src/main/java/net/pterodactylus/rhynodge/engine/ReactionRunner.java

   1 package net.pterodactylus.rhynodge.engine;
   2
   3 import static java.lang.String.format;
   4 import static java.util.Optional.ofNullable;
   5 import static net.pterodactylus.rhynodge.states.FailedState.INSTANCE;
   6 import static org.apache.log4j.Logger.getLogger;
   7
   8 import java.util.Optional;
   9
  10 import net.pterodactylus.rhynodge.Action;
  11 import net.pterodactylus.rhynodge.Filter;
  12 import net.pterodactylus.rhynodge.Query;
  13 import net.pterodactylus.rhynodge.Reaction;
  14 import net.pterodactylus.rhynodge.State;
  15 import net.pterodactylus.rhynodge.Trigger;
  16 import net.pterodactylus.rhynodge.states.FailedState;
  17
  18 import org.apache.log4j.Logger;
  19
  20 /**
  21  * Runs a {@link Reaction}, starting with its {@link Query}, running the {@link
  22  * State} through its {@link Filter}s, and finally checking the {@link Trigger}
  23  * for whether an {@link Action} needs to be executed.
  24  *
  25  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  26  */
  27 public class ReactionRunner implements Runnable {
  28
  29         private static final Logger logger = getLogger(ReactionRunner.class);
  30         private final Reaction reaction;
  31         private final ReactionState reactionState;
  32
  33         public ReactionRunner(Reaction reaction, ReactionState reactionState) {
  34                 this.reactionState = reactionState;
  35                 this.reaction = reaction;
  36         }
  37
  38         @Override
  39         public void run() {
  40                 State state = runQuery();
  41                 state = runStateThroughFilters(state);
  42                 if (!state.success()) {
  43                         logger.info(format("Reaction %s failed.", reaction.name()));
  44                         saveStateWithIncreasedFailCount(state);
  45                         return;
  46                 }
  47                 Optional<State> lastSuccessfulState = reactionState.loadLastSuccessfulState();
  48                 if (!lastSuccessfulState.isPresent()) {
  49                         logger.info(format("No last state for %s.", reaction.name()));
  50                         reactionState.saveState(state);
  51                         return;
  52                 }
  53                 Trigger trigger = reaction.trigger();
  54                 State newState = trigger.mergeStates(lastSuccessfulState.get(), state);
  55                 reactionState.saveState(newState);
  56                 if (trigger.triggers()) {
  57                         logger.info(format("Trigger was hit for %s, executing action...", reaction.name()));
  58                         reaction.action().execute(trigger.output(reaction));
  59                 }
  60                 logger.info(format("Reaction %s finished.", reaction.name()));
  61         }
  62
  63         private void saveStateWithIncreasedFailCount(State state) {
  64                 Optional<State> lastState = reactionState.loadLastState();
  65                 state.setFailCount(lastState.map(State::failCount).orElse(0) + 1);
  66                 reactionState.saveState(state);
  67         }
  68
  69         private State runQuery() {
  70                 logger.info(format("Querying %s...", reaction.name()));
  71                 try {
  72                         return ofNullable(reaction.query().state()).orElse(INSTANCE);
  73                 } catch (Throwable t1) {
  74                         logger.warn(format("Could not query %s.", reaction.name()), t1);
  75                         return new FailedState(t1);
  76                 }
  77         }
  78
  79         private State runStateThroughFilters(State state) {
  80                 State currentState = state;
  81                 for (Filter filter : reaction.filters()) {
  82                         if (currentState.success()) {
  83                                 logger.debug(format("Filtering state through %s...", filter.getClass().getSimpleName()));
  84                                 try {
  85                                         currentState = filter.filter(currentState);
  86                                 } catch (Throwable t1) {
  87                                         logger.warn(format("Error during filter %s for %s.", filter.getClass().getSimpleName(), reaction.name()), t1);
  88                                 }
  89                         }
  90                 }
  91                 return currentState;
  92         }
  93
  94 }