GPT classify price

classifyPrice.ts

type Currency =
  | "USD" | "EUR" | "GBP" | "JPY" | "AUD" | "CAD" | "CHF" | "CNY" | "SEK" | "NZD"
  | "MXN" | "SGD" | "HKD" | "NOK" | "KRW" | "TRY" | "INR" | "RUB" | "BRL" | "ZAR"
  | "DKK" | "PLN" | "THB" | "IDR" | "MYR" | "PHP" | "CZK" | "HUF" | "ILS" | "SAR"
  | "AED" | "CLP" | "COP" | "ARS" | "VND" | "EGP" | "BDT" | "PKR" | "NGN" | "GHS";

interface PriceRange {
  low: number;    // Lower bound for "low" in USD
  medium: number; // Lower bound for "medium" in USD
  high: number;   // Lower bound for "high" in USD
}

const conversionRates: Record<Currency, number> = {
  USD: 1,
  EUR: 1.1,
  GBP: 1.25,
  JPY: 0.007,
  AUD: 0.65,
  CAD: 0.75,
  CHF: 1.1,
  CNY: 0.14,
  SEK: 0.095,
  NZD: 0.6,
  MXN: 0.05,
  SGD: 0.73,
  HKD: 0.13,
  NOK: 0.095,
  KRW: 0.00076,
  TRY: 0.036,
  INR: 0.012,
  RUB: 0.01,
  BRL: 0.2,
  ZAR: 0.05,
  DKK: 0.15,
  PLN: 0.24,
  THB: 0.028,
  IDR: 0.000065,
  MYR: 0.21,
  PHP: 0.017,
  CZK: 0.042,
  HUF: 0.0027,
  ILS: 0.25,
  SAR: 0.27,
  AED: 0.27,
  CLP: 0.0011,
  COP: 0.00025,
  ARS: 0.0027,
  VND: 0.000041,
  EGP: 0.032,
  BDT: 0.0092,
  PKR: 0.0035,
  NGN: 0.0013,
  GHS: 0.08,
};

function classifyPrice(
  input: string,
  priceRange: PriceRange,
  defaultCurrency: Currency = "USD"
): string {
  // Handle predefined classifications ($, $$, $$$)
  if (["$", "$$", "$$$"].includes(input.trim())) {
    return input.trim();
  }

  // Extract numeric range and currency
  const currencyRegex = /[€£¥₹₽₩₺฿₴₦₱]/;
  const rangeRegex = /(\d+)(?:–|-|to)?(\d+)?|\d+\+/;
  
  const currencySymbol = input.match(currencyRegex)?.[0];
  const rangeMatch = input.match(rangeRegex);
  
  const lowerStr = rangeMatch?.[1];
  const upperStr = rangeMatch?.[2];

  const lower = lowerStr ? parseFloat(lowerStr) : undefined;
  const upper = upperStr ? parseFloat(upperStr) : undefined;
  const isOpenEnded = input.includes("+");

  const currency = getCurrencyFromSymbol(currencySymbol) || defaultCurrency;

  // Convert prices to USD
  const conversionRate = conversionRates[currency] || 1;
  const lowerUSD = lower !== undefined ? lower * conversionRate : undefined;
  const upperUSD = upper !== undefined ? upper * conversionRate : undefined;

  // Determine the price value to compare against ranges
  const priceToEvaluate = isOpenEnded ? (lowerUSD || 0) : ((lowerUSD || 0) + (upperUSD || lowerUSD || 0)) / 2;

  // Classify the price
  if (priceToEvaluate < priceRange.low) return "$";
  if (priceToEvaluate < priceRange.medium) return "$$";
  return "$$$";
}

function getCurrencyFromSymbol(symbol?: string): Currency | undefined {
  const symbolToCurrency: Record<string, Currency> = {
    "$": "USD",
    "€": "EUR",
    "£": "GBP",
    "¥": "JPY",
    "₹": "INR",
    "₽": "RUB",
    "₩": "KRW",
    "₺": "TRY",
    "฿": "THB",
    "₴": "UAH",
    "₦": "NGN",
    "₱": "PHP",
  };
  return symbol ? symbolToCurrency[symbol] : undefined;
}

