/*
 * Copyright 2021 The Error Prone Authors.
 *
 * 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.errorprone.bugpatterns;

import com.google.errorprone.BugCheckerRefactoringTestHelper;
import com.google.errorprone.BugCheckerRefactoringTestHelper.FixChoosers;
import com.google.errorprone.CompilationTestHelper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Tests for {@link OptionalOfRedundantMethod}. */
@RunWith(JUnit4.class)
public class OptionalOfRedundantMethodTest {

  private final CompilationTestHelper compilationTestHelper =
      CompilationTestHelper.newInstance(OptionalOfRedundantMethod.class, getClass());
  private final BugCheckerRefactoringTestHelper refactoringTestHelper =
      BugCheckerRefactoringTestHelper.newInstance(OptionalOfRedundantMethod.class, getClass());

  @Test
  public void positive_ifPresent() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                // BUG: Diagnostic contains: ifPresent
                Optional.of("test").ifPresent(String::length);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_ifPresent_refactoring_ofNullableFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                Optional.of("test").ifPresent(String::length);
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                Optional.ofNullable("test").ifPresent(String::length);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_orElse() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                // BUG: Diagnostic contains: orElse
                Optional.of("test").orElse("test2");
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_orElse_refactoring_ofNullableFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              String f() {
                return Optional.of("test").orElse("test2");
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              String f() {
                return Optional.ofNullable("test").orElse("test2");
              }
            }
            """)
        .setFixChooser(FixChoosers.FIRST)
        .doTest();
  }

  @Test
  public void positive_orElse_refactoring_simplifyExpressionFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              String f() {
                return Optional.of("test").orElse("test2");
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              String f() {
                return "test";
              }
            }
            """)
        .setFixChooser(FixChoosers.SECOND)
        .doTest();
  }

  @Test
  public void positive_orElseGet() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                // BUG: Diagnostic contains: orElseGet
                Optional.of("test").orElseGet(() -> "test2");
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_orElseGet_refactoring_ofNullableFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              String f() {
                return Optional.of("test").orElseGet(() -> "test2");
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              String f() {
                return Optional.ofNullable("test").orElseGet(() -> "test2");
              }
            }
            """)
        .setFixChooser(FixChoosers.FIRST)
        .doTest();
  }

  @Test
  public void positive_orElseGet_refactoring_simplifyExpressionFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              String f() {
                return Optional.of("test").orElseGet(() -> "test2");
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              String f() {
                return "test";
              }
            }
            """)
        .setFixChooser(FixChoosers.SECOND)
        .doTest();
  }

  @Test
  public void positive_orElseThrow() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import java.util.Optional;
            import com.google.common.collect.ImmutableMap;

            class Test {
              static String f(ImmutableMap<String, String> map) {
                // BUG: Diagnostic contains: orElseThrow
                return Optional.of(map.get("test")).orElseThrow(IllegalArgumentException::new);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_orElseThrow_refactoring_ofNullableFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;
            import com.google.common.collect.ImmutableMap;

            class Test {
              static String f(ImmutableMap<String, String> map) {
                return Optional.of(map.get("test")).orElseThrow(IllegalArgumentException::new);
              }
            }
            """)
        .addOutputLines(
            "Test.java",
"""
import java.util.Optional;
import com.google.common.collect.ImmutableMap;

class Test {
  static String f(ImmutableMap<String, String> map) {
    return Optional.ofNullable(map.get("test")).orElseThrow(IllegalArgumentException::new);
  }
}
""")
        .setFixChooser(FixChoosers.FIRST)
        .doTest();
  }

  @Test
  public void positive_orElseThrow_refactoring_simplifyExpressionFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;
            import com.google.common.collect.ImmutableMap;

            class Test {
              static String f(ImmutableMap<String, String> map) {
                return Optional.of(map.get("test")).orElseThrow(IllegalArgumentException::new);
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;
            import com.google.common.collect.ImmutableMap;

            class Test {
              static String f(ImmutableMap<String, String> map) {
                return map.get("test");
              }
            }
            """)
        .setFixChooser(FixChoosers.SECOND)
        .doTest();
  }

  @Test
  public void positive_isPresent() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                // BUG: Diagnostic contains: isPresent
                if (Optional.of("test").isPresent()) {}
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_isPresent_refactoring_ofNullableFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                if (Optional.of("test").isPresent()) {}
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                if (Optional.ofNullable("test").isPresent()) {}
              }
            }
            """)
        .setFixChooser(FixChoosers.FIRST)
        .doTest();
  }

  @Test
  public void positive_isPresent_refactoring_simplifyExpressionFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                if (Optional.of("test").isPresent()) {}
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f() {
                if (true) {}
              }
            }
            """)
        .setFixChooser(FixChoosers.SECOND)
        .doTest();
  }

  @Test
  public void positive_guavaIsPresent() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                // BUG: Diagnostic contains: isPresent
                Optional.of("test").isPresent();
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_guavaIsPresent_refactoring_fromNullableFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                Optional.of("test").isPresent();
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                Optional.fromNullable("test").isPresent();
              }
            }
            """)
        .setFixChooser(FixChoosers.FIRST)
        .doTest();
  }

  @Test
  public void positive_guavaIsPresent_refactoring_simplifyExpressionFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                if (Optional.of("test").isPresent()) {}
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                if (true) {}
              }
            }
            """)
        .setFixChooser(FixChoosers.SECOND)
        .doTest();
  }

  @Test
  public void positive_guavaOr() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                // BUG: Diagnostic contains: or
                Optional.of("test").or("");
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_guavaOr_refactoring_fromNullableFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                Optional.of("test").or("");
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                Optional.fromNullable("test").or("");
              }
            }
            """)
        .setFixChooser(FixChoosers.FIRST)
        .doTest();
  }

  @Test
  public void positive_guavaOr_refactoring_simplifyExpressionFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              String f() {
                return Optional.of("test").or("");
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              String f() {
                return "test";
              }
            }
            """)
        .setFixChooser(FixChoosers.SECOND)
        .doTest();
  }

  @Test
  public void positive_guavaOrNull() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                // BUG: Diagnostic contains: orNull
                Optional.of("test").orNull();
              }
            }
            """)
        .doTest();
  }

  @Test
  public void positive_guavaOrNull_refactoring_fromNullableFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                Optional.of("test").orNull();
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              void f() {
                Optional.fromNullable("test").orNull();
              }
            }
            """)
        .setFixChooser(FixChoosers.FIRST)
        .doTest();
  }

  @Test
  public void positive_guavaOrNull_refactoring_simplifyExpressionFix() {
    refactoringTestHelper
        .addInputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              String f() {
                return Optional.of("test").orNull();
              }
            }
            """)
        .addOutputLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              String f() {
                return "test";
              }
            }
            """)
        .setFixChooser(FixChoosers.SECOND)
        .doTest();
  }

  @Test
  public void negative_ifPresent() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f(Optional<String> maybeString) {
                maybeString.ifPresent(String::length);
              }
            }
            """)
        .doTest();
  }

  @Test
  public void negative_orElse() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import java.util.Optional;

            class Test {
              void f(String value) {
                Optional.of(value).filter(x -> x.length() < 5).orElse("test");
              }
            }
            """)
        .doTest();
  }

  @Test
  public void negative_guavaIsPresent() {
    compilationTestHelper
        .addSourceLines(
            "Test.java",
            """
            import com.google.common.base.Optional;

            class Test {
              boolean f(Optional<String> maybeString) {
                return maybeString.isPresent();
              }
            }
            """)
        .doTest();
  }
}
