// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import "package:test/test.dart";

import "package:collection/collection.dart";

// Test unmodifiable collection views.
// The collections should pass through the operations that are allowed,
// an throw on the ones that aren't without affecting the original.

main() {
  var list = <int>[];
  testUnmodifiableList(list, UnmodifiableListView(list), "empty");
  list = [42];
  testUnmodifiableList(list, UnmodifiableListView(list), "single-42");
  list = [7];
  testUnmodifiableList(list, UnmodifiableListView(list), "single!42");
  list = [1, 42, 10];
  testUnmodifiableList(list, UnmodifiableListView(list), "three-42");
  list = [1, 7, 10];
  testUnmodifiableList(list, UnmodifiableListView(list), "three!42");

  list = [];
  testNonGrowableList(list, NonGrowableListView(list), "empty");
  list = [42];
  testNonGrowableList(list, NonGrowableListView(list), "single-42");
  list = [7];
  testNonGrowableList(list, NonGrowableListView(list), "single!42");
  list = [1, 42, 10];
  testNonGrowableList(list, NonGrowableListView(list), "three-42");
  list = [1, 7, 10];
  testNonGrowableList(list, NonGrowableListView(list), "three!42");

  var aSet = Set<int>();
  testUnmodifiableSet(aSet, UnmodifiableSetView(aSet), "empty");
  aSet = Set();
  testUnmodifiableSet(aSet, const UnmodifiableSetView.empty(), "const empty");
  aSet = Set.of([42]);
  testUnmodifiableSet(aSet, UnmodifiableSetView(aSet), "single-42");
  aSet = Set.of([7]);
  testUnmodifiableSet(aSet, UnmodifiableSetView(aSet), "single!42");
  aSet = Set.of([1, 42, 10]);
  testUnmodifiableSet(aSet, UnmodifiableSetView(aSet), "three-42");
  aSet = Set.of([1, 7, 10]);
  testUnmodifiableSet(aSet, UnmodifiableSetView(aSet), "three!42");
}

void testUnmodifiableList(List<int> original, List<int> wrapped, String name) {
  name = "unmodifiable-list-$name";
  testIterable(original, wrapped, name);
  testReadList(original, wrapped, name);
  testNoWriteList(original, wrapped, name);
  testNoChangeLengthList(original, wrapped, name);
}

void testNonGrowableList(List<int> original, List<int> wrapped, String name) {
  name = "nongrowable-list-$name";
  testIterable(original, wrapped, name);
  testReadList(original, wrapped, name);
  testWriteList(original, wrapped, name);
  testNoChangeLengthList(original, wrapped, name);
}

void testUnmodifiableSet(Set<int> original, Set<int> wrapped, String name) {
  name = "unmodifiable-set-$name";
  testIterable(original, wrapped, name);
  testReadSet(original, wrapped, name);
  testNoChangeSet(original, wrapped, name);
}

void testIterable(Iterable<int> original, Iterable<int> wrapped, String name) {
  test("$name - any", () {
    expect(wrapped.any((x) => true), equals(original.any((x) => true)));
    expect(wrapped.any((x) => false), equals(original.any((x) => false)));
  });

  test("$name - contains", () {
    expect(wrapped.contains(0), equals(original.contains(0)));
  });

  test("$name - elementAt", () {
    if (original.isEmpty) {
      expect(() => wrapped.elementAt(0), throwsRangeError);
    } else {
      expect(wrapped.elementAt(0), equals(original.elementAt(0)));
    }
  });

  test("$name - every", () {
    expect(wrapped.every((x) => true), equals(original.every((x) => true)));
    expect(wrapped.every((x) => false), equals(original.every((x) => false)));
  });

  test("$name - expand", () {
    expect(
        wrapped.expand((x) => [x, x]), equals(original.expand((x) => [x, x])));
  });

  test("$name - first", () {
    if (original.isEmpty) {
      expect(() => wrapped.first, throwsStateError);
    } else {
      expect(wrapped.first, equals(original.first));
    }
  });

  test("$name - firstWhere", () {
    if (original.isEmpty) {
      expect(() => wrapped.firstWhere((_) => true), throwsStateError);
    } else {
      expect(wrapped.firstWhere((_) => true),
          equals(original.firstWhere((_) => true)));
    }
    expect(() => wrapped.firstWhere((_) => false), throwsStateError);
  });

  test("$name - fold", () {
    expect(wrapped.fold(0, (x, y) => x + y),
        equals(original.fold(0, (x, y) => x + y)));
  });

  test("$name - forEach", () {
    int wrapCtr = 0;
    int origCtr = 0;
    wrapped.forEach((x) {
      wrapCtr += x;
    });
    original.forEach((x) {
      origCtr += x;
    });
    expect(wrapCtr, equals(origCtr));
  });

