/**
 * Date formatting utilities for consistent date/time display
 */

/**
 * Formats a date string for simple display
 * @param dateString - ISO date string
 * @returns Localized date string
 */
export function formatDate(dateString: string): string {
  const date = new Date(dateString);
  return date.toLocaleDateString();
}

/**
 * Formats a date/time for audio player display with localization
 * Includes weekday, date, time, and optional duration
 * 
 * @param dateString - ISO date string
 * @param durationSeconds - Optional duration in seconds
 * @param language - Language code for localization (e.g., 'en', 'de-DE')
 * @returns Formatted date/time string with weekday and duration
 */
export function formatDateTimeForAudio(
  dateString: string, 
  durationSeconds?: number,
  language: string
): string {
  const date = new Date(dateString);
  
  // Get localized weekday name
  const weekday = date.toLocaleDateString(language, { weekday: 'long' });
  const formattedDate = date.toLocaleDateString(language);
  
  // Use language-aware time formatting
  const langCode = language.split('-')[0];
  const is12Hour = ['en', 'hi', 'ur', 'tl', 'ms'].includes(langCode);
  const formattedTime = date.toLocaleTimeString(language, {
    hour: '2-digit',
    minute: '2-digit',
    hour12: is12Hour,
  });
  
  // Apply language-specific time formatting
  let timeWithDuration = formattedTime;
  if (langCode === 'de') timeWithDuration = `${formattedTime} Uhr`;
  else if (langCode === 'nl') timeWithDuration = `${formattedTime} uur`;
  else if (langCode === 'da') timeWithDuration = `kl. ${formattedTime.replace(':', '.')}`;
  else if (langCode === 'sv' || langCode === 'nb') timeWithDuration = `kl. ${formattedTime}`;
  else if (langCode === 'it') timeWithDuration = `alle ${formattedTime}`;
  else if (langCode === 'es') timeWithDuration = `a las ${formattedTime}`;
  else if (langCode === 'pt') timeWithDuration = `às ${formattedTime}`;
  else if (langCode === 'fr') timeWithDuration = `à ${formattedTime.replace(':', 'h')}`;
  else if (langCode === 'hi' || langCode === 'ur') timeWithDuration = formattedTime;
  else if (langCode === 'ja') timeWithDuration = formattedTime;
  
  // Add duration if available
  if (durationSeconds && durationSeconds > 0) {
    const minutes = Math.floor(durationSeconds / 60);
    const seconds = Math.floor(durationSeconds % 60);
    const durationStr = `${minutes}:${seconds.toString().padStart(2, '0')}`;
    timeWithDuration += ` • ${durationStr}`;
  }
  
  return `${weekday}, ${formattedDate} ${timeWithDuration}`;
}

/**
 * Formats a duration in seconds to a human-readable string
 * @param seconds - Duration in seconds
 * @returns Formatted duration string (e.g., "1h 23min" or "45min")
 */
export function formatDuration(seconds: number): string {
  if (!seconds || seconds <= 0) return '';
  
  const minutes = Math.floor(seconds / 60);
  const hours = Math.floor(minutes / 60);
  const remainingMinutes = minutes % 60;
  
  if (hours > 0) {
    return `${hours}h ${remainingMinutes}min`;
  }
  return `${minutes}min`;
}

/**
 * Formats a date to show relative time (e.g., "2 hours ago", "yesterday")
 * @param dateString - ISO date string
 * @param language - Language code for localization
 * @param now - Optional current date for testing
 * @returns Relative time string
 */
export function formatRelativeTime(
  dateString: string, 
  language: string,
  now: Date = new Date()
): string {
  const date = new Date(dateString);
  const diffMs = now.getTime() - date.getTime();
  const diffSeconds = Math.floor(diffMs / 1000);
  const diffMinutes = Math.floor(diffSeconds / 60);
  const diffHours = Math.floor(diffMinutes / 60);
  const diffDays = Math.floor(diffHours / 24);
  
  // For very recent times, show exact time
  if (diffMinutes < 1) {
    return 'Just now';
  }
  
  // Use Intl.RelativeTimeFormat if available
  if (typeof Intl !== 'undefined' && Intl.RelativeTimeFormat) {
    const rtf = new Intl.RelativeTimeFormat(language, { numeric: 'auto' });
    
    if (diffDays > 0 && diffDays < 7) {
      return rtf.format(-diffDays, 'day');
    } else if (diffHours > 0 && diffHours < 24) {
      return rtf.format(-diffHours, 'hour');
    } else if (diffMinutes > 0 && diffMinutes < 60) {
      return rtf.format(-diffMinutes, 'minute');
    }
  }
  
  // Fallback for older browsers or if more than a week
  if (diffDays > 7) {
    return formatDate(dateString);
  } else if (diffDays > 0) {
    return `${diffDays} day${diffDays > 1 ? 's' : ''} ago`;
  } else if (diffHours > 0) {
    return `${diffHours} hour${diffHours > 1 ? 's' : ''} ago`;
  } else {
    return `${diffMinutes} minute${diffMinutes > 1 ? 's' : ''} ago`;
  }
}