/**
 * Copyright © 2016-2018 The Thingsboard Authors
 *
 * 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 org.thingsboard.server.service.script;

import com.datastax.driver.core.utils.UUIDs;
import com.google.common.collect.Sets;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.thingsboard.rule.engine.api.ScriptEngine;
import org.thingsboard.server.common.data.id.EntityId;
import org.thingsboard.server.common.data.id.RuleNodeId;
import org.thingsboard.server.common.msg.TbMsg;
import org.thingsboard.server.common.msg.TbMsgMetaData;

import javax.script.ScriptException;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;

import static org.junit.Assert.*;

public class RuleNodeJsScriptEngineTest {

    private ScriptEngine scriptEngine;
    private TestNashornJsInvokeService jsSandboxService;

    private EntityId ruleNodeId = new RuleNodeId(UUIDs.timeBased());

    @Before
    public void beforeTest() throws Exception {
        jsSandboxService = new TestNashornJsInvokeService(false, 1, 100, 3);
    }

    @After
    public void afterTest() throws Exception {
        jsSandboxService.stop();
    }

    @Test
    public void msgCanBeUpdated() throws ScriptException {
        String function = "metadata.temp = metadata.temp * 10; return {metadata: metadata};";
        scriptEngine = new RuleNodeJsScriptEngine(jsSandboxService, ruleNodeId, function);

        TbMsgMetaData metaData = new TbMsgMetaData();
        metaData.putValue("temp", "7");
        metaData.putValue("humidity", "99");
        String rawJson = "{\"name\": \"Vit\", \"passed\": 5, \"bigObj\": {\"prop\":42}}";

        TbMsg msg = new TbMsg(UUIDs.timeBased(), "USER", null, metaData, rawJson, null, null, 0L);

        TbMsg actual = scriptEngine.executeUpdate(msg);
        assertEquals("70", actual.getMetaData().getValue("temp"));
        scriptEngine.destroy();
    }

    @Test
    public void newAttributesCanBeAddedInMsg() throws ScriptException {
        String function = "metadata.newAttr = metadata.humidity - msg.passed; return {metadata: metadata};";
        scriptEngine = new RuleNodeJsScriptEngine(jsSandboxService, ruleNodeId, function);
        TbMsgMetaData metaData = new TbMsgMetaData();
        metaData.putValue("temp", "7");
        metaData.putValue("humidity", "99");
        String rawJson = "{\"name\": \"Vit\", \"passed\": 5, \"bigObj\": {\"prop\":42}}";

        TbMsg msg = new TbMsg(UUIDs.timeBased(), "USER", null, metaData, rawJson, null, null, 0L);

        TbMsg actual = scriptEngine.executeUpdate(msg);
        assertEquals("94", actual.getMetaData().getValue("newAttr"));
        scriptEngine.destroy();
    }

    @Test
    public void payloadCanBeUpdated() throws ScriptException {
        String function = "msg.passed = msg.passed * metadata.temp; msg.bigObj.newProp = 'Ukraine'; return {msg: msg};";
        scriptEngine = new RuleNodeJsScriptEngine(jsSandboxService, ruleNodeId, function);
        TbMsgMetaData metaData = new TbMsgMetaData();
        metaData.putValue("temp", "7");
        metaData.putValue("humidity", "99");
        String rawJson = "{\"name\":\"Vit\",\"passed\": 5,\"bigObj\":{\"prop\":42}}";

        TbMsg msg = new TbMsg(UUIDs.timeBased(), "USER", null, metaData, rawJson, null, null, 0L);

        TbMsg actual = scriptEngine.executeUpdate(msg);

        String expectedJson = "{\"name\":\"Vit\",\"passed\":35,\"bigObj\":{\"prop\":42,\"newProp\":\"Ukraine\"}}";
        assertEquals(expectedJson, actual.getData());
        scriptEngine.destroy();
    }

    @Test
    public void metadataAccessibleForFilter() throws ScriptException {
        String function = "return metadata.humidity < 15;";
        scriptEngine = new RuleNodeJsScriptEngine(jsSandboxService, ruleNodeId, function);
        TbMsgMetaData metaData = new TbMsgMetaData();
        metaData.putValue("temp", "7");
        metaData.putValue("humidity", "99");
        String rawJson = "{\"name\": \"Vit\", \"passed\": 5, \"bigObj\": {\"prop\":42}}";

        TbMsg msg = new TbMsg(UUIDs.timeBased(), "USER", null, metaData, rawJson, null, null, 0L);
        assertFalse(scriptEngine.executeFilter(msg));
        scriptEngine.destroy();
    }

    @Test
    public void dataAccessibleForFilter() throws ScriptException {
        String function = "return msg.passed < 15 && msg.name === 'Vit' && metadata.temp == 7 && msg.bigObj.prop == 42;";
        scriptEngine = new RuleNodeJsScriptEngine(jsSandboxService, ruleNodeId, function);
        TbMsgMetaData metaData = new TbMsgMetaData();
        metaData.putValue("temp", "7");
        metaData.putValue("humidity", "99");
        String rawJson = "{\"name\": \"Vit\", \"passed\": 5, \"bigObj\": {\"prop\":42}}";