  test("$name - isEmpty", () {
    expect(wrapped.isEmpty, equals(original.isEmpty));
  });

  test("$name - isNotEmpty", () {
    expect(wrapped.isNotEmpty, equals(original.isNotEmpty));
  });

  test("$name - iterator", () {
    Iterator wrapIter = wrapped.iterator;
    Iterator origIter = original.iterator;
    while (origIter.moveNext()) {
      expect(wrapIter.moveNext(), equals(true));
      expect(wrapIter.current, equals(origIter.current));
    }
    expect(wrapIter.moveNext(), equals(false));
  });

  test("$name - join", () {
    expect(wrapped.join(""), equals(original.join("")));
    expect(wrapped.join("-"), equals(original.join("-")));
  });

  test("$name - last", () {
    if (original.isEmpty) {
      expect(() => wrapped.last, throwsStateError);
    } else {
      expect(wrapped.last, equals(original.last));
    }
  });

  test("$name - lastWhere", () {
    if (original.isEmpty) {
      expect(() => wrapped.lastWhere((_) => true), throwsStateError);
    } else {
      expect(wrapped.lastWhere((_) => true),
          equals(original.lastWhere((_) => true)));
    }
    expect(() => wrapped.lastWhere((_) => false), throwsStateError);
  });

  test("$name - length", () {
    expect(wrapped.length, equals(original.length));
  });

  test("$name - map", () {
    expect(wrapped.map((x) => "[$x]"), equals(original.map((x) => "[$x]")));
  });

  test("$name - reduce", () {
    if (original.isEmpty) {
      expect(() => wrapped.reduce((x, y) => x + y), throwsStateError);
    } else {
      expect(wrapped.reduce((x, y) => x + y),
          equals(original.reduce((x, y) => x + y)));
    }
  });

  test("$name - single", () {
    if (original.length != 1) {
      expect(() => wrapped.single, throwsStateError);
    } else {
      expect(wrapped.single, equals(original.single));
    }
  });

  test("$name - singleWhere", () {
    if (original.length != 1) {
      expect(() => wrapped.singleWhere((_) => true), throwsStateError);
    } else {
      expect(wrapped.singleWhere((_) => true),
          equals(original.singleWhere((_) => true)));
    }
    expect(() => wrapped.singleWhere((_) => false), throwsStateError);
  });

  test("$name - skip", () {
    expect(wrapped.skip(0), orderedEquals(original.skip(0)));
    expect(wrapped.skip(1), orderedEquals(original.skip(1)));
    expect(wrapped.skip(5), orderedEquals(original.skip(5)));
  });

  test("$name - skipWhile", () {
    expect(wrapped.skipWhile((x) => true),
        orderedEquals(original.skipWhile((x) => true)));
    expect(wrapped.skipWhile((x) => false),
        orderedEquals(original.skipWhile((x) => false)));
    expect(wrapped.skipWhile((x) => x != 42),
        orderedEquals(original.skipWhile((x) => x != 42)));
  });

  test("$name - take", () {
    expect(wrapped.take(0), orderedEquals(original.take(0)));
    expect(wrapped.take(1), orderedEquals(original.take(1)));
    expect(wrapped.take(5), orderedEquals(original.take(5)));
  });

  test("$name - takeWhile", () {
    expect(wrapped.takeWhile((x) => true),
        orderedEquals(original.takeWhile((x) => true)));
    expect(wrapped.takeWhile((x) => false),
        orderedEquals(original.takeWhile((x) => false)));
    expect(wrapped.takeWhile((x) => x != 42),
        orderedEquals(original.takeWhile((x) => x != 42)));
  });

  test("$name - toList", () {
    expect(wrapped.toList(), orderedEquals(original.toList()));
    expect(wrapped.toList(growable: false),
        orderedEquals(original.toList(growable: false)));
  });

  test("$name - toSet", () {
    expect(wrapped.toSet(), unorderedEquals(original.toSet()));
  });

  test("$name - where", () {
    expect(
        wrapped.where((x) => true), orderedEquals(original.where((x) => true)));
    expect(wrapped.where((x) => false),
        orderedEquals(original.where((x) => false)));
    expect(wrapped.where((x) => x != 42),
        orderedEquals(original.where((x) => x != 42)));
  });
}

void testReadList(List original, List wrapped, String name) {
  test("$name - length", () {
    expect(wrapped.length, equals(original.length));
  });

  test("$name - isEmpty", () {
    expect(wrapped.isEmpty, equals(original.isEmpty));
  });

  test("$name - isNotEmpty", () {
    expect(wrapped.isNotEmpty, equals(original.isNotEmpty));
  });

  test("$name - []", () {
    if (original.isEmpty) {
      expect(() {
        wrapped[0];
      }, throwsRangeError);
    } else {
      expect(wrapped[0], equals(original[0]));
    }
  });

