From 0a721d111a0f55b2a196f7d10918ccd7cf3a3a50 Mon Sep 17 00:00:00 2001
From: Sage Vaillancourt <sagev9000@tutanota.com>
Date: Tue, 29 Dec 2020 08:25:17 -0500
Subject: [PATCH] Checkmate framework in place

---
 src/index.js | 118 +++++++++++++++++++++++++++++++++++----------------
 1 file changed, 82 insertions(+), 36 deletions(-)

diff --git a/src/index.js b/src/index.js
index 520c855..7e1bc67 100644
--- a/src/index.js
+++ b/src/index.js
@@ -223,7 +223,6 @@ class Board extends React.Component {
         }
       }
     } else if (isBishop(piece)) {
-      console.log("Bishop");
       // Down-Right
       for (i = 1; i < 8; i++) {
         if (tryAddMove(x + i, y + i) !== 0) {
@@ -254,7 +253,6 @@ class Board extends React.Component {
         [Pieces.WhiteRook, Pieces.WhiteBishop];
       moves = moves.concat(this.getValidMovesAt(rook, x, y));
       moves = moves.concat(this.getValidMovesAt(bishop, x, y));
-      console.log(moves);
     } else if (isKnight(piece)) {
       tryAddMove(x + 2, y + 1);
       tryAddMove(x + 2, y - 1);
@@ -278,24 +276,22 @@ class Board extends React.Component {
     return moves;
   }
 
-  inCheck() {
-    var blackKing = null;
-    var whiteKing = null;
-    for(var i = 0; i < this.state.squares.length; i++) {
-      if(this.state.squares[i] === Pieces.BlackKing) {
-        blackKing = this.getXandY(i);
-      } else if(this.state.squares[i] === Pieces.WhiteKing) {
-        whiteKing = this.getXandY(i);
+  inCheck(piece) {
+    var kingPos;
+    for(var i = 0; i < this.squareCount(); i++) {
+      if(this.state.squares[i] === piece) {
+        kingPos = this.getXandY(i);
       }
     }
 
-    for(i = 0; i < this.state.squares.length; i++) {
-      let moves = this.getValidMoves(i);
-      for(var j = 0; j < moves.length; j++) {
-        if(moves[j][0] === blackKing[0] && moves[j][1] === blackKing[1]) {
-          return Pieces.BlackKing;
-        } else if(moves[j][0] === whiteKing[0] && moves[j][1] === whiteKing[1]) {
-          return Pieces.WhiteKing;
+    for(i = 0; i < this.squareCount(); i++) {
+      let [x, y] = this.getXandY(i);
+      if(this.isEnemyOf(piece, x, y)) {
+        let moves = this.getValidMoves(i);
+        for(var j = 0; j < moves.length; j++) {
+          if(moves[j][0] === kingPos[0] && moves[j][1] === kingPos[1]) {
+            return piece;
+          }
         }
       }
     }
@@ -303,13 +299,57 @@ class Board extends React.Component {
     return null;
   }
 
+  whoInCheck() {
+    let blackKing = this.inCheck(Pieces.BlackKing);
+    return blackKing ? blackKing : this.inCheck(Pieces.WhiteKing);
+  }
+
+  squareCount() {
+    return this.state.squares.length;
+  }
+
+  squareAt(i) {
+    return i >= 0 && i < 64 ? this.state.squares[i] : null;
+  }
+
   checkmate() {
+    let checkedKing = this.whoInCheck();
+    if (checkedKing != null) {
+      // For piece in board
+      //   If piece is on the checked team,
+      //     Copy the board
+      //     Make one of the piece's moves on the board
+      //     Return false if the king is no longer in check
+
+      // For each square
+      console.log("Square count: " + this.squareCount());
+      for(var i = 0; i < this.squareCount(); i++) {
+        let piece = this.squareAt(i);
+        // If that piece is on the checked team
+        if (piece != null && isBlack(piece) === isBlack(checkedKing)) {
+          console.log("Trying moves for " + Images[piece])
+          // Copy the board
+          var board = new Board();
+          board.state.squares = this.state.squares.slice();
+          // For each move of the above piece
+          let moves = board.getValidMoves(i)
+          for(var j = 0; j < moves.length; j++) {
+            let [from, to] = moves[j];
+            board.makeMove(from, to);
+            if (board.inCheck(checkedKing) !== checkedKing) {
+              return false;
+            }
+          }
+        }
+      }
+      return true;
+    }
+
     return false;
   }
 
   getValidMoves(source) {
     let [x, y] = this.getXandY(source);
-    console.log([x, y]);
 
     let piece = this.state.squares[source];
     return this.getValidMovesAt(piece, x, y);
@@ -320,7 +360,6 @@ class Board extends React.Component {
 
     let validMoves = this.getValidMoves(source);
     if (validMoves == null) {
-      console.log("Null moves");
       return false;
     }
 
@@ -342,28 +381,35 @@ class Board extends React.Component {
     return this.state.hand.heldPiece;
   }
 
-  handleClick(i) {
+  makeMove(from, to) {
     const squares = this.state.squares.slice();
+    if (this.isValidMove(from, to)) {
+      squares[to] = squares[from];
+      squares[from] = null;
+      this.setHand({
+          heldPiece: null,
+      });
+      this.setState({
+        squares: squares,
+        blackIsNext: !this.state.blackIsNext,
+      });
+      return 0;
+    }
+    return 1;
+  }
+
+  handleClick(i) {
     if (this.isHoldingPiece()) {
-      if (this.isValidMove(this.heldPiece(), i)) {
-        squares[i] = squares[this.heldPiece()];
-        squares[this.heldPiece()] = null;
-        this.setHand({
-            heldPiece: null,
-        });
-        this.setState({
-          squares: squares,
-          blackIsNext: !this.state.blackIsNext,
-        });
-      } else {
+      if (this.makeMove(this.heldPiece(), i) !== 0) {
         this.setHand({
             heldPiece: null,
         });
       }
-    } else if (squares[i] != null) {
-      let isSquareBlack = isBlack(squares[i]);
+      return;
+    } 
+    if (this.state.squares[i] != null) {
+      let isSquareBlack = isBlack(this.state.squares[i]);
       if(isSquareBlack === this.state.blackIsNext) {
-        console.log(this.getValidMoves(i));
         this.setHand({
             heldPiece: i,
         });
@@ -402,8 +448,8 @@ class Board extends React.Component {
   }
 
   render() {
-    let checkMsg = this.inCheck() ? "Check! " : "";
-    const status =
+    let checkMsg = this.whoInCheck() ? "Check! " : "";
+    const status = this.checkmate() ? "CHECKMATE" :
       checkMsg + (this.state.blackIsNext ? 'Black' : 'White') + "'s Turn";
 
     var texttext =