Disallow placing piece in places with invalid adjacent connections

interface/index.ts

@@ -11,5 +11,4 @@ export * from "./types/ExternalNode";
 export * from "./types/InternalNode";
 export * from "./types/Piece";
 export * from "./types/PlacedPiece";
-export * from "./types/Node";
 export * from "./BoardBuilder";

interface/types/Cell.ts

@@ -1,7 +1,10 @@
 import { CellType } from "../constants/CellType";
 import { Direction } from "../constants/Direction";
+import { ExitType } from "../constants/ExitType";
 import { PieceId, pieceMap } from "../constants/Pieces";
+import { Exit } from "./Exit";
 import { ExternalNode } from "./ExternalNode";
+import { InternalNode } from "./InternalNode";
 import { PlacedPiece } from "./PlacedPiece";
 
 export class Cell {
@@ -30,8 +33,44 @@ export class Cell {
 
   public placePiece(pieceId: PieceId) {
     if (this.placedPiece !== undefined) return;
+    const piece = pieceMap[pieceId];
+    const connectionTypes = Array.from(piece.tracks).flatMap((track) => {
+      const directions =
+        track.joinedPoints.secondPoint instanceof InternalNode
+          ? [track.joinedPoints.firstPoint]
+          : [track.joinedPoints.firstPoint, track.joinedPoints.secondPoint];
+      return directions.map((direction) => {
+        return { direction: direction, type: track.type };
+      });
+    });
+    connectionTypes.forEach(({ direction, type }) => {
+      const adjacentPoint = this.getNodeAt(direction).traverseBorder();
+      if (adjacentPoint instanceof Exit) {
+        if (
+          adjacentPoint.type !== ExitType.AMBIVALENT &&
+          adjacentPoint.type.toString() !== type.toString()
+        ) {
+          throw Error(
+            `Unable to place piece, invalid border at direction ${direction}`,
+          );
+        }
+      } else {
+        if (adjacentPoint.cell.placedPiece !== undefined) {
+          const adjacentTrack =
+            adjacentPoint.cell.placedPiece.piece.findTrackForDirection(
+              adjacentPoint.direction,
+            );
+          if (adjacentTrack !== undefined && adjacentTrack.type !== type) {
+            throw Error(
+              `Unable to place piece next to another due to conflicting track types at ${direction}`,
+            );
+          }
+        }
+      }
+    });
+
     this.placedPiece = {
-      piece: pieceMap[pieceId].toPlacedPiece(this),
+      piece: piece.toPlacedPiece(this),
       id: pieceId,
     };
   }

interface/types/Node.ts

@@ -1,4 +0,0 @@
-import { ExternalNode } from "./ExternalNode";
-import { InternalNode } from "./InternalNode";
-
-export type Node = ExternalNode | InternalNode;

interface/types/PlacedPiece.ts

@@ -1,22 +1,25 @@
+import { Direction } from "../constants/Direction";
 import { TrackType } from "../constants/TrackType";
 import { Cell } from "./Cell";
+import { ExternalNode } from "./ExternalNode";
 import { InternalNode } from "./InternalNode";
-import { Node } from "./Node";
 
 export class PlacedPiece {
   tracks: Set<{
     nodes: {
-      firstNode: Node;
-      secondNode: Node;
+      firstNode: ExternalNode;
+      secondNode: ExternalNode | InternalNode;
     };
     type: TrackType;
   }>;
   internalNode?: InternalNode;
   cell: Cell;
-
   constructor(
     tracks: Set<{
-      nodes: { firstNode: Node; secondNode: Node };
+      nodes: {
+        firstNode: ExternalNode;
+        secondNode: ExternalNode | InternalNode;
+      };
       type: TrackType;
     }>,
     internalNodes: InternalNode | undefined,
@@ -26,4 +29,13 @@ export class PlacedPiece {
     this.internalNode = internalNodes;
     this.cell = cell;
   }
+
+  public findTrackForDirection(direction: Direction) {
+    return Array.from(this.tracks).find(
+      (track) =>
+        track.nodes.firstNode.direction === direction ||
+        (track.nodes.secondNode instanceof ExternalNode &&
+          track.nodes.secondNode.direction === direction),
+    );
+  }
 }

web/src/pages/game/components/BoardCell.tsx

@@ -25,7 +25,12 @@ const BoardCell = (props: BoardCellProps) => {
   const handleBoardCellClick = () => {
     const selectedDie = dice.find((die) => die.isSelected);
     if (!selectedDie) return;
+    try {
       cell.placePiece(selectedDie.pieceId);
+    } catch (error) {
+      console.log(error);
+      return;
+    }
     setDice(
       dice.map((die) => {
         return die !== selectedDie