/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the "Elastic License
 * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
 * Public License v 1"; you may not use this file except in compliance with, at
 * your election, the "Elastic License 2.0", the "GNU Affero General Public
 * License v3.0 only", or the "Server Side Public License, v 1".
 */

package org.elasticsearch.bootstrap;

import com.carrotsearch.randomizedtesting.annotations.ThreadLeakFilters;

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.LogManager;
import org.apache.lucene.tests.util.LuceneTestCase;
import org.apache.lucene.util.Constants;
import org.elasticsearch.Version;
import org.elasticsearch.common.logging.LogConfigurator;
import org.elasticsearch.common.logging.Loggers;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.env.Environment;
import org.elasticsearch.env.TestEnvironment;
import org.elasticsearch.plugins.Platforms;
import org.elasticsearch.plugins.PluginTestUtil;
import org.elasticsearch.test.GraalVMThreadsFilter;
import org.elasticsearch.test.MockLog;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.attribute.PosixFileAttributeView;
import java.nio.file.attribute.PosixFilePermission;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import java.util.function.Function;

import static org.hamcrest.Matchers.empty;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.is;

/**
 * Create a simple "daemon controller", put it in the right place and check that it runs.
 *
 * Extends LuceneTestCase rather than ESTestCase as ESTestCase installs a system call filter, and
 * that prevents the Spawner class from doing its job. Also needs to run in a separate JVM to other
 * tests that extend ESTestCase for the same reason.
 */
@ThreadLeakFilters(filters = { GraalVMThreadsFilter.class })
public class SpawnerNoBootstrapTests extends LuceneTestCase {

    private static final String CONTROLLER_SOURCE = """
        #!/bin/bash

        echo I am alive
        echo "I am an error" >&2

        read SOMETHING
        """;

    static {
        // normally done by ESTestCase, but need here because spawner depends on logging
        LogConfigurator.loadLog4jPlugins();
        MockLog.init();
    }

    /**
     * Simplest case: a module with no controller daemon.
     */
    public void testNoControllerSpawn() throws IOException {
        Path esHome = createTempDir().resolve("esHome");
        Settings.Builder settingsBuilder = Settings.builder();
        settingsBuilder.put(Environment.PATH_HOME_SETTING.getKey(), esHome.toString());
        Settings settings = settingsBuilder.build();

        Environment environment = TestEnvironment.newEnvironment(settings);

        // This plugin will NOT have a controller daemon
        Path plugin = environment.modulesDir().resolve("a_plugin");
        Files.createDirectories(environment.modulesDir());
        Files.createDirectories(plugin);
        PluginTestUtil.writePluginProperties(
            plugin,
            "description",
            "a_plugin",
            "version",
            Version.CURRENT.toString(),
            "elasticsearch.version",
            Version.CURRENT.toString(),
            "name",
            "a_plugin",
            "java.version",
            "1.8",
            "classname",
            "APlugin",
            "has.native.controller",
            "false"
        );

        try (Spawner spawner = new Spawner()) {
            spawner.spawnNativeControllers(environment);
            assertThat(spawner.getProcesses(), is(empty()));
        }
    }

    /**
     * Two plugins - one with a controller daemon and one without.
     */
    public void testControllerSpawn() throws Exception {
        assertControllerSpawns(Environment::pluginsDir, false);
        assertControllerSpawns(Environment::modulesDir, true);
    }

    private void assertControllerSpawns(final Function<Environment, Path> pluginsDirFinder, boolean expectSpawn) throws Exception {
        /*
         * On Windows you can not directly run a batch file - you have to run cmd.exe with the batch
         * file as an argument and that's out of the remit of the controller daemon process spawner.
         */
        assumeFalse("This test does not work on Windows", Constants.WINDOWS);

        Path esHome = createTempDir().resolve("esHome");
        Settings.Builder settingsBuilder = Settings.builder();
        settingsBuilder.put(Environment.PATH_HOME_SETTING.getKey(), esHome.toString());
        Settings settings = settingsBuilder.build();

        Environment environment = TestEnvironment.newEnvironment(settings);

        // this plugin will have a controller daemon
        Path plugin = pluginsDirFinder.apply(environment).resolve("test_plugin");
        Files.createDirectories(environment.modulesDir());
        Files.createDirectories(environment.pluginsDir());
        Files.createDirectories(plugin);
        PluginTestUtil.writePluginProperties(
            plugin,
            "description",
            "test_plugin",
            "version",
            Version.CURRENT.toString(),
            "elasticsearch.version",
            Version.CURRENT.toString(),
            "name",
            "test_plugin",
            "java.version",
            "1.8",
            "classname",
            "TestPlugin",
            "has.native.controller",
            "true"
        );
        Path controllerProgram = Platforms.nativeControllerPath(plugin);
        createControllerProgram(controllerProgram);

        // this plugin will not have a controller daemon
        Path otherPlugin = pluginsDirFinder.apply(environment).resolve("other_plugin");
        Files.createDirectories(otherPlugin);
        PluginTestUtil.writePluginProperties(
            otherPlugin,
            "description",
            "other_plugin",
            "version",
            Version.CURRENT.toString(),
            "elasticsearch.version",
            Version.CURRENT.toString(),
            "name",
            "other_plugin",
            "java.version",
            "1.8",
            "classname",
            "OtherPlugin",
            "has.native.controller",
            "false"
        );

