/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.jackrabbit.webdav.client.methods;

import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpConnection;
import org.apache.commons.httpclient.HttpMethodBase;
import org.apache.commons.httpclient.HttpState;
import org.apache.jackrabbit.webdav.DavMethods;
import org.apache.jackrabbit.webdav.DavServletResponse;
import org.apache.jackrabbit.webdav.version.OptionsInfo;
import org.apache.jackrabbit.webdav.version.OptionsResponse;
import org.w3c.dom.Element;

/**
 * <code>OptionsMethod</code>...
 */
public class OptionsMethod extends DavMethodBase {

    private final Set<String> allowedMethods = new HashSet<String>();
    private final Set<String> complianceClasses = new HashSet<String>();

    public OptionsMethod(String uri) {
	super(uri);
    }

    public OptionsMethod(String uri, String[] optionsEntries) throws IOException {
        this(uri, new OptionsInfo(optionsEntries));
    }

    public OptionsMethod(String uri, OptionsInfo optionsInfo) throws IOException {
        super(uri);
        if (optionsInfo != null) {
            setRequestBody(optionsInfo);
        }
    }

    /**
     * @throws IOException
     */
    public OptionsResponse getResponseAsOptionsResponse() throws IOException {
        checkUsed();
        OptionsResponse or = null;
        Element rBody = getRootElement();
        if (rBody != null) {
            or = OptionsResponse.createFromXml(rBody);
        }
        return or;
    }

    /**
     * Checks if the specified method is a supported method by the resource
     * identified by the original URI.
     *
     * @param method
     * @return true if the given method is contained in the 'Allow' response header.
     */
    public boolean isAllowed(String method) {
        checkUsed();
        return allowedMethods.contains(method.toUpperCase());
    }


    /**
     * Returns an array of String listing the allowed methods.
     *
     * @return all methods allowed on the resource specified by the original URI.
     */
    public String[] getAllowedMethods() {
        checkUsed();
        return allowedMethods.toArray(new String[allowedMethods.size()]);
    }

    /**
     * Checks if the specified compliance class is supported by the resource
     * identified by the original URI.
     *
     * @param complianceClass WebDAV compliance class
     * @return true if the given compliance class is contained in the 'DAV' response header.
     */
    public boolean hasComplianceClass(String complianceClass) {
        checkUsed();
        return complianceClasses.contains(complianceClass);
    }


    /**
     * Returns an array of String listing the WebDAV compliance classes.
     *
     * @return all compliance classes supported by the resource specified by the original URI.
     */
    public String[] getComplianceClasses() {
        checkUsed();
        return complianceClasses.toArray(new String[complianceClasses.size()]);
    }

    //---------------------------------------------------------< HttpMethod >---
    /**
     * @see org.apache.commons.httpclient.HttpMethod#getName()
     */
    @Override
    public String getName() {
        return DavMethods.METHOD_OPTIONS;
    }

    //-----------------------------------------------------< HttpMethodBase >---
    /**
     * <p>
     * This implementation will parse the <tt>Allow</tt> and <tt>DAV</tt> headers to obtain
     * the set of HTTP methods and WebDAV compliance classes supported by the resource
     * identified by the Request-URI.
     * </p>
     *
     * @param state the {@link HttpState state} information associated with this method
     * @param conn the {@link HttpConnection connection} used to execute
     *        this HTTP method
     * @see HttpMethodBase#processResponseHeaders(HttpState, HttpConnection)
     */
    @Override
    protected void processResponseHeaders(HttpState state, HttpConnection conn) {
        Header allow = getResponseHeader("Allow");
        if (allow != null) {
            for (String method : allow.getValue().split(",")) {
                allowedMethods.add(method.trim().toUpperCase());
            }
        }
        Header dav = getResponseHeader("DAV");
        if (dav != null) {
            for (String cl : dav.getValue().split(",")) {
                complianceClasses.add(cl.trim());
            }
        }
    }

    //------------------------------------------------------< DavMethodBase >---
    /**
     *
     * @param statusCode
     * @return true if status code is {@link DavServletResponse#SC_OK 200 (OK)}.
     */
    @Override
    protected boolean isSuccess(int statusCode) {
        return statusCode == DavServletResponse.SC_OK;
    }
}
