// 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:async_helper/async_helper.dart';
import 'package:expect/expect.dart';
import 'package:compiler/src/types/types.dart';

import 'compiler_helper.dart';

const String CODE = """
class A {}
class B extends A {}
class C extends A {}

class D implements A {}

class E {}
class F extends E {}
class G implements E {}

class H {}
class I implements H {}
class J extends D implements I {}

class K {}
class M extends K with A {}

class N extends H with I {}

main() {
  print([new A(), new B(), new C(), new D(), new E(), new F(), new G(),
      new H(), new I(), new J(), new K(), new M(), new N()]);
}
""";

Uri uri = new Uri(scheme: 'source');
var compiler = compilerFor(CODE, uri);
dynamic world = compiler.resolutionWorldBuilder.closedWorldForTesting;

main() {
  asyncTest(() => compiler.run(uri).then((_) {
        // Empty
        check(' ! ', ' ! '); // both non-null
        check(' ! ', '   '); // one non-null
        check('   ', ' ! '); // one non-null
        check('   ', '   ', areDisjoint: false); // null is common

        // Exact
        check('A!=', 'A!=', areDisjoint: false);
        check('A!=', 'B!=');
        check('A!=', 'E!=');
        check('A =', 'E =', areDisjoint: false); // null is common
        check('M!=', 'K!=');
        check('M!=', 'A!=');

        // Exact with subclass
        check('A!=', 'A!<', areDisjoint: false);
        check('B!=', 'A!<', areDisjoint: false);
        check('A!=', 'B!<');
        check('A!=', 'E!<');
        check('A =', 'E!<');
        check('A =', 'E <', areDisjoint: false);
        check('M!=', 'K!<', areDisjoint: false);
        check('M!=', 'A!<');

        // Exact with subtype
        check('A!=', 'A!*', areDisjoint: false);
        check('B!=', 'A!*', areDisjoint: false);
        check('A!=', 'B!*');
        check('A!=', 'E!*');
        check('A!=', 'I!*');
        check('J!=', 'H!*', areDisjoint: false);
        check('M!=', 'K!*', areDisjoint: false);
        check('M!=', 'A!*', areDisjoint: false);

        // Subclass with subclass
        check('A!<', 'A!<', areDisjoint: false);
        check('A!<', 'B!<', areDisjoint: false);
        check('A!<', 'E!<');
        check('A!<', 'H!<');
        check('D!<', 'I!<');
        check('H!<', 'I!*', areDisjoint: false);

        // Subclass with subtype
        check('A!<', 'A!*', areDisjoint: false);
        check('A!<', 'B!*', areDisjoint: false);
        check('A!<', 'E!*');
        check('A!<', 'H!*');
        check('D!<', 'I!*', areDisjoint: false);

        // Subtype with subtype
        check('A!*', 'A!*', areDisjoint: false);
        check('A!*', 'B!*', areDisjoint: false);
        check('A!*', 'E!*');
        check('A!*', 'H!*', areDisjoint: false);
        check('D!*', 'I!*', areDisjoint: false);

        // Unions!
        checkUnions(['B!=', 'C!='], ['A!=']);
        checkUnions(['B!=', 'C!='], ['A =']);
        checkUnions(['B!=', 'C ='], ['A ='], areDisjoint: false);

        checkUnions(['B!=', 'C!='], ['A!<'], areDisjoint: false);
        checkUnions(['B!=', 'C!='], ['B!='], areDisjoint: false);
        checkUnions(['A!<', 'E!<'], ['C!='], areDisjoint: false);
        checkUnions(['A!<', 'E!<'], ['F!='], areDisjoint: false);

        checkUnions(['A!=', 'E!='], ['C!=', 'F!=']);
        checkUnions(['A!=', 'E!='], ['A!=', 'F!='], areDisjoint: false);
        checkUnions(['B!=', 'E!='], ['A!<', 'F!='], areDisjoint: false);
        checkUnions(['A!<', 'E!<'], ['C!=', 'F!='], areDisjoint: false);
        checkUnions(['A!=', 'E!='], ['C!=', 'F!=']);
      }));
}

/// Checks the expectation of `isDisjoint` for two mask. Also checks that the
/// result is consistent with an equivalent (but slower) implementation based on
/// intersection.
checkMask(TypeMask m1, TypeMask m2, {areDisjoint: false}) {
  print('masks: $m1 $m2');
  Expect.equals(areDisjoint, m1.isDisjoint(m2, world));
  Expect.equals(areDisjoint, m2.isDisjoint(m1, world));
  var i1 = m1.intersection(m2, world);
  Expect.equals(areDisjoint, i1.isEmpty && !i1.isNullable);
  var i2 = m2.intersection(m1, world);
  Expect.equals(areDisjoint, i2.isEmpty && !i2.isNullable);
}

/// Checks the expectation of `isDisjoint` for two mask descriptors (see
/// [maskOf] for details).
check(String typeMaskDescriptor1, String typeMaskDescriptor2,
    {areDisjoint: true}) {
  print('[$typeMaskDescriptor1] & [$typeMaskDescriptor2]');
  checkMask(maskOf(typeMaskDescriptor1), maskOf(typeMaskDescriptor2),
      areDisjoint: areDisjoint);
}

checkUnions(List descriptors1, List descriptors2, {areDisjoint: true}) {
  print('[$descriptors1] & [$descriptors2]');
  var m1 = new TypeMask.unionOf(descriptors1.map(maskOf).toList(), world);
  var m2 = new TypeMask.unionOf(descriptors2.map(maskOf).toList(), world);
  checkMask(m1, m2, areDisjoint: areDisjoint);
}

Map _maskCache = {};
Map _elementCache = {};

/// Parses a descriptor of a flat mask. A descriptor is of the form "AXY" where:
///   A: either a type T or " " (base class or empty)
///   X: can be either ! or " " (nullable/nonnullable)
///   Y: can be either " " (no flag), = (exact), < (subclass), * (subtype)
///
/// Examples:
///   "-! " - empty, non-null
///   "-  " - null
///   "Type!=" - non-null exact Type
///   "Type =" - nullable exact Type
///   "Type!<" - non-null subclass of Type
///   "Type!*" - non-null subtype of Type
TypeMask maskOf(String descriptor) => _maskCache.putIfAbsent(descriptor, () {
      Expect.isTrue(descriptor.length >= 3);
      var type = descriptor.substring(0, descriptor.length - 2);
      bool isNullable = descriptor[descriptor.length - 2] != '!';
      bool isExact = descriptor[descriptor.length - 1] == '=';
      bool isSubclass = descriptor[descriptor.length - 1] == '<';
      bool isSubtype = descriptor[descriptor.length - 1] == '*';

      if (type == " ") {
        Expect.isFalse(isExact || isSubclass || isSubtype);
        return isNullable ? new TypeMask.empty() : new TypeMask.nonNullEmpty();
      }

      Expect.isTrue(isExact || isSubclass || isSubtype);
      var element = _elementCache.putIfAbsent(
          type, () => type == " " ? null : findElement(compiler, type));

      var mask = isExact
          ? new TypeMask.nonNullExact(element, world)
          : (isSubclass
              ? new TypeMask.nonNullSubclass(element, world)
              : new TypeMask.nonNullSubtype(element, world));
      return isNullable ? mask.nullable() : mask;
    });