feat: available movements considering a piece of the same owner

src/components/board/state/board-state-reducer.ts

@@ -1,26 +1,25 @@
 import boardModel from "models/board";
-import { getAvailableMovements } from "models/movements";
 
 function boardStateReducer(
   state: BoardState,
   action: BoardStateAction
 ): BoardState {
   console.debug(`boardStateReducer(${action.type})`);
-  // const board = boardModel(state);
 
+  const board = boardModel(state);
   switch (action.type) {
     case "select-tile": {
       if (!action.tile) {
         throw Error('Inconsistent state: "select-tile" action requires "tile"');
       }
-      // if (board.hasAnySelectedTile()) {
-      //   state[board.getSelectedTile()].status = "idle";
-      // }
+      if (board.hasAnySelectedTile()) {
+        state[board.getSelectedTile()].status = "idle";
+      }
       const tile = state[action.tile];
       tile.status = "selected";
 
       if (tile.piece && tile.piece?.type === "soldier") {
-        getAvailableMovements(action.tile).forEach((availableTile) => {
+        board.getAvailableMovements(action.tile).forEach((availableTile) => {
           state[availableTile].status = "available";
         });
       }

src/models/board.ts

@@ -1,3 +1,5 @@
+import { rangeTiles as tilesInRange } from "./tiles";
+
 function boardModel(b: BoardState) {
   return {
     hasAnySelectedTile() {
@@ -11,15 +13,24 @@ function boardModel(b: BoardState) {
     },
 
     getSelectedTile() {
-      const selectedTile = Object.entries(b).find(
+      const selectedTileID = Object.entries(b).find(
         ([, tile]) => tile.status === "selected"
       )?.[0];
-      if (!selectedTile) {
+      if (!selectedTileID) {
         throw new Error(
           'Inconsistent state: "getSelectedTileID" was unable to find any selected tile'
         );
       }
-      return selectedTile as TileID;
+      return selectedTileID as TileID;
+    },
+
+    getAvailableMovements(tile: TileID) {
+      return tilesInRange(tile).filter(
+        (candidateTile) =>
+          /* valid options: */
+          !b[candidateTile].piece ||
+          b[candidateTile].piece?.owner !== b[tile].piece?.owner
+      );
     },
   };
 }

src/models/tiles.ts

@@ -74,3 +74,35 @@ export function asTileID({ x, y }: { x: number; y: number }): TileID | null {
 export function row(n: -3 | -2 | -1 | 0 | 1 | 2 | 3): TileID[] {
   return tiles.filter((id) => coordinates(id).y === n);
 }
+
+export function rangeTiles(tile: TileID, range = 1): TileID[] {
+  const { x, y } = coordinates(tile);
+
+  // TODO use range param instead of fixed array?
+  const range1Movements =
+    y % 2 === 0
+      ? [
+          [0, -1],
+          [+1, -1],
+          [-1, 0],
+          [+1, 0],
+          [0, +1],
+          [+1, +1],
+        ]
+      : [
+          [-1, -1],
+          [0, -1],
+          [-1, 0],
+          [+1, 0],
+          [-1, +1],
+          [0, +1],
+        ];
+
+  return range1Movements.flatMap((variance) => {
+    const tileIdStr = asTileID({
+      x: x + variance[0],
+      y: y + variance[1],
+    });
+    return tileIdStr ? [tileIdStr] : [];
+  });
+}