/*
 * 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.action.support.local;

import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.ActionRequestValidationException;
import org.elasticsearch.action.ActionResponse;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.action.support.ActionTestUtils;
import org.elasticsearch.action.support.PlainActionFuture;
import org.elasticsearch.action.support.TransportAction;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.block.ClusterBlock;
import org.elasticsearch.cluster.block.ClusterBlockException;
import org.elasticsearch.cluster.block.ClusterBlockLevel;
import org.elasticsearch.cluster.block.ClusterBlocks;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.util.concurrent.EsExecutors;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.tasks.CancellableTask;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.tasks.TaskCancelHelper;
import org.elasticsearch.tasks.TaskCancelledException;
import org.elasticsearch.tasks.TaskId;
import org.elasticsearch.tasks.TaskManager;
import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.threadpool.TestThreadPool;
import org.elasticsearch.threadpool.ThreadPool;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;

import java.io.IOException;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

import static org.elasticsearch.test.ClusterServiceUtils.createClusterService;
import static org.elasticsearch.test.ClusterServiceUtils.setState;

public class TransportLocalClusterStateActionTests extends ESTestCase {

    private static ThreadPool threadPool;

    private ClusterService clusterService;
    private TaskManager taskManager;

    @BeforeClass
    public static void beforeClass() {
        threadPool = new TestThreadPool(getTestClass().getName());
    }

    @Override
    @Before
    public void setUp() throws Exception {
        super.setUp();
        clusterService = createClusterService(threadPool);
        taskManager = new TaskManager(clusterService.getSettings(), threadPool, Set.of());
    }

    @After
    public void tearDown() throws Exception {
        super.tearDown();
        clusterService.close();
    }

    @AfterClass
    public static void afterClass() {
        ThreadPool.terminate(threadPool, 30, TimeUnit.SECONDS);
        threadPool = null;
    }

    public void testNoBlock() throws ExecutionException, InterruptedException {
        var request = new Request();
        PlainActionFuture<Response> listener = new PlainActionFuture<>();
        ActionTestUtils.execute(new Action(taskManager, clusterService), null, request, listener);
        assertTrue(listener.isDone());
        listener.get();
    }

    public void testRetryAfterBlock() throws ExecutionException, InterruptedException {
        var request = new Request();
        ClusterBlock block = new ClusterBlock(randomInt(), "", true, true, false, randomFrom(RestStatus.values()), ClusterBlockLevel.ALL);
        var state = ClusterState.builder(clusterService.state()).blocks(ClusterBlocks.builder().addGlobalBlock(block)).build();
        setState(clusterService, state);

        PlainActionFuture<Response> listener = new PlainActionFuture<>();
        ActionTestUtils.execute(new Action(taskManager, clusterService), null, request, listener);

        assertFalse(listener.isDone());
        setState(clusterService, ClusterState.builder(state).blocks(ClusterBlocks.EMPTY_CLUSTER_BLOCK).build());
        assertTrue(listener.isDone());
        listener.get();
    }

    public void testNonRetryableBlock() {
        var request = new Request();
        ClusterBlock block = new ClusterBlock(randomInt(), "", false, true, false, randomFrom(RestStatus.values()), ClusterBlockLevel.ALL);
        var state = ClusterState.builder(clusterService.state()).blocks(ClusterBlocks.builder().addGlobalBlock(block)).build();
        setState(clusterService, state);

        PlainActionFuture<Response> listener = new PlainActionFuture<>();
        ActionTestUtils.execute(new Action(taskManager, clusterService), null, request, listener);

        assertTrue(listener.isDone());
        var exception = assertThrows(ExecutionException.class, listener::get);
        assertTrue(exception.getCause() instanceof ClusterBlockException);
    }

    public void testTaskCancelledImmediately() {
        var request = new Request();
        ClusterBlock block = new ClusterBlock(randomInt(), "", true, true, false, randomFrom(RestStatus.values()), ClusterBlockLevel.ALL);
        var state = ClusterState.builder(clusterService.state()).blocks(ClusterBlocks.builder().addGlobalBlock(block)).build();
        setState(clusterService, state);

        CancellableTask task = new CancellableTask(randomLong(), "test", Action.ACTION_NAME, "", TaskId.EMPTY_TASK_ID, Map.of());
        PlainActionFuture<Response> listener = new PlainActionFuture<>();
        ActionTestUtils.execute(new Action(taskManager, clusterService), task, request, listener);

        TaskCancelHelper.cancel(task, "test");
        assertTrue(listener.isDone());
        var exception = assertThrows(ExecutionException.class, listener::get);
        assertTrue(exception.getCause() instanceof TaskCancelledException);
    }

    public void testTaskCancelled() {
        var request = new Request();
        ClusterBlock block = new ClusterBlock(randomInt(), "", true, true, false, randomFrom(RestStatus.values()), ClusterBlockLevel.ALL);
        var state = ClusterState.builder(clusterService.state()).blocks(ClusterBlocks.builder().addGlobalBlock(block)).build();
        setState(clusterService, state);

        CancellableTask task = new CancellableTask(randomLong(), "test", Action.ACTION_NAME, "", TaskId.EMPTY_TASK_ID, Map.of());
        PlainActionFuture<Response> listener = new PlainActionFuture<>();
        ActionTestUtils.execute(new Action(taskManager, clusterService), task, request, listener);

        TaskCancelHelper.cancel(task, "test");
        setState(clusterService, ClusterState.builder(state).blocks(ClusterBlocks.EMPTY_CLUSTER_BLOCK).build());
        assertTrue(listener.isDone());
        var exception = assertThrows(ExecutionException.class, listener::get);
        assertTrue(exception.getCause() instanceof TaskCancelledException);
    }

    private static class Request extends LocalClusterStateRequest {

        protected Request() {
            super(TEST_REQUEST_TIMEOUT);
        }

        @Override
        public ActionRequestValidationException validate() {
            return null;
        }
    }

    private static class Response extends ActionResponse {

        @Override
        public void writeTo(StreamOutput out) throws IOException {
            TransportAction.localOnly();
        }
    }

    private static class Action extends TransportLocalClusterStateAction<Request, Response> {
        static final String ACTION_NAME = "internal:testAction";

        Action(TaskManager taskManager, ClusterService clusterService) {
            super(ACTION_NAME, new ActionFilters(Set.of()), taskManager, clusterService, EsExecutors.DIRECT_EXECUTOR_SERVICE);
        }

        @Override
        protected void localClusterStateOperation(Task task, Request request, ClusterState state, ActionListener<Response> listener)
            throws Exception {
            listener.onResponse(new Response());
        }

        @Override
        protected ClusterBlockException checkBlock(Request request, ClusterState state) {
            Set<ClusterBlock> blocks = state.blocks().global();
            return blocks.isEmpty() ? null : new ClusterBlockException(blocks);
        }
    }
}