// Every official fixture of testdata/ through the formats: the PRELUDE, the
// sections and header_binding of each .dkc, its PUBLIC_HEADER and its
// CONTROL_CBOR, decoded and written back to the same bytes, the profile and
// the round time of its DateKey, P = rule(L), and in format 3 the frame of
// BODY, the security area and the place of the head and of the files; and
// each .dkk, whose capsule_digest is the SHA-256 of its .dkc. The values are
// those of the records <name>.json and <name>.dkk.json, which Go wrote.
@TestOn('vm')
library;

import 'dart:convert';
import 'dart:io';
import 'dart:typed_data';

import 'package:datekeys/src/accesskey.dart';
import 'package:datekeys/src/body.dart';
import 'package:datekeys/src/bytes.dart';
import 'package:datekeys/src/control.dart';
import 'package:datekeys/src/datekey.dart';
import 'package:datekeys/src/digest.dart';
import 'package:datekeys/src/errors.dart';
import 'package:datekeys/src/extension.dart';
import 'package:datekeys/src/framing.dart';
import 'package:datekeys/src/header.dart';
import 'package:datekeys/src/padding.dart';
import 'package:datekeys/src/profile.dart';
import 'package:test/test.dart';

typedef Json = Map<String, Object?>;

Json readJson(String path) => jsonDecode(File(path).readAsStringSync()) as Json;

Uint8List readBytes(String path) => File(path).readAsBytesSync();

/// The extensions of a record, as `{critical, id, version, data}`.
List<Object?> recordExtensions(Object? v) => [
  for (final e in ((v as List<Object?>?) ?? const []).cast<Json>())
    [e['critical'], e['id'], e['version'], e['data']],
];

List<Object?> extensionsOf(List<Extension> critical, List<Extension> non) => [
  for (final (c, list) in [(true, critical), (false, non)])
    for (final e in list)
      [c, e.id, e.version, e.data == null ? null : toHex(e.data!)],
];

String codeOf(void Function() body) {
  try {
    body();
    return 'ok';
  } on DateKeysException catch (e) {
    return e.code.code;
  }
}

void main() {
  final names =
      Directory('testdata/fixtures')
          .listSync()
          .map((f) => f.uri.pathSegments.last)
          .where((n) => n.endsWith('.dkc'))
          .map((n) => n.substring(0, n.length - 4))
          .toList()
        ..sort();
  final keys =
      Directory('testdata/fixtures')
          .listSync()
          .map((f) => f.uri.pathSegments.last)
          .where((n) => n.endsWith('.dkk'))
          .toList()
        ..sort();

  test('there are the 26 capsules and the 6 access keys of spec §67, §68', () {
    expect(names, hasLength(26));
    expect(keys, hasLength(6));
  });

  for (final name in names) {
    test(name, () {
      final r = readJson('testdata/fixtures/$name.json');
      final dkc = readBytes('testdata/fixtures/$name.dkc');
      expect(toHex(capsuleDigest(dkc)), r['sha256']);

      // The frame.
      final format = CapsuleFormat.fromVersion(r['format']! as int)!;
      final prelude = parsePrelude(dkc.sublist(0, dkcPreludeSize));
      expect(prelude.format, format);
      expect(toHex(preludeBytes(prelude)), r['prelude']);
      final s = splitCapsule(dkc);
      expect(s.prelude, prelude);
      expect(toHex(s.preludeBytes), r['prelude']);
      expect(toHex(s.publicHeader), r['public_header']);
      expect(s.sealedControl, hasLength(prelude.sealedControlLen));
      expect(s.payload.length, dkc.length - payloadOffset(prelude));
      expect(
        toHex(headerBinding(s.preludeBytes, s.publicHeader)),
        r['header_binding'],
      );

      // PUBLIC_HEADER, its profile and its round.
      final h = decodeHeader(s.publicHeader);
      expect(
        [h.capsuleIdHex, compactDateKey(h.dateKey), h.policy.label],
        [r['capsule_id'], r['datekey'], r['access_policy']],
      );
      expect(
        extensionsOf(h.critical, h.noncritical),
        recordExtensions(r['header_extensions']),
      );
      expect(toHex(encodeHeader(h)), r['public_header']);
      final p = defaultRegistry().lookup(h.dateKey.profileId)!;
      validateDateKey(h.dateKey, p);
      expect(formatRfc3339(unlockAt(h.dateKey, p)!), r['unlock_at']);

