${recipient.address}>`
        : recipient.address
    ).join(', ');
  };

  // Handle editor input
  const handleEditorInput = (e: React.FormEvent<HTMLDivElement>) => {
    // Only store the content of the editable area, not the entire HTML with CSS
    // This prevents breaking complex CSS when editing
    if (editorRef.current) {
      // If we're in forward mode and the editor contains our wrapper structure
      const editableContent = editorRef.current.querySelector('.editable-content');
      if (type === 'forward' && editableContent) {
        // Only update the editable portion, preserving the CSS and header
        const headerSection = editorRef.current.querySelector('.forwarded-header');
        const styleSection = editorRef.current.querySelector('.email-styles');
        
        // Combine the preserved sections with the updated editable content
        const updatedContent = (styleSection?.outerHTML || '') + 
                              (headerSection?.outerHTML || '') + 
                              editableContent.innerHTML;
        setBody(updatedContent);
      } else {
        // For new emails or replies, we can use the entire content
        setBody(e.currentTarget.innerHTML);
      }
    }
  };

  // Modified initializeForwardedEmail to separate CSS from content
  const initializeForwardedEmail = async () => {
    if (!initialEmail) {
      console.error('No email available for forwarding');
      setBody('<div style="color: #666; font-style: italic;">No email available for forwarding</div>');
      return;
    }

    // Helper functions remain the same
    try {
      setSending(true); // Use sending state to show loading
      
      // Format subject with Fwd: prefix if needed
      const cleanSubject = initialEmail.subject.replace(/^(Fwd|FW|Forward):\s*/i, '').trim();
      const formattedSubject = initialEmail.subject.match(/^(Fwd|FW|Forward):/i) 
        ? initialEmail.subject 
        : `Fwd: ${cleanSubject}`;
      
      setSubject(formattedSubject);
      
      // Create a forwarded message header with proper formatting
      const headerContent = `
<div class="forwarded-header" contenteditable="false" style="border-bottom: 1px solid #e2e2e2; margin-bottom: 15px; padding-bottom: 15px; font-family: Arial, sans-serif; color: #333;">
  <p style="margin: 5px 0; font-size: 14px;">---------- Forwarded message ---------</p>
  <p style="margin: 5px 0; font-size: 14px;"><b>From:</b> ${formatSender(initialEmail.from)}</p>
  <p style="margin: 5px 0; font-size: 14px;"><b>Date:</b> ${formatDate(initialEmail.date)}</p>
  <p style="margin: 5px 0; font-size: 14px;"><b>Subject:</b> ${initialEmail.subject || ''}</p>
  <p style="margin: 5px 0; font-size: 14px;"><b>To:</b> ${formatRecipients(initialEmail.to)}</p>
</div>`;
      
      // Process content
      let contentBody = '';
      let styleContent = '';
      
      // Check if email content exists
      if (!initialEmail.content || initialEmail.content.trim() === '') {
        contentBody = '<div class="editable-content" style="color: #666; font-style: italic; margin-top: 10px;">No content available</div>';
      } else {
        try {
          // Parse content to extract styles and make content editable
          const content = initialEmail.content;
          
          // Extract style tags to preserve them
          const styleRegex = /<style[^>]*>([\s\S]*?)<\/style>/gi;
          const styles: string[] = [];
          let styleMatch;
          
          // Find all style tags and collect them
          while ((styleMatch = styleRegex.exec(content)) !== null) {
            styles.push(styleMatch[0]);
          }
          
          // Combine all styles into one non-editable section
          if (styles.length > 0) {
            styleContent = `<div class="email-styles" contenteditable="false">${styles.join('')}</div>`;
          }
          
          // Use DOMPurify to sanitize the rest of the HTML content
          const sanitizedContent = DOMPurify.sanitize(content, {
            ADD_TAGS: ['style', 'meta', 'link', 'table', 'thead', 'tbody', 'tr', 'td', 'th', 'hr', 'font', 'div', 'span', 'a', 'img', 'b', 'strong', 'i', 'em', 'u', 'br', 'p', 'ul', 'ol', 'li', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'blockquote', 'pre', 'code', 'center', 'section', 'header', 'footer', 'article', 'nav', 'keyframes'],
            ADD_ATTR: ['*', 'colspan', 'rowspan', 'cellpadding', 'cellspacing', 'border', 'bgcolor', 'width', 'height', 'align', 'valign', 'class', 'id', 'style', 'color', 'face', 'size', 'background', 'src', 'href', 'target', 'rel', 'alt', 'title', 'name', 'animation', 'animation-name', 'animation-duration', 'animation-fill-mode'],
            ALLOW_UNKNOWN_PROTOCOLS: true,
            WHOLE_DOCUMENT: true,
            KEEP_CONTENT: true,
            FORBID_TAGS: ['script', 'iframe', 'object', 'embed', 'form', 'input', 'button', 'select', 'option', 'textarea', 'canvas', 'video', 'audio'],
            FORBID_ATTR: ['onerror', 'onload', 'onclick', 'onmouseover', 'onmouseout', 'onchange', 'onsubmit'],
            USE_PROFILES: { html: true, svg: false, svgFilters: false, mathMl: false },
            FORCE_BODY: true
          });
          
