Parse UUID Pipe

import {
  PipeTransform,
  Injectable,
  BadRequestException,
  ArgumentMetadata,
} from "@nestjs/common";

type UuidVersion = 1 | 2 | 3 | 4 | 5 | "all";

const UUID_REGEX: Record<UuidVersion, RegExp> = {
  1: /^[0-9a-f]{8}-[0-9a-f]{4}-1[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i,
  2: /^[0-9a-f]{8}-[0-9a-f]{4}-2[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i,
  3: /^[0-9a-f]{8}-[0-9a-f]{4}-3[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i,
  4: /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i,
  5: /^[0-9a-f]{8}-[0-9a-f]{4}-5[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i,
  all: /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i,
};

export interface ParseUuidPipeOptions {
  version?: UuidVersion;
  optional?: boolean;
  errorHttpStatusCode?: number;
}

@Injectable()
export class ParseUuidPipe implements PipeTransform<string> {
  private readonly version: UuidVersion;
  private readonly optional: boolean;

  constructor(options: ParseUuidPipeOptions = {}) {
    this.version = options.version ?? "all";
    this.optional = options.optional ?? false;
  }

  transform(value: string, metadata: ArgumentMetadata): string {
    // Handle optional values
    if (this.optional && (value === undefined || value === null)) {
      return value;
    }

    if (!value) {
      throw new BadRequestException(
        `Validation failed (uuid is expected for ${metadata.data || "parameter"})`
      );
    }

    const regex = UUID_REGEX[this.version];
    
    if (!regex.test(value)) {
      const versionMessage =
        this.version === "all"
          ? "valid UUID"
          : `UUID version ${this.version}`;
          
      throw new BadRequestException(
        `Validation failed (${versionMessage} expected for ${metadata.data || "parameter"})`
      );
    }

    return value.toLowerCase();
  }
}

// Usage examples:
/*
import { ParseUuidPipe } from "./pipes/parse-uuid.pipe";

@Controller("users")
export class UsersController {
  // Default - accepts any UUID version
  @Get(":id")
  findOne(@Param("id", ParseUuidPipe) id: string) {}

  // Specific version
  @Get("v4/:id")
  findOneV4(@Param("id", new ParseUuidPipe({ version: 4 })) id: string) {}

  // Optional UUID
  @Get()
  findAll(@Query("parentId", new ParseUuidPipe({ optional: true })) parentId?: string) {}
}
*/