      // CONTROL_CBOR, in its format and in no other.
      final control = decodeControl(
        fromHex(r['control_cbor']! as String),
        format,
      );
      expect(
        [toHex(control.headerBinding), toHex(control.payloadIdentity)],
        [r['header_binding'], r['payload_identity']],
      );
      expect(
        extensionsOf(control.critical, control.noncritical),
        recordExtensions(r['control_extensions']),
      );
      expect(toHex(encodeControl(control, format)), r['control_cbor']);
      for (final other in CapsuleFormat.values.where((f) => f != format)) {
        expect(
          codeOf(
            () => decodeControl(fromHex(r['control_cbor']! as String), other),
          ),
          'ERR_UNSUPPORTED_VERSION',
        );
      }
      final plaintext = readBytes('testdata/fixtures/${r['plaintext_file']}');
      if (!format.isPadded) {
        expect([control.payloadLength, control.padding], [null, null]);
        expect(r.containsKey('padding'), isFalse);
        expect(plaintext.length, r['payload_length']);
        return;
      }
      final l = control.payloadLength!;
      final rule = control.padding!;
      expect([l, rule.code], [r['payload_length'], r['padding']]);
      final padded = paddedLength(l, rule);
      expect(padded, r['padded_length']);
      expect(plaintext.length, l);

      // The plaintext of PAYLOAD_AGE is the content and zeros up to P.
      final check = PaddingCheck(l, padded);
      final content = BytesBuilder()
        ..add(check.add(plaintext))
        ..add(check.add(Uint8List(padded - l)));
      check.close();
      expect(content.takeBytes(), plaintext);
      if (format != CapsuleFormat.format3) return;

      // BODY: its frame, the security area, the head and the files.
      final frame = parseBodyFrame(plaintext.sublist(0, bodyFrameSize), l);
      expect(frame.areaLen, r['area_len']);
      final area = plaintext.sublist(
        bodyFrameSize,
        bodyFrameSize + frame.areaLen,
      );
      checkArea(area, frame.securityLen);
      expect(toHex(area.sublist(0, frame.securityLen)), r['security_cbor']);
      final headStart = bodyFrameSize + frame.areaLen;
      expect(
        toHex(plaintext.sublist(headStart, headStart + frame.headLen)),
        r['head_cbor'],
      );
      expect(headStart + frame.headLen, r['content_offset']);
      final files = (r['files'] as List<Object?>?) ?? const [];
      expect(
        contentLength(frame, l),
        [
          0,
          for (final f in files) (f! as Json)['size']! as int,
        ].reduce((a, b) => a + b),
      );
    });
  }

  for (final key in keys) {
    test(key, () {
      final r = readJson('testdata/fixtures/$key.json');
      final raw = readBytes('testdata/fixtures/$key');
      expect(toHex(capsuleDigest(raw)), r['sha256']);
      final k = decodeAccessKey(raw);
      expect(
        [
          toHex(k.credentialId),
          toHex(k.capsuleId),
          k.type,
          toHex(k.material),
          k.verification == null ? null : toHex(k.verification!.capsuleDigest),
        ],
        [
          r['credential_id'],
          r['capsule_id'],
          r['access_type'],
          r['access_material'],
          r['capsule_digest'],
        ],
      );
      expect(
        extensionsOf(k.critical, k.noncritical),
        recordExtensions(r['extensions']),
      );
      checkAccessKeyMaterial(k);
      // capsule_digest is the SHA-256 of the exact bytes of its .dkc, and its
      // capsule_id that of the header of that capsule.
      final dkc = readBytes('testdata/fixtures/${r['capsule']}');
      checkCapsuleDigest(capsuleDigest(dkc), k.verification!.capsuleDigest);
      expect(
        decodeHeader(splitCapsule(dkc).publicHeader).capsuleId,
        k.capsuleId,
      );
      expect(
        codeOf(
          () => checkCapsuleDigest(
            capsuleDigest(raw),
            k.verification!.capsuleDigest,
          ),
        ),
        'ERR_ACCESS_INVALID',
      );
      expect(toHex(encodeAccessKey(k)), toHex(raw));
      k.wipe();
      expect(k.material.every((b) => b == 0), isTrue);
    });
  }
}