Add groundwork for checking rules.

api/move.go

@@ -1,11 +1,14 @@
 package api
 
-import "local/m/mchess_server/types"
+import (
+	"encoding/json"
+	"local/m/mchess_server/types"
+)
 
 type WebsocketMessage struct {
 	Type  MessageType       `json:"messageType"`
 	Move  *types.Move       `json:"move,omitempty"`
-	Color *Color      `json:"color,omitempty"`
+	Color *types.ChessColor `json:"color,omitempty"`
 }
 
 type MessageType string
@@ -15,13 +18,6 @@ const (
 	ColorDetermined MessageType = "colorDetermined"
 )
 
-type Color string
-
-const (
-	Black Color = "black"
-	White Color = "white"
-)
-
 func (m WebsocketMessage) IsValidMove() bool {
 	if m.Type != MoveMessage {
 		return false
@@ -31,3 +27,8 @@ func (m WebsocketMessage) IsValidMove() bool {
 	}
 	return true
 }
+
+func GetColorDeterminedMessage(color types.ChessColor) ([]byte, error) {
+	return json.Marshal(WebsocketMessage{Type: ColorDetermined, Color: &color})
+
+}

chess/board.go

@@ -0,0 +1,55 @@
+package chess
+
+import "local/m/mchess_server/types"
+
+type Board map[types.Coordinate]types.Piece
+
+func (b Board) Init() {
+	var coord types.Coordinate
+
+	for i := 1; i <= 8; i++ {
+		coord.Row = 2
+		coord.Col = i
+		b[coord] = types.Piece{Class: types.Pawn, Color: types.White}
+
+		coord.Row = 7
+		coord.Col = i
+		b[coord] = types.Piece{Class: types.Pawn, Color: types.Black}
+	}
+
+	b[types.Coordinate{Row: 1, Col: 1}] = types.Piece{Class: types.Rook, Color: types.White}
+	b[types.Coordinate{Row: 1, Col: 2}] = types.Piece{Class: types.Knight, Color: types.White}
+	b[types.Coordinate{Row: 1, Col: 3}] = types.Piece{Class: types.Bishop, Color: types.White}
+	b[types.Coordinate{Row: 1, Col: 4}] = types.Piece{Class: types.Queen, Color: types.White}
+	b[types.Coordinate{Row: 1, Col: 5}] = types.Piece{Class: types.King, Color: types.White}
+	b[types.Coordinate{Row: 1, Col: 6}] = types.Piece{Class: types.Bishop, Color: types.White}
+	b[types.Coordinate{Row: 1, Col: 7}] = types.Piece{Class: types.Knight, Color: types.White}
+	b[types.Coordinate{Row: 1, Col: 8}] = types.Piece{Class: types.Rook, Color: types.White}
+
+	b[types.Coordinate{Row: 8, Col: 1}] = types.Piece{Class: types.Rook, Color: types.Black}
+	b[types.Coordinate{Row: 8, Col: 2}] = types.Piece{Class: types.Knight, Color: types.Black}
+	b[types.Coordinate{Row: 8, Col: 3}] = types.Piece{Class: types.Bishop, Color: types.Black}
+	b[types.Coordinate{Row: 8, Col: 4}] = types.Piece{Class: types.Queen, Color: types.Black}
+	b[types.Coordinate{Row: 8, Col: 5}] = types.Piece{Class: types.King, Color: types.Black}
+	b[types.Coordinate{Row: 8, Col: 6}] = types.Piece{Class: types.Bishop, Color: types.Black}
+	b[types.Coordinate{Row: 8, Col: 7}] = types.Piece{Class: types.Knight, Color: types.Black}
+	b[types.Coordinate{Row: 8, Col: 8}] = types.Piece{Class: types.Rook, Color: types.Black}
+}
+
+func (b Board) GetPieceAt(coord types.Coordinate) (types.Piece, bool) {
+	piece, found := b[coord]
+
+	if !found {
+		piece = types.Piece{}
+	}
+
+	return piece, found
+}
+func (b *Board) CheckMove(move types.Move) (bool, string) {
+	_, found := b.GetPieceAt(move.StartSquare)
+	if !found {
+		return false, "no piece at start square"
+	}
+
+	return true, ""
+}

