import assert from 'node:assert';
import { describe, test } from 'node:test';
import {
  base32Decode,
  base32Encode,
  base64UrlDecode,
  base64UrlEncode,
  buildCarFile,
  bytesToHex,
  cborDecode,
  cborEncode,
  cidToString,
  createAccessJwt,
  createCid,
  createRefreshJwt,
  createTid,
  generateKeyPair,
  getKeyDepth,
  hexToBytes,
  importPrivateKey,
  sign,
  varint,
  verifyAccessJwt,
} from '../src/pds.js';

describe('CBOR Encoding', () => {
  test('encodes simple map', () => {
    const encoded = cborEncode({ hello: 'world', num: 42 });
    // Expected: a2 65 68 65 6c 6c 6f 65 77 6f 72 6c 64 63 6e 75 6d 18 2a
    const expected = new Uint8Array([
      0xa2, 0x65, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x65, 0x77, 0x6f, 0x72, 0x6c,
      0x64, 0x63, 0x6e, 0x75, 0x6d, 0x18, 0x2a,
    ]);
    assert.deepStrictEqual(encoded, expected);
  });

  test('encodes null', () => {
    const encoded = cborEncode(null);
    assert.deepStrictEqual(encoded, new Uint8Array([0xf6]));
  });

  test('encodes booleans', () => {
    assert.deepStrictEqual(cborEncode(true), new Uint8Array([0xf5]));
    assert.deepStrictEqual(cborEncode(false), new Uint8Array([0xf4]));
  });

  test('encodes small integers', () => {
    assert.deepStrictEqual(cborEncode(0), new Uint8Array([0x00]));
    assert.deepStrictEqual(cborEncode(1), new Uint8Array([0x01]));
    assert.deepStrictEqual(cborEncode(23), new Uint8Array([0x17]));
  });

  test('encodes integers >= 24', () => {
    assert.deepStrictEqual(cborEncode(24), new Uint8Array([0x18, 0x18]));
    assert.deepStrictEqual(cborEncode(255), new Uint8Array([0x18, 0xff]));
  });

  test('encodes negative integers', () => {
    assert.deepStrictEqual(cborEncode(-1), new Uint8Array([0x20]));
    assert.deepStrictEqual(cborEncode(-10), new Uint8Array([0x29]));
  });

  test('encodes strings', () => {
    const encoded = cborEncode('hello');
    // 0x65 = text string of length 5
    assert.deepStrictEqual(
      encoded,
      new Uint8Array([0x65, 0x68, 0x65, 0x6c, 0x6c, 0x6f]),
    );
  });

  test('encodes byte strings', () => {
    const bytes = new Uint8Array([1, 2, 3]);
    const encoded = cborEncode(bytes);
    // 0x43 = byte string of length 3
    assert.deepStrictEqual(encoded, new Uint8Array([0x43, 1, 2, 3]));
  });

  test('encodes arrays', () => {
    const encoded = cborEncode([1, 2, 3]);
    // 0x83 = array of length 3
    assert.deepStrictEqual(encoded, new Uint8Array([0x83, 0x01, 0x02, 0x03]));
  });

  test('sorts map keys deterministically', () => {
    const encoded1 = cborEncode({ z: 1, a: 2 });
    const encoded2 = cborEncode({ a: 2, z: 1 });
    assert.deepStrictEqual(encoded1, encoded2);
    // First key should be 'a' (0x61)
    assert.strictEqual(encoded1[1], 0x61);
  });

  test('encodes large integers >= 2^31 without overflow', () => {
    // 2^31 would overflow with bitshift operators (treated as signed 32-bit)
    const twoTo31 = 2147483648;
    const encoded = cborEncode(twoTo31);
    const decoded = cborDecode(encoded);
    assert.strictEqual(decoded, twoTo31);

    // 2^32 - 1 (max unsigned 32-bit)
    const maxU32 = 4294967295;
    const encoded2 = cborEncode(maxU32);
    const decoded2 = cborDecode(encoded2);
    assert.strictEqual(decoded2, maxU32);
  });

  test('encodes 2^31 with correct byte format', () => {
    // 2147483648 = 0x80000000
    // CBOR: major type 0 (unsigned int), additional info 26 (4-byte follows)
    const encoded = cborEncode(2147483648);
    assert.strictEqual(encoded[0], 0x1a); // type 0 | info 26
    assert.strictEqual(encoded[1], 0x80);
    assert.strictEqual(encoded[2], 0x00);
    assert.strictEqual(encoded[3], 0x00);
    assert.strictEqual(encoded[4], 0x00);
  });
});

