started on path finder porting

src/main/java/baritone/bot/pathing/calc/AbstractNodeCostSearch.java

@@ -0,0 +1,74 @@
+package baritone.bot.pathing.calc;
+
+import baritone.bot.pathing.goals.Goal;
+import net.minecraft.util.math.BlockPos;
+
+import java.util.HashMap;
+
+public abstract class AbstractNodeCostSearch implements IPathFinder {
+
+    //TODO this shouldn't be necessary!!
+    public static AbstractNodeCostSearch currentlyRunning = null;
+
+
+    protected final BlockPos start;
+    protected final Goal goal;
+    protected final HashMap<BlockPos, PathNode> map;
+    protected PathNode startNode;
+    protected PathNode mostRecentConsidered;
+    protected PathNode[] bestSoFar;
+    private volatile boolean isFinished;
+
+    /**
+     * This is really complicated and hard to explain. I wrote a comment in the old version of MineBot but it was so
+     * long it was easier as a Google Doc (because I could insert charts).
+     * https://docs.google.com/document/d/1WVHHXKXFdCR1Oz__KtK8sFqyvSwJN_H4lftkHFgmzlc/edit
+     */
+    protected static final double[] COEFFICIENTS = {1.5, 2, 2.5, 3, 4, 5, 10};
+
+    public AbstractNodeCostSearch(BlockPos start, Goal goal) {
+        this.start = start;
+        this.goal = goal;
+        this.map = new HashMap<>();
+    }
+
+    public synchronized IPath calculatePath() {
+        if (isFinished) {
+            throw new IllegalStateException("Unable to re-use path finder");
+        }
+        IPath path = calculate();
+        isFinished = true;
+        return path;
+    }
+
+    protected abstract IPath calculate();
+
+    @Override
+    public boolean isFinished() {
+        return isFinished;
+    }
+
+    @Override
+    public Goal getGoal() {
+        return goal;
+    }
+
+    @Override
+    public BlockPos getStart() {
+        return start;
+    }
+
+
+    @Override
+    public Path bestPathSoFar() {
+        if (startNode == null || bestSoFar[0] == null) {
+            return null;
+        }
+        return new Path(startNode, bestSoFar[0], goal);
+    }
+
+    @Override
+    public Path pathToMostRecentNodeConsidered() {
+        return mostRecentConsidered == null ? null : new Path(startNode, mostRecentConsidered, goal);
+    }
+}