// The samples of the interoperability of the age writer: age files that
// this library writes with SeededRandomSource, from recipes, for Go to open
// (tool/age_interop_dart_samples.dart writes them, and
// tool/age_interop_go_verdicts.go opens them with filippo.io/age and the
// identities of agewrap and writes test/vectors/age_interop.json). Each
// recipe names its seed, its recipients, its plaintext (the pattern of its
// length, or another age file, as INNER_ACCESS_AGE inside OUTER_TIME_AGE),
// the pieces in which the plaintext arrives, and the identities that open
// it. They read no file.

import 'dart:typed_data';

import 'package:datekeys/datekeys.dart';
import 'package:datekeys/src/age.dart';
import 'package:datekeys/src/age_writer.dart';
import 'package:datekeys/src/agewrap.dart';
import 'package:datekeys/src/sha256.dart';

import 'age_writer_support.dart';

String _x(String label) => X25519Recipient.of(labelIdentity(label)).toString();

String _secret(String label) => labelIdentity(label).toString();

String _raw(String label) => toHex(labelIdentity(label).secretKey);

/// The recipes of the samples, in the form of age_interop.json.
List<Json> interopSamples() {
  final sixteen = [for (var i = 0; i < 16; i++) 'interop slot $i'];
  Json access(List<String> labels, int slots) => {
    'access': [for (final l in labels) _raw(l)],
    'slots': slots,
  };
  return [
    for (final n in [0, 1, 65535, 65536, 65537, 131072, 3 << 20 | 1])
      {
        'name': 'x25519, $n bytes',
        'seed': 'interop x25519 $n',
        'recipients': [
          {'x25519': _x('interop one')},
        ],
        'length': n,
        'node': n <= 131072,
        'openers': [
          {'x25519': _secret('interop one')},
          {'payload': _raw('interop one')},
          {'x25519': _secret('interop stranger')},
          {'payload': _raw('interop stranger')},
        ],
      },
    {
      'name': 'x25519, 200000 bytes in pieces',
      'seed': 'interop pieces',
      'recipients': [
        {'x25519': _x('interop one')},
      ],
      'length': 200000,
      'pieces': [1, 7, 65535, 65537, 1000, 3],
      'node': true,
      'openers': [
        {'x25519': _secret('interop one')},
      ],
    },
    {
      'name': 'x25519, three recipients',
      'seed': 'interop three',
      'recipients': [
        for (final l in ['interop a', 'interop b', 'interop c'])
          {'x25519': _x(l)},
      ],
      'length': 1000,
      'node': true,
      'openers': [
        for (final l in ['interop a', 'interop b', 'interop c'])
          {'x25519': _secret(l)},
        access(['interop b'], 0),
        access(['interop a', 'interop stranger'], 0),
        {'payload': _raw('interop a')},
        access(['interop a'], 16),
      ],
    },
    {
      'name': 'x25519, sixteen recipients',
      'seed': 'interop sixteen',
      'recipients': [
        for (final l in sixteen) {'x25519': _x(l)},
      ],
      'length': 103,
      'node': true,
      'openers': [
        access([sixteen[0]], 16),
        access([sixteen[7]], 16),
        access([sixteen[15]], 16),
        access([sixteen[3], sixteen[9]], 16),
        access(['interop stranger'], 16),
        access([sixteen[5]], 0),
      ],
    },
    {
      'name': 'tlock, round 1000',
      'seed': 'interop tlock',
      'recipients': [
        {'tlock': 1000},
      ],
      'length': 103,
      'node': true,
      'openers': [
        {'tlock': 1000, 'release': 1000},
        {'tlock': 1001, 'release': 1001},
      ],
    },
    {
      'name': 'tlock over sixteen x25519, as SEALED_CONTROL',
      'seed': 'interop sealed control',
      'recipients': [
        {'tlock': 1000},
      ],
      'inner': {
        'seed': 'interop inner access',
        'recipients': [
          for (final l in sixteen) {'x25519': _x(l)},
        ],
        'length': 103,
      },
      'node': false,
      'openers': [
        {
          'tlock': 1000,
          'release': 1000,
          'then': access([sixteen[11]], 16),
        },
        {
          'tlock': 1000,
          'release': 1000,
          'then': access(['interop stranger'], 16),
        },
      ],
    },
    for (final wf in [10, 16])
      {
        'name': 'scrypt, work factor $wf',
        'seed': 'interop scrypt $wf',
        'recipients': [
          {'scrypt': 'una contraseña larga de prueba', 'work_factor': wf},
        ],
        'length': 120,
        'node': wf <= 10,
        'openers': [
          {'scrypt': 'una contraseña larga de prueba', 'max_work_factor': 16},
          {'scrypt': 'otra contraseña', 'max_work_factor': 16},
          {
            'scrypt': 'una contraseña larga de prueba',
            'max_work_factor': wf - 1,
          },
        ],
      },
  ];
}

/// The file of [sample], as this library writes it from its recipe.
Uint8List writeSample(Json sample) {
  final rs = [for (final r in listOf(sample['recipients'])) recipientOf(r)];
  final inner = sample['inner'] as Json?;
  final plain = inner == null
      ? pattern(sample['length']! as int)
      : writeSample(inner);
  final source = seeded(sample['seed']! as String);
  final pieces = sample['pieces'] as List?;
  if (pieces == null) return ageEncrypt(plain, rs, random: source);
  return encryptInPieces(plain, rs, source, pieces.cast<int>());
}

/// The plaintext that [sample] holds in the end: the pattern of its length,
/// in its inner file when it has one.
Uint8List finalPlaintext(Json sample) {
  final inner = sample['inner'] as Json?;
  return pattern((inner ?? sample)['length']! as int);
}

/// What this library makes of [file] with [opener], in the form of the
/// verdicts of Go: the SHA-256 and the length of the plaintext, or the text
/// of the error.
Json openWith(Uint8List file, Json opener) {
  try {
    final plain = _open(file, opener);
    return {
      'plaintext_length': plain.length,
      'plaintext_sha256': toHex(sha256(plain)),
    };
  } on AgeException catch (e) {
    return {'error': e.message};
  } on DateKeysException catch (e) {
    return {'error': e.message};
  }
}

Uint8List _open(Uint8List file, Json o) {
  final AgeIdentity id;
  if (o['x25519'] case final String s) {
    id = X25519Identity.parse(s);
  } else if (o['payload'] case final String raw) {
    id = PayloadIdentity(fromHex(raw));
  } else if (o['access'] case final List<Object?> ids) {
    id = AccessIdentity(o['slots']! as int, [
      for (final r in ids.cast<String>()) X25519Identity(fromHex(r)),
    ]);
  } else if (o['scrypt'] case final String pass) {
    id = ScryptIdentity(pass, maxWorkFactor: o['max_work_factor']! as int);
  } else {
    final round = o['tlock']! as int;
    final release = o['release']! as int;
    id = TimeIdentity(
      quicknet(),
      round,
      Release(release, fromHex(releases[release]!)),
    );
  }
  final plain = ageDecrypt(file, [id]);
  final then = o['then'] as Json?;
  return then == null ? plain : _open(plain, then);
}