package scorekeep;

import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;

import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClientBuilder;

import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper;

import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBQueryExpression;

import com.amazonaws.services.dynamodbv2.model.AttributeValue;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

/** Saves state objects to DynamoDB

Loads state objects from DynamoDB

Loads all state objects for a game

**/

public class StateModel {

/** AWS SDK credentials. */

private AmazonDynamoDB client = AmazonDynamoDBClientBuilder.standard()

.build();

private DynamoDBMapper mapper = new DynamoDBMapper(client);

private final SessionModel sessionModel = new SessionModel();

private final GameModel gameModel = new GameModel();

public void saveState(State state) throws SessionNotFoundException, GameNotFoundException {

// check session

String sessionId = state.getSession();

String gameId = state.getGame();

if (sessionModel.loadSession(sessionId) == null ) {

throw new SessionNotFoundException(sessionId);

}

if (gameModel.loadGame(gameId) == null ) {

throw new GameNotFoundException(gameId);

}

mapper.save(state);

}

public State loadState(String stateId) throws StateNotFoundException {

State state = mapper.load(State.class, stateId);

if ( state == null ) {

throw new StateNotFoundException(stateId);

}

return state;

}

public List<State> loadStates(String sessionId, String gameId) throws SessionNotFoundException, GameNotFoundException {

if ( sessionModel.loadSession(sessionId) == null ) {

throw new SessionNotFoundException(sessionId);

}

if ( gameModel.loadGame(gameId) == null ) {

throw new GameNotFoundException(gameId);

}

Map<String, AttributeValue> attributeValues = new HashMap<String, AttributeValue>();

attributeValues.put(":val1", new AttributeValue().withS(gameId));

Map<String, String> attributeNames = new HashMap<String, String>();

attributeNames.put("#key1", "game");

DynamoDBQueryExpression<State> queryExpression = new DynamoDBQueryExpression<State>()

.withIndexName("game-index")

.withExpressionAttributeValues(attributeValues)

.withExpressionAttributeNames(attributeNames)

.withKeyConditionExpression("#key1 = :val1")

.withConsistentRead(false);

List<State> gameStates = mapper.query(State.class, queryExpression);

return gameStates;

}

public void deleteState(String stateId) throws StateNotFoundException {

State state = mapper.load(State.class, stateId);

if ( state == null ) {

throw new StateNotFoundException(stateId);

}

mapper.delete(state);

}

}