import { describe, test, expect } from 'bun:test';
import { readFileSync } from 'fs';
import { join } from 'path';
import { SubtleCryptoProvider } from '@shade/crypto-web';
import {
  computeFingerprint,
  kdfRootKey,
  kdfChainKey,
  deriveInitialRootKey,
} from '../src/index.js';
import { encodeEnvelope, decodeEnvelope } from '@shade/proto';
import type { RatchetMessage, ShadeEnvelope } from '../src/index.js';

const crypto = new SubtleCryptoProvider();

const VECTORS_DIR = join(import.meta.dir, '..', '..', '..', 'test-vectors');

function hex(bytes: Uint8Array): string {
  return Array.from(bytes, (b) => b.toString(16).padStart(2, '0')).join('');
}

function fromHex(str: string): Uint8Array {
  const bytes = new Uint8Array(str.length / 2);
  for (let i = 0; i < bytes.length; i++) {
    bytes[i] = parseInt(str.substring(i * 2, i * 2 + 2), 16);
  }
  return bytes;
}

function loadVectors(name: string): any {
  return JSON.parse(readFileSync(join(VECTORS_DIR, name), 'utf-8'));
}

describe('Cross-platform test vectors', () => {
  test('HKDF vectors match', async () => {
    const { vectors } = loadVectors('hkdf.json');
    for (const v of vectors) {
      const out = await crypto.hkdf(
        fromHex(v.ikm),
        fromHex(v.salt),
        new TextEncoder().encode(v.info),
        v.length,
      );
      expect(hex(out)).toBe(v.output);
    }
  });

  test('KDF chain vectors match', async () => {
    const { vectors } = loadVectors('kdf-chain.json');

    const rootVec = vectors[0];
    const rootResult = await kdfRootKey(
      crypto,
      fromHex(rootVec.rootKey),
      fromHex(rootVec.dhOutput),
    );
    expect(hex(rootResult.newRootKey)).toBe(rootVec.newRootKey);
    expect(hex(rootResult.chainKey)).toBe(rootVec.chainKey);

    const chainVec = vectors[1];
    const chainResult = await kdfChainKey(crypto, fromHex(chainVec.chainKey));
    expect(hex(chainResult.newChainKey)).toBe(chainVec.newChainKey);
    expect(hex(chainResult.messageKey)).toBe(chainVec.messageKey);
  });

  test('X3DH initial root key vectors match', async () => {
    const { vectors } = loadVectors('x3dh.json');
    for (const v of vectors) {
      const rootKey = await deriveInitialRootKey(
        crypto,
        v.secrets.map((s: string) => fromHex(s)),
      );
      expect(hex(rootKey)).toBe(v.rootKey);
    }
  });

  test('Fingerprint vectors match', async () => {
    const { vectors } = loadVectors('fingerprint.json');
    for (const v of vectors) {
      const fp = await computeFingerprint(crypto, fromHex(v.signingKey), fromHex(v.dhKey));
      expect(fp).toBe(v.fingerprint);
    }
  });

  test('Wire format vectors match', () => {
    const { vectors } = loadVectors('wire-format.json');
    const v = vectors[0];

    const msg: RatchetMessage = {
      dhPublicKey: fromHex(v.message.dhPublicKey),
      previousCounter: v.message.previousCounter,
      counter: v.message.counter,
      ciphertext: fromHex(v.message.ciphertext),
      nonce: fromHex(v.message.nonce),
    };
    const envelope: ShadeEnvelope = {
      type: 'ratchet',
      content: msg,
      timestamp: 0,
      senderAddress: '',
    };
    const encoded = encodeEnvelope(envelope);
    expect(hex(encoded)).toBe(v.encoded);

    // Also verify round-trip decode
    const decoded = decodeEnvelope(encoded);
    expect(decoded.type).toBe('ratchet');
    const rm = decoded.content as RatchetMessage;
    expect(rm.counter).toBe(msg.counter);
    expect(hex(rm.ciphertext)).toBe(hex(msg.ciphertext));
  });
});