feat: 1vs BOT

src/app/pages/game/game.facade.ts

@@ -1,7 +1,7 @@
 import { DestroyRef, Injectable, OnDestroy, inject } from '@angular/core';
 import { Router } from '@angular/router';
 import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
-import { interval, startWith, Subscription, switchMap } from 'rxjs';
+import { interval, startWith, Subscription, switchMap, delay } from 'rxjs';
 import { getPieceAtSquare, isPieceColor } from '../../core/chess/fen.utils';
 import { getErrorMessage } from '../../core/http/error-message.util';
 import { GameFull, GameState, GameStreamEvent, LegalMove } from '../../models/game.models';
@@ -25,16 +25,37 @@ export class GameFacade implements OnDestroy {
   private readonly destroyRef = inject(DestroyRef);
   private streamSubscription: Subscription | null = null;
   private pollSubscription: Subscription | null = null;
+  private botMoveSubscription: Subscription | null = null;
 
   ngOnDestroy(): void {
     this.streamSubscription?.unsubscribe();
     this.pollSubscription?.unsubscribe();
+    this.botMoveSubscription?.unsubscribe();
   }
 
   get state(): GameState | null {
     return this.game?.state ?? null;
   }
 
+  private isBotPlayer(playerId: string): boolean {
+    return playerId.startsWith('bot-');
+  }
+
+  private isPlayingAgainstBot(): boolean {
+    if (!this.game) {
+      return false;
+    }
+    return this.isBotPlayer(this.game.white.id) || this.isBotPlayer(this.game.black.id);
+  }
+
+  private isCurrentPlayerBot(): boolean {
+    if (!this.game || !this.state) {
+      return false;
+    }
+    const currentPlayer = this.state.turn === 'white' ? this.game.white : this.game.black;
+    return this.isBotPlayer(currentPlayer.id);
+  }
+
   setGameId(gameId: string): void {
     this.gameId = gameId;
     this.loadGame();
@@ -94,6 +115,7 @@ export class GameFacade implements OnDestroy {
           }
           this.moveInput = '';
           this.clearSelection();
+          this.tryMakeBotMove();
         },
         error: (error) => {
           this.errorMessage = getErrorMessage(error, 'Move rejected.');
@@ -153,6 +175,7 @@ export class GameFacade implements OnDestroy {
     this.clearSelection();
     this.streamSubscription?.unsubscribe();
     this.pollSubscription?.unsubscribe();
+    this.botMoveSubscription?.unsubscribe();
     this.pollSubscription = null;
 
     this.gameApi
@@ -163,6 +186,7 @@ export class GameFacade implements OnDestroy {
           this.game = game;
           this.loading = false;
           this.startStream();
+          this.tryMakeBotMove();
         },
         error: (error) => {
           this.errorMessage = getErrorMessage(error, `Could not load game ${this.gameId}.`);
@@ -205,6 +229,7 @@ export class GameFacade implements OnDestroy {
           this.game = game;
           if (previousMoves !== game.state.moves.join(',')) {
             this.clearSelection();
+            this.tryMakeBotMove();
           }
         }
       });
@@ -214,6 +239,7 @@ export class GameFacade implements OnDestroy {
     if (event.type === 'gameFull') {
       this.game = event.game;
       this.clearSelection();
+      this.tryMakeBotMove();
       return;
     }
 
@@ -222,6 +248,7 @@ export class GameFacade implements OnDestroy {
       this.game = { ...this.game, state: event.state };
       if (event.state.moves.length !== moveCountBefore) {
         this.clearSelection();
+        this.tryMakeBotMove();
       }
       return;
     }
@@ -231,6 +258,45 @@ export class GameFacade implements OnDestroy {
     }
   }
 
+  private tryMakeBotMove(): void {
+    if (!this.isPlayingAgainstBot() || !this.isCurrentPlayerBot() || !this.state) {
+      return;
+    }
+
+    this.botMoveSubscription?.unsubscribe();
+    this.botMoveSubscription = this.gameApi
+      .getLegalMoves(this.gameId)
+      .pipe(
+        delay(1000),
+        takeUntilDestroyed(this.destroyRef)
+      )
+      .subscribe({
+        next: (response) => {
+          if (response.moves.length === 0) {
+            return;
+          }
+          const botMove = response.moves[Math.floor(Math.random() * response.moves.length)];
+          this.gameApi
+            .makeMove(this.gameId, botMove.uci)
+            .pipe(takeUntilDestroyed(this.destroyRef))
+            .subscribe({
+              next: (state) => {
+                if (this.game) {
+                  this.game = { ...this.game, state };
+                }
+                this.clearSelection();
+              },
+              error: (error) => {
+                this.errorMessage = getErrorMessage(error, 'Bot move failed.');
+              }
+            });
+        },
+        error: () => {
+          this.errorMessage = 'Could not get legal moves for bot move.';
+        }
+      });
+  }
+
   private clearSelection(): void {
     this.selectedSquare = null;
     this.selectedSquareMoves = [];