// Copyright 2020 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.buildtool;

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

import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.actions.BuildFailedException;
import com.google.devtools.build.lib.bazel.BazelWorkspaceStatusModule;
import com.google.devtools.build.lib.buildtool.util.GoogleBuildIntegrationTestCase;
import com.google.devtools.build.lib.causes.Cause;
import com.google.devtools.build.lib.packages.util.MockGenruleSupport;
import com.google.devtools.build.lib.runtime.BlazeModule;
import com.google.devtools.build.lib.testutil.Suite;
import com.google.devtools.build.lib.testutil.TestSpec;
import com.google.devtools.build.lib.vfs.Path;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/**
 * Tests related to "missing input file" errors.
 */
@TestSpec(size = Suite.MEDIUM_TESTS)
@RunWith(JUnit4.class)
public class MissingInputActionTest extends GoogleBuildIntegrationTestCase {
  @Override
  protected BlazeModule getBuildInfoModule() {
    return new BazelWorkspaceStatusModule();
  }

  // Regression test for bug #904676: Blaze does not consider missing inputs
  // an error.
  @Test
  public void testNoInput() throws Exception {
    // Multiple missing inputs means error is non-deterministic in --nokeep_going case.
    this.addOptions("--keep_going");
    MockGenruleSupport.setup(mockToolsConfig);
    write("dummy/BUILD",
          "genrule(name = 'dummy', ",
          "        srcs = ['in1', 'in2', 'in3'], ",
          "        outs = ['out1', 'out2'],  ",
          "        cmd = '/bin/true')");
    write("dummy/in1");

    assertMissingInputOnBuild("//dummy", /*don't check error message*/0);
    events.assertDoesNotContainEvent("missing input file '" + "//" + "dummy" + ":" + "in1'");
    events.assertContainsError("missing input file '" + "//" + "dummy" + ":" + "in2'");
    events.assertContainsError("missing input file '" + "//" + "dummy" + ":" + "in3'");
  }

  // The next two tests are inherently flakily successful with respect to the workspace status
  // action: even if we don't correctly suppress the workspace status action error message, we might
  // not have started it at all because Skyframe aborted quickly. That doesn't happen in practice,
  // though: the workspace status action starts right away.

  @Test
  public void testMissingInputRacesWithWorkspaceStatusAction() throws Exception {
    MockGenruleSupport.setup(mockToolsConfig);
    write(
        "dummy/BUILD",
        "genrule(name = 'dummy', srcs = ['in'], outs = ['out'], cmd = '/bin/false')");
    Path sleepPath = write("sleep.sh", "sleep infinity");
    sleepPath.setExecutable(true);
    addOptions("--workspace_status_command=" + sleepPath.getPathString());
    for (int i = 0; i < 2; i++) {
      assertMissingInputOnBuild("//dummy", 1);
      events.assertContainsError("dummy/BUILD:1:8: //dummy:dummy: missing input file '//dummy:in'");
      events.assertContainsEventWithFrequency("missing input file", 1);
      events.assertDoesNotContainEvent("Failed to determine build info");
      events.clear();
    }
  }

  @Test
  public void testMissingTopLevelInputRacesWithWorkspaceStatusAction() throws Exception {
    // Create a rule that exports a missing source file as a top-level artifact so that the missing
    // file will be detected by the TargetCompletion function, not an ActionExecution function.
    write(
        "foo/missing.bzl",
        "def _missing_impl(ctx):",
        "    return DefaultInfo(files = depset(ctx.files.srcs))",
        "",
        "missing = rule(",
        "               implementation = _missing_impl,",
        "               attrs = { 'srcs': attr.label_list(allow_files = True) }",
        ")");
    write(
        "foo/BUILD",
        "load('missing.bzl', 'missing')",
        "missing(name = 'foo', srcs = ['missing.sh'])");
    Path sleepPath = write("sleep.sh", "sleep infinity");
    sleepPath.setExecutable(true);
    addOptions("--workspace_status_command=" + sleepPath.getPathString());
    for (int i = 0; i < 2; i++) {
      assertMissingInputOnBuild("//foo:foo", 0);
      events.assertContainsError("foo/BUILD:2:8: //foo:foo: missing input file '//foo:missing.sh'");
      events.assertContainsEventWithFrequency("missing input file", 1);
      events.assertDoesNotContainEvent("Failed to determine build info");
      events.clear();
    }
  }

  private void assertMissingInputOnBuild(String label, int numMissing) {
    BuildFailedException e = assertThrows(BuildFailedException.class, () -> buildTarget(label));
    if (numMissing > 0) {
      String expected = numMissing + " input file(s) do not exist";
        assertThat(e).hasMessageThat().contains(expected);
      ImmutableList<Cause> causes = e.getRootCauses().toList();
      assertThat(causes).hasSize(1);
      assertThat(causes.get(0).getLabel()).isNotNull();
    }
  }
}