  test("$name - indexOf", () {
    expect(wrapped.indexOf(42), equals(original.indexOf(42)));
  });

  test("$name - lastIndexOf", () {
    expect(wrapped.lastIndexOf(42), equals(original.lastIndexOf(42)));
  });

  test("$name - getRange", () {
    int len = original.length;
    expect(wrapped.getRange(0, len), equals(original.getRange(0, len)));
    expect(wrapped.getRange(len ~/ 2, len),
        equals(original.getRange(len ~/ 2, len)));
    expect(
        wrapped.getRange(0, len ~/ 2), equals(original.getRange(0, len ~/ 2)));
  });

  test("$name - sublist", () {
    int len = original.length;
    expect(wrapped.sublist(0), equals(original.sublist(0)));
    expect(wrapped.sublist(len ~/ 2), equals(original.sublist(len ~/ 2)));
    expect(wrapped.sublist(0, len ~/ 2), equals(original.sublist(0, len ~/ 2)));
  });

  test("$name - asMap", () {
    expect(wrapped.asMap(), equals(original.asMap()));
  });
}

void testNoWriteList(List<int> original, List<int> wrapped, String name) {
  var copy = List.of(original);

  testThrows(name, thunk) {
    test(name, () {
      expect(thunk, throwsUnsupportedError);
      // No modifications happened.
      expect(original, equals(copy));
    });
  }

  testThrows("$name - []= throws", () {
    wrapped[0] = 42;
  });

  testThrows("$name - sort throws", () {
    wrapped.sort();
  });

  testThrows("$name - fillRange throws", () {
    wrapped.fillRange(0, wrapped.length, 42);
  });

  testThrows("$name - setRange throws", () {
    wrapped.setRange(
        0, wrapped.length, Iterable.generate(wrapped.length, (i) => i));
  });

  testThrows("$name - setAll throws", () {
    wrapped.setAll(0, Iterable.generate(wrapped.length, (i) => i));
  });
}

void testWriteList(List<int> original, List wrapped, String name) {
  var copy = List.of(original);

  test("$name - []=", () {
    if (original.isNotEmpty) {
      int originalFirst = original[0];
      wrapped[0] = originalFirst + 1;
      expect(original[0], equals(originalFirst + 1));
      original[0] = originalFirst;
    } else {
      expect(() {
        wrapped[0] = 42;
      }, throwsRangeError);
    }
  });

  test("$name - sort", () {
    List sortCopy = List.of(original);
    sortCopy.sort();
    wrapped.sort();
    expect(original, orderedEquals(sortCopy));
    original.setAll(0, copy);
  });

  test("$name - fillRange", () {
    wrapped.fillRange(0, wrapped.length, 37);
    for (int i = 0; i < original.length; i++) {
      expect(original[i], equals(37));
    }
    original.setAll(0, copy);
  });

  test("$name - setRange", () {
    List reverseList = original.reversed.toList();
    wrapped.setRange(0, wrapped.length, reverseList);
    expect(original, equals(reverseList));
    original.setAll(0, copy);
  });

  test("$name - setAll", () {
    List reverseList = original.reversed.toList();
    wrapped.setAll(0, reverseList);
    expect(original, equals(reverseList));
    original.setAll(0, copy);
  });
}

void testNoChangeLengthList(
    List<int> original, List<int> wrapped, String name) {
  var copy = List.of(original);

  void testThrows(String name, thunk) {
    test(name, () {
      expect(thunk, throwsUnsupportedError);
      // No modifications happened.
      expect(original, equals(copy));
    });
  }

  testThrows("$name - length= throws", () {
    wrapped.length = 100;
  });

  testThrows("$name - add throws", () {
    wrapped.add(42);
  });

  testThrows("$name - addAll throws", () {
    wrapped.addAll([42]);
  });

  testThrows("$name - insert throws", () {
    wrapped.insert(0, 42);
  });

  testThrows("$name - insertAll throws", () {
    wrapped.insertAll(0, [42]);
  });

  testThrows("$name - remove throws", () {
    wrapped.remove(42);
  });

  testThrows("$name - removeAt throws", () {
    wrapped.removeAt(0);
  });

  testThrows("$name - removeLast throws", () {
    wrapped.removeLast();
  });

  testThrows("$name - removeWhere throws", () {
    wrapped.removeWhere((element) => false);
  });

  testThrows("$name - retainWhere throws", () {
    wrapped.retainWhere((element) => true);
  });

  testThrows("$name - removeRange throws", () {
    wrapped.removeRange(0, wrapped.length);
  });

  testThrows("$name - replaceRange throws", () {
    wrapped.replaceRange(0, wrapped.length, [42]);
  });

