// Copyright 2016 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.cpp;

import static com.google.devtools.build.lib.testutil.MoreAsserts.assertThrows;
import static org.mockito.Mockito.mock;

import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.actions.ActionExecutionException;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.actions.Artifact.SpecialArtifact;
import com.google.devtools.build.lib.actions.ArtifactOwner;
import com.google.devtools.build.lib.actions.ArtifactResolver;
import com.google.devtools.build.lib.actions.ArtifactRoot;
import com.google.devtools.build.lib.actions.util.ActionsTestUtil;
import com.google.devtools.build.lib.collect.nestedset.NestedSet;
import com.google.devtools.build.lib.vfs.FileSystem;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.inmemoryfs.InMemoryFileSystem;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Test. */
@RunWith(JUnit4.class)
public class HeaderDiscoveryTest {

  private final FileSystem fs = new InMemoryFileSystem();
  private final Path execRoot = fs.getPath("/execroot");
  private final Path derivedRoot = execRoot.getRelative("derived");
  private final ArtifactRoot artifactRoot = ArtifactRoot.asDerivedRoot(execRoot, derivedRoot);

  /**
   * Test that an included header is satisfied (=doesn't cause an error) if it provided by a tree
   * artifact.
   */
  @Test
  public void treeArtifactInclusionCheck() throws Exception {
    ArtifactResolver artifactResolver = mock(ArtifactResolver.class);

    checkHeaderInclusion(
        artifactResolver,
        ImmutableList.of(
            derivedRoot.getRelative("tree_artifact/foo.h"),
            derivedRoot.getRelative("tree_artifact/subdir/foo.h")),
        ImmutableList.of(treeArtifact(derivedRoot.getRelative("tree_artifact"))));

    // Implicitly check that there are no exceptions thrown.
  }

  @Test
  public void errorsWhenMissingHeaders() {
    ArtifactResolver artifactResolver = mock(ArtifactResolver.class);

    assertThrows(
        ActionExecutionException.class,
        () ->
            checkHeaderInclusion(
                artifactResolver,
                ImmutableList.of(
                    derivedRoot.getRelative("tree_artifact1/foo.h"),
                    derivedRoot.getRelative("tree_artifact1/subdir/foo.h")),
                ImmutableList.of(treeArtifact(derivedRoot.getRelative("tree_artifact2")))));
  }

  private NestedSet<Artifact> checkHeaderInclusion(
      ArtifactResolver artifactResolver,
      ImmutableList<Path> dependencies,
      ImmutableList<Artifact> includedHeaders)
      throws ActionExecutionException {
    return new HeaderDiscovery.Builder()
        .shouldValidateInclusions()
        .setAction(new ActionsTestUtil.NullAction())
        .setPermittedSystemIncludePrefixes(ImmutableList.of())
        .setSourceFile(new Artifact(derivedRoot.getRelative("foo.cc"), artifactRoot))
        .setDependencies(dependencies)
        .setAllowedDerivedinputs(includedHeaders)
        .build()
        .discoverInputsFromDependencies(execRoot, artifactResolver);
  }

  private SpecialArtifact treeArtifact(Path path) {
    return new SpecialArtifact(
        artifactRoot,
        artifactRoot.getExecPath().getRelative(artifactRoot.getRoot().relativize(path)),
        ArtifactOwner.NullArtifactOwner.INSTANCE,
        Artifact.SpecialArtifactType.TREE);
  }
}