ContentNegotiationChecker.java

/*
 * Copyright (C) 2014 Stefan Niederhauser (nidin@gmx.ch)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package guru.nidi.ramltester.core;

import guru.nidi.ramltester.model.RamlRequest;
import guru.nidi.ramltester.model.RamlResponse;
import guru.nidi.ramltester.util.InvalidMediaTypeException;
import guru.nidi.ramltester.util.MediaType;
import guru.nidi.ramltester.util.Message;
import org.raml.model.Action;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 *
 */
class ContentNegotiationChecker {
    private final RamlViolations requestViolations, responseViolations;

    public ContentNegotiationChecker(RamlViolations requestViolations, RamlViolations responseViolations) {
        this.requestViolations = requestViolations;
        this.responseViolations = responseViolations;
    }

    public void check(RamlRequest request, RamlResponse response, Action action, MediaTypeMatch typeMatch) {
        final String accept = acceptHeader(request, response, typeMatch);
        if (accept == null) {
            return;
        }

        MediaType bestMatch = null;
        for (final MediaType acceptType : acceptMediaTypes(accept)) {
            for (final MediaType modelType : typeMatch.getDefinedTypes()) {
                if (acceptType.isCompatibleWith(modelType)) {
                    if (bestMatch == null) {
                        bestMatch = acceptType;
                    }
                    if (typeMatch.getMatchingMedia().equals(modelType)) {
                        if (acceptType.getQualityParameter() < bestMatch.getQualityParameter()) {
                            final Locator locator = new Locator(action);
                            locator.responseCode(Integer.toString(response.getStatus()));
                            responseViolations.add(new Message("mediaType.better", locator, accept, bestMatch, response.getContentType()));
                        }
                        return;
                    }
                }
            }
        }
        responseViolations.add(new Message("contentType.mismatch", accept, response.getContentType()));
    }

    private String acceptHeader(RamlRequest request, RamlResponse response, MediaTypeMatch typeMatch) {
        if (typeMatch == null || response.getContentType() == null || response.getContentType().isEmpty()) {
            return null;
        }
        final List<Object> header = request.getHeaderValues().get("Accept");
        if (header == null || header.isEmpty()) {
            return null;
        }
        final String accept = header.get(0).toString().trim();
        if (accept.length() == 0) {
            return null;
        }
        return accept;
    }

    private List<MediaType> acceptMediaTypes(String accept) {
        final List<MediaType> acceptTypes = new ArrayList<>();
        for (final String type : accept.split(",")) {
            try {
                final MediaType acceptType = MediaType.valueOf(type);
                acceptTypes.add(acceptType);
            } catch (InvalidMediaTypeException e) {
                requestViolations.add(new Message("mediaType.illegal", new Message("accept.header"), type, e.getMessage()));
            }
        }
        Collections.sort(acceptTypes, MediaType.QUALITY_COMPARATOR);
        return acceptTypes;
    }

}