/**
 * Formatting Utilities for Horux Strategy
 * Currency, percentage, date, and other formatting functions
 */

import { DEFAULT_LOCALE, DEFAULT_TIMEZONE, CURRENCIES, DEFAULT_CURRENCY } from '../constants';

// ============================================================================
// Currency Formatting
// ============================================================================

export interface CurrencyFormatOptions {
  currency?: string;
  locale?: string;
  showSymbol?: boolean;
  showCode?: boolean;
  minimumFractionDigits?: number;
  maximumFractionDigits?: number;
  signDisplay?: 'auto' | 'always' | 'exceptZero' | 'never';
}

/**
 * Format a number as currency (default: Mexican Pesos)
 *
 * @example
 * formatCurrency(1234.56) // "$1,234.56"
 * formatCurrency(1234.56, { currency: 'USD' }) // "US$1,234.56"
 * formatCurrency(-1234.56) // "-$1,234.56"
 * formatCurrency(1234.56, { showCode: true }) // "$1,234.56 MXN"
 */
export function formatCurrency(
  amount: number,
  options: CurrencyFormatOptions = {}
): string {
  const {
    currency = DEFAULT_CURRENCY,
    locale = DEFAULT_LOCALE,
    showSymbol = true,
    showCode = false,
    minimumFractionDigits,
    maximumFractionDigits,
    signDisplay = 'auto',
  } = options;

  const currencyInfo = CURRENCIES[currency] || CURRENCIES[DEFAULT_CURRENCY];
  const decimals = minimumFractionDigits ?? maximumFractionDigits ?? currencyInfo.decimals;

  try {
    const formatter = new Intl.NumberFormat(locale, {
      style: showSymbol ? 'currency' : 'decimal',
      currency: showSymbol ? currency : undefined,
      minimumFractionDigits: decimals,
      maximumFractionDigits: maximumFractionDigits ?? decimals,
      signDisplay,
    });

    let formatted = formatter.format(amount);

    // Add currency code if requested
    if (showCode) {
      formatted = `${formatted} ${currency}`;
    }

    return formatted;
  } catch {
    // Fallback formatting
    const symbol = showSymbol ? currencyInfo.symbol : '';
    const sign = amount < 0 ? '-' : '';
    const absAmount = Math.abs(amount).toFixed(decimals);
    const [intPart, decPart] = absAmount.split('.');
    const formattedInt = intPart.replace(/\B(?=(\d{3})+(?!\d))/g, ',');

    let result = `${sign}${symbol}${formattedInt}`;
    if (decPart) {
      result += `.${decPart}`;
    }
    if (showCode) {
      result += ` ${currency}`;
    }
    return result;
  }
}

/**
 * Format currency for display in compact form
 *
 * @example
 * formatCurrencyCompact(1234) // "$1.2K"
 * formatCurrencyCompact(1234567) // "$1.2M"
 */
export function formatCurrencyCompact(
  amount: number,
  options: Omit<CurrencyFormatOptions, 'minimumFractionDigits' | 'maximumFractionDigits'> = {}
): string {
  const {
    currency = DEFAULT_CURRENCY,
    locale = DEFAULT_LOCALE,
    showSymbol = true,
  } = options;

  try {
    const formatter = new Intl.NumberFormat(locale, {
      style: showSymbol ? 'currency' : 'decimal',
      currency: showSymbol ? currency : undefined,
      notation: 'compact',
      compactDisplay: 'short',
      maximumFractionDigits: 1,
    });

    return formatter.format(amount);
  } catch {
    // Fallback
    const currencyInfo = CURRENCIES[currency] || CURRENCIES[DEFAULT_CURRENCY];
    const symbol = showSymbol ? currencyInfo.symbol : '';
    const absAmount = Math.abs(amount);
    const sign = amount < 0 ? '-' : '';

    if (absAmount >= 1000000000) {
      return `${sign}${symbol}${(absAmount / 1000000000).toFixed(1)}B`;
    }
    if (absAmount >= 1000000) {
      return `${sign}${symbol}${(absAmount / 1000000).toFixed(1)}M`;
    }
    if (absAmount >= 1000) {
      return `${sign}${symbol}${(absAmount / 1000).toFixed(1)}K`;
    }
    return `${sign}${symbol}${absAmount.toFixed(0)}`;
  }
}

