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   1 /**
   2  * Copyright (c) 2010-2022 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.http.internal.converter;
  14
  15 import java.util.function.Consumer;
  16
  17 import org.eclipse.jdt.annotation.NonNullByDefault;
  18 import org.eclipse.jdt.annotation.Nullable;
  19 import org.openhab.binding.http.internal.config.HttpChannelConfig;
  20 import org.openhab.binding.http.internal.config.HttpChannelMode;
  21 import org.openhab.binding.http.internal.http.Content;
  22 import org.openhab.binding.http.internal.transform.ValueTransformation;
  23 import org.openhab.core.types.Command;
  24 import org.openhab.core.types.State;
  25
  26 /**
  27  * The {@link AbstractTransformingItemConverter} is a base class for an item converter with transformations
  28  *
  29  * @author Jan N. Klug - Initial contribution
  30  */
  31 @NonNullByDefault
  32 public abstract class AbstractTransformingItemConverter implements ItemValueConverter {
  33     private final Consumer<State> updateState;
  34     private final Consumer<Command> postCommand;
  35     private final @Nullable Consumer<String> sendHttpValue;
  36     private final ValueTransformation stateTransformations;
  37     private final ValueTransformation commandTransformations;
  38
  39     protected HttpChannelConfig channelConfig;
  40
  41     public AbstractTransformingItemConverter(Consumer<State> updateState, Consumer<Command> postCommand,
  42             @Nullable Consumer<String> sendHttpValue, ValueTransformation stateTransformations,
  43             ValueTransformation commandTransformations, HttpChannelConfig channelConfig) {
  44         this.updateState = updateState;
  45         this.postCommand = postCommand;
  46         this.sendHttpValue = sendHttpValue;
  47         this.stateTransformations = stateTransformations;
  48         this.commandTransformations = commandTransformations;
  49         this.channelConfig = channelConfig;
  50     }
  51
  52     @Override
  53     public void process(Content content) {
  54         if (channelConfig.mode != HttpChannelMode.WRITEONLY) {
  55             stateTransformations.apply(content.getAsString()).ifPresent(transformedValue -> {
  56                 Command command = toCommand(transformedValue);
  57                 if (command != null) {
  58                     postCommand.accept(command);
  59                 } else {
  60                     updateState.accept(toState(transformedValue));
  61                 }
  62             });
  63         } else {
  64             throw new IllegalStateException("Write-only channel");
  65         }
  66     }
  67
  68     @Override
  69     public void send(Command command) {
  70         Consumer<String> sendHttpValue = this.sendHttpValue;
  71         if (sendHttpValue != null && channelConfig.mode != HttpChannelMode.READONLY) {
  72             commandTransformations.apply(toString(command)).ifPresent(sendHttpValue);
  73         } else {
  74             throw new IllegalStateException("Read-only channel");
  75         }
  76     }
  77
  78     /**
  79      * check if this converter received a value that needs to be sent as command
  80      *
  81      * @param value the value
  82      * @return the command or null
  83      */
  84     protected abstract @Nullable Command toCommand(String value);
  85
  86     /**
  87      * convert the received value to a state
  88      *
  89      * @param value the value
  90      * @return the state that represents the value of UNDEF if conversion failed
  91      */
  92     protected abstract State toState(String value);
  93
  94     /**
  95      * convert a command to a string
  96      *
  97      * @param command the command
  98      * @return the string representation of the command
  99      */
 100     protected abstract String toString(Command command);
 101
 102     @FunctionalInterface
 103     public interface Factory {
 104         ItemValueConverter create(Consumer<State> updateState, Consumer<Command> postCommand,
 105                 @Nullable Consumer<String> sendHttpValue, ValueTransformation stateTransformations,
 106                 ValueTransformation commandTransformations, HttpChannelConfig channelConfig);
 107     }
 108 }