use reflection to invoke rules dynamically

Author: mwunderl

bin/test-api.sh

@@ -14,7 +14,7 @@ do
   GAMEID=$(curl --silent -X POST $API/game/$SESSIONID | jq -r .id)
   echo "configuring game, "
   curl --silent -X POST $API/game/$SESSIONID/$GAMEID/users -H "Content-Type: application/json" --data "[\"$USER1ID\",\"$USER2ID\"]"
-  curl --silent -X PUT $API/game/$SESSIONID/$GAMEID/rules/TICTACTOE
+  curl --silent -X PUT $API/game/$SESSIONID/$GAMEID/rules/TicTacToe
   curl --silent -X PUT $API/game/$SESSIONID/$GAMEID/name/tic-tac-toe-test
   EPOCH=$(date +%s)
   curl --silent -X PUT $API/game/$SESSIONID/$GAMEID/starttime/$EPOCH

src/main/java/scorekeep/MoveController.java

@@ -31,7 +31,7 @@ public List<Move> getMoves(@PathVariable String sessionId, @PathVariable String
   }
   /* POST /move/SESSION/GAME/USER ; move string */
   @RequestMapping(value="/{userId}", method=RequestMethod.POST)
-  public Move newMove(@PathVariable String sessionId, @PathVariable String gameId, @PathVariable String userId, @RequestBody String move) throws SessionNotFoundException, GameNotFoundException, StateNotFoundException {
+  public Move newMove(@PathVariable String sessionId, @PathVariable String gameId, @PathVariable String userId, @RequestBody String move) throws SessionNotFoundException, GameNotFoundException, StateNotFoundException, RulesException {
     return moveFactory.newMove(sessionId, gameId, userId, move);
   }
   /** GET /move/SESSION/GAME/MOVE **/

src/main/java/scorekeep/MoveFactory.java

@@ -5,8 +5,14 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Set;
+import java.lang.Class;
+import java.lang.reflect.Method;
+import java.lang.reflect.InvocationTargetException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class MoveFactory {
+  private static final Logger logger = LoggerFactory.getLogger("scorekeep.MoveFactory");
   private SecureRandom random = new SecureRandom();
   private final HashMap<String, Move> allMoves = new HashMap<String, Move>(1);
   private MoveModel moveModel = new MoveModel();
@@ -18,10 +24,11 @@ public class MoveFactory {
   public MoveFactory(){
   }
 
-  public Move newMove(String sessionId, String gameId, String userId, String moveText) throws SessionNotFoundException, GameNotFoundException, StateNotFoundException {
+  public Move newMove(String sessionId, String gameId, String userId, String moveText) throws SessionNotFoundException, GameNotFoundException, StateNotFoundException, RulesException {
     String moveId = new BigInteger(40, random).toString(32).toUpperCase();
     String stateId = new BigInteger(40, random).toString(32).toUpperCase();
     Move move = new Move(moveId, sessionId, gameId, userId, moveText);
+    String newStateText = "";
     // load game state
     Game game = gameController.getGame(sessionId, gameId);
     List<String> states = game.getStates();
@@ -37,7 +44,14 @@ public Move newMove(String sessionId, String gameId, String userId, String moveT
     if (newTurn.size() != 1) {
       newTurn.remove(userId);
     }
-    String newStateText = TicTacToe.move(oldState.getState(), moveText);
+    try {
+      Class<?> rules = Class.forName("scorekeep." + game.getRules());
+      Method moveMethod = rules.getMethod("move", String.class, String.class);
+      newStateText = (String) moveMethod.invoke(null, oldState.getState(), moveText);
+    } catch ( ClassNotFoundException e ) { throw new RulesException(game.getRules()); }
+    catch ( NoSuchMethodException f ) { throw new RulesException(game.getRules()); }
+    catch ( IllegalAccessException g ) { throw new RulesException(game.getRules()); }
+    catch ( InvocationTargetException h ) { throw new RulesException(game.getRules()); }
     // save new game state
     State newState = new State(stateId, sessionId, gameId, newStateText, newTurn);
     // register state and move id to game

src/main/java/scorekeep/RulesException.java

@@ -0,0 +1,16 @@
+package scorekeep;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.http.HttpStatus;
+
+@ResponseStatus(value=HttpStatus.BAD_REQUEST, reason="Rules move invocation failed.")
+public class RulesException extends Exception{
+  private String rulesId;
+  public RulesException(String rulesId)
+  {
+    this.rulesId = rulesId;
+  }
+  public String getRulesId()
+  {
+    return rulesId;
+  }
+}

src/main/java/scorekeep/RulesFactory.java

@@ -8,7 +8,7 @@ public class RulesFactory {
   private final HashMap<String, Rules> allRules = new HashMap<String, Rules>(1);
 
   public RulesFactory(){
-    String id = "TICTACTOE";
+    String id = "TicTacToe";
     String name = "Tic Tac Toe";
     String[] categories = { "head to head", "quick" };
     Integer[] users = { 2 };