// The key of words (spec §38.1) against test/vectors/wordkey_vectors.json,
// whose expected values the Go reference computed
// (tool/wordkey_go_vectors.go): the words of wordkey.Normalize, the refusals
// of wordkey.Check with their texts, and the salt and the password of
// wordkey.Key, with PBKDF2 at 1000 iterations. The vectors come from a Dart
// constant, so that these tests also run compiled to JavaScript; the keys of
// 600 000 iterations and their identities are in wordkey_vm_test.dart.

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

import 'package:datekeys/src/bytes.dart';
import 'package:datekeys/src/sha256.dart';
import 'package:datekeys/src/wordkey.dart';
import 'package:test/test.dart';

import 'vectors/wordkey_vectors.g.dart';
import 'wordkey_support.dart';

final Map<String, Object?> vectors =
    jsonDecode(wordkeyVectorsJson) as Map<String, Object?>;

List<Map<String, Object?>> cases(String name) =>
    (vectors[name]! as List).cast<Map<String, Object?>>();

/// "ok", or the message of the [WordKeyException] that [f] throws.
String outcome(void Function() f) {
  try {
    f();
    return 'ok';
  } on WordKeyException catch (e) {
    return e.message;
  }
}

String label(Map<String, Object?> c) =>
    c['name'] as String? ?? '${c['in'] ?? c['words']}';

void main() {
  test('the constants are those of Go', () {
    expect(vectors['rounds'], wordKeyRounds);
    expect(vectors['min_words'], minWords);
    expect(vectors['min_letters'], minLetters);
  });

  test('normalizeWords reads the words as wordkey.Normalize', () {
    final all = cases('normalize');
    expect(all, hasLength(greaterThan(350)));
    var strings = 0;
    for (final c in all) {
      final input = fromHex(c['in']! as String);
      final want = [
        for (final w in (c['words']! as List).cast<String>())
          decodeUtf8(fromHex(w))!,
      ];
      expect(normalizeWordsUtf8(input), want, reason: label(c));
      final s = fromWtf8(input);
      if (s != null) {
        strings++;
        expect(normalizeWords(s), want, reason: label(c));
      }
    }
    expect(strings, greaterThan(300));
  });

  test('checkWords refuses words as wordkey.Check, with its texts', () {
    final all = cases('check');
    expect(all, hasLength(greaterThan(450)));
    var refused = 0;
    for (final c in all) {
      final words = wordBytes(c);
      final want = c['result']! as String;
      expect(outcome(() => checkWordsUtf8(words)), want, reason: label(c));
      if (want != 'ok') refused++;
      final strings = [for (final w in words) fromWtf8(w)];
      if (strings.every((s) => s != null)) {
        expect(
          outcome(() => checkWords([for (final s in strings) s!])),
          want,
          reason: label(c),
        );
      }
    }
    expect(refused, greaterThan(400));
  });

  test('the salt and the password of wordkey.Key', () {
    for (final c in cases('keys')) {
      final words = [for (final w in wordBytes(c)) fromWtf8(w)!];
      final chain = fromHex(c['chain_hash']! as String);
      final round = c['round']! as int;
      final capsuleId = fromHex(c['capsule_id']! as String);
      final salt = wordKeySalt(chain, round, capsuleId);
      expect(salt, utf8Bytes(c['salt']! as String), reason: label(c));
      // The password is the words joined by one U+0020, in UTF-8: with the
      // salt and 1000 iterations, the PBKDF2 of Go. wordKey derives with
      // the same two and 600 000 iterations, on the VM in
      // wordkey_vm_test.dart.
      final password = wordKeyPassword(words);
      expect(toHex(password), c['password'], reason: label(c));
      expect(
        toHex(pbkdf2HmacSha256(password, salt, 1000, 32)),
        c['key_1000'],
        reason: label(c),
      );
    }
  });

  test('a round is an int of 0 to 2^53-1', () {
    final chain = Uint8List(32);
    final id = Uint8List(16);
    expect(() => wordKeySalt(chain, -1, id), throwsRangeError);
    expect(
      () => wordKeySalt(chain, 9007199254740991 + 1, id),
      throwsRangeError,
    );
    expect(
      utf8.decode(wordKeySalt(chain, 9007199254740991, id)),
      contains('|9007199254740991|'),
    );
  });

  test('the examples of spec §38.1 give the same words', () {
    // The three spellings of «abaco arbol», by the names of their cases, and
    // the punctuation that counts.
    final examples = [
      for (final c in cases('normalize'))
        if ((c['name'] as String? ?? '').contains('38.1: ')) c,
    ];
    final spellings = [
      for (final c in examples)
        if ((c['name']! as String).contains('baco')) c['words'],
    ];
    expect(spellings, hasLength(3));
    expect(spellings[0], hasLength(2));
    expect(spellings[1], spellings[0]);
    expect(spellings[2], spellings[0]);
    final punctuation = examples.singleWhere(
      (c) => (c['name']! as String).endsWith('punctuation counts'),
    );
    expect(normalizeWordsUtf8(fromHex(punctuation['in']! as String)), [
      'perro,',
      'perro',
    ]);
  });
}