unified table cell logic between frontend and backend; unified autoplay; implemented autoplay on frontend

src/backend/components/boardgame.tsx

@@ -1,13 +1,6 @@
 import { sequence } from "../../shared/array-utils.ts";
-import {
-  BoardgameStateType,
-  CurrentOutcome,
-  GameRules,
-  Player,
-  SquareState,
-  formatSquareState,
-} from "../../shared/datatypes.ts";
-import { ClassNames, getDisplayStates } from "../../shared/display.ts";
+import { BoardgameStateType, CurrentOutcome, GameRules, Player } from "../../shared/datatypes.ts";
+import { ClassNames, getCellDisplayData, getDisplayStates } from "../../shared/display.ts";
 
 const getClassAndDisplayAttributes = (
   className: ClassNames,
@@ -37,22 +30,11 @@ const getCellHtml = ({
   row: number;
   column: number;
 }) => {
-  if (!gameState.board) {
-    return (
-      <button {...getSubmitAttributes(key, gameState)} disabled>
-        {" "}
-      </button>
-    );
-  }
+  const { isDisabled, nextGameState, text } = getCellDisplayData({ gameState, currentOutcome, row, column });
 
-  const squareState = gameState.board.get(row, column);
-  const nextGameState =
-    squareState === SquareState.Unoccupied && currentOutcome === CurrentOutcome.Undecided
-      ? gameState.withMove(row, column)
-      : gameState;
   return (
-    <button {...getSubmitAttributes(key, nextGameState)} disabled={nextGameState === gameState}>
-      {formatSquareState(squareState)}
+    <button {...getSubmitAttributes(key, nextGameState)} disabled={isDisabled}>
+      {text}
     </button>
   );
 };

src/backend/main/boardgame-handler.ts

@@ -3,9 +3,7 @@ import { rewriteQueryParamsWith, safeGetQueryValue } from "../utils.ts";
 import { BoardgameState } from "../../shared/boardgame-state.ts";
 import { getBoardgameHtml } from "../components/boardgame.tsx";
 import { gamesRules } from "../../shared/rules.ts";
-import { getAllSolutions } from "../../shared/solver-cache.ts";
-import { CurrentOutcome } from "../../shared/datatypes.ts";
-import { createOpponent } from "../../shared/opponent.ts";
+import { getTargetGameState } from "../../shared/boardgame.ts";
 
 // Returns nothing if query parameter is uninitialized and a redirect was made,
 // or component if query parameter is initialized.
@@ -13,24 +11,13 @@ export const handleBoardgame = (req: Request, res: Response, key: string) => {
   const rules = gamesRules.tictactoe;
 
   const serializedState = safeGetQueryValue(req, key);
-  const state = BoardgameState.fromSerialized(serializedState);
+  const inputState = BoardgameState.fromSerialized(serializedState);
 
-  if (!state) {
-    const newState = BoardgameState.createWithoutBoard(3, 3);
-    rewriteQueryParamsWith(req, res, { [key]: newState.serialize() });
+  const state = inputState ? getTargetGameState(inputState, rules) : BoardgameState.createWithoutBoard(3, 3);
+  if (state !== inputState) {
+    rewriteQueryParamsWith(req, res, { [key]: state.serialize() });
     return;
   }
 
-  if (state.board && state.currentPlayer && state.autoPlayers.has(state.currentPlayer)) {
-    const currentOutcome = rules.getBoardOutcome(state.board);
-    if (currentOutcome === CurrentOutcome.Undecided) {
-      const solutions = getAllSolutions(state.rows, state.columns, rules);
-      const nextMove = createOpponent(solutions).getNextMove(state.board, state.currentPlayer);
-      const newState = state.withMove(nextMove.row, nextMove.column);
-      rewriteQueryParamsWith(req, res, { [key]: newState.serialize() });
-      return;
-    }
-  }
-
   return getBoardgameHtml(key, state, rules);
 };

