/**
 * =============================================================================
 *
 * ORCID (R) Open Source
 * http://orcid.org
 *
 * Copyright (c) 2012-2014 ORCID, Inc.
 * Licensed under an MIT-Style License (MIT)
 * http://orcid.org/open-source-license
 *
 * This copyright and license information (including a link to the full license)
 * shall be included in its entirety in all copies or substantial portion of
 * the software.
 *
 * =============================================================================
 */
package org.orcid.core.web.filters;

import static org.orcid.core.api.OrcidApiConstants.APPLICATION_RDFXML;
import static org.orcid.core.api.OrcidApiConstants.JSON_LD;
import static org.orcid.core.api.OrcidApiConstants.N_TRIPLES;
import static org.orcid.core.api.OrcidApiConstants.ORCID_JSON;
import static org.orcid.core.api.OrcidApiConstants.ORCID_XML;
import static org.orcid.core.api.OrcidApiConstants.TEXT_N3;
import static org.orcid.core.api.OrcidApiConstants.TEXT_TURTLE;
import static org.orcid.core.api.OrcidApiConstants.VND_ORCID_JSON;
import static org.orcid.core.api.OrcidApiConstants.VND_ORCID_XML;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import javax.ws.rs.core.MediaType;

import org.orcid.core.manager.impl.OrcidUrlManager;
import org.springframework.web.filter.OncePerRequestFilter;

/**
 * 
 * @author Robert Peters (rcpeters)
 * 
 */

public class AcceptFilter extends OncePerRequestFilter {

    private static String[] accpetTypesArray = { VND_ORCID_XML, ORCID_XML, MediaType.APPLICATION_XML, VND_ORCID_JSON, ORCID_JSON, MediaType.APPLICATION_JSON, TEXT_TURTLE,
            TEXT_N3, N_TRIPLES, JSON_LD, APPLICATION_RDFXML };

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        String accept = request.getHeader("accept");
        String path = ((HttpServletRequest) request).getRequestURI();
        String contentType = request.getHeader("Content-Type");

        if (accept == null || accept.equals("*/*")) {
            HttpServletRequestWrapper requestWrapper = null;
            if (isValidAcceptType(contentType))
                requestWrapper = new AcceptHeaderRequestWrapper(request, contentType);
            else
                if (OrcidUrlManager.getPathWithoutContextPath(request).startsWith("/oauth/"))
                    requestWrapper = new AcceptHeaderRequestWrapper(request, MediaType.APPLICATION_JSON);
                else
                    requestWrapper = new AcceptHeaderRequestWrapper(request, VND_ORCID_XML);
            filterChain.doFilter(requestWrapper, response);
        } else {
            filterChain.doFilter(request, response);
        }
    }

    private boolean isValidAcceptType(String testAccept) {
        if (testAccept == null)
            return false;
        for (String accept : accpetTypesArray)
            if (accept.toLowerCase().indexOf(testAccept) != -1)
                return true;
        return false;
    }
}