// The head, the note, the inspection and the opening, on the VM and
// compiled to JavaScript: the parts of the vectors of Go that
// test/vectors/open_vectors.g.dart holds, with the small fixtures they edit,
// and what the API does with the caller: its errors, the output and the
// sinks, the evaluator of the security area and accept.
library;

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

import 'package:datekeys/datekeys.dart';
import 'package:test/test.dart';

import 'open_support.dart';
import 'tlock_support.dart' show applyEdits;
import 'vectors/open_vectors.g.dart';

final Map<String, Uint8List> _fixtures = {
  for (final e in (jsonDecode(openFixturesJson) as Json).entries)
    e.key: fromHex(e.value! as String),
};

Uint8List fixture(String file) => _fixtures[file]!;

final Json _cases = jsonDecode(openCasesJson) as Json;

/// The case of the part of open_cases.json named [name].
Json caseNamed(String name) => [
  ...(_cases['fixtures']! as List).cast<Json>(),
  ...(_cases['steps']! as List).cast<Json>(),
].firstWhere((c) => c['name'] == name);

/// The options of the opening of the case [name], with [output] and [sink].
OpenOptions optionsOf(
  Json c, {
  ByteSink? output,
  FileSink? sink,
  SecurityEvaluator? evaluator,
  Map<String, String> authorKeys = const {},
  void Function(Verdicts v)? accept,
  ReleaseSource? source,
}) {
  final rel = c['release']! as Json;
  final file = c['dkk_file'] as String?;
  return OpenOptions(
    source:
        source ??
        suppliedRelease(
          Release(rel['round']! as int, fromHex(str(rel, 'signature'))),
        ),
    now: () => parseRfc3339(str(c, 'now')),
    accessKeyFile: file == null ? null : fromHex(file),
    output: output,
    sink: sink,
    evaluator: evaluator ?? evaluateSecurityInput,
    authorKeys: authorKeys,
    accept: accept,
  );
}

void main() {
  group('the vectors of Go', () {
    for (final section in ['fixtures', 'steps']) {
      final cases = (_cases[section]! as List).cast<Json>();
      for (var i = 0; i < cases.length; i++) {
        final c = cases[i];
        test('$section: ${c['name']}', () async {
          final dkc = capsuleOf(c, fixture);
          expect(differences(c, await openCase(c, dkc)), isEmpty);
          // From a source, every fourth: the others run on the VM.
          if (i % 4 == 0) {
            expect(
              differences(c, await openCase(c, dkc, fromSource: true)),
              isEmpty,
            );
          }
        });
      }
    }

    test('the heads', () {
      final h = jsonDecode(openHeadsJson) as Json;
      checkDecodeCases((h['decode']! as List).cast<Json>());
      checkEncodeCases((h['encode']! as List).cast<Json>());
    });

    test('the notes', () {
      final n = jsonDecode(openNotesJson) as Json;
      checkNoteCases(
        (n['check']! as List).cast<Json>(),
        (n['note']! as List).cast<Json>(),
        (n['standard']! as List).cast<Json>(),
      );
    });

    test('the inspection: the views and the mutations', () {
      final v = jsonDecode(openInspectJson) as Json;
      for (final c in (v['views']! as List).cast<Json>()) {
        final r = inspectCapsule(
          capsuleOf(c, fixture),
          extensions: switch (c['registry']) {
            'standard' => const StandardExtensions(),
            'reject_all' => const RejectAll('not today'),
            _ => null,
          },
        );
        expect(
          inspectJson(inspectView(r, file: 'capsule.dkc')),
          c['view'],
          reason: str(c, 'name'),
        );
      }
      final mutations = (v['mutations']! as List).cast<Json>();
      expect(mutations, hasLength(greaterThan(300)));
      for (final m in mutations) {
        final dkc = applyEdits(fixture(str(m, 'base')), m['edits']! as List);
        final r = inspectCapsule(dkc);
        final c = r.checks.last;
        expect(
          [c.step, c.ok, c.error ?? 'ok', if (!c.ok) c.detail],
          [
            m['step'] ?? 8,
            m['result'] == 'ok',
            m['result'],
            if (m['result'] != 'ok') m['text'],
          ],
          reason: 'mutation ${m['index']}',
        );
      }
    });
  });

  group('the caller', () {
    final single = caseNamed('format3_single');
    final keyed = caseNamed('time_and_key_recipients: the .dkk, decoded');
    final plain = caseNamed('time_only_extensions');

