/**
 * DEPRECATED - USE email-utils.ts INSTEAD
 * 
 * This file is maintained for backward compatibility only.
 * New code should import directly from email-utils.ts, which contains
 * the canonical implementations of these functions.
 */

import { sanitizeHtml } from './dom-purify-config';
import { formatEmailAddresses, formatEmailDate, formatReplyEmail, formatForwardedEmail, formatEmailForReplyOrForward } from './email-utils';
import { applyTextDirection } from './text-direction';
import type { EmailMessage, EmailAddress } from '@/types/email';

// Re-export the functions from email-utils for backward compatibility
export { 
  formatEmailAddresses,
  formatEmailDate,
  formatReplyEmail,
  formatForwardedEmail,
  formatEmailForReplyOrForward,
  sanitizeHtml
};

// Re-export types for backward compatibility
export type { EmailAddress, EmailMessage };

/**
 * Format a date in a relative format
 * Simple implementation for email display
 */
function formatDateRelative(date: Date): 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();
  }
}

/**
 * Parse text and find URLs to turn into clickable links
 * This is a utility function used only in this file
 */
function parseUrlsToLinks(text: string): string {
  const urlRegex = /(https?:\/\/[^\s]+)/g;
  return text.replace(
    urlRegex,
    url => `<a href="${url}" target="_blank" rel="noopener noreferrer">${url}</a>`
  );
}

/**
 * Convert plain text email content to HTML with proper line breaks
 * This is a utility function used only in this file
 */
function textToHtml(text: string): string {
  if (!text) return '';
  
  // Escape HTML characters first
  const escaped = text
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&#39;');
  
  // Convert line breaks and wrap in a div
  const withLineBreaks = escaped.replace(/\n/g, '<br>');
  
  // Parse URLs to make them clickable
  const withLinks = parseUrlsToLinks(withLineBreaks);
  
  return withLinks;
}

/**
 * Decode compose content from MIME format to HTML and text
 */
export async function decodeComposeContent(content: string): Promise<{
  html: string | null;
  text: string | null;
}> {
  if (!content.trim()) {
    return { html: null, text: null };
  }

  try {
    const response = await fetch('/api/parse-email', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({ email: content }),
    });

    if (!response.ok) {
      throw new Error('Failed to parse email');
    }

    const parsed = await response.json();
    
    // Apply sanitization to the parsed content
    return {
      html: parsed.html ? sanitizeHtml(parsed.html) : null,
      text: parsed.text || null
    };
  } catch (error) {
    console.error('Error parsing email content:', error);
    // Fallback to basic content handling with sanitization
    return {
      html: sanitizeHtml(content),
      text: content
    };
  }
}

/**
 * Encode compose content to MIME format for sending
 */
export function encodeComposeContent(content: string): string {
  if (!content.trim()) {
    throw new Error('Email content is empty');
  }

  // Create MIME headers
  const mimeHeaders = {
    'MIME-Version': '1.0',
    'Content-Type': 'text/html; charset="utf-8"',
    'Content-Transfer-Encoding': 'quoted-printable'
  };

  // Combine headers and content
  return Object.entries(mimeHeaders)
    .map(([key, value]) => `${key}: ${value}`)
    .join('\n') + '\n\n' + content;
}

// Utility function to get the reply subject line
export function getReplySubject(subject: string): string {
  return subject.startsWith('Re:') ? subject : `Re: ${subject}`;
}

// Utility function to get the forward subject line
export function getForwardSubject(subject: string): string {
  return subject.startsWith('Fwd:') ? subject : `Fwd: ${subject}`;
}