// 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.worker;

import static com.google.common.truth.Truth.assertThat;
import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.devtools.build.lib.vfs.DigestHashFunction;
import com.google.devtools.build.lib.vfs.FileSystemUtils;
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;

/** Tests for {@link ErrorMessage}. */
@RunWith(JUnit4.class)
public class ErrorMessageTest {
  String logText = "\n\nabcdefghijklmnopqrstuvwxyz\n\n";

  @Test
  public void testEmptyErrorMessage() {
    ErrorMessage errorMessage = ErrorMessage.builder().build();
    assertThat(errorMessage.toString()).isEqualTo("Unknown error");
  }

  @Test
  public void testSimpleErrorMessage() {
    ErrorMessage errorMessage = ErrorMessage.builder().message("Error").build();
    assertThat(errorMessage.toString()).isEqualTo("Error");
  }

  @Test
  public void testErrorMessageWithLogText() {
    ErrorMessage errorMessage =
        ErrorMessage.builder().message("Error with log text").logText(logText).build();
    assertThat(errorMessage.toString())
        .isEqualTo(
            "Error with log text\n\n"
                + "---8<---8<--- Start of log ---8<---8<---\n"
                + "abcdefghijklmnopqrstuvwxyz\n"
                + "---8<---8<--- End of log ---8<---8<---");
  }

  @Test
  public void testErrorMessageWithEmptyLogText() {
    ErrorMessage errorMessage =
        ErrorMessage.builder().message("Error with log text").logText("").build();
    assertThat(errorMessage.toString())
        .isEqualTo(
            "Error with log text\n\n"
                + "---8<---8<--- Start of log ---8<---8<---\n"
                + "(empty)\n"
                + "---8<---8<--- End of log ---8<---8<---");
  }

  @Test
  public void testErrorMessageWithTruncatedLogText() {
    ErrorMessage errorMessage =
        ErrorMessage.builder()
            .message("Error with log text")
            .logText(logText)
            .logSizeLimit(13)
            .build();
    assertThat(errorMessage.toString())
        .isEqualTo(
            "Error with log text\n\n"
                + "---8<---8<--- Start of log snippet ---8<---8<---\n"
                + "[... truncated ...]\n"
                + "nopqrstuvwxyz\n"
                + "---8<---8<--- End of log snippet, 13 chars omitted ---8<---8<---");
  }

  @Test
  public void testErrorMessageWithLogFile() throws Exception {
    InMemoryFileSystem fs = new InMemoryFileSystem(DigestHashFunction.SHA256);
    Path logFile = fs.getPath("/log.txt");
    FileSystemUtils.writeContent(logFile, UTF_8, logText);
    ErrorMessage errorMessage =
        ErrorMessage.builder().message("Error with log file").logFile(logFile).build();
    assertThat(errorMessage.toString())
        .isEqualTo(
            "Error with log file\n\n"
                + "---8<---8<--- Start of log, file at /log.txt ---8<---8<---\n"
                + "abcdefghijklmnopqrstuvwxyz\n"
                + "---8<---8<--- End of log ---8<---8<---");
  }

  @Test
  public void testErrorMessageWithUnreadableLogFile() {
    InMemoryFileSystem fs = new InMemoryFileSystem(DigestHashFunction.SHA256);
    // This file does not exist.
    Path logFile = fs.getPath("/nope.txt");
    ErrorMessage errorMessage =
        ErrorMessage.builder().message("Error with log file").logFile(logFile).build();
    assertThat(errorMessage.toString())
        .startsWith(
            "Error with log file\n\n"
                + "---8<---8<--- Start of log, file at /nope.txt ---8<---8<---\n"
                + "ERROR: IOException while trying to read log file:\n"
                + "java.io.FileNotFoundException: /nope.txt (No such file or directory)");
    assertThat(errorMessage.toString()).endsWith("---8<---8<--- End of log ---8<---8<---");
  }

  @Test
  public void testErrorMessageWithException() {
    ErrorMessage errorMessage =
        ErrorMessage.builder()
            .message("An exception occurred.")
            .exception(new IllegalStateException("Hello World"))
            .build();
    assertThat(errorMessage.toString())
        .startsWith(
            "An exception occurred.\n\n"
                + "---8<---8<--- Exception details ---8<---8<---\n"
                + "java.lang.IllegalStateException: Hello World");
  }
}
