package net.curisit.securis;

import javax.persistence.EntityManager;
import javax.servlet.http.HttpServletRequest;
import javax.ws.rs.ForbiddenException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.core.SecurityContext;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;

import net.curisit.securis.services.exception.SeCurisServiceException;
import net.curisit.securis.services.exception.SeCurisServiceException.ErrorCodes;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

@Provider
public class DefaultExceptionHandler implements ExceptionMapper<Exception> {
    private static final Logger LOG = LogManager.getLogger(DefaultExceptionHandler.class);

    public static final int DEFAULT_APP_ERROR_STATUS_CODE = 418;
    public static final String ERROR_MESSAGE_HEADER = "X-SECURIS-ERROR-MSG";
    public static final String ERROR_CODE_MESSAGE_HEADER = "X-SECURIS-ERROR-CODE";

    public DefaultExceptionHandler() {
        LOG.info("Creating DefaultExceptionHandler ");
    }

    @Context
    HttpServletRequest request;
    @Context
    SecurityContext bsc;
    @Context
    EntityManager em;

    @Override
    public Response toResponse(Exception e) {
        releaseEntityManager();
        if (e instanceof ForbiddenException) {
            LOG.warn("ForbiddenException: {}", e);
            return Response.status(Status.UNAUTHORIZED).header(ERROR_CODE_MESSAGE_HEADER, ErrorCodes.INVALID_CREDENTIALS)
                    .header(ERROR_MESSAGE_HEADER, "Unathorized access to the application").type(MediaType.APPLICATION_JSON).build();
        }

        if (e instanceof SeCurisServiceException) {
            LOG.warn("SeCurisServiceException: {}", e);
            return Response.status(DEFAULT_APP_ERROR_STATUS_CODE).header(ERROR_CODE_MESSAGE_HEADER, ((SeCurisServiceException) e).getStatus())
                    .header(ERROR_MESSAGE_HEADER, e.getMessage()).type(MediaType.APPLICATION_JSON).build();
        }

        LOG.error("Unexpected error accesing to '{}' by user: {}", request.getPathInfo(), bsc.getUserPrincipal());
        LOG.error("Request sent from {}, with User-Agent: {}", request.getRemoteHost(), request.getHeader("User-Agent"));
        LOG.error("Request url: " + request.getRequestURL(), e);
        return Response.serverError().header(ERROR_MESSAGE_HEADER, "Unexpected error: " + e.toString()).type(MediaType.APPLICATION_JSON).build();
    }

    private void releaseEntityManager() {
        try {
            if (em != null && em.isOpen()) {
                LOG.debug("CLOSING EM: {}, trans: {}", em, em.isJoinedToTransaction());
                if (em.isJoinedToTransaction()) {
                    em.getTransaction().rollback();
                    LOG.info("ROLLBACK");
                }
                em.close();
            }
        } catch (Exception ex) {
            ex.printStackTrace();
            LOG.error("Error closing EM: {}, {}", em, ex);
        }
    }
}