package de.bwlehrpool.bwlp_guac;

import java.util.*;

import org.apache.guacamole.GuacamoleException;
import org.apache.guacamole.net.auth.*;
import org.apache.guacamole.net.auth.credentials.GuacamoleCredentialsException;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.map.ObjectMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.servlet.http.HttpServletRequest;

import org.apache.guacamole.form.Field;
import org.apache.guacamole.net.auth.credentials.GuacamoleInsufficientCredentialsException;
import org.apache.guacamole.net.auth.credentials.CredentialsInfo;

public class BwlpAuthenticationProvider implements AuthenticationProvider {

	Logger LOGGER = LoggerFactory.getLogger(BwlpAuthenticationProvider.class);

	public String getIdentifier() {
		return "de.bwlehrpool.bwgpul";
	}

	public Object getResource() throws GuacamoleException {
		return new BwlpREST();
	}

	public AuthenticatedUser authenticateUser(Credentials credentials) throws GuacamoleException {
		return null;
	}

	public AuthenticatedUser updateAuthenticatedUser(AuthenticatedUser authenticatedUser, Credentials credentials)
			throws GuacamoleException {
		return null;
	}

	public UserContext getUserContext(AuthenticatedUser authenticatedUser) throws GuacamoleException {
		LOGGER.warn("Ignoring getUserContext for " + authenticatedUser.toString());
		return null;
	}

	public UserContext updateUserContext(UserContext context, AuthenticatedUser authenticatedUser,
										 Credentials credentials) throws GuacamoleException {
		LOGGER.warn("Ignoring updateUserContext called with " + context.toString());
		return null;
	}

	public UserContext decorate(UserContext context, AuthenticatedUser authenticatedUser, Credentials credentials)
			throws GuacamoleException {
		return context;
	}

	private Map<String, BwlpUserContext> oldMappings = Collections
			.synchronizedMap(new WeakHashMap<String, BwlpUserContext>());

	public UserContext redecorate(UserContext decorated, UserContext context, AuthenticatedUser authenticatedUser,
			Credentials credentials) throws GuacamoleException {

		String username = Util.getUsername(authenticatedUser);
		if (username == null) {
			LOGGER.warn("redecorate: Ignoring user without name");
			return context;
		}

		LOGGER.warn("REdecorate called for " + username);
		BwlpUserContext user = oldMappings.get(username);

		if (user != null && user.hasValidConnection())
			return user;
		
		WrappedConnection exConn = ConnectionManager.getExistingConnection(username);
		if (exConn != null) {
			user = new BwlpUserContext(authenticatedUser, context, exConn);
		} else {
			UserResponse response = requestGroup(credentials);
			LOGGER.warn("Doing the REdecoration");
			user = new BwlpUserContext(authenticatedUser, context, response.groupid, response.resolution);
		}
		oldMappings.put(username, user);

		return user;
	}

	final class UserResponse {
		public int groupid = 0;
		public String resolution = "1920x1080";
	}

	private UserResponse requestGroup(Credentials credentials) throws GuacamoleException {
		UserResponse response = new UserResponse();

		// Request the user to select a group
		ConnectionManager.updateList();
		HttpServletRequest request = credentials.getRequest();
		String groupJson = request.getParameter("group");

		if (groupJson == null) {
			throw new GuacamoleInsufficientCredentialsException(
					"GROUP_SELECTION.TITLE", new CredentialsInfo(
					Collections.<Field>singletonList(new GroupField())
			));
		}

		ObjectMapper mapper = new ObjectMapper();

		String message = "GROUP_SELECTION.TITLE";

		boolean tryAgain = false;
		String password = "";
		String correctPassword = null;
		try {
			JsonNode group = mapper.readTree(groupJson);
			response.resolution = group.get("resolution").asText();

			response.groupid = Integer.parseInt(group.get("id").asText());
			if (response.groupid != 0) {
				password = group.get("password").asText();
				correctPassword = ConnectionManager.getGroup(response.groupid).password;
			}
		} catch (Exception e) {
			LOGGER.info("Error reading group choice by user, asking again...", e);
			tryAgain = true;
		}

		if (response.groupid != 0 && correctPassword != null && !password.equals(correctPassword)) {
			tryAgain = true;
			message = "GROUP_SELECTION.PASSWORD_ERROR";
		}

		if (tryAgain) {
			throw new GuacamoleCredentialsException(
					message, new CredentialsInfo(
					Collections.<Field>singletonList(new GroupField())
			));
		}

		return response;
	}

	public void shutdown() {
	}

}