src/frontend/components/board-game.ts

@@ -1,19 +1,29 @@
 import { BoardgameState } from "../../shared/boardgame-state.ts";
-import { CurrentOutcome, SquareState, formatSquareState } from "../../shared/datatypes.ts";
-import { getDisplayStates } from "../../shared/display.ts";
+import { getTargetGameState } from "../../shared/boardgame.ts";
+import { CurrentOutcome } from "../../shared/datatypes.ts";
+import { getCellDisplayData, getDisplayStates } from "../../shared/display.ts";
 import { gamesRules } from "../../shared/rules.ts";
+import { replaceLocation } from "../lib/navigation-utils.ts";
 import { TrackingTools } from "../lib/query-tracking-utils.ts";
+import { updateWithQueryParams } from "../lib/url-utils.ts";
 
 export class BoardGameComponent extends HTMLElement {
   private readonly trackingTools = new TrackingTools(this);
 
-  handleTrackedValueUpdate(newValue: string | null) {
+  handleTrackedValueUpdate(newValue: string | null, key: string) {
     const rules = gamesRules.tictactoe;
 
-    const gameState = BoardgameState.fromSerialized(newValue);
-    if (!gameState) {
+    const inputGameState = BoardgameState.fromSerialized(newValue);
+    if (!inputGameState) {
       throw new Error("Empty game state");
     }
+
+    const gameState = getTargetGameState(inputGameState, rules);
+    if (gameState !== inputGameState) {
+      replaceLocation(updateWithQueryParams(new URL(window.location.href), [[key, gameState.serialize()]]));
+      return;
+    }
+
     const currentOutcome = gameState.board ? rules.getBoardOutcome(gameState.board) : CurrentOutcome.Undecided;
 
     const displayStates = getDisplayStates(gameState, currentOutcome);
@@ -37,21 +47,19 @@ export class BoardGameComponent extends HTMLElement {
             continue;
           }
 
+          const { isDisabled, nextGameState, text } = getCellDisplayData({
+            gameState,
+            currentOutcome,
+            row: rowNumber,
+            column: columnNumber,
+          });
           for (const button of cell.querySelectorAll("button")) {
-            if (!gameState.board) {
-              button.value = gameState.serialize();
-              button.disabled = true;
-              button.innerText = " ";
-            } else {
-              const squareState = gameState.board.get(rowNumber, columnNumber);
-              const nextGameState =
-                squareState === SquareState.Unoccupied && currentOutcome === CurrentOutcome.Undecided
-                  ? gameState.withMove(rowNumber, columnNumber)
-                  : gameState;
-
-              button.value = nextGameState.serialize();
-              button.disabled = nextGameState === gameState;
-              button.innerText = formatSquareState(squareState);
+            button.value = nextGameState.serialize();
+            if (button.disabled !== isDisabled) {
+              button.disabled = isDisabled;
+            }
+            if (button.innerText !== text) {
+              button.innerText = text;
             }
           }
         }

src/frontend/components/progressive-form.ts

@@ -1,15 +1,8 @@
-const submitListener = function (this: HTMLFormElement, e: SubmitEvent) {
-  const targetUrl = new URL(this.action);
-  const formData = new FormData(this, e.submitter);
-  for (const [key, value] of formData.entries()) {
-    if (typeof value !== "string") {
-      throw new Error("File fields are not supported; falling back to regular form submission");
-    }
+import { goToLocation } from "../lib/navigation-utils.ts";
+import { updateWithQueryParams } from "../lib/url-utils.ts";
 
-    targetUrl.searchParams.set(key, value);
-  }
-
-  window.history.pushState({}, "", targetUrl.toString());
+const submitListener = function (this: HTMLFormElement, e: SubmitEvent) {
+  goToLocation(updateWithQueryParams(new URL(this.action), new FormData(this, e.submitter)));
   e.preventDefault();
 };
 

src/frontend/lib/navigation-utils.ts

@@ -29,3 +29,11 @@ export const onLocationChange = (observer: () => void) => {
 export const onLocationChangeUnsubscribe = (observer: () => void) => {
   observers.delete(observer);
 };
+
+export const goToLocation = (targetUrl: URL) => {
+  window.history.pushState({}, "", targetUrl.toString());
+};
+
+export const replaceLocation = (targetUrl: URL) => {
+  window.history.replaceState({}, "", targetUrl.toString());
+};

src/frontend/lib/query-tracking-utils.ts

@@ -1,12 +1,12 @@
 import { onLocationChange, onLocationChangeUnsubscribe } from "./navigation-utils.ts";
 