describe('Base32 Encoding', () => {
  test('encodes bytes to base32lower', () => {
    const bytes = new Uint8Array([0x01, 0x71, 0x12, 0x20]);
    const encoded = base32Encode(bytes);
    assert.strictEqual(typeof encoded, 'string');
    assert.match(encoded, /^[a-z2-7]+$/);
  });
});

describe('CID Generation', () => {
  test('creates CIDv1 with dag-cbor codec', async () => {
    const data = cborEncode({ test: 'data' });
    const cid = await createCid(data);

    assert.strictEqual(cid.length, 36); // 2 prefix + 2 multihash header + 32 hash
    assert.strictEqual(cid[0], 0x01); // CIDv1
    assert.strictEqual(cid[1], 0x71); // dag-cbor
    assert.strictEqual(cid[2], 0x12); // sha-256
    assert.strictEqual(cid[3], 0x20); // 32 bytes
  });

  test('cidToString returns base32lower with b prefix', async () => {
    const data = cborEncode({ test: 'data' });
    const cid = await createCid(data);
    const cidStr = cidToString(cid);

    assert.strictEqual(cidStr[0], 'b');
    assert.match(cidStr, /^b[a-z2-7]+$/);
  });

  test('same input produces same CID', async () => {
    const data1 = cborEncode({ test: 'data' });
    const data2 = cborEncode({ test: 'data' });
    const cid1 = cidToString(await createCid(data1));
    const cid2 = cidToString(await createCid(data2));

    assert.strictEqual(cid1, cid2);
  });

  test('different input produces different CID', async () => {
    const cid1 = cidToString(await createCid(cborEncode({ a: 1 })));
    const cid2 = cidToString(await createCid(cborEncode({ a: 2 })));

    assert.notStrictEqual(cid1, cid2);
  });
});

describe('TID Generation', () => {
  test('creates 13-character TIDs', () => {
    const tid = createTid();
    assert.strictEqual(tid.length, 13);
  });

  test('uses valid base32-sort characters', () => {
    const tid = createTid();
    assert.match(tid, /^[234567abcdefghijklmnopqrstuvwxyz]+$/);
  });

  test('generates monotonically increasing TIDs', () => {
    const tid1 = createTid();
    const tid2 = createTid();
    const tid3 = createTid();

    assert.ok(tid1 < tid2, `${tid1} should be less than ${tid2}`);
    assert.ok(tid2 < tid3, `${tid2} should be less than ${tid3}`);
  });

  test('generates unique TIDs', () => {
    const tids = new Set();
    for (let i = 0; i < 100; i++) {
      tids.add(createTid());
    }
    assert.strictEqual(tids.size, 100);
  });
});

describe('P-256 Signing', () => {
  test('generates key pair with correct sizes', async () => {
    const kp = await generateKeyPair();

    assert.strictEqual(kp.privateKey.length, 32);
    assert.strictEqual(kp.publicKey.length, 33); // compressed
    assert.ok(kp.publicKey[0] === 0x02 || kp.publicKey[0] === 0x03);
  });

  test('can sign data with generated key', async () => {
    const kp = await generateKeyPair();
    const key = await importPrivateKey(kp.privateKey);
    const data = new TextEncoder().encode('test message');
    const sig = await sign(key, data);

    assert.strictEqual(sig.length, 64); // r (32) + s (32)
  });

  test('different messages produce different signatures', async () => {
    const kp = await generateKeyPair();
    const key = await importPrivateKey(kp.privateKey);

    const sig1 = await sign(key, new TextEncoder().encode('message 1'));
    const sig2 = await sign(key, new TextEncoder().encode('message 2'));

    assert.notDeepStrictEqual(sig1, sig2);
  });

  test('bytesToHex and hexToBytes roundtrip', () => {
    const original = new Uint8Array([0x00, 0x0f, 0xf0, 0xff, 0xab, 0xcd]);
    const hex = bytesToHex(original);
    const back = hexToBytes(hex);

    assert.strictEqual(hex, '000ff0ffabcd');
    assert.deepStrictEqual(back, original);
  });

  test('importPrivateKey rejects invalid key lengths', async () => {
    // Too short
    await assert.rejects(
      () => importPrivateKey(new Uint8Array(31)),
      /expected 32 bytes, got 31/,
    );

    // Too long
    await assert.rejects(
      () => importPrivateKey(new Uint8Array(33)),
      /expected 32 bytes, got 33/,
    );