    test('gets an ArgumentError for options that do not go together, with '
        'the output aborted', () async {
      final dkc = capsuleOf(keyed, fixture);
      final key = decodeAccessKey(fromHex(str(keyed, 'dkk')));
      final out = RecordingOutput();
      await expectLater(
        openCapsule(
          dkc,
          OpenOptions(
            source: suppliedRelease(),
            now: () => Instant(0),
            accessKey: key,
            accessKeyFile: fromHex(str(keyed, 'dkk')),
            output: out,
          ),
        ),
        throwsArgumentError,
      );
      expect([out.aborted, out.closed], [isArgumentError, false]);
      await expectLater(
        openCapsule(
          dkc,
          OpenOptions(
            source: suppliedRelease(),
            now: () => Instant(0),
            identities: [Uint8List(31)],
            output: RecordingOutput(),
          ),
        ),
        throwsArgumentError,
      );
    });

    test('needs the sink for format 3 and the output for formats 1 and 2, '
        'right after step 2, before any request', () async {
      final calls = CaseSource(null, null);
      final dkc = capsuleOf(single, fixture);
      final out = RecordingOutput();
      await expectLater(
        openCapsule(dkc, optionsOf(single, source: calls, output: out)),
        throwsA(
          isArgumentError.having(
            (e) => '${e.message}',
            'message',
            'open: a format 3 capsule holds files: OpenOptions.sink is '
                'required',
          ),
        ),
      );
      expect(
        [calls.calls, out.aborted, out.log],
        [
          0,
          isArgumentError,
          ['abort'],
        ],
      );
      // Steps 3 to 8 do not matter: a truncated PUBLIC_HEADER after a valid
      // prelude.
      await expectLater(
        openCapsule(dkc.sublist(0, 20), optionsOf(single, source: calls)),
        throwsArgumentError,
      );
      await expectLater(
        openCapsule(
          capsuleOf(plain, fixture),
          optionsOf(plain, source: calls, sink: MemoryFileSink()),
        ),
        throwsA(
          isArgumentError.having(
            (e) => '${e.message}',
            'message',
            'open: a capsule of format 1 or 2 holds one content: '
                'OpenOptions.output is required',
          ),
        ),
      );
      expect(calls.calls, 0);
      // Steps 1 and 2 fail first: no format, nothing needed.
      final r = await openCapsule(dkc.sublist(0, 10), optionsOf(single));
      expect([r.error?.code, r.checks.last.step], [ErrorCode.integrity, 1]);
    });

    test('leaves the sink untouched in formats 1 and 2, and the output in '
        'format 3', () async {
      final sink = RecordingSink();
      final out = RecordingOutput();
      final r = await openCapsule(
        capsuleOf(plain, fixture),
        optionsOf(plain, output: out, sink: sink),
      );
      expect([r.ok, sink.log, out.closed], [true, isEmpty, true]);
      expect(out.log.last, 'close');
      final out3 = RecordingOutput();
      final s = await openCapsule(
        capsuleOf(single, fixture),
        optionsOf(single, output: out3, sink: MemoryFileSink()),
      );
      expect([s.ok, out3.log], [true, isEmpty]);
    });

    test('hands the sink the files in the order of the head, each closed '
        'before the next, and commits last', () async {
      final sink = RecordingSink();
      final r = await openCapsule(
        capsuleOf(single, fixture),
        optionsOf(single, sink: sink),
      );
      expect(r.ok, isTrue);
      expect(sink.log, [
        'begin',
        'create 0',
        for (final l in sink.log.where((l) => l.startsWith('write 0 '))) l,
        'close 0',
        'commit',
      ]);
      final written = sink.log
          .where((l) => l.startsWith('write 0 '))
          .map((l) => int.parse(l.split(' ')[2]))
          .fold(0, (a, b) => a + b);
      expect(written, r.head!.files.single.size);
    });

    test('keeps the files in a MemoryFileSink, given once committed', () async {
      final sink = MemoryFileSink();
      final r = await openCapsule(
        capsuleOf(single, fixture),
        optionsOf(single, sink: sink),
      );
      expect(sink.head, same(r.head));
      expect(sink.files!.single, hasLength(r.head!.files.single.size));
      expect(
        canonical(
          filesOf(Outcome(r, RecordingOutput(), _asRecording(sink), 0, [])),
        ),
        canonical(single['files']),
      );
      expect(sink.aborted, isFalse);
    });