        String stdoutLoggerName = "test_plugin-controller-stdout";
        String stderrLoggerName = "test_plugin-controller-stderr";
        Loggers.setLevel(LogManager.getLogger(stdoutLoggerName), Level.TRACE);
        Loggers.setLevel(LogManager.getLogger(stderrLoggerName), Level.TRACE);

        if (expectSpawn) {
            final Process process;
            try (var mockLog = MockLog.capture(stdoutLoggerName, stderrLoggerName)) {
                mockLog.addExpectation(new MockLog.SeenEventExpectation("stdout", stdoutLoggerName, Level.WARN, "I am alive"));
                mockLog.addExpectation(new MockLog.SeenEventExpectation("stderr", stderrLoggerName, Level.WARN, "I am an error"));

                try (var spawner = new Spawner()) {
                    spawner.spawnNativeControllers(environment);
                    List<Process> processes = spawner.getProcesses();

                    // as there should only be a reference in the list for the module that had the controller daemon, we expect one here
                    assertThat(processes, hasSize(1));
                    process = processes.get(0);
                    // fail if we don't get the expected log messages soonish
                    mockLog.awaitAllExpectationsMatched();
                }
            }

            // fail if the process does not die within one second; usually it will be even quicker but it depends on OS scheduling
            assertTrue(process.waitFor(1, TimeUnit.SECONDS));
        } else {
            try (var spawner = new Spawner()) {
                spawner.spawnNativeControllers(environment);
                assertThat(spawner.getProcesses(), is(empty()));
            }
        }
    }

    public void testControllerSpawnWithIncorrectDescriptor() throws IOException {
        // this plugin will have a controller daemon
        Path esHome = createTempDir().resolve("esHome");
        Settings.Builder settingsBuilder = Settings.builder();
        settingsBuilder.put(Environment.PATH_HOME_SETTING.getKey(), esHome.toString());
        Settings settings = settingsBuilder.build();

        Environment environment = TestEnvironment.newEnvironment(settings);

        Path plugin = environment.modulesDir().resolve("test_plugin");
        Files.createDirectories(plugin);
        PluginTestUtil.writePluginProperties(
            plugin,
            "description",
            "test_plugin",
            "version",
            Version.CURRENT.toString(),
            "elasticsearch.version",
            Version.CURRENT.toString(),
            "name",
            "test_plugin",
            "java.version",
            "1.8",
            "classname",
            "TestPlugin",
            "has.native.controller",
            "false"
        );
        Path controllerProgram = Platforms.nativeControllerPath(plugin);
        createControllerProgram(controllerProgram);

        Spawner spawner = new Spawner();
        IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> spawner.spawnNativeControllers(environment));
        assertThat(e.getMessage(), equalTo("module [test_plugin] does not have permission to fork native controller"));
    }

    public void testSpawnerHandlingOfDesktopServicesStoreFiles() throws IOException {
        final Path esHome = createTempDir().resolve("home");
        final Settings settings = Settings.builder().put(Environment.PATH_HOME_SETTING.getKey(), esHome.toString()).build();

        final Environment environment = TestEnvironment.newEnvironment(settings);

        Files.createDirectories(environment.modulesDir());
        Files.createDirectories(environment.pluginsDir());

        final Path desktopServicesStore = environment.modulesDir().resolve(".DS_Store");
        Files.createFile(desktopServicesStore);

        final Spawner spawner = new Spawner();
        if (Constants.MAC_OS_X) {
            // if the spawner were not skipping the Desktop Services Store files on macOS this would explode
            spawner.spawnNativeControllers(environment);
        } else {
            // we do not ignore these files on non-macOS systems
            var e = expectThrows(IllegalStateException.class, () -> spawner.spawnNativeControllers(environment));
            assertThat(e.getMessage(), equalTo("Plugin [.DS_Store] is missing a descriptor properties file."));
        }
    }

    private void createControllerProgram(final Path outputFile) throws IOException {
        final Path outputDir = outputFile.getParent();
        Files.createDirectories(outputDir);
        Files.writeString(outputFile, CONTROLLER_SOURCE);
        final PosixFileAttributeView view = Files.getFileAttributeView(outputFile, PosixFileAttributeView.class);
        if (view != null) {
            final Set<PosixFilePermission> perms = new HashSet<>();
            perms.add(PosixFilePermission.OWNER_READ);
            perms.add(PosixFilePermission.OWNER_WRITE);
            perms.add(PosixFilePermission.OWNER_EXECUTE);
            perms.add(PosixFilePermission.GROUP_READ);
            perms.add(PosixFilePermission.GROUP_EXECUTE);
            perms.add(PosixFilePermission.OTHERS_READ);
            perms.add(PosixFilePermission.OTHERS_EXECUTE);
            Files.setPosixFilePermissions(outputFile, perms);
        }
    }

}