/**
 * Parse a currency string to number
 *
 * @example
 * parseCurrency("$1,234.56") // 1234.56
 * parseCurrency("-$1,234.56") // -1234.56
 */
export function parseCurrency(value: string): number {
  // Remove currency symbols, spaces, and thousand separators
  const cleaned = value
    .replace(/[^0-9.,-]/g, '')
    .replace(/,/g, '');

  const number = parseFloat(cleaned);
  return isNaN(number) ? 0 : number;
}

// ============================================================================
// Percentage Formatting
// ============================================================================

export interface PercentFormatOptions {
  locale?: string;
  minimumFractionDigits?: number;
  maximumFractionDigits?: number;
  signDisplay?: 'auto' | 'always' | 'exceptZero' | 'never';
  multiply?: boolean; // If true, multiply by 100 (e.g., 0.16 -> 16%)
}

/**
 * Format a number as percentage
 *
 * @example
 * formatPercent(16.5) // "16.5%"
 * formatPercent(0.165, { multiply: true }) // "16.5%"
 * formatPercent(-5.2, { signDisplay: 'always' }) // "-5.2%"
 */
export function formatPercent(
  value: number,
  options: PercentFormatOptions = {}
): string {
  const {
    locale = DEFAULT_LOCALE,
    minimumFractionDigits = 0,
    maximumFractionDigits = 2,
    signDisplay = 'auto',
    multiply = false,
  } = options;

  const displayValue = multiply ? value : value / 100;

  try {
    const formatter = new Intl.NumberFormat(locale, {
      style: 'percent',
      minimumFractionDigits,
      maximumFractionDigits,
      signDisplay,
    });

    return formatter.format(displayValue);
  } catch {
    // Fallback
    const sign = signDisplay === 'always' && value > 0 ? '+' : '';
    const actualValue = multiply ? value * 100 : value;
    return `${sign}${actualValue.toFixed(maximumFractionDigits)}%`;
  }
}

/**
 * Format a percentage change with color indicator
 * Returns an object with formatted value and direction
 */
export function formatPercentChange(
  value: number,
  options: PercentFormatOptions = {}
): {
  formatted: string;
  direction: 'up' | 'down' | 'unchanged';
  isPositive: boolean;
} {
  const formatted = formatPercent(value, { ...options, signDisplay: 'exceptZero' });
  const direction = value > 0 ? 'up' : value < 0 ? 'down' : 'unchanged';

  return {
    formatted,
    direction,
    isPositive: value > 0,
  };
}

// ============================================================================
// Date Formatting
// ============================================================================

export interface DateFormatOptions {
  locale?: string;
  timezone?: string;
  format?: 'short' | 'medium' | 'long' | 'full' | 'relative' | 'iso';
  includeTime?: boolean;
}

/**
 * Format a date
 *
 * @example
 * formatDate(new Date()) // "31/01/2024"
 * formatDate(new Date(), { format: 'long' }) // "31 de enero de 2024"
 * formatDate(new Date(), { includeTime: true }) // "31/01/2024 14:30"
 */
export function formatDate(
  date: Date | string | number,
  options: DateFormatOptions = {}
): string {
  const {
    locale = DEFAULT_LOCALE,
    timezone = DEFAULT_TIMEZONE,
    format = 'short',
    includeTime = false,
  } = options;

  const dateObj = date instanceof Date ? date : new Date(date);

  if (isNaN(dateObj.getTime())) {
    return 'Fecha inválida';
  }

  // ISO format
  if (format === 'iso') {
    return dateObj.toISOString();
  }

  // Relative format
  if (format === 'relative') {
    return formatRelativeTime(dateObj, locale);
  }

