feat: Add deserialization for JS move notation

src/Game/Move.php

@@ -165,12 +165,27 @@ class Move {
         return join(",", [
             $this->piece->toJS(),
             $this->target,
-            $this->captures ?? "",
+            $this->captures?->toJS() ?? "",
             $this->promoteTo?->getShort() ?? "",
-            $this->castleWith ?? ""
+            $this->castleWith?->toJS() ?? ""
         ]);
     }
 
+    static public function fromJS(string $jsStr): Move {
+        $components = explode(",", $jsStr);
+        if (count($components) != 5) {
+            throw new \InvalidArgumentException("unable to deserialize move string: " . $jsStr);
+        }
+
+        return new Move(
+            Piece::fromJS($components[0]),
+            Position::fromString($components[1]),
+            $components[2] != "" ? Piece::fromJS($components[2]) : null,
+            $components[3] != "" ? PieceType::fromShort($components[3]) : null,
+            $components[4] != "" ? Piece::fromJS($components[4]) : null,
+        );
+    }
+
     public function __toString(): string {
         return $this->getLong();
     }

src/Game/Piece.php

@@ -55,6 +55,19 @@ abstract class Piece {
         ]);
     }
 
+    public static function fromJS(string $jsStr): Piece {
+        $components = explode("-", $jsStr);
+        if (count($components) != 3) {
+            throw new \InvalidArgumentException("unable to deserialize piece string: " . $jsStr);
+        }
+
+        return self::ofType(
+            PieceType::fromShort($components[1]),
+            Position::fromString($components[2]),
+            Side::fromShort($components[0]),
+        );
+    }
+
     private static function getClassForType(PieceType $type): string {
         switch ($type) {
             case PieceType::PAWN:

src/Game/PieceType.php

@@ -25,6 +25,18 @@ enum PieceType {
         };
     }
 
+    public static function fromShort(string $short): PieceType {
+        return match (strtoupper($short)) {
+            "" => self::PAWN,
+            "B" => self::BISHOP,
+            "N" => self::KNIGHT,
+            "R" => self::ROOK,
+            "Q" => self::QUEEN,
+            "K" => self::KING,
+            default => throw new \InvalidArgumentException("unknown piece type: " . $short)
+        };
+    }
+
     public function getLong(): string {
         return match ($this) {
             self::PAWN => "Pawn",

src/Game/Position.php

@@ -33,6 +33,18 @@ class Position {
         return $this->getFileString() . $this->getRankString();
     }
 
+    public static function fromString(string $str): Position {
+        $str = strtolower($str);
+        $file = ord($str[0]) - ord("a");
+        $rank = ord($str[1]) - ord("1");
+
+        $position = new Position($file, $rank);
+        if (!$position->isValid()) {
+            throw new \InvalidArgumentException("position is not valid: " . $str);
+        }
+        return $position;
+    }
+
     public function equals(Position $position): bool {
         return $this->file == $position->file && $this->rank == $position->rank;
     }

src/Game/Side.php

@@ -21,4 +21,12 @@ enum Side {
             return "b";
         }
     }
+
+    public static function fromShort(string $short): Side {
+        return match ($short) {
+            "w" => self::WHITE,
+            "b" => self::BLACK,
+            default => throw new \InvalidArgumentException("unknown side: " . $short),
+        };
+    }
 }

tests/Game/MoveTest.php

@@ -97,4 +97,54 @@ final class MoveTest extends TestCase {
         $this->assertEquals("Nc2xd4++", $subject->getShort($game));
     }
 
+    public function testToJS_capturesAndPromotes() {
+        $move = new Move(
+            new Pawn(new Position(1, 6), Side::WHITE),
+            new Position(2, 7),
+            new Queen(new Position(2, 7), Side::BLACK),
+            PieceType::QUEEN,
+        );
+
+        $this->assertEquals("w--b7,c8,b-Q-c8,Q,", $move->toJS());
+    }
+
+    public function testToJS_minimal() {
+        $move = new Move(
+            new Queen(new Position(1, 6), Side::WHITE),
+            new Position(3, 4)
+        );
+
+        $this->assertEquals("w-Q-b7,d5,,,", $move->toJS());
+    }
+
+    public function testToJS_castle() {
+        $move = new Move(
+            new King(new Position(4, 0), Side::WHITE),
+            new Position(2, 0),
+            null,
+            null,
+            new Rook(new Position(0, 0), Side::WHITE)
+        );
+
+        $this->assertEquals("w-K-e1,c1,,,w-R-a1", $move->toJS());
+    }
+
+    public function testFromJS_capturesAndPromotes() {
+        $move = Move::fromJS("w--b7,c8,b-Q-c8,Q,");
+
+        $this->assertEquals("b7xc8Q", $move->getLong());
+    }
+
+    public function testFromJS_minimal() {
+        $move = Move::fromJS("w-Q-b7,d5,,,");
+
+        $this->assertEquals("Qb7d5", $move->getLong());
+    }
+
+    public function testFromJS_castle() {
+        $move = Move::fromJS("w-K-e1,c1,,,w-R-a1");
+
+        $this->assertEquals("O-O-O", $move->getLong());
+    }
+
 }