import 'dart:convert';

import 'package:cookit/src/bundle/bundle_codec.dart';
import 'package:cookit/src/recipes/models/recipe.dart';
import 'package:cookit/src/sharing/recipe_code.dart';
import 'package:flutter_test/flutter_test.dart';

import '../support/fixtures.dart';

void main() {
  final now = DateTime(2026, 10, 23);

  Matcher fails(RecipeCodeError error) => throwsA(isA<RecipeCodeException>().having((e) => e.error, 'error', error));

  group('Base45 (RFC 9285 examples)', () {
    const examples = {'AB': 'BB8', 'Hello!!': '%69 VD92EX0', 'base-45': 'UJCLQE7W581', 'ietf!': 'QED8WEX0'};
    examples.forEach((plain, encoded) {
      test(plain, () {
        expect(base45Encode(utf8.encode(plain)), encoded);
        expect(utf8.decode(base45Decode(encoded)), plain);
      });
    });

    test('rejects text that is not Base45', () {
      expect(() => base45Decode('GGW'), throwsFormatException); // 65536
      expect(() => base45Decode('ab'), throwsFormatException);
    });
  });

  test('a Recipe survives the round trip, without what is personal', () {
    final text = RecipeCode.encode(
      recipe(favourite: true, reviewReasons: ['Portionen fehlen.'], photos: ['a.jpg']),
      courseName: 'Brot',
      units: const [BundleUnit(key: 'own-1', label: 'Würfel', direct: true)],
    );
    expect(text, startsWith('COOKIT1:'));
    expect(RegExp(r'^[0-9A-Z $%*+\-./:]+$').hasMatch(text), isTrue, reason: 'QR alphanumeric mode only');

    final shared = RecipeCode.decode(text, now: now);
    final r = shared.recipe;
    expect(shared.courseName, 'Brot');
    expect(shared.units.single.label, 'Würfel');
    expect(r.name, 'Focaccia');
    expect(r.servings, 4);
    expect(r.prepMinutes, 30);
    expect(r.calories?.kcal, 775);
    expect(r.ingredientGroups[0].lines[1].amountMax, 3);
    expect(r.ingredientGroups[0].lines[1].remark, 'gutes');
    expect(r.ingredientGroups[1].name, 'Topping');
    expect(r.stepSections.single.steps, ['Kneten.', 'Gehen lassen.']);
    expect(r.sources, ['https://example.org/focaccia']);
    expect(r.notes, '22x22 cm Form');
    expect(r.favourite, isFalse);
    expect(r.reviewReasons, isEmpty);
    expect(r.photos, isEmpty);
    expect(r.createdAt, now);
  });

  test('notes stay home when asked to', () {
    final text = RecipeCode.encode(recipe(), includeNotes: false);
    expect(RecipeCode.decode(text, now: now).recipe.notes, isNull);
  });

  test('other codes, newer versions and damaged codes are told apart', () {
    final good = RecipeCode.encode(recipe());
    expect(() => RecipeCode.decode('https://example.org', now: now), fails(RecipeCodeError.notARecipeCode));
    expect(() => RecipeCode.decode('COOKITX:123', now: now), fails(RecipeCodeError.notARecipeCode));
    expect(
      () => RecipeCode.decode(good.replaceFirst('COOKIT1', 'COOKIT2'), now: now),
      fails(RecipeCodeError.newerVersion),
    );
    expect(() => RecipeCode.decode(good.substring(0, good.length - 7), now: now), fails(RecipeCodeError.damaged));
  });

  test('the QR code is as small as the text allows, and too much is refused', () {
    final small = RecipeCode.qrCode(RecipeCode.encode(recipe()));
    expect(small.typeNumber, lessThan(20));

    // A long Recipe still fits one code…
    final steps = [for (var i = 0; i < 40; i++) 'Schritt $i: ${'Rühren und abschmecken, dann weiter. ' * 2}'];
    final long = recipe(stepSections: [StepSection(steps: steps)]);
    expect(RecipeCode.qrCode(RecipeCode.encode(long)).typeNumber, greaterThan(small.typeNumber));

    // …but text no compression can shrink does not.
    final noise = [for (var i = 0; i < 3000; i++) String.fromCharCode(0x4E00 + (i * 7919) % 20000)].join();
    final huge = recipe(
      stepSections: [
        StepSection(steps: [noise]),
      ],
    );
    expect(() => RecipeCode.qrCode(RecipeCode.encode(huge)), fails(RecipeCodeError.tooLong));
  });
}