    test('gives the evaluator what Go\'s newSecurityContext takes, once the '
        'head is read, and never fails for it', () async {
      final seen = <SecurityInput>[];
      final dkc = capsuleOf(single, fixture);
      final keys = {'dkauthor1x': 'Ana'};
      final r = await openCapsule(
        dkc,
        optionsOf(
          single,
          sink: MemoryFileSink(),
          authorKeys: keys,
          evaluator: (input) {
            seen.add(input);
            // The control is whole while the evaluator runs.
            expect(input.control.payloadIdentity.any((b) => b != 0), isTrue);
            return Verdicts(
              signature: Verdict.noSignature,
              seal: Verdict.noSeal,
            );
          },
        ),
      );
      expect(r.ok, isTrue);
      final input = seen.single;
      final s = splitCapsule(dkc);
      expect(
        [
          input.format,
          input.roundTime,
          input.authorKeys,
          toHex(input.control.headerBinding),
          decodeHead(input.head).files.single.path,
          input.security.isNotEmpty,
          input.security.length <= r.areaLen!,
        ],
        [
          CapsuleFormat.format3,
          r.inspection.unlockAt,
          keys,
          toHex(headerBinding(s.preludeBytes, s.publicHeader)),
          r.head!.files.single.path,
          true,
          true,
        ],
      );
      expect(
        [r.verdicts!.signature, r.verdicts!.seal],
        [Verdict.noSignature, Verdict.noSeal],
      );
      // I_PAYLOAD is wiped once the opening ends.
      expect(input.control.payloadIdentity.every((b) => b == 0), isTrue);

      // An evaluator that throws: the capsule opens, not evaluated.
      final t = await openCapsule(
        dkc,
        optionsOf(
          single,
          sink: MemoryFileSink(),
          evaluator: (_) => throw StateError('broken'),
        ),
      );
      expect(
        [t.ok, t.verdicts!.evaluated, t.verdicts!.error],
        [true, false, isStateError],
      );
      // The default evaluates as Go: an area without a signature or a seal
      // is F0 and S0.
      expect(
        OpenOptions(
          source: suppliedRelease(r.release!),
          now: () => r.inspection.unlockAt!,
        ).evaluator,
        same(evaluateSecurityInput),
      );
      final d = await openCapsule(
        dkc,
        optionsOf(single, sink: MemoryFileSink()),
      );
      final want = single['verdicts']! as Json;
      expect(
        [
          d.verdicts!.signature?.code,
          d.verdicts!.seal?.code,
          d.verdicts!.lines,
        ],
        [want['signature'], want['seal'], want['lines']],
      );
      expect(want['signature'], 'F0');
    });

    test('shows the verdicts to accept before step 18, which may refuse '
        'them', () async {
      final dkc = capsuleOf(single, fixture);
      final verdicts = Verdicts(
        signature: Verdict.signedOther,
        seal: Verdict.noSeal,
        authorKey: Uint8List(32),
      );
      Verdicts? shown;
      final sink = RecordingSink();
      final out = RecordingOutput();
      final r = await openCapsule(
        dkc,
        optionsOf(
          single,
          sink: sink,
          output: out,
          evaluator: (_) => verdicts,
          accept: (v) {
            shown = v;
            expect(sink.log, isNot(contains('commit')));
            throw 'not signed by Ana';
          },
        ),
      );
      expect(shown, same(verdicts));
      expect(
        [r.ok, r.error, r.refusal, r.head, r.verdicts],
        [false, null, 'not signed by Ana', null, null],
      );
      expect(sink.state, 'aborted');
      expect(out.aborted, 'not signed by Ana');
      expect(
        [r.checks.last.step, r.checks.last.ok, r.checks.last.detail],
        [
          17,
          true,
          'payload authenticated; the caller refused its verdicts and nothing '
              'was published',
        ],
      );
      // Accepted, they are those of the result.
      final a = await openCapsule(
        dkc,
        optionsOf(
          single,
          sink: MemoryFileSink(),
          evaluator: (_) => verdicts,
          accept: (v) {},
        ),
      );
      expect([a.ok, a.verdicts], [true, same(verdicts)]);
    });

