// Copyright 2017 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.analysis;

import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.fail;

import com.google.common.base.Suppliers;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.actions.Root;
import com.google.devtools.build.lib.analysis.LocationExpander.LocationFunction;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.vfs.FileSystem;
import com.google.devtools.build.lib.vfs.inmemoryfs.InMemoryFileSystem;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.stream.Collectors;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Unit tests for {@link LocationExpander.LocationFunction}. */
@RunWith(JUnit4.class)
public class LocationFunctionTest {
  private FileSystem fs;

  @Before
  public void createFileSystem() throws Exception {
    fs = new InMemoryFileSystem();
  }

  private Artifact makeArtifact(String path) {
    if (path.startsWith("/exec/out")) {
      return new Artifact(
          fs.getPath(path), Root.asDerivedRoot(fs.getPath("/exec"), fs.getPath("/exec/out")));
    } else {
      return new Artifact(fs.getPath(path), Root.asSourceRoot(fs.getPath("/exec")));
    }
  }

  @Test
  public void absoluteAndRelativeLabels() throws Exception {
    LocationFunction func =
        new LocationFunctionBuilder("//foo", false).add("//foo", "/exec/src/bar").build();
    assertThat(func.apply("//foo")).isEqualTo("src/bar");
    assertThat(func.apply(":foo")).isEqualTo("src/bar");
    assertThat(func.apply("foo")).isEqualTo("src/bar");
  }

  @Test
  public void pathUnderExecRootUsesDotSlash() throws Exception {
    LocationFunction func =
        new LocationFunctionBuilder("//foo", false).add("//foo", "/exec/bar").build();
    assertThat(func.apply("//foo")).isEqualTo("./bar");
  }

  @Test
  public void noSuchLabel() throws Exception {
    LocationFunction func = new LocationFunctionBuilder("//foo", false).build();
    try {
      func.apply("//bar");
      fail();
    } catch (IllegalStateException expected) {
      assertThat(expected).hasMessageThat()
          .isEqualTo(
              "label '//bar:bar' in $(location) expression is not a declared prerequisite of this "
              + "rule");
    }
  }

  @Test
  public void emptyList() throws Exception {
    LocationFunction func = new LocationFunctionBuilder("//foo", false).add("//foo").build();
    try {
      func.apply("//foo");
      fail();
    } catch (IllegalStateException expected) {
      assertThat(expected).hasMessageThat()
          .isEqualTo("label '//foo:foo' in $(location) expression expands to no files");
    }
  }

  @Test
  public void tooMany() throws Exception {
    LocationFunction func =
        new LocationFunctionBuilder("//foo", false).add("//foo", "/exec/1", "/exec/2").build();
    try {
      func.apply("//foo");
      fail();
    } catch (IllegalStateException expected) {
      assertThat(expected).hasMessageThat()
          .isEqualTo(
              "label '//foo:foo' in $(location) expression expands to more than one file, "
              + "please use $(locations //foo:foo) instead.  Files (at most 5 shown) are: "
              + "[./1, ./2]");
    }
  }

  @Test
  public void noSuchLabelMultiple() throws Exception {
    LocationFunction func = new LocationFunctionBuilder("//foo", true).build();
    try {
      func.apply("//bar");
      fail();
    } catch (IllegalStateException expected) {
      assertThat(expected).hasMessageThat()
          .isEqualTo(
              "label '//bar:bar' in $(locations) expression is not a declared prerequisite of this "
              + "rule");
    }
  }

  @Test
  public void fileWithSpace() throws Exception {
    LocationFunction func =
        new LocationFunctionBuilder("//foo", false).add("//foo", "/exec/file/with space").build();
    assertThat(func.apply("//foo")).isEqualTo("'file/with space'");
  }

  @Test
  public void multipleFiles() throws Exception {
    LocationFunction func = new LocationFunctionBuilder("//foo", true)
        .add("//foo", "/exec/foo/bar", "/exec/out/foo/foobar")
        .build();
    assertThat(func.apply("//foo")).isEqualTo("foo/bar foo/foobar");
  }

  @Test
  public void filesWithSpace() throws Exception {
    LocationFunction func = new LocationFunctionBuilder("//foo", true)
        .add("//foo", "/exec/file/with space", "/exec/file/with spaces ")
        .build();
    assertThat(func.apply("//foo")).isEqualTo("'file/with space' 'file/with spaces '");
  }

  @Test
  public void execPath() throws Exception {
    LocationFunction func = new LocationFunctionBuilder("//foo", true)
        .setExecPaths(true)
        .add("//foo", "/exec/bar", "/exec/out/foobar")
        .build();
    assertThat(func.apply("//foo")).isEqualTo("./bar out/foobar");
  }

  private final class LocationFunctionBuilder {
    private final Label root;
    private final boolean multiple;
    private boolean execPaths;
    private final Map<Label, Collection<Artifact>> labelMap = new HashMap<>();

    LocationFunctionBuilder(String rootLabel, boolean multiple) {
      this.root = Label.parseAbsoluteUnchecked(rootLabel);
      this.multiple = multiple;
    }

    public LocationFunction build() {
      return new LocationFunction(root, Suppliers.ofInstance(labelMap), execPaths, multiple);
    }

    public LocationFunctionBuilder setExecPaths(boolean execPaths) {
      this.execPaths = execPaths;
      return this;
    }

    public LocationFunctionBuilder add(String label, String... paths) {
      labelMap.put(
          Label.parseAbsoluteUnchecked(label),
          Arrays.stream(paths)
              .map(LocationFunctionTest.this::makeArtifact)
              .collect(Collectors.toList()));
      return this;
    }
  }
}