  try {
    const dateStyle = format === 'short' ? 'short'
      : format === 'medium' ? 'medium'
      : format === 'long' ? 'long'
      : 'full';

    const formatter = new Intl.DateTimeFormat(locale, {
      dateStyle,
      timeStyle: includeTime ? 'short' : undefined,
      timeZone: timezone,
    });

    return formatter.format(dateObj);
  } catch {
    // Fallback
    const day = dateObj.getDate().toString().padStart(2, '0');
    const month = (dateObj.getMonth() + 1).toString().padStart(2, '0');
    const year = dateObj.getFullYear();
    let result = `${day}/${month}/${year}`;

    if (includeTime) {
      const hours = dateObj.getHours().toString().padStart(2, '0');
      const minutes = dateObj.getMinutes().toString().padStart(2, '0');
      result += ` ${hours}:${minutes}`;
    }

    return result;
  }
}

/**
 * Format a date as relative time (e.g., "hace 2 días")
 */
export function formatRelativeTime(
  date: Date | string | number,
  locale: string = DEFAULT_LOCALE
): string {
  const dateObj = date instanceof Date ? date : new Date(date);
  const now = new Date();
  const diffMs = now.getTime() - dateObj.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);
  const diffWeeks = Math.floor(diffDays / 7);
  const diffMonths = Math.floor(diffDays / 30);
  const diffYears = Math.floor(diffDays / 365);

  try {
    const rtf = new Intl.RelativeTimeFormat(locale, { numeric: 'auto' });

    if (Math.abs(diffSeconds) < 60) {
      return rtf.format(-diffSeconds, 'second');
    }
    if (Math.abs(diffMinutes) < 60) {
      return rtf.format(-diffMinutes, 'minute');
    }
    if (Math.abs(diffHours) < 24) {
      return rtf.format(-diffHours, 'hour');
    }
    if (Math.abs(diffDays) < 7) {
      return rtf.format(-diffDays, 'day');
    }
    if (Math.abs(diffWeeks) < 4) {
      return rtf.format(-diffWeeks, 'week');
    }
    if (Math.abs(diffMonths) < 12) {
      return rtf.format(-diffMonths, 'month');
    }
    return rtf.format(-diffYears, 'year');
  } catch {
    // Fallback for environments without Intl.RelativeTimeFormat
    if (diffSeconds < 60) return 'hace un momento';
    if (diffMinutes < 60) return `hace ${diffMinutes} minuto${diffMinutes !== 1 ? 's' : ''}`;
    if (diffHours < 24) return `hace ${diffHours} hora${diffHours !== 1 ? 's' : ''}`;
    if (diffDays < 7) return `hace ${diffDays} día${diffDays !== 1 ? 's' : ''}`;
    if (diffWeeks < 4) return `hace ${diffWeeks} semana${diffWeeks !== 1 ? 's' : ''}`;
    if (diffMonths < 12) return `hace ${diffMonths} mes${diffMonths !== 1 ? 'es' : ''}`;
    return `hace ${diffYears} año${diffYears !== 1 ? 's' : ''}`;
  }
}

/**
 * Format a date range
 *
 * @example
 * formatDateRange(start, end) // "1 - 31 de enero de 2024"
 */
export function formatDateRange(
  start: Date | string | number,
  end: Date | string | number,
  options: Omit<DateFormatOptions, 'includeTime'> = {}
): string {
  const { locale = DEFAULT_LOCALE, timezone = DEFAULT_TIMEZONE } = options;

  const startDate = start instanceof Date ? start : new Date(start);
  const endDate = end instanceof Date ? end : new Date(end);

  try {
    const formatter = new Intl.DateTimeFormat(locale, {
      dateStyle: 'long',
      timeZone: timezone,
    });

    return formatter.formatRange(startDate, endDate);
  } catch {
    // Fallback
    return `${formatDate(startDate, options)} - ${formatDate(endDate, options)}`;
  }
}