          // Remove style tags from sanitized content (we'll add them back separately)
          let contentWithoutStyles = sanitizedContent.replace(/<style[^>]*>[\s\S]*?<\/style>/gi, '');
          
          // Wrap the remaining content in an editable div
          contentBody = `<div class="editable-content">${contentWithoutStyles}</div>`;
        } catch (e) {
          console.error('Error sanitizing HTML content:', e);
          contentBody = '<div class="editable-content" style="color: #666; font-style: italic; margin-top: 10px;">Error processing original content</div>';
        }
      }
      
      // Set the complete forwarded email with styles preserved separately
      setBody(styleContent + headerContent + contentBody);
    } catch (error) {
      console.error('Error initializing forwarded email:', error);
      // Still provide the headers even if there's an error with the content
      const errorHeaderContent = `
<div class="forwarded-header" contenteditable="false" style="border-bottom: 1px solid #e2e2e2; margin-bottom: 15px; padding-bottom: 15px; font-family: Arial, sans-serif; color: #333;">
  <p style="margin: 5px 0; font-size: 14px;">---------- Forwarded message ---------</p>
  <p style="margin: 5px 0; font-size: 14px;"><b>From:</b> ${initialEmail.from ? formatSender(initialEmail.from) : 'Unknown'}</p>
  <p style="margin: 5px 0; font-size: 14px;"><b>Date:</b> ${initialEmail.date ? formatDate(initialEmail.date) : ''}</p>
  <p style="margin: 5px 0; font-size: 14px;"><b>Subject:</b> ${initialEmail.subject || ''}</p>
  <p style="margin: 5px 0; font-size: 14px;"><b>To:</b> ${initialEmail.to ? formatRecipients(initialEmail.to) : ''}</p>
</div>
<div class="editable-content" style="color: #ef4444; font-style: italic; margin-top: 10px;">Error loading forwarded content</div>`;
      setBody(errorHeaderContent);
    } finally {
      setSending(false);
    }
  };

  // Handle attachment selection
  const handleAttachmentClick = () => {
    attachmentInputRef.current?.click();
  };

  // Process selected files
  const handleFileSelection = async (e: React.ChangeEvent<HTMLInputElement>) => {
    const files = e.target.files;
    if (!files || files.length === 0) return;

    // Convert selected files to attachments
    const newAttachments = Array.from(files).map(file => ({
      file,
      uploading: true
    }));

    // Read files as data URLs
    for (const file of files) {
      const reader = new FileReader();
      
      reader.onload = (event) => {
        const content = event.target?.result as string;
        
        setAttachments(current => [
          ...current,
          {
            name: file.name,
            content: content.split(',')[1], // Remove data:mime/type;base64, prefix
            type: file.type
          }
        ]);
      };
      
      reader.readAsDataURL(file);
    }
    
    // Reset file input
    if (e.target) {
      e.target.value = '';
    }
  };

  // Remove attachment
  const removeAttachment = (index: number) => {
    setAttachments(current => current.filter((_, i) => i !== index));
  };

  // Send the email
  const handleSend = async () => {
    if (!to) {
      alert('Please specify at least one recipient');
      return;
    }

    try {
      setSending(true);
      
      // Get the email content
      let emailBody = '';
      if (editorRef.current) {
        // For forwarded emails, make sure to include both the style and content sections
        if (type === 'forward') {
          // Gather all parts: styles, header, and editable content
          const styleSection = editorRef.current.querySelector('.email-styles');
          const headerSection = editorRef.current.querySelector('.forwarded-header');
          const editableContent = editorRef.current.querySelector('.editable-content');
          
          // Combine all sections for the final email body
          emailBody = 
            (styleSection?.outerHTML || '') +
            (headerSection?.outerHTML || '') + 
            (editableContent?.innerHTML || editorRef.current.innerHTML);
            
          // Remove contenteditable attributes as they're not needed in the sent email
          emailBody = emailBody.replace(/contenteditable="[^"]*"/g, '');
        } else {
          // For new emails or replies, use the entire content
          emailBody = editorRef.current.innerHTML;
        }
      } else {
        // Fallback to using body state
        emailBody = body;
      }
      
      await onSend({
        to,
        cc: cc || undefined,
        bcc: bcc || undefined,
        subject,
        body: emailBody,
        attachments
      });
      
      onClose();
    } catch (error) {
      console.error('Error sending email:', error);
      alert('Failed to send email. Please try again.');
    } finally {
      setSending(false);
    }
  };

  return (
    <Card className="w-full h-full flex flex-col overflow-hidden shadow-lg">
      <CardHeader className="border-b py-2 px-4">
        <div className="flex justify-between items-center">
          <CardTitle className="text-lg">
            {type === 'new' ? 'New Message' : 
              type === 'reply' ? 'Reply' : 
              type === 'reply-all' ? 'Reply All' : 
              'Forward'}
          </CardTitle>
          <Button variant="ghost" size="icon" onClick={onClose}>
            <X className="h-4 w-4" />
          </Button>
        </div>
      </CardHeader>
      
