// Copyright 2018 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.rules.python;

import static com.google.common.truth.Truth.assertThat;
import static com.google.devtools.build.lib.rules.python.PythonTestUtils.ensureDefaultIsPY2;
import static com.google.devtools.build.lib.testutil.MoreAsserts.assertThrows;

import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
import com.google.devtools.build.lib.analysis.util.ConfigurationTestCase;
import com.google.devtools.common.options.OptionsParsingException;
import com.google.devtools.common.options.TriState;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Tests for {@link PythonOptions} and {@link PythonConfiguration}. */
@RunWith(JUnit4.class)
public class PythonConfigurationTest extends ConfigurationTestCase {

  private PythonOptions parsePythonOptions(String... cmdline) throws Exception {
    BuildConfiguration config = create(cmdline);
    return config.getOptions().get(PythonOptions.class);
  }

  @Test
  public void invalidTargetPythonValue_NotATargetValue() {
    OptionsParsingException expected =
        assertThrows(OptionsParsingException.class, () -> create("--force_python=PY2AND3"));
    assertThat(expected).hasMessageThat().contains("Not a valid Python major version");
  }

  @Test
  public void invalidTargetPythonValue_UnknownValue() {
    OptionsParsingException expected =
        assertThrows(
            OptionsParsingException.class,
            () -> create("--force_python=BEETLEJUICE"));
    assertThat(expected).hasMessageThat().contains("Not a valid Python major version");
  }

  @Test
  public void oldVersionFlagGatedByExperimentalFlag() throws Exception {
    create("--experimental_remove_old_python_version_api=false", "--force_python=PY2");
    checkError(
        "`--force_python` is disabled by `--experimental_remove_old_python_version_api`",
        "--experimental_remove_old_python_version_api=true",
        "--force_python=PY2");
  }

  @Test
  public void getPythonVersion_HardcodedDefaultWhenOmitted() throws Exception {
    ensureDefaultIsPY2();
    PythonOptions opts = parsePythonOptions();
    assertThat(opts.getPythonVersion()).isEqualTo(PythonVersion.PY2);
  }

  @Test
  public void getPythonVersion_NewFlagTakesPrecedence() throws Exception {
    ensureDefaultIsPY2();
    // --force_python is superseded by --python_version.
    PythonOptions opts = parsePythonOptions("--force_python=PY2", "--python_version=PY3");
    assertThat(opts.getPythonVersion()).isEqualTo(PythonVersion.PY3);
  }

  @Test
  public void getPythonVersion_FallBackOnOldFlag() throws Exception {
    ensureDefaultIsPY2();
    // --force_python is used because --python_version is absent.
    PythonOptions opts = parsePythonOptions("--force_python=PY3");
    assertThat(opts.getPythonVersion()).isEqualTo(PythonVersion.PY3);
  }

  @Test
  public void canTransitionPythonVersion_OldSemantics_Yes() throws Exception {
    ensureDefaultIsPY2();
    PythonOptions opts =
        parsePythonOptions("--experimental_allow_python_version_transitions=false");
    assertThat(opts.canTransitionPythonVersion(PythonVersion.PY3)).isTrue();
  }

  @Test
  public void canTransitionPythonVersion_OldSemantics_NoBecauseAlreadySet() throws Exception {
    ensureDefaultIsPY2();
    PythonOptions optsWithOldFlag =
        parsePythonOptions(
            "--experimental_allow_python_version_transitions=false",
            "--experimental_remove_old_python_version_api=false",
            "--force_python=PY2");
    PythonOptions optsWithNewFlag =
        parsePythonOptions(
            "--experimental_allow_python_version_transitions=false", "--python_version=PY2");
    assertThat(optsWithOldFlag.canTransitionPythonVersion(PythonVersion.PY3)).isFalse();
    assertThat(optsWithNewFlag.canTransitionPythonVersion(PythonVersion.PY3)).isFalse();
  }

  @Test
  public void canTransitionPythonVersion_OldSemantics_NoBecauseNewValueSameAsDefault()
      throws Exception {
    ensureDefaultIsPY2();
    PythonOptions opts =
        parsePythonOptions("--experimental_allow_python_version_transitions=false");
    assertThat(opts.canTransitionPythonVersion(PythonVersion.PY2)).isFalse();
  }

  @Test
  public void canTransitionPythonVersion_NewSemantics_Yes() throws Exception {
    PythonOptions opts =
        parsePythonOptions(
            "--experimental_allow_python_version_transitions=true", "--python_version=PY3");
    assertThat(opts.canTransitionPythonVersion(PythonVersion.PY2)).isTrue();
  }

  @Test
  public void canTransitionPythonVersion_NewSemantics_NoBecauseSameAsCurrent() throws Exception {
    PythonOptions opts =
        parsePythonOptions(
            "--experimental_allow_python_version_transitions=true",
            // Set --force_python too, or else we fall into the "make --force_python consistent"
            // case.
            "--experimental_remove_old_python_version_api=false",
            "--force_python=PY3",
            "--python_version=PY3");
    assertThat(opts.canTransitionPythonVersion(PythonVersion.PY3)).isFalse();
  }

  @Test
  public void canTransitionPythonVersion_NewApi_YesBecauseForcePythonDisagrees() throws Exception {
    PythonOptions opts =
        parsePythonOptions(
            "--experimental_allow_python_version_transitions=true",
            "--experimental_remove_old_python_version_api=false",
            // Test that even though getPythonVersion() would not be affected by a transition (it is
            // PY3 before and after), the transition is still considered necessary because
            // --force_python's value needs to be brought in sync.
            "--force_python=PY2",
            "--python_version=PY3");
    assertThat(opts.canTransitionPythonVersion(PythonVersion.PY3)).isTrue();
  }

  @Test
  public void setPythonVersion() throws Exception {
    PythonOptions opts = parsePythonOptions("--force_python=PY2", "--python_version=PY2");
    opts.setPythonVersion(PythonVersion.PY3);
    assertThat(opts.forcePython).isEqualTo(PythonVersion.PY3);
    assertThat(opts.pythonVersion).isEqualTo(PythonVersion.PY3);
  }

  @Test
  public void getHost_CopiesMostValues() throws Exception {
    PythonOptions opts =
        parsePythonOptions(
            "--experimental_allow_python_version_transitions=true",
            "--experimental_remove_old_python_version_api=true",
            "--build_python_zip=true");
    PythonOptions hostOpts = (PythonOptions) opts.getHost();
    assertThat(hostOpts.experimentalAllowPythonVersionTransitions).isTrue();
    assertThat(hostOpts.experimentalRemoveOldPythonVersionApi).isTrue();
    assertThat(hostOpts.buildPythonZip).isEqualTo(TriState.YES);
  }

  @Test
  public void getHost_AppliesHostForcePython() throws Exception {
    ensureDefaultIsPY2();
    PythonOptions optsWithOldFlag =
        parsePythonOptions(
            "--experimental_remove_old_python_version_api=false",
            "--force_python=PY2",
            "--host_force_python=PY3");
    PythonOptions optsWithNewFlag =
        parsePythonOptions("--python_version=PY2", "--host_force_python=PY3");
    PythonOptions hostOptsWithOldFlag = (PythonOptions) optsWithOldFlag.getHost();
    PythonOptions hostOptsWithNewFlag = (PythonOptions) optsWithNewFlag.getHost();
    assertThat(hostOptsWithOldFlag.getPythonVersion()).isEqualTo(PythonVersion.PY3);
    assertThat(hostOptsWithNewFlag.getPythonVersion()).isEqualTo(PythonVersion.PY3);
  }
}