    test('does not wipe the credentials of the caller, and wipes the .dkk it '
        'decodes', () async {
      final dkc = capsuleOf(keyed, fixture);
      final key = decodeAccessKey(fromHex(str(keyed, 'dkk')));
      final material = Uint8List.fromList(key.material);
      final identity = Uint8List.fromList(material);
      final out = MemoryByteSink();
      final rel = keyed['release']! as Json;
      final r = await openCapsule(
        dkc,
        OpenOptions(
          source: suppliedRelease(
            Release(rel['round']! as int, fromHex(str(rel, 'signature'))),
          ),
          now: () => parseRfc3339(str(keyed, 'now')),
          accessKey: key,
          identities: [identity],
          output: out,
        ),
      );
      expect(r.ok, isTrue);
      expect([key.material, identity], [material, material]);
      expect(out.bytes, isNotNull);
    });
  });

  group('the sinks of memory', () {
    test('MemoryByteSink gives its bytes once closed, and wipes them on '
        'abort', () {
      final s = MemoryByteSink();
      final a = Uint8List.fromList([1, 2, 3]);
      s.add(a);
      s.add(Uint8List.fromList([4]));
      expect(s.bytes, isNull);
      s.close();
      expect(s.bytes, [1, 2, 3, 4]);
      expect(() => s.add(Uint8List(1)), throwsStateError);
      final t = MemoryByteSink();
      final b = Uint8List.fromList([9, 9]);
      t.add(b);
      t.abort('failed');
      expect(
        [t.bytes, t.abortReason, b],
        [
          null,
          'failed',
          [0, 0],
        ],
      );
      expect(t.close, throwsStateError);
    });

    test('MemoryFileSink gives its files only once committed', () {
      final s = MemoryFileSink();
      final h = Head(
        salt: Uint8List(32),
        files: [
          HeadFile(path: 'a', size: 1, start: 0, end: 1, sha256: Uint8List(32)),
          HeadFile(path: 'b', size: 0, start: 1, end: 1, sha256: Uint8List(32)),
        ],
      );
      s.begin(h);
      s.create(0)
        ..add(Uint8List.fromList([7]))
        ..close();
      s.create(1).close();
      expect([s.head, s.files], [null, null]);
      s.commit();
      expect(s.head, same(h));
      expect(s.files, [
        [7],
        isEmpty,
      ]);
      final t = MemoryFileSink()..begin(h);
      final f = t.create(0)..add(Uint8List.fromList([5]));
      t.abort('no');
      expect([t.aborted, t.files, f.bytes], [true, null, null]);
    });
  });

  group('the sources', () {
    test('BytesSource reads views of its bytes, and readRange keeps '
        'reading', () async {
      final b = Uint8List.fromList(List.generate(100, (i) => i));
      final s = BytesSource(b);
      expect(s.length, 100);
      expect(await s.read(98, 10), [98, 99]);
      expect(await s.read(100, 10), isEmpty);
      final c = ChunkySource(b, 7);
      final r = await readSource(c, 3, 50);
      expect(r, List.generate(50, (i) => i + 3));
      expect(c.reads, 8);
      expect(await readSource(c, 90, 50), List.generate(10, (i) => 90 + i));
    });

    test('a source that gives nothing before its end is an error of the '
        'caller', () async {
      final r = await openCapsuleSource(
        _Short(capsuleOf(singleCase(), fixture)),
        optionsOf(singleCase(), sink: MemoryFileSink()),
      ).then<Object?>((o) => o, onError: (Object e) => e);
      expect(r, isStateError);
    });
  });
}

Json singleCase() => caseNamed('format3_single');

/// readRange of source.dart, which lib/datekeys.dart does not export.
Future<Uint8List> readSource(ByteSource s, int offset, int n) async {
  final out = BytesBuilder();
  for (var at = offset; at < offset + n && at < s.length;) {
    final piece = await s.read(at, offset + n - at);
    if (piece.isEmpty) break;
    out.add(piece);
    at += piece.length;
  }
  return out.takeBytes();
}

// A source whose reads past its first 100 bytes give nothing.
final class _Short implements ByteSource {
  _Short(this._b);
  final Uint8List _b;

  @override
  int get length => _b.length;

  @override
  Future<Uint8List> read(int offset, int n) async {
    if (offset >= 100) return Uint8List(0);
    final end = offset + n < 100 ? offset + n : 100;
    return Uint8List.sublistView(_b, offset, end);
  }
}

// A RecordingSink with the files of [m], for filesOf.
RecordingSink _asRecording(MemoryFileSink m) {
  final r = RecordingSink();
  r.files = [for (final f in m.files!) BytesBuilder()..add(f)];
  return r;
}