GuidShortener

GuidShortener.ts

class GuidShortener {
  public static guidToBase95(guid: string): string {
      const bigInt = this.hexToBigInt(guid);
      let base95String = this.bigIntToBase95(bigInt);

      // Pad the result to ensure it's exactly 20 characters long
      while (base95String.length < 20) {
          base95String = ' ' + base95String; // Using space to pad for simplicity
      }

      return base95String;
  }  

  public static base95ToGUID(base95String: string): string {
    const bigInt = this.base95ToBigInt(base95String);
    const hexString = this.bigIntToHex(bigInt);
    return this.formatGUID(hexString);
  }
  
  private static hexToBigInt(hexString: string): bigint {
      // Remove any hyphens and convert hex string to a BigInt
      return BigInt(`0x${hexString.replace(/-/g, '')}`);
  }

  private static bigIntToBase95(bigInt: bigint): string {
      const base = 95n;
      const characters = Array.from({ length: 95 }, (_, i) => String.fromCharCode(i + 32));
      let result = '';

      while (bigInt > 0n) {
          result = characters[Number(bigInt % base)] + result;
          bigInt /= base;
      }

      return result;
  }

  private static base95ToBigInt(base95String: string): bigint {
      const base = 95n;
      const characters = Array.from({ length: 95 }, (_, i) => String.fromCharCode(i + 32));
      let bigInt = 0n;

      for (let char of base95String.trim()) {
          bigInt = bigInt * base + BigInt(characters.indexOf(char));
      }

      return bigInt;
  }

  private static bigIntToHex(bigInt: bigint): string {
      // Convert BigInt to hex, remove the '0x' prefix, and pad to 32 characters
      let hexString = bigInt.toString(16).padStart(32, '0');
      return hexString;
  }

  private static formatGUID(hexString: string): string {
      // Insert hyphens to format it as a GUID: 8-4-4-4-12
      return `${hexString.slice(0, 8)}-${hexString.slice(8, 12)}-${hexString.slice(12, 16)}-${hexString.slice(16, 20)}-${hexString.slice(20)}`;
  } 
}