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   1 /**
   2  * Copyright (c) 2010-2024 Contributors to the openHAB project
   3  *
   4  * See the NOTICE file(s) distributed with this work for additional
   5  * information.
   6  *
   7  * This program and the accompanying materials are made available under the
   8  * terms of the Eclipse Public License 2.0 which is available at
   9  * http://www.eclipse.org/legal/epl-2.0
  10  *
  11  * SPDX-License-Identifier: EPL-2.0
  12  */
  13 package org.openhab.binding.boschshc.internal.devices.bridge;
  14
  15 import static org.eclipse.jetty.http.HttpMethod.POST;
  16
  17 import java.util.concurrent.ExecutionException;
  18 import java.util.concurrent.ScheduledExecutorService;
  19 import java.util.concurrent.TimeUnit;
  20 import java.util.concurrent.TimeoutException;
  21 import java.util.function.Consumer;
  22
  23 import org.eclipse.jdt.annotation.NonNullByDefault;
  24 import org.eclipse.jdt.annotation.Nullable;
  25 import org.eclipse.jetty.client.api.Request;
  26 import org.eclipse.jetty.client.api.Result;
  27 import org.eclipse.jetty.client.util.BufferingResponseListener;
  28 import org.openhab.binding.boschshc.internal.devices.bridge.dto.LongPollError;
  29 import org.openhab.binding.boschshc.internal.devices.bridge.dto.LongPollResult;
  30 import org.openhab.binding.boschshc.internal.devices.bridge.dto.SubscribeResult;
  31 import org.openhab.binding.boschshc.internal.exceptions.BoschSHCException;
  32 import org.openhab.binding.boschshc.internal.exceptions.LongPollingFailedException;
  33 import org.openhab.binding.boschshc.internal.serialization.GsonUtils;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36
  37 /**
  38  * Handles the long polling to the Smart Home Controller.
  39  *
  40  * @author Christian Oeing - Initial contribution
  41  */
  42 @NonNullByDefault
  43 public class LongPolling {
  44
  45     private final Logger logger = LoggerFactory.getLogger(LongPolling.class);
  46
  47     /**
  48      * Executor to schedule long polls.
  49      */
  50     private final ScheduledExecutorService scheduler;
  51
  52     /**
  53      * Handler for long poll results.
  54      */
  55     private final Consumer<LongPollResult> handleResult;
  56
  57     /**
  58      * Handler for unrecoverable.
  59      */
  60     private final Consumer<Throwable> handleFailure;
  61
  62     /**
  63      * Current running long polling request.
  64      */
  65     private @Nullable Request request;
  66
  67     /**
  68      * Indicates if long polling was aborted.
  69      */
  70     private boolean aborted = false;
  71
  72     public LongPolling(ScheduledExecutorService scheduler, Consumer<LongPollResult> handleResult,
  73             Consumer<Throwable> handleFailure) {
  74         this.scheduler = scheduler;
  75         this.handleResult = handleResult;
  76         this.handleFailure = handleFailure;
  77     }
  78
  79     public void start(BoschHttpClient httpClient) throws LongPollingFailedException {
  80         // Subscribe to state updates.
  81         String subscriptionId = this.subscribe(httpClient);
  82         this.executeLongPoll(httpClient, subscriptionId);
  83     }
  84
  85     public void stop() {
  86         // Abort long polling.
  87         this.aborted = true;
  88         Request request = this.request;
  89         if (request != null) {
  90             request.abort(new AbortLongPolling());
  91             this.request = null;
  92         }
  93     }
  94
  95     /**
  96      * Subscribe to events and store the subscription ID needed for long polling.
  97      *
  98      * @param httpClient Http client to use for sending subscription request
  99      * @return Subscription id
 100      */
 101     private String subscribe(BoschHttpClient httpClient) throws LongPollingFailedException {
 102         try {
 103             String url = httpClient.getBoschShcUrl("remote/json-rpc");
 104             JsonRpcRequest subscriptionRequest = new JsonRpcRequest("2.0", "RE/subscribe",
 105                     new String[] { "com/bosch/sh/remote/*", null });
 106             logger.debug("Subscribe: Sending request: {} - using httpClient {}", subscriptionRequest, httpClient);
 107             Request httpRequest = httpClient.createRequest(url, POST, subscriptionRequest);
 108             SubscribeResult response = httpClient.sendRequest(httpRequest, SubscribeResult.class,
 109                     SubscribeResult::isValid, null);
 110
 111             logger.debug("Subscribe: Got subscription ID: {} {}", response.getResult(), response.getJsonrpc());
 112             return response.getResult();
 113         } catch (TimeoutException | ExecutionException | BoschSHCException e) {
 114             throw new LongPollingFailedException(
 115                     String.format("Error on subscribe (Http client: %s): %s", httpClient.toString(), e.getMessage()),
 116                     e);
 117         } catch (InterruptedException e) {
 118             Thread.currentThread().interrupt();
 119             throw new LongPollingFailedException(
 120                     String.format("Interrupted subscribe (Http client: %s): %s", httpClient.toString(), e.getMessage()),
 121                     e);
 122         }
 123     }
 124
 125     /**
 126      * Create a new subscription for long polling.