      <CardContent className="p-0 flex-1 flex flex-col overflow-hidden">
        {/* Email header fields */}
        <div className="p-3 border-b space-y-2">
          <div className="flex items-center">
            <span className="w-16 text-sm font-medium">To:</span>
            <Input 
              value={to} 
              onChange={(e) => setTo(e.target.value)} 
              className="flex-1 border-0 shadow-none h-8 focus-visible:ring-0"
              placeholder="recipient@example.com"
            />
          </div>
          
          {showCc && (
            <div className="flex items-center">
              <span className="w-16 text-sm font-medium">Cc:</span>
              <Input 
                value={cc} 
                onChange={(e) => setCc(e.target.value)} 
                className="flex-1 border-0 shadow-none h-8 focus-visible:ring-0"
                placeholder="cc@example.com"
              />
            </div>
          )}
          
          {showBcc && (
            <div className="flex items-center">
              <span className="w-16 text-sm font-medium">Bcc:</span>
              <Input 
                value={bcc} 
                onChange={(e) => setBcc(e.target.value)} 
                className="flex-1 border-0 shadow-none h-8 focus-visible:ring-0"
                placeholder="bcc@example.com"
              />
            </div>
          )}
          
          {/* CC/BCC controls */}
          <div className="flex items-center text-xs">
            <button 
              className="text-primary hover:underline mr-3 flex items-center"
              onClick={() => setShowCc(!showCc)}
            >
              {showCc ? (
                <>
                  <ChevronUp className="h-3 w-3 mr-0.5" />
                  Hide Cc
                </>
              ) : (
                <>
                  <ChevronDown className="h-3 w-3 mr-0.5" />
                  Show Cc
                </>
              )}
            </button>
            
            <button 
              className="text-primary hover:underline flex items-center"
              onClick={() => setShowBcc(!showBcc)}
            >
              {showBcc ? (
                <>
                  <ChevronUp className="h-3 w-3 mr-0.5" />
                  Hide Bcc
                </>
              ) : (
                <>
                  <ChevronDown className="h-3 w-3 mr-0.5" />
                  Show Bcc
                </>
              )}
            </button>
          </div>
          
          <div className="flex items-center">
            <span className="w-16 text-sm font-medium">Subject:</span>
            <Input 
              value={subject} 
              onChange={(e) => setSubject(e.target.value)} 
              className="flex-1 border-0 shadow-none h-8 focus-visible:ring-0"
              placeholder="Subject"
            />
          </div>
        </div>
        
        {/* Email body editor */}
        <div 
          ref={editorRef}
          className="flex-1 overflow-auto p-4 focus:outline-none email-content"
          contentEditable={true}
          onInput={handleEditorInput}
          dangerouslySetInnerHTML={{ __html: body }}
          style={{ minHeight: '200px' }}
        />
        
        {/* Attachments list */}
        {attachments.length > 0 && (
          <div className="border-t p-2">
            <div className="text-sm font-medium mb-1">Attachments:</div>
            <div className="flex flex-wrap gap-2">
              {attachments.map((attachment, index) => (
                <div key={index} className="flex items-center gap-1 text-sm bg-muted px-2 py-1 rounded">
                  <Paperclip className="h-3 w-3" />
                  <span>{attachment.name}</span>
                  <button 
                    onClick={() => removeAttachment(index)}
                    className="ml-1 text-muted-foreground hover:text-destructive"
                  >
                    <X className="h-3 w-3" />
                  </button>
                </div>
              ))}
            </div>
          </div>
        )}
      </CardContent>
      
      <CardFooter className="border-t p-3 flex justify-between">
        <div>
          <input
            type="file"
            ref={attachmentInputRef}
            className="hidden"
            onChange={handleFileSelection}
            multiple
          />
          <Button
            variant="outline"
            size="sm"
            onClick={handleAttachmentClick}
          >
            <Paperclip className="h-4 w-4 mr-1" />
            Attach
          </Button>
        </div>
        
        <Button 
          size="sm" 
          onClick={handleSend}
          disabled={sending}
        >
          {sending ? (
            <>
              <Loader2 className="h-4 w-4 mr-1 animate-spin" />
              Sending...
            </>
          ) : (
            <>
              <SendHorizontal className="h-4 w-4 mr-1" />
              Send
            </>
          )}
        </Button>
      </CardFooter>
    </Card>
  );
}