/**
 * Format time only
 */
export function formatTime(
  date: Date | string | number,
  options: { locale?: string; timezone?: string; style?: 'short' | 'medium' } = {}
): string {
  const { locale = DEFAULT_LOCALE, timezone = DEFAULT_TIMEZONE, style = 'short' } = options;
  const dateObj = date instanceof Date ? date : new Date(date);

  try {
    const formatter = new Intl.DateTimeFormat(locale, {
      timeStyle: style,
      timeZone: timezone,
    });
    return formatter.format(dateObj);
  } catch {
    const hours = dateObj.getHours().toString().padStart(2, '0');
    const minutes = dateObj.getMinutes().toString().padStart(2, '0');
    return `${hours}:${minutes}`;
  }
}

// ============================================================================
// Number Formatting
// ============================================================================

export interface NumberFormatOptions {
  locale?: string;
  minimumFractionDigits?: number;
  maximumFractionDigits?: number;
  notation?: 'standard' | 'scientific' | 'engineering' | 'compact';
  signDisplay?: 'auto' | 'always' | 'exceptZero' | 'never';
}

/**
 * Format a number with thousand separators
 *
 * @example
 * formatNumber(1234567.89) // "1,234,567.89"
 * formatNumber(1234567, { notation: 'compact' }) // "1.2M"
 */
export function formatNumber(
  value: number,
  options: NumberFormatOptions = {}
): string {
  const {
    locale = DEFAULT_LOCALE,
    minimumFractionDigits,
    maximumFractionDigits,
    notation = 'standard',
    signDisplay = 'auto',
  } = options;

  try {
    const formatter = new Intl.NumberFormat(locale, {
      minimumFractionDigits,
      maximumFractionDigits,
      notation,
      signDisplay,
    });
    return formatter.format(value);
  } catch {
    return value.toLocaleString();
  }
}

/**
 * Format a number in compact notation
 *
 * @example
 * formatCompactNumber(1234) // "1.2K"
 * formatCompactNumber(1234567) // "1.2M"
 */
export function formatCompactNumber(
  value: number,
  options: Omit<NumberFormatOptions, 'notation'> = {}
): string {
  return formatNumber(value, { ...options, notation: 'compact' });
}

/**
 * Format bytes to human readable size
 *
 * @example
 * formatBytes(1024) // "1 KB"
 * formatBytes(1536) // "1.5 KB"
 * formatBytes(1048576) // "1 MB"
 */
export function formatBytes(
  bytes: number,
  options: { locale?: string; decimals?: number } = {}
): string {
  const { locale = DEFAULT_LOCALE, decimals = 1 } = options;

  if (bytes === 0) return '0 Bytes';

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

  try {
    const formatter = new Intl.NumberFormat(locale, {
      minimumFractionDigits: 0,
      maximumFractionDigits: decimals,
    });
    return `${formatter.format(value)} ${sizes[i]}`;
  } catch {
    return `${value.toFixed(decimals)} ${sizes[i]}`;
  }
}

// ============================================================================
// Text Formatting
// ============================================================================

/**
 * Truncate text with ellipsis
 *
 * @example
 * truncate("Hello World", 8) // "Hello..."
 */
export function truncate(text: string, maxLength: number, suffix = '...'): string {
  if (text.length <= maxLength) return text;
  return text.slice(0, maxLength - suffix.length).trim() + suffix;
}

/**
 * Capitalize first letter
 *
 * @example
 * capitalize("hello world") // "Hello world"
 */
export function capitalize(text: string): string {
  if (!text) return '';
  return text.charAt(0).toUpperCase() + text.slice(1).toLowerCase();
}

/**
 * Title case
 *
 * @example
 * titleCase("hello world") // "Hello World"
 */
export function titleCase(text: string): string {
  return text
    .toLowerCase()
    .split(' ')
    .map(word => word.charAt(0).toUpperCase() + word.slice(1))
    .join(' ');
}