    // Empty
    await assert.rejects(
      () => importPrivateKey(new Uint8Array(0)),
      /expected 32 bytes, got 0/,
    );
  });

  test('importPrivateKey rejects non-Uint8Array input', async () => {
    // Arrays have .length but aren't Uint8Array
    await assert.rejects(
      () => importPrivateKey([1, 2, 3]),
      /Invalid private key/,
    );

    // Strings don't work either
    await assert.rejects(
      () => importPrivateKey('not bytes'),
      /Invalid private key/,
    );

    // null/undefined
    await assert.rejects(() => importPrivateKey(null), /Invalid private key/);
  });
});

describe('MST Key Depth', () => {
  test('returns a non-negative integer', async () => {
    const depth = await getKeyDepth('app.bsky.feed.post/abc123');
    assert.strictEqual(typeof depth, 'number');
    assert.ok(depth >= 0);
  });

  test('is deterministic for same key', async () => {
    const key = 'app.bsky.feed.post/test123';
    const depth1 = await getKeyDepth(key);
    const depth2 = await getKeyDepth(key);
    assert.strictEqual(depth1, depth2);
  });

  test('different keys can have different depths', async () => {
    // Generate many keys and check we get some variation
    const depths = new Set();
    for (let i = 0; i < 100; i++) {
      depths.add(await getKeyDepth(`collection/key${i}`));
    }
    // Should have at least 1 unique depth (realistically more)
    assert.ok(depths.size >= 1);
  });

  test('handles empty string', async () => {
    const depth = await getKeyDepth('');
    assert.strictEqual(typeof depth, 'number');
    assert.ok(depth >= 0);
  });

  test('handles unicode strings', async () => {
    const depth = await getKeyDepth('app.bsky.feed.post/émoji🎉');
    assert.strictEqual(typeof depth, 'number');
    assert.ok(depth >= 0);
  });
});

describe('CBOR Decoding', () => {
  test('decodes what encode produces (roundtrip)', () => {
    const original = { hello: 'world', num: 42 };
    const encoded = cborEncode(original);
    const decoded = cborDecode(encoded);
    assert.deepStrictEqual(decoded, original);
  });

  test('decodes null', () => {
    const encoded = cborEncode(null);
    const decoded = cborDecode(encoded);
    assert.strictEqual(decoded, null);
  });

  test('decodes booleans', () => {
    assert.strictEqual(cborDecode(cborEncode(true)), true);
    assert.strictEqual(cborDecode(cborEncode(false)), false);
  });

  test('decodes integers', () => {
    assert.strictEqual(cborDecode(cborEncode(0)), 0);
    assert.strictEqual(cborDecode(cborEncode(42)), 42);
    assert.strictEqual(cborDecode(cborEncode(255)), 255);
    assert.strictEqual(cborDecode(cborEncode(-1)), -1);
    assert.strictEqual(cborDecode(cborEncode(-10)), -10);
  });

  test('decodes strings', () => {
    assert.strictEqual(cborDecode(cborEncode('hello')), 'hello');
    assert.strictEqual(cborDecode(cborEncode('')), '');
  });

  test('decodes arrays', () => {
    assert.deepStrictEqual(cborDecode(cborEncode([1, 2, 3])), [1, 2, 3]);
    assert.deepStrictEqual(cborDecode(cborEncode([])), []);
  });

  test('decodes nested structures', () => {
    const original = { arr: [1, { nested: true }], str: 'test' };
    const decoded = cborDecode(cborEncode(original));
    assert.deepStrictEqual(decoded, original);
  });
});

describe('CAR File Builder', () => {
  test('varint encodes small numbers', () => {
    assert.deepStrictEqual(varint(0), new Uint8Array([0]));
    assert.deepStrictEqual(varint(1), new Uint8Array([1]));
    assert.deepStrictEqual(varint(127), new Uint8Array([127]));
  });

  test('varint encodes multi-byte numbers', () => {
    // 128 = 0x80 -> [0x80 | 0x00, 0x01] = [0x80, 0x01]
    assert.deepStrictEqual(varint(128), new Uint8Array([0x80, 0x01]));
    // 300 = 0x12c -> [0xac, 0x02]
    assert.deepStrictEqual(varint(300), new Uint8Array([0xac, 0x02]));
  });

  test('base32 encode/decode roundtrip', () => {
    const original = new Uint8Array([0x01, 0x71, 0x12, 0x20, 0xab, 0xcd]);
    const encoded = base32Encode(original);
    const decoded = base32Decode(encoded);
    assert.deepStrictEqual(decoded, original);
  });