-const createQueryStringTracker = (key: string, onChange: (newValue: string | null) => void) => {
+const createQueryStringTracker = (key: string, onChange: (newValue: string | null, trackKey: string) => void) => {
   let currentValue = new URLSearchParams(window.location.search).get(key);
   const observer = () => {
     const newValue = new URLSearchParams(window.location.search).get(key);
     if (newValue !== currentValue) {
       currentValue = newValue;
-      onChange(newValue);
+      onChange(newValue, key);
     }
   };
 
@@ -17,7 +17,9 @@ const createQueryStringTracker = (key: string, onChange: (newValue: string | nul
 };
 
 export class TrackingTools<
-  TElement extends HTMLElement & { handleTrackedValueUpdate(this: TElement, newValue: string | null): void },
+  TElement extends HTMLElement & {
+    handleTrackedValueUpdate(this: TElement, newValue: string | null, trackKey: string): void;
+  },
 > {
   private currentTrackKey: string | null = null;
   private clearTracker: (() => void) | null = null;

src/frontend/lib/url-utils.ts

@@ -0,0 +1,11 @@
+export const updateWithQueryParams = (targetUrl: URL, data: Iterable<[string, FormDataEntryValue]>) => {
+  for (const [key, value] of data) {
+    if (typeof value !== "string") {
+      throw new Error("File fields are not supported; falling back to regular form submission");
+    }
+
+    targetUrl.searchParams.set(key, value);
+  }
+
+  return targetUrl;
+};

src/shared/boardgame.ts

@@ -0,0 +1,28 @@
+import { BoardgameState } from "./boardgame-state.ts";
+import { CurrentOutcome, GameRules } from "./datatypes.ts";
+import { createOpponent } from "./opponent.ts";
+import { getAllSolutions } from "./solver-cache.ts";
+
+export const getTargetGameState = (state: BoardgameState, rules: GameRules) => {
+  if (!state.board) {
+    return state;
+  }
+
+  if (!state.currentPlayer) {
+    return state;
+  }
+
+  if (!state.autoPlayers.has(state.currentPlayer)) {
+    return state;
+  }
+
+  const currentOutcome = rules.getBoardOutcome(state.board);
+  if (currentOutcome !== CurrentOutcome.Undecided) {
+    return state;
+  }
+
+  const solutions = getAllSolutions(state.rows, state.columns, rules);
+  const nextMove = createOpponent(solutions).getNextMove(state.board, state.currentPlayer);
+  const newState = state.withMove(nextMove.row, nextMove.column);
+  return newState;
+};

src/shared/display.ts

@@ -1,4 +1,4 @@
-import { BoardgameStateType, CurrentOutcome, Player } from "./datatypes.ts";
+import { BoardgameStateType, CurrentOutcome, Player, SquareState, formatSquareState } from "./datatypes.ts";
 
 export const getDisplayStates = (gameState: BoardgameStateType, currentOutcome: CurrentOutcome) => ({
   "outcome-winx": currentOutcome === CurrentOutcome.WinX,
@@ -13,3 +13,35 @@ export const getDisplayStates = (gameState: BoardgameStateType, currentOutcome:
 });
 
 export type ClassNames = keyof ReturnType<typeof getDisplayStates>;
+
+export const getCellDisplayData = ({
+  gameState,
+  currentOutcome,
+  row,
+  column,
+}: {
+  gameState: BoardgameStateType;
+  currentOutcome: CurrentOutcome;
+  row: number;
+  column: number;
+}) => {
+  if (!gameState.board) {
+    return {
+      nextGameState: gameState,
+      isDisabled: true,
+      text: " ",
+    };
+  }
+
+  const squareState = gameState.board.get(row, column);
+  const nextGameState =
+    squareState === SquareState.Unoccupied && currentOutcome === CurrentOutcome.Undecided
+      ? gameState.withMove(row, column)
+      : gameState;
+
+  return {
+    nextGameState: nextGameState,
+    isDisabled: nextGameState === gameState,
+    text: formatSquareState(squareState),
+  };
+};