/**
 * Formatting utility functions
 */

/**
 * Format duration from seconds to MM:SS or HH:MM:SS format
 */
export function formatDuration(seconds: number): string {
  if (!Number.isFinite(seconds) || seconds < 0) {
    return '--:--';
  }

  const hours = Math.floor(seconds / 3600);
  const minutes = Math.floor((seconds % 3600) / 60);
  const remainingSeconds = Math.floor(seconds % 60);

  if (hours > 0) {
    return `${hours}:${minutes.toString().padStart(2, '0')}:${remainingSeconds.toString().padStart(2, '0')}`;
  }

  return `${minutes}:${remainingSeconds.toString().padStart(2, '0')}`;
}

/**
 * Format duration from milliseconds
 */
export function formatDurationFromMs(milliseconds: number): string {
  return formatDuration(milliseconds / 1000);
}

/**
 * Format duration with units (e.g., "2 min 30 sec" or "1h 23m")
 */
export function formatDurationWithUnits(
  seconds: number,
  locale: 'en' | 'de' = 'en'
): string {
  if (!Number.isFinite(seconds) || seconds < 0) {
    return locale === 'de' ? 'keine Zeit' : 'no time';
  }

  const hours = Math.floor(seconds / 3600);
  const minutes = Math.floor((seconds % 3600) / 60);
  const remainingSeconds = Math.floor(seconds % 60);

  if (hours > 0) {
    return minutes > 0 ? `${hours}h ${minutes}m` : `${hours}h`;
  }

  if (minutes > 0) {
    return remainingSeconds > 0 && minutes < 5
      ? `${minutes}m ${remainingSeconds}s`
      : `${minutes}m`;
  }

  return `${remainingSeconds}s`;
}

/**
 * Format duration to human readable text
 */
export function formatDurationHumanReadable(
  seconds: number,
  locale: 'en' | 'de' = 'de'
): string {
  if (!Number.isFinite(seconds) || seconds < 0) {
    return locale === 'de' ? 'keine Zeit' : 'no time';
  }

  const hours = Math.floor(seconds / 3600);
  const minutes = Math.floor((seconds % 3600) / 60);
  const remainingSeconds = Math.floor(seconds % 60);

  const parts: string[] = [];

  if (locale === 'de') {
    if (hours > 0) {
      parts.push(`${hours} ${hours === 1 ? 'Stunde' : 'Stunden'}`);
    }
    if (minutes > 0) {
      parts.push(`${minutes} ${minutes === 1 ? 'Minute' : 'Minuten'}`);
    }
    if (remainingSeconds > 0 && hours === 0) {
      parts.push(`${remainingSeconds} ${remainingSeconds === 1 ? 'Sekunde' : 'Sekunden'}`);
    }
    return parts.length === 0 ? '0 Sekunden' : parts.join(' ');
  } else {
    if (hours > 0) {
      parts.push(`${hours} ${hours === 1 ? 'hour' : 'hours'}`);
    }
    if (minutes > 0) {
      parts.push(`${minutes} ${minutes === 1 ? 'minute' : 'minutes'}`);
    }
    if (remainingSeconds > 0 && hours === 0) {
      parts.push(`${remainingSeconds} ${remainingSeconds === 1 ? 'second' : 'seconds'}`);
    }
    return parts.length === 0 ? '0 seconds' : parts.join(' ');
  }
}

/**
 * Format file size from bytes to human readable string
 */
export function formatFileSize(bytes: number, decimals: number = 1): string {
  if (bytes === 0) return '0 B';
  if (!Number.isFinite(bytes) || bytes < 0) return '--';

  const k = 1024;
  const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
  const i = Math.floor(Math.log(bytes) / Math.log(k));

  return `${parseFloat((bytes / Math.pow(k, i)).toFixed(decimals))} ${sizes[i]}`;
}

/**
 * Format number with thousands separator
 */
export function formatNumber(
  num: number,
  locale: string = 'de-DE'
): string {
  return num.toLocaleString(locale);
}

/**
 * Format currency
 */
export function formatCurrency(
  amount: number,
  currency: string = 'EUR',
  locale: string = 'de-DE'
): string {
  return new Intl.NumberFormat(locale, {
    style: 'currency',
    currency,
  }).format(amount);
}

/**
 * Format percentage
 */
export function formatPercent(
  value: number,
  decimals: number = 0,
  locale: string = 'de-DE'
): string {
  return new Intl.NumberFormat(locale, {
    style: 'percent',
    minimumFractionDigits: decimals,
    maximumFractionDigits: decimals,
  }).format(value);
}