// Example Usage
const priceRange: PriceRange = { low: 10, medium: 50, high: 100 };
const inputs = [
  "$$", "€10–20", "€20–30", "€10–20", "€10–20", "€10–20",
  "$$$", "€20–40", "€10–20", "€20–30", "$$$", "€10–20",
  "$$", "$$$", "€10–20", "$$$", "€20–30", "$$", "€100+", "€10–20"
];

inputs.forEach(input => {
  console.log(`${input} => ${classifyPrice(input, priceRange)}`);
});

more optimized ver

type Currency =
  | "USD" | "EUR" | "GBP" | "JPY" | "AUD" | "CAD" | "CHF" | "CNY" | "SEK" | "NZD"
  | "MXN" | "SGD" | "HKD" | "NOK" | "KRW" | "TRY" | "INR" | "RUB" | "BRL" | "ZAR"
  | "DKK" | "PLN" | "THB" | "IDR" | "MYR" | "PHP" | "CZK" | "HUF" | "ILS" | "SAR"
  | "AED" | "CLP" | "COP" | "ARS" | "VND" | "EGP" | "BDT" | "PKR" | "NGN" | "GHS";

interface PriceRange {
  low: number;    // Lower bound for "low" in USD
  medium: number; // Lower bound for "medium" in USD
  high: number;   // Lower bound for "high" in USD
}

const conversionRates: Record<Currency, number> = {
  USD: 1, EUR: 1.1, GBP: 1.25, JPY: 0.007, AUD: 0.65, CAD: 0.75,
  CHF: 1.1, CNY: 0.14, SEK: 0.095, NZD: 0.6, MXN: 0.05, SGD: 0.73,
  HKD: 0.13, NOK: 0.095, KRW: 0.00076, TRY: 0.036, INR: 0.012, RUB: 0.01,
  BRL: 0.2, ZAR: 0.05, DKK: 0.15, PLN: 0.24, THB: 0.028, IDR: 0.000065,
  MYR: 0.21, PHP: 0.017, CZK: 0.042, HUF: 0.0027, ILS: 0.25, SAR: 0.27,
  AED: 0.27, CLP: 0.0011, COP: 0.00025, ARS: 0.0027, VND: 0.000041,
  EGP: 0.032, BDT: 0.0092, PKR: 0.0035, NGN: 0.0013, GHS: 0.08,
};

// Precompile Regex for reuse
const currencyRegex = /[€£¥₹₽₩₺฿₴₦₱]/;
const rangeRegex = /(\d+)(?:–|-|to)?(\d+)?|\d+\+/;

const symbolToCurrency: Record<string, Currency> = {
  "$": "USD", "€": "EUR", "£": "GBP", "¥": "JPY", "₹": "INR",
  "₽": "RUB", "₩": "KRW", "₺": "TRY", "฿": "THB", "₴": "UAH",
  "₦": "NGN", "₱": "PHP",
};

function classifyPrice(
  input: string,
  priceRange: PriceRange,
  defaultCurrency: Currency = "USD"
): string {
  // Early return for predefined classifications
  const predefined = input.trim();
  if (predefined === "$" || predefined === "$$" || predefined === "$$$") {
    return predefined;
  }

  // Extract currency symbol and range
  const currencySymbol = input.match(currencyRegex)?.[0];
  const rangeMatch = input.match(rangeRegex);

  // Parse price range
  const lower = rangeMatch?.[1] ? parseFloat(rangeMatch[1]) : undefined;
  const upper = rangeMatch?.[2] ? parseFloat(rangeMatch[2]) : undefined;
  const isOpenEnded = input.includes("+");

  const currency = symbolToCurrency[currencySymbol!] || defaultCurrency;
  const conversionRate = conversionRates[currency] || 1;

  // Convert prices to USD
  const lowerUSD = lower !== undefined ? lower * conversionRate : undefined;
  const upperUSD = upper !== undefined ? upper * conversionRate : undefined;

  // Determine price for classification
  const priceToEvaluate = isOpenEnded
    ? lowerUSD || 0
    : ((lowerUSD || 0) + (upperUSD || lowerUSD || 0)) / 2;

  // Classify price
  if (priceToEvaluate < priceRange.low) return "$";
  if (priceToEvaluate < priceRange.medium) return "$$";
  return "$$$";
}

// Example Usage
const priceRange: PriceRange = { low: 10, medium: 50, high: 100 };
const inputs = [
  "$$", "€10–20", "€20–30", "€10–20", "€10–20", "€10–20",
  "$$$", "€20–40", "€10–20", "€20–30", "$$$", "€10–20",
  "$$", "$$$", "€10–20", "$$$", "€20–30", "$$", "€100+", "€10–20"
];

inputs.forEach(input => {
  console.log(`${input} => ${classifyPrice(input, priceRange)}`);
});