import { createHash } from "node:crypto";
import { createReadStream } from "node:fs";
import { pipeline } from "node:stream/promises";

/**
 * Calculate SHA-256 hash of a file
 */
export async function calculateFileHash(filePath: string): Promise<string> {
  const hash = createHash("sha256");
  const stream = createReadStream(filePath);

  await pipeline(stream, hash);

  return `sha256:${hash.digest("hex")}`;
}

/**
 * Calculate SHA-256 hash of a string or buffer
 */
export function calculateHash(content: string | Buffer): string {
  const hash = createHash("sha256");
  hash.update(content);
  return `sha256:${hash.digest("hex")}`;
}

/**
 * Compare two hashes
 */
export function hashesMatch(hash1: string, hash2: string): boolean {
  // Normalize hashes (remove prefix if present)
  const normalize = (hash: string) => {
    if (hash.startsWith("sha256:")) {
      return hash.substring(7);
    }
    return hash;
  };

  return normalize(hash1) === normalize(hash2);
}