added bird ai to hang around birdhouse if active (#9)

* added bird ai to hang around birdhouse if active

* fixed styling errors

* fixed small bug. Removed extraneous functions

* rebased from main, restructured goal logic to fit new ticking structure

* Styling changes, removed dead code in hangoutaroundbirdhousegoal class. Refactored goal class. Added comments

* added bird ai to hang around birdhouse if active

* fixed styling errors

* fixed small bug. Removed extraneous functions

src/main/java/com/ocelotslovebirds/birdhaus/blocks/BirdhouseBlockEntity.java

@@ -1,7 +1,9 @@
 package com.ocelotslovebirds.birdhaus.blocks;
 
+import java.util.List;
 import java.util.concurrent.ThreadLocalRandom;
 
+import com.ocelotslovebirds.birdhaus.mobai.HangAroundBirdhouseGoal;
 import com.ocelotslovebirds.birdhaus.setup.Registration;
 import com.ocelotslovebirds.birdhaus.ticker.FixedIntervalTicker;
 import com.ocelotslovebirds.birdhaus.ticker.Ticker;
@@ -11,12 +13,15 @@
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.entity.EntityType;
+import net.minecraft.world.entity.ai.goal.Goal;
+import net.minecraft.world.entity.ai.goal.WrappedGoal;
 import net.minecraft.world.entity.animal.Parrot;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.block.Block;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.state.BlockState;
 import net.minecraft.world.level.block.state.properties.BlockStateProperties;
+import net.minecraft.world.phys.AABB;
 import net.minecraftforge.common.Tags;
 import net.minecraftforge.common.capabilities.Capability;
 import net.minecraftforge.common.util.LazyOptional;
@@ -35,10 +40,18 @@ public class BirdhouseBlockEntity extends BlockEntity {
 
     private Ticker tickerForBirdSpawns = new FixedIntervalTicker(150);
     private Ticker tickerForSeedConsumption = new FixedIntervalTicker(100);
+    private Ticker tickerForBirdhouseGoalModification = new FixedIntervalTicker(100);
 
     // The block is active if it able to consume seeds
     private Boolean isActive = false;
-
+    private AABB birdHouseBB = new AABB(
+        this.getBlockPos().getX() - 10,
+        this.getBlockPos().getY(),
+        this.getBlockPos().getZ() - 10,
+        this.getBlockPos().getX() + 10,
+        this.getBlockPos().getY() + 10,
+        this.getBlockPos().getZ() + 10
+        );
     /**
      * @param pos   Position of the block.
      * @param state State of the block being created.
@@ -69,18 +82,16 @@ public void load(CompoundTag tag) {
         super.load(tag);
     }
 
-
     /**
-     * This is the main loop for the birdhouse. It needs to be improved to allow for the spawning of birds however at
-     * the moment it works well for
-     * 1. Extracting seeds from the inventory stack,
-     * 2. Reacting to seeds being placed in the stack.
-     * 3. Creates a ticker that can be used to time bird spawns eventually.
+     * This is the main loop for the birdhouse.
+     * It ticks all the events that should be happening
+     * after a certain interval.
      */
 
     public void tickServer() {
         handleSeedsForTick();
         handleBirdSpawnForTick();
+        handleParrotGoalForTick();
     }
 
     /*
@@ -110,29 +121,84 @@ private void handleBirdSpawnForTick() {
             // Random z offset
             int zOffset = ThreadLocalRandom.current().nextInt(-20, 20);
             spawnNewBird(xOffset, yOffset, zOffset);
+
+        }
+    }
+
+    private void handleParrotGoalForTick() {
+        if (tickerForBirdhouseGoalModification.tick()) {
+            if (this.isActive) {
+                applyBirdHouseGoalToSurroundingParrots();
+            } else {
+                removeBirdHouseGoalToSurroundingParrots();
+            }
+        }
+    }
+
+    /**
+     * Applies the "HangingAroundBirdhouseGoal" to birds in the
+     * birdhouse bounding box.
+     *
+     * TODO: Make this threadsafe.
+     */
+    private void applyBirdHouseGoalToSurroundingParrots() {
+        List<Parrot> parrots = this.level.getEntitiesOfClass(Parrot.class, this.birdHouseBB);
+        for (Parrot temp:parrots) {
+            // Check to see if they already have the goal applied. If not, apply it.
+            if (!temp.goalSelector.getAvailableGoals().stream()
+                .anyMatch(wg -> wg.getGoal() instanceof HangAroundBirdhouseGoal)) {
+                temp.goalSelector.addGoal(0, new HangAroundBirdhouseGoal(temp, 1.0, 60, false, this.getBlockPos()));
+            }
+        }
+    }
+
+    /**
+     * Removes the "HangingAroundBirdhouseGoal" to birds in the
+     * birdhouse bounding box.
+     *
+     * TODO: Make this threadsafe.
+     */
+    private void removeBirdHouseGoalToSurroundingParrots() {
+        List<Parrot> parrots = this.level.getEntitiesOfClass(Parrot.class, this.birdHouseBB);
+        for (Parrot temp:parrots) {
+            // Check to see if they already have the goal applied. If not, apply it.
+            if (temp.goalSelector.getAvailableGoals().stream()
+                .anyMatch(wg -> wg.getGoal() instanceof HangAroundBirdhouseGoal)) {
+                Goal toRemove = null;
+                for (WrappedGoal g : temp.goalSelector.getAvailableGoals()) {
+                    if (g.getGoal() instanceof HangAroundBirdhouseGoal) {
+                        toRemove = g.getGoal();
+                    }
+                }
+                if (toRemove != null) {
+                    temp.goalSelector.removeGoal(toRemove);
+                }
+            }
         }
     }
 
