package io.hosuaby.restful.services;
import io.hosuaby.restful.domain.TeapotMessage;
import io.hosuaby.restful.repositories.WebSocketSessionRepository;
import io.hosuaby.restful.services.exceptions.teapots.TeapotInternalErrorException;
import io.hosuaby.restful.services.exceptions.teapots.TeapotNotConnectedException;
import java.io.IOException;
import java.util.GregorianCalendar;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
import java.util.regex.Pattern;
import javax.servlet.http.HttpServletRequest;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;
import org.springframework.web.context.request.async.DeferredResult;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import com.fasterxml.jackson.databind.ObjectMapper;
/**
* Implementation of the {@link TeapotCommandService}.
*/
@Service
// TODO: implement appropriate thread synchronization
public class TeapotCommandServiceImpl implements TeapotCommandService {
/**
* Pattern for request id. Id must start with sequence "req-".
*/
private static final Pattern REQUEST_ID_PATTERN = Pattern.compile("^req-.*");
/** Repository for websocket sessions of teapots */
@Autowired
@Qualifier("teapotSessionsRepository")
private WebSocketSessionRepository sessionRepository;
/** Jackson object mapper */
@Autowired
private ObjectMapper jacksonMapper;
/** Map of session ids by teapot ids */
private Map<String, String> mapTeapotIdSessionId;
/** Map of teapot ids by session ids */
private Map<String, String> mapSessionIdTeapotId;
/** Deferred results for command executions in Ajax mode */
private Map<String, DeferredResult<String>> results;
/**
* Partial results returned by teapots during execution of the command.
* Used to buffer content of multiple subsequent messages before EOT
* character is received and DeferredResult object associated with request
* can be fulfilled.
* Partial results are mapped by request id.
*/
private Map<String, String> partialResults;
/**
* Constructor.
*/
public TeapotCommandServiceImpl() {
mapTeapotIdSessionId = new HashMap<>();
mapSessionIdTeapotId = new HashMap<>();
results = new HashMap<>();
partialResults = new HashMap<>();
}
/** {@inheritDoc} */
@Override
public synchronized void register(String teapotId,
WebSocketSession session) {
String sessionId = session.getId();
sessionRepository.save(session);
mapTeapotIdSessionId.put(teapotId, sessionId);
mapSessionIdTeapotId.put(sessionId, teapotId);
}
/** {@inheritDoc} */
@Override
public synchronized void unregister(WebSocketSession teapotSession) {
String sessionId = teapotSession.getId();
String teapotId = mapSessionIdTeapotId.get(sessionId);
sessionRepository.delete(teapotSession);
mapTeapotIdSessionId.remove(teapotId);
mapSessionIdTeapotId.remove(sessionId);
}
/** {@inheritDoc} */
@Override
public void shutdown(String teapotId) throws IOException,
TeapotNotConnectedException {
if (mapTeapotIdSessionId.containsKey(teapotId)) {
sessionRepository
.getSession(mapTeapotIdSessionId.get(teapotId))
.close();
} else {
throw new TeapotNotConnectedException(teapotId);
}
}
/** {@inheritDoc} */
@Override
public synchronized String[] getRegisteredTeapotsIds() {
return (String[]) mapTeapotIdSessionId.keySet().toArray();
}
/** {@inheritDoc} */
@Override
public synchronized boolean isTeapotConnected(String teapotId) {
return mapTeapotIdSessionId.containsKey(teapotId);
}
/** {@inheritDoc} */
@Override
public DeferredResult<String> sendMessage(HttpServletRequest req,
String teapotId, String msg) {
/* Create unique request id */
String requestId = new StringBuilder("req-")
.append(req.getSession().getId()) // HTTP session id
.append('-')
.append(new GregorianCalendar().getTimeInMillis()) // timestamp
.toString();
/* Create message object */
TeapotMessage message = new TeapotMessage(requestId, msg);
/* Get teapot websocket session */
WebSocketSession teapotSession = sessionRepository.getSession(
mapTeapotIdSessionId.get(teapotId));
DeferredResult<String> result = new DeferredResult<>();
if (teapotSession != null) {
try {
String msgJson = jacksonMapper.writeValueAsString(message);
teapotSession.sendMessage(new TextMessage(msgJson));
results.put(requestId, result);
partialResults.put(requestId, "");
} catch (IOException e) {
/* Reject deferred result */
result.setErrorResult(e);
e.printStackTrace();
}
} else {
/* Reject deferred result */
result.setErrorResult(new TeapotNotConnectedException(teapotId));
}
return result;
}
/** {@inheritDoc} */
@Override
public void submitResponse(String clientId, String msg) {
if (REQUEST_ID_PATTERN.matcher(clientId).matches()) {
/* This is request id */
String partial = Optional
.ofNullable(partialResults.get(clientId))
.map(s -> s + "\n")
.orElse("") + msg;
partialResults.remove(clientId);
results.computeIfPresent(clientId, (id, result) -> {
result.setResult(partial);
return null;
});
} else {
/* This is websocket session id */
// TODO: code this behaiviour
}
}
/** {@inheritDoc} */
@Override
public void submitResponse(String clientId, String msg, boolean isLast) {
if (REQUEST_ID_PATTERN.matcher(clientId).matches()) {
/* This is request id */
String partial = Optional
.ofNullable(partialResults.get(clientId))
.map(s -> s + "\n")
.orElse("") + msg;
if (isLast) {
results.computeIfPresent(clientId, (id, result) -> {
result.setResult(partial);
return null;
});
} else {
partialResults.put(clientId, partial);
}
} else {
/* This is websocket session id */
// TODO: code this behaiviour
}
}
/** {@inheritDoc} */
@Override
public void submitError(String clientId, String error) {
if (REQUEST_ID_PATTERN.matcher(clientId).matches()) {
/* This is request id */
// TODO: use Optional of Java8 instead
String partial = partialResults.get(clientId);
if (partial == null) {
partial = "";
}
partial += (partial.isEmpty() ? "" : "\n") + error;
partialResults.remove(clientId);
// TODO: use Optional maybe
if (results.containsKey(clientId)) {
results.get(clientId).setErrorResult(
new TeapotInternalErrorException(partial));
results.remove(clientId);
}
} else {
/* This is websocket session id */
// TODO: code this behaiviour
}
}
}