chess/game.go

@@ -1,7 +1,6 @@
 package chess
 
 import (
-	"encoding/json"
 	"local/m/mchess_server/api"
 	"local/m/mchess_server/types"
 	"log"
@@ -12,19 +11,23 @@ import (
 
 type Game struct {
 	id                uuid.UUID
+	board             Board
 	players           []*Player
 	currentTurnPlayer *Player
 }
 
 const (
-	PlayerToMove      = 0
+	PlayerToMove = iota
-	CheckPlayerChange = 1
+	CheckMove
+	CheckPlayerChange
 )
 
 func NewGame() *Game {
 	var game Game = Game{
 		id:    uuid.New(),
+		board: make(map[types.Coordinate]types.Piece),
 	}
+	game.board.Init()
 
 	return &game
 }
@@ -69,8 +72,15 @@ func (game *Game) Handle() {
 			}
 			log.Println("Player ", game.currentTurnPlayer, " moved:\n", receivedMove)
 
-			gameState = CheckPlayerChange
+			gameState = CheckMove
 
+		case CheckMove:
+			valid, reason := game.board.CheckMove(receivedMove)
+			log.Println(reason)
+
+			if valid {
+				gameState = CheckPlayerChange
+			}
 		case CheckPlayerChange:
 			if game.currentTurnPlayer.Uuid == game.players[0].Uuid {
 				game.currentTurnPlayer = game.players[1]
@@ -122,14 +132,12 @@ func (game *Game) waitForWebsocketConnections() bool {
 }
 
 func (game Game) notifyPlayersAboutGameStart() error {
-	white := api.White
+	colorDeterminedPlayer1, err := api.GetColorDeterminedMessage(types.White)
-	black := api.Black
-	colorDeterminedPlayer1, err := json.Marshal(api.WebsocketMessage{Type: api.ColorDetermined, Color: &white})
 	if err != nil {
 		log.Println("Error marshalling 'colorDetermined' message for player 1", err)
 		return err
 	}
-	colorDeterminedPlayer2, err := json.Marshal(api.WebsocketMessage{Type: api.ColorDetermined, Color: &black})
+	colorDeterminedPlayer2, err := api.GetColorDeterminedMessage(types.Black)
 	if err != nil {
 		log.Println("Error marshalling 'colorDetermined' message for player 2", err)
 		return err

types/chess_types.go

@@ -1,11 +0,0 @@
-package types
-
-type Coordinate struct {
-	Col int `json:"col"`
-	Row int `json:"row"`
-}
-
-type Move struct {
-	StartSquare Coordinate `json:"startSquare"`
-	EndSquare   Coordinate `json:"endSquare"`
-}

types/common.go

@@ -0,0 +1,35 @@
+package types
+
+type Coordinate struct {
+	Col int `json:"col"`
+	Row int `json:"row"`
+}
+
+type Move struct {
+	StartSquare Coordinate `json:"startSquare"`
+	EndSquare   Coordinate `json:"endSquare"`
+}
+
+type PieceClass string
+
+const (
+	Pawn   PieceClass = "pawn"
+	Rook   PieceClass = "rook"
+	Knight PieceClass = "knight"
+	Bishop PieceClass = "bishop"
+	Queen  PieceClass = "queen"
+	King   PieceClass = "king"
+)
+
+type ChessColor string
+
+const (
+	White ChessColor = "white"
+	Black ChessColor = "black"
+)
+
+type Piece struct {
+	Class    PieceClass
+	Color    ChessColor
+	HasMoved bool //we need this for pawns (first move is special) and rooks+king (for castling)
+}