Move game into separate source file and add encode method.

src/Go/Game.cr

@@ -0,0 +1,81 @@
+module Go
+    enum Color
+        Black
+        White
+    end
+
+    enum Size
+        Small = 9,
+        Medium = 13,
+        Large = 19
+    end
+
+    alias Board = Hash(Tuple(Int8, Int8), Color)
+
+    class Game
+        property size : Size
+        property board  : Board
+        property turn : Color
+        property sockets : Array(HTTP::WebSocket)
+
+        def initialize(size : Size)
+            @size = size
+            @board = Board.new
+            @turn = Color::Black
+            @sockets = [] of HTTP::WebSocket
+        end
+
+        private def cell_json(index, color, json)
+            json.object do
+                json.field "index" do
+                    json.object do
+                        json.field "x", index[0]
+                        json.field "y", index[1]
+                    end
+                end
+                json.field "color", color.to_s
+            end
+        end
+
+        private def board_json(board, json)
+            json.array do
+                board.each do |key, value|
+                    cell_json(key, value, json)
+                end
+            end
+        end
+
+        def to_string
+            JSON.build do |json|
+                json.object do
+                    json.field "turn", @turn.to_s
+                    json.field "board" { board_json(@board, json) }
+                end
+            end
+        end
+
+        def update(x, y, color)
+            @board[{x, y}] = color
+        end
+
+        private def color_char(color)
+            color == Color::Black ? 'B' : 'W'
+        end
+
+        private def board_string(board)
+            String.build do |str|
+                (0...@size.value).each do |x|
+                    (0...@size.value).each do |y|
+                        color = @board[{x.to_i8, y.to_i8}]?
+                        char = color ? color_char(color) : 'E'
+                        str << char
+                    end
+                end
+            end
+        end
+
+        def encode
+            { @turn.to_s, @size.value, board_string(@board) }
+        end
+    end
+end