 127      *
 128      * @param httpClient Http client to send requests to
 129      */
 130     private void resubscribe(BoschHttpClient httpClient) {
 131         try {
 132             String subscriptionId = this.subscribe(httpClient);
 133             this.executeLongPoll(httpClient, subscriptionId);
 134         } catch (LongPollingFailedException e) {
 135             this.handleFailure.accept(e);
 136         }
 137     }
 138
 139     private void executeLongPoll(BoschHttpClient httpClient, String subscriptionId) {
 140         scheduler.execute(() -> this.longPoll(httpClient, subscriptionId));
 141     }
 142
 143     /**
 144      * Start long polling the home controller. Once a long poll resolves, a new one is started.
 145      */
 146     private void longPoll(BoschHttpClient httpClient, String subscriptionId) {
 147         logger.debug("Sending long poll request");
 148
 149         JsonRpcRequest requestContent = new JsonRpcRequest("2.0", "RE/longPoll", new String[] { subscriptionId, "20" });
 150         String url = httpClient.getBoschShcUrl("remote/json-rpc");
 151         Request longPollRequest = httpClient.createRequest(url, POST, requestContent);
 152
 153         // Long polling responds after 20 seconds with an empty response if no update has happened.
 154         // 10 second threshold was added to not time out if response from controller takes a bit longer than 20 seconds.
 155         longPollRequest.timeout(30, TimeUnit.SECONDS);
 156
 157         this.request = longPollRequest;
 158         LongPolling longPolling = this;
 159         longPollRequest.send(new BufferingResponseListener() {
 160             @Override
 161             public void onComplete(@Nullable Result result) {
 162                 // NOTE: This handler runs inside the HTTP thread, so we schedule the response handling in a new thread
 163                 // because the HTTP thread is terminated after the timeout expires.
 164                 scheduler.execute(() -> longPolling.onLongPollComplete(httpClient, subscriptionId, result,
 165                         this.getContentAsString()));
 166             }
 167         });
 168     }
 169
 170     /**
 171      * This is the handler for responses of long poll requests.
 172      *
 173      * @param httpClient HTTP client which received the response
 174      * @param subscriptionId Id of subscription the response is for
 175      * @param result Complete result of the response
 176      * @param content Content of the response
 177      */
 178     private void onLongPollComplete(BoschHttpClient httpClient, String subscriptionId, @Nullable Result result,
 179             String content) {
 180         // Check if thing is still online
 181         if (this.aborted) {
 182             logger.debug("Canceling long polling for subscription id {} because it was aborted", subscriptionId);
 183             return;
 184         }
 185
 186         // Check if response was failure or success
 187         Throwable failure = result != null ? result.getFailure() : null;
 188         if (failure != null) {
 189             handleLongPollFailure(subscriptionId, failure);
 190         } else {
 191             logger.debug("Long poll response: {}", content);
 192
 193             String nextSubscriptionId = subscriptionId;
 194
 195             LongPollResult longPollResult = GsonUtils.DEFAULT_GSON_INSTANCE.fromJson(content, LongPollResult.class);
 196             if (longPollResult != null && longPollResult.result != null) {
 197                 this.handleResult.accept(longPollResult);
 198             } else {
 199                 logger.debug("Long poll response contained no result: {}", content);
 200
 201                 // Check if we got a proper result from the SHC
 202                 LongPollError longPollError = GsonUtils.DEFAULT_GSON_INSTANCE.fromJson(content, LongPollError.class);
 203
 204                 if (longPollError != null && longPollError.error != null) {
 205                     logger.debug("Got long poll error: {} (code: {})", longPollError.error.message,
 206                             longPollError.error.code);
 207
 208                     if (longPollError.error.code == LongPollError.SUBSCRIPTION_INVALID) {
 209                         logger.debug("Subscription {} became invalid, subscribing again", subscriptionId);
 210                         this.resubscribe(httpClient);
 211                         return;
 212                     }
 213                 }
 214             }
 215
 216             // Execute next run
 217             this.longPoll(httpClient, nextSubscriptionId);
 218         }
 219     }
 220
 221     private void handleLongPollFailure(String subscriptionId, Throwable failure) {
 222         if (failure instanceof ExecutionException) {
 223             if (failure.getCause() instanceof AbortLongPolling) {
 224                 logger.debug("Canceling long polling for subscription id {} because it was aborted", subscriptionId);
 225             } else {
 226                 this.handleFailure.accept(
 227                         new LongPollingFailedException("Unexpected exception during long polling request", failure));
 228             }
 229         } else {
 230             this.handleFailure.accept(
 231                     new LongPollingFailedException("Unexpected exception during long polling request", failure));
 232         }
 233     }
 234
 235     @SuppressWarnings("serial")
 236     private class AbortLongPolling extends BoschSHCException {
 237     }
 238 }