// Copyright 2006 The Bazel Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.devtools.build.lib.syntax;

import static com.google.common.truth.Truth.assertThat;
import static com.google.devtools.build.lib.testutil.MoreAsserts.assertThrows;

import com.google.common.collect.ImmutableMap;
import com.google.devtools.build.lib.packages.StructProvider;
import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
import com.google.devtools.build.lib.syntax.EvalUtils.ComparisonException;
import com.google.devtools.build.lib.syntax.util.EvaluationTestCase;
import javax.annotation.Nullable;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/**
 *  Test properties of the evaluator's datatypes and utility functions
 *  without actually creating any parse trees.
 */
@RunWith(JUnit4.class)
public class EvalUtilsTest extends EvaluationTestCase {

  private static StarlarkList<Object> makeList(@Nullable Mutability mu) {
    return StarlarkList.of(mu, 1, 2, 3);
  }

  private static Dict<Object, Object> makeDict(@Nullable Mutability mu) {
    return Dict.of(mu, 1, 1, 2, 2);
  }

  /** MockClassA */
  @SkylarkModule(name = "MockClassA", doc = "MockClassA")
  public static class MockClassA implements StarlarkValue {}

  /** MockClassB */
  public static class MockClassB extends MockClassA {
  }

  @Test
  public void testDataTypeNames() throws Exception {
    assertThat(EvalUtils.getDataTypeName("foo")).isEqualTo("string");
    assertThat(EvalUtils.getDataTypeName(3)).isEqualTo("int");
    assertThat(EvalUtils.getDataTypeName(Tuple.of(1, 2, 3))).isEqualTo("tuple");
    assertThat(EvalUtils.getDataTypeName(makeList(null))).isEqualTo("list");
    assertThat(EvalUtils.getDataTypeName(makeDict(null))).isEqualTo("dict");
    assertThat(EvalUtils.getDataTypeName(Starlark.NONE)).isEqualTo("NoneType");
    assertThat(EvalUtils.getDataTypeName(new MockClassA())).isEqualTo("MockClassA");
    assertThat(EvalUtils.getDataTypeName(new MockClassB())).isEqualTo("MockClassA");
  }

  @Test
  public void testDatatypeMutabilityPrimitive() throws Exception {
    assertThat(EvalUtils.isImmutable("foo")).isTrue();
    assertThat(EvalUtils.isImmutable(3)).isTrue();
  }

  @Test
  public void testDatatypeMutabilityShallow() throws Exception {
    assertThat(EvalUtils.isImmutable(Tuple.of(1, 2, 3))).isTrue();

    assertThat(EvalUtils.isImmutable(makeList(null))).isTrue();
    assertThat(EvalUtils.isImmutable(makeDict(null))).isTrue();
    assertThat(EvalUtils.isImmutable(makeList(thread.mutability()))).isFalse();
    assertThat(EvalUtils.isImmutable(makeDict(thread.mutability()))).isFalse();
  }

  @Test
  public void testDatatypeMutabilityDeep() throws Exception {
    assertThat(EvalUtils.isImmutable(Tuple.of(makeList(null)))).isTrue();

    assertThat(EvalUtils.isImmutable(Tuple.of(makeList(thread.mutability())))).isFalse();
  }

  @Test
  public void testComparatorWithDifferentTypes() throws Exception {
    Object[] objects = {
      "1",
      2,
      true,
      Starlark.NONE,
      Tuple.of(1, 2, 3),
      Tuple.of("1", "2", "3"),
      StarlarkList.of(thread.mutability(), 1, 2, 3),
      StarlarkList.of(thread.mutability(), "1", "2", "3"),
      Dict.of(thread.mutability(), "key", 123),
      Dict.of(thread.mutability(), 123, "value"),
      StructProvider.STRUCT.create(ImmutableMap.of("key", (Object) "value"), "no field %s"),
    };

    for (int i = 0; i < objects.length; ++i) {
      for (int j = 0; j < objects.length; ++j) {
        if (i != j) {
          Object first = objects[i];
          Object second = objects[j];
          assertThrows(
              ComparisonException.class, () -> EvalUtils.SKYLARK_COMPARATOR.compare(first, second));
        }
      }
    }
  }

  @Test
  public void testComparatorWithNones() throws Exception {
    assertThrows(
        ComparisonException.class,
        () -> EvalUtils.SKYLARK_COMPARATOR.compare(Starlark.NONE, Starlark.NONE));
  }

  @SkylarkModule(name = "ParentType", doc = "A parent class annotated with @SkylarkModule.")
  private static class ParentClassWithSkylarkModule implements StarlarkValue {}

  private static class ChildClass extends ParentClassWithSkylarkModule {}

  private static class StarlarkValueSubclass implements StarlarkValue {
    @Override
    public void repr(Printer printer) {
      printer.append("StarlarkValueSubclass");
    }
  }

  private static class NonStarlarkValueSubclass {}

  @Test
  public void testGetSkylarkType() {
    assertThat(EvalUtils.getSkylarkType(ParentClassWithSkylarkModule.class))
        .isEqualTo(ParentClassWithSkylarkModule.class);
    assertThat(EvalUtils.getSkylarkType(ChildClass.class))
        .isEqualTo(ParentClassWithSkylarkModule.class);
    assertThat(EvalUtils.getSkylarkType(StarlarkValueSubclass.class))
        .isEqualTo(StarlarkValueSubclass.class);

    IllegalArgumentException expected =
        assertThrows(
            IllegalArgumentException.class,
            () -> EvalUtils.getSkylarkType(NonStarlarkValueSubclass.class));
    assertThat(expected)
        .hasMessageThat()
        .contains(
            "class com.google.devtools.build.lib.syntax.EvalUtilsTest$NonStarlarkValueSubclass "
                + "is not allowed as a Starlark value");
  }

  @Test
  public void testLen() {
    assertThat(Starlark.len("abc")).isEqualTo(3);
    assertThat(Starlark.len(Tuple.of(1, 2, 3))).isEqualTo(3);
    assertThat(Starlark.len(StarlarkList.of(null, 1, 2, 3))).isEqualTo(3);
    assertThat(Starlark.len(Dict.of(null, "one", 1, "two", 2))).isEqualTo(2);
    assertThat(Starlark.len(true)).isEqualTo(-1);
    assertThrows(IllegalArgumentException.class, () -> Starlark.len(this));
  }
}