/**
 * Format RFC for display (with spaces)
 *
 * @example
 * formatRFC("XAXX010101000") // "XAXX 010101 000"
 */
export function formatRFC(rfc: string): string {
  const cleaned = rfc.replace(/\s/g, '').toUpperCase();
  if (cleaned.length === 12) {
    // Persona física
    return `${cleaned.slice(0, 4)} ${cleaned.slice(4, 10)} ${cleaned.slice(10)}`;
  }
  if (cleaned.length === 13) {
    // Persona moral
    return `${cleaned.slice(0, 3)} ${cleaned.slice(3, 9)} ${cleaned.slice(9)}`;
  }
  return cleaned;
}

/**
 * Mask sensitive data
 *
 * @example
 * maskString("1234567890", 4) // "******7890"
 * maskString("email@example.com", 3, { maskChar: '*', type: 'email' }) // "ema***@example.com"
 */
export function maskString(
  value: string,
  visibleChars: number = 4,
  options: { maskChar?: string; position?: 'start' | 'end' } = {}
): string {
  const { maskChar = '*', position = 'end' } = options;

  if (value.length <= visibleChars) return value;

  const maskLength = value.length - visibleChars;
  const mask = maskChar.repeat(maskLength);

  if (position === 'start') {
    return value.slice(0, visibleChars) + mask;
  }
  return mask + value.slice(-visibleChars);
}

/**
 * Format CLABE for display
 *
 * @example
 * formatCLABE("123456789012345678") // "123 456 789012345678"
 */
export function formatCLABE(clabe: string): string {
  const cleaned = clabe.replace(/\s/g, '');
  if (cleaned.length !== 18) return clabe;
  return `${cleaned.slice(0, 3)} ${cleaned.slice(3, 6)} ${cleaned.slice(6)}`;
}

/**
 * Format phone number (Mexican format)
 *
 * @example
 * formatPhone("5512345678") // "(55) 1234-5678"
 */
export function formatPhone(phone: string): string {
  const cleaned = phone.replace(/\D/g, '');

  if (cleaned.length === 10) {
    return `(${cleaned.slice(0, 2)}) ${cleaned.slice(2, 6)}-${cleaned.slice(6)}`;
  }
  if (cleaned.length === 12 && cleaned.startsWith('52')) {
    const national = cleaned.slice(2);
    return `+52 (${national.slice(0, 2)}) ${national.slice(2, 6)}-${national.slice(6)}`;
  }

  return phone;
}

// ============================================================================
// Pluralization
// ============================================================================

/**
 * Simple Spanish pluralization
 *
 * @example
 * pluralize(1, 'factura', 'facturas') // "1 factura"
 * pluralize(5, 'factura', 'facturas') // "5 facturas"
 */
export function pluralize(
  count: number,
  singular: string,
  plural: string
): string {
  const word = count === 1 ? singular : plural;
  return `${formatNumber(count)} ${word}`;
}

/**
 * Format a list of items with proper grammar
 *
 * @example
 * formatList(['a', 'b', 'c']) // "a, b y c"
 * formatList(['a', 'b']) // "a y b"
 * formatList(['a']) // "a"
 */
export function formatList(
  items: string[],
  options: { locale?: string; type?: 'conjunction' | 'disjunction' } = {}
): string {
  const { locale = DEFAULT_LOCALE, type = 'conjunction' } = options;

  if (items.length === 0) return '';
  if (items.length === 1) return items[0];

  try {
    const formatter = new Intl.ListFormat(locale, {
      style: 'long',
      type,
    });
    return formatter.format(items);
  } catch {
    // Fallback
    const connector = type === 'conjunction' ? 'y' : 'o';
    if (items.length === 2) {
      return `${items[0]} ${connector} ${items[1]}`;
    }
    return `${items.slice(0, -1).join(', ')} ${connector} ${items[items.length - 1]}`;
  }
}