  test('buildCarFile produces valid structure', async () => {
    const data = cborEncode({ test: 'data' });
    const cid = await createCid(data);
    const cidStr = cidToString(cid);

    const car = buildCarFile(cidStr, [{ cid: cidStr, data }]);

    assert.ok(car instanceof Uint8Array);
    assert.ok(car.length > 0);
    // First byte should be varint of header length
    assert.ok(car[0] > 0);
  });
});

describe('JWT Base64URL', () => {
  test('base64UrlEncode encodes bytes correctly', () => {
    const input = new TextEncoder().encode('hello world');
    const encoded = base64UrlEncode(input);
    assert.strictEqual(encoded, 'aGVsbG8gd29ybGQ');
    assert.ok(!encoded.includes('+'));
    assert.ok(!encoded.includes('/'));
    assert.ok(!encoded.includes('='));
  });

  test('base64UrlDecode decodes string correctly', () => {
    const decoded = base64UrlDecode('aGVsbG8gd29ybGQ');
    const str = new TextDecoder().decode(decoded);
    assert.strictEqual(str, 'hello world');
  });

  test('base64url roundtrip', () => {
    const original = new Uint8Array([0, 1, 2, 255, 254, 253]);
    const encoded = base64UrlEncode(original);
    const decoded = base64UrlDecode(encoded);
    assert.deepStrictEqual(decoded, original);
  });
});

describe('JWT Creation', () => {
  test('createAccessJwt creates valid JWT structure', async () => {
    const did = 'did:web:test.example';
    const secret = 'test-secret-key';
    const jwt = await createAccessJwt(did, secret);

    const parts = jwt.split('.');
    assert.strictEqual(parts.length, 3);

    // Decode header
    const header = JSON.parse(
      new TextDecoder().decode(base64UrlDecode(parts[0])),
    );
    assert.strictEqual(header.typ, 'at+jwt');
    assert.strictEqual(header.alg, 'HS256');

    // Decode payload
    const payload = JSON.parse(
      new TextDecoder().decode(base64UrlDecode(parts[1])),
    );
    assert.strictEqual(payload.scope, 'com.atproto.access');
    assert.strictEqual(payload.sub, did);
    assert.strictEqual(payload.aud, did);
    assert.ok(payload.iat > 0);
    assert.ok(payload.exp > payload.iat);
  });

  test('createRefreshJwt creates valid JWT with jti', async () => {
    const did = 'did:web:test.example';
    const secret = 'test-secret-key';
    const jwt = await createRefreshJwt(did, secret);

    const parts = jwt.split('.');
    const header = JSON.parse(
      new TextDecoder().decode(base64UrlDecode(parts[0])),
    );
    assert.strictEqual(header.typ, 'refresh+jwt');

    const payload = JSON.parse(
      new TextDecoder().decode(base64UrlDecode(parts[1])),
    );
    assert.strictEqual(payload.scope, 'com.atproto.refresh');
    assert.ok(payload.jti); // has unique token ID
  });
});

describe('JWT Verification', () => {
  test('verifyAccessJwt returns payload for valid token', async () => {
    const did = 'did:web:test.example';
    const secret = 'test-secret-key';
    const jwt = await createAccessJwt(did, secret);

    const payload = await verifyAccessJwt(jwt, secret);
    assert.strictEqual(payload.sub, did);
    assert.strictEqual(payload.scope, 'com.atproto.access');
  });

  test('verifyAccessJwt throws for wrong secret', async () => {
    const did = 'did:web:test.example';
    const jwt = await createAccessJwt(did, 'correct-secret');

    await assert.rejects(
      () => verifyAccessJwt(jwt, 'wrong-secret'),
      /invalid signature/i,
    );
  });

  test('verifyAccessJwt throws for expired token', async () => {
    const did = 'did:web:test.example';
    const secret = 'test-secret-key';
    // Create token that expired 1 second ago
    const jwt = await createAccessJwt(did, secret, -1);

    await assert.rejects(() => verifyAccessJwt(jwt, secret), /expired/i);
  });

  test('verifyAccessJwt throws for refresh token', async () => {
    const did = 'did:web:test.example';
    const secret = 'test-secret-key';
    const jwt = await createRefreshJwt(did, secret);

    await assert.rejects(
      () => verifyAccessJwt(jwt, secret),
      /invalid token type/i,
    );
  });
});