        TbMsg msg = new TbMsg(UUIDs.timeBased(), "USER", null, metaData, rawJson, null, null, 0L);
        assertTrue(scriptEngine.executeFilter(msg));
        scriptEngine.destroy();
    }

    @Test
    public void dataAccessibleForSwitch() throws ScriptException {
        String jsCode = "function nextRelation(metadata, msg) {\n" +
                "    if(msg.passed == 5 && metadata.temp == 10)\n" +
                "        return 'one'\n" +
                "    else\n" +
                "        return 'two';\n" +
                "};\n" +
                "\n" +
                "return nextRelation(metadata, msg);";
        scriptEngine = new RuleNodeJsScriptEngine(jsSandboxService, ruleNodeId, jsCode);
        TbMsgMetaData metaData = new TbMsgMetaData();
        metaData.putValue("temp", "10");
        metaData.putValue("humidity", "99");
        String rawJson = "{\"name\": \"Vit\", \"passed\": 5, \"bigObj\": {\"prop\":42}}";

        TbMsg msg = new TbMsg(UUIDs.timeBased(), "USER", null, metaData, rawJson, null, null, 0L);
        Set<String> actual = scriptEngine.executeSwitch(msg);
        assertEquals(Sets.newHashSet("one"), actual);
        scriptEngine.destroy();
    }

    @Test
    public void multipleRelationsReturnedFromSwitch() throws ScriptException {
        String jsCode = "function nextRelation(metadata, msg) {\n" +
                "    if(msg.passed == 5 && metadata.temp == 10)\n" +
                "        return ['three', 'one']\n" +
                "    else\n" +
                "        return 'two';\n" +
                "};\n" +
                "\n" +
                "return nextRelation(metadata, msg);";
        scriptEngine = new RuleNodeJsScriptEngine(jsSandboxService, ruleNodeId, jsCode);
        TbMsgMetaData metaData = new TbMsgMetaData();
        metaData.putValue("temp", "10");
        metaData.putValue("humidity", "99");
        String rawJson = "{\"name\": \"Vit\", \"passed\": 5, \"bigObj\": {\"prop\":42}}";

        TbMsg msg = new TbMsg(UUIDs.timeBased(), "USER", null, metaData, rawJson, null, null, 0L);
        Set<String> actual = scriptEngine.executeSwitch(msg);
        assertEquals(Sets.newHashSet("one", "three"), actual);
        scriptEngine.destroy();
    }

    @Test
    public void concurrentReleasedCorrectly() throws InterruptedException, ExecutionException {
        String code = "metadata.temp = metadata.temp * 10; return {metadata: metadata};";

        int repeat = 1000;
        ExecutorService service = Executors.newFixedThreadPool(repeat);
        Map<UUID, Object> scriptIds = new ConcurrentHashMap<>();
        CountDownLatch startLatch = new CountDownLatch(repeat);
        CountDownLatch finishLatch = new CountDownLatch(repeat);
        AtomicInteger failedCount = new AtomicInteger(0);

        for (int i = 0; i < repeat; i++) {
            service.submit(() -> runScript(startLatch, finishLatch, failedCount, scriptIds, code));
        }

        finishLatch.await();
        assertTrue(scriptIds.size() == 1);
        assertTrue(failedCount.get() == 0);

        CountDownLatch nextStart = new CountDownLatch(repeat);
        CountDownLatch nextFinish = new CountDownLatch(repeat);
        for (int i = 0; i < repeat; i++) {
            service.submit(() -> runScript(nextStart, nextFinish, failedCount, scriptIds, code));
        }

        nextFinish.await();
        assertTrue(scriptIds.size() == 1);
        assertTrue(failedCount.get() == 0);
        service.shutdownNow();
    }

    @Test
    public void concurrentFailedEvaluationShouldThrowException() throws InterruptedException {
        String code = "metadata.temp = metadata.temp * 10; urn {metadata: metadata};";

        int repeat = 10000;
        ExecutorService service = Executors.newFixedThreadPool(repeat);
        Map<UUID, Object> scriptIds = new ConcurrentHashMap<>();
        CountDownLatch startLatch = new CountDownLatch(repeat);
        CountDownLatch finishLatch = new CountDownLatch(repeat);
        AtomicInteger failedCount = new AtomicInteger(0);
        for (int i = 0; i < repeat; i++) {
            service.submit(() -> {
                service.submit(() -> runScript(startLatch, finishLatch, failedCount, scriptIds, code));
            });
        }

        finishLatch.await();
        assertTrue(scriptIds.isEmpty());
        assertEquals(repeat, failedCount.get());
        service.shutdownNow();
    }

    private void runScript(CountDownLatch startLatch, CountDownLatch finishLatch, AtomicInteger failedCount,
                           Map<UUID, Object> scriptIds, String code) {
        try {
            for (int k = 0; k < 10; k++) {
                startLatch.countDown();
                startLatch.await();
                UUID scriptId = jsSandboxService.eval(JsScriptType.RULE_NODE_SCRIPT, code).get();
                scriptIds.put(scriptId, new Object());
                jsSandboxService.invokeFunction(scriptId, "{}", "{}", "TEXT").get();
                jsSandboxService.release(scriptId).get();
            }
        } catch (Throwable th) {
            failedCount.incrementAndGet();
        } finally {
            finishLatch.countDown();
        }
    }

}