     private void handleSeedsForTick() {
-        if (isActive) {
-            // If the birdhouse is active, try consuming a seed
+        // Tick the birdhouse to check it needs to consume a seed
+        if (tickerForSeedConsumption.tick()) {
+            // If a seed was successfully extracted from the birdhouse
             if (!itemHandler.extractItem(0, 1, false).isEmpty()) {
-                // If a seed was successfully consumed, set birdhouse to inactive
-                isActive = false;
-            }
-        } else {
-            // If birdhouse is inactive, start ticking to eventually reactivate it
-            if (tickerForSeedConsumption.tick()) {
-                isActive = true;
+                // Check if the state of the BHouse is not active
+                if (!this.isActive) {
+                    // If not active, set to active
+                    this.isActive = true;
+                }
+            } else { // If nothing was extracted from the BHouse (inventory was empty)
+                // Set BHouse state to false
+                this.isActive = false;
             }
         }
 
         // Update the block state if there was a change
         BlockState blockState = getBlockState();
-        if (blockState.getValue(BlockStateProperties.CONDITIONAL) != isActive) {
+        if (blockState.getValue(BlockStateProperties.CONDITIONAL) != this.isActive) {
             level.setBlock(
                 worldPosition,
-                blockState.setValue(BlockStateProperties.CONDITIONAL, isActive),
+                blockState.setValue(BlockStateProperties.CONDITIONAL, this.isActive),
                 Block.UPDATE_ALL
             );
         }

src/main/java/com/ocelotslovebirds/birdhaus/mobai/HangAroundBirdhouseGoal.java

@@ -0,0 +1,41 @@
+package com.ocelotslovebirds.birdhaus.mobai;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.entity.PathfinderMob;
+import net.minecraft.world.entity.ai.goal.RandomStrollGoal;
+import net.minecraft.world.phys.Vec3;
+
+
+public class HangAroundBirdhouseGoal extends RandomStrollGoal {
+
+    private Vec3 bHousePosVec;
+
+    /**
+     * Constructor for the parrot goal. Makes parrots stay
+     * around a birdhouse when it has seeds in its internal inventory.
+     * @param pMob the mob getting this goal
+     * @param pSpeedModifier modifies mob move speed
+     * @param pInterval interval to check if the goal should be sought
+     * @param pCheckNoActionTime boolean to check to see if the mob has not been performing an action
+     * @param bHousePos position of the birdhouse passing the goal to the mob
+     */
+    public HangAroundBirdhouseGoal(PathfinderMob pMob, double pSpeedModifier,
+        int pInterval, boolean pCheckNoActionTime, BlockPos bHousePos) {
+        super(pMob, pSpeedModifier, pInterval, pCheckNoActionTime);
+        this.bHousePosVec = new Vec3(bHousePos.getX(), bHousePos.getY(), bHousePos.getZ());
+    }
+
+    /**
+     * Returns the position for the parrot to move to. This will be the position of the birdhouse that gave it the goal.
+     * If for some reason, the bird is left with this goal with no birdhouse in sight, it will default to behaving like
+     * "RandomWanderGoal".
+     */
+    @Override
+       protected Vec3 getPosition() {
+        if (this.bHousePosVec != null) {
+            return this.bHousePosVec;
+        } else {
+            return super.getPosition();
+        }
+    }
+}