  testThrows("$name - clear throws", () {
    wrapped.clear();
  });
}

void testReadSet(Set<int> original, Set<int> wrapped, String name) {
  var copy = Set.of(original);

  test("$name - containsAll", () {
    expect(wrapped.containsAll(copy), isTrue);
    expect(wrapped.containsAll(copy.toList()), isTrue);
    expect(wrapped.containsAll([]), isTrue);
    expect(wrapped.containsAll([42]), equals(original.containsAll([42])));
  });

  test("$name - intersection", () {
    expect(wrapped.intersection(Set()), isEmpty);
    expect(wrapped.intersection(copy), unorderedEquals(original));
    expect(wrapped.intersection(Set.of([42])),
        Set.of(original.contains(42) ? [42] : []));
  });

  test("$name - union", () {
    expect(wrapped.union(Set()), unorderedEquals(original));
    expect(wrapped.union(copy), unorderedEquals(original));
    expect(wrapped.union(Set.of([42])), equals(original.union(Set.of([42]))));
  });

  test("$name - difference", () {
    expect(wrapped.difference(Set()), unorderedEquals(original));
    expect(wrapped.difference(copy), isEmpty);
    expect(wrapped.difference(Set.of([42])),
        equals(original.difference(Set.of([42]))));
  });
}

void testNoChangeSet(Set<int> original, Set<int> wrapped, String name) {
  var originalElements = original.toList();

  testThrows(name, thunk) {
    test(name, () {
      expect(thunk, throwsUnsupportedError);
      // No modifications happened.
      expect(original.toList(), equals(originalElements));
    });
  }

  testThrows("$name - add throws", () {
    wrapped.add(42);
  });

  testThrows("$name - addAll throws", () {
    wrapped.addAll([42]);
  });

  testThrows("$name - addAll empty throws", () {
    wrapped.addAll([]);
  });

  testThrows("$name - remove throws", () {
    wrapped.remove(42);
  });

  testThrows("$name - removeAll throws", () {
    wrapped.removeAll([42]);
  });

  testThrows("$name - removeAll empty throws", () {
    wrapped.removeAll([]);
  });

  testThrows("$name - retainAll throws", () {
    wrapped.retainAll([42]);
  });

  testThrows("$name - removeWhere throws", () {
    wrapped.removeWhere((_) => false);
  });

  testThrows("$name - retainWhere throws", () {
    wrapped.retainWhere((_) => true);
  });

  testThrows("$name - clear throws", () {
    wrapped.clear();
  });
}

void testReadMap(Map<int, int> original, Map<int, int> wrapped, String name) {
  test("$name length", () {
    expect(wrapped.length, equals(original.length));
  });

  test("$name isEmpty", () {
    expect(wrapped.isEmpty, equals(original.isEmpty));
  });

  test("$name isNotEmpty", () {
    expect(wrapped.isNotEmpty, equals(original.isNotEmpty));
  });

  test("$name operator[]", () {
    expect(wrapped[0], equals(original[0]));
    expect(wrapped[999], equals(original[999]));
  });

  test("$name containsKey", () {
    expect(wrapped.containsKey(0), equals(original.containsKey(0)));
    expect(wrapped.containsKey(999), equals(original.containsKey(999)));
  });

  test("$name containsValue", () {
    expect(wrapped.containsValue(0), equals(original.containsValue(0)));
    expect(wrapped.containsValue(999), equals(original.containsValue(999)));
  });

  test("$name forEach", () {
    int origCnt = 0;
    int wrapCnt = 0;
    wrapped.forEach((k, v) {
      wrapCnt += 1 << k + 3 * v;
    });
    original.forEach((k, v) {
      origCnt += 1 << k + 3 * v;
    });
    expect(wrapCnt, equals(origCnt));
  });

  test("$name keys", () {
    expect(wrapped.keys, orderedEquals(original.keys));
  });

  test("$name values", () {
    expect(wrapped.values, orderedEquals(original.values));
  });
}

testNoChangeMap(Map<int, int> original, Map<int, int> wrapped, String name) {
  var copy = Map.of(original);

  testThrows(name, thunk) {
    test(name, () {
      expect(thunk, throwsUnsupportedError);
      // No modifications happened.
      expect(original, equals(copy));
    });
  }

  testThrows("$name operator[]= throws", () {
    wrapped[0] = 42;
  });

  testThrows("$name putIfAbsent throws", () {
    wrapped.putIfAbsent(0, () => 42);
  });

  testThrows("$name addAll throws", () {
    wrapped.addAll(Map()..[42] = 42);
  });

  testThrows("$name addAll empty throws", () {
    wrapped.addAll(Map());
  });

  testThrows("$name remove throws", () {
    wrapped.remove(0);
  });

  testThrows("$name clear throws", () {
    wrapped.clear();
  });
}