/*
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 *
 * 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 org.guvnor.tools.utils.webdav;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLDecoder;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

/**
 * Utilities for dealing with streams.
 */
public class StreamProcessingUtils {

    private static final SimpleDateFormat CREATION_DATE_FORMAT = new SimpleDateFormat(
    "yyyy-MM-dd'T'HH:mm:ss'Z'");
    
    private static final SimpleDateFormat LAST_MODIFIED_DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
    
    protected static final SimpleDateFormat GUNVOR_TOOLS_DATE_FORMAT = new SimpleDateFormat(
            "EEE, dd MMM yyyy HH:mm:ss z", Locale.getDefault());

    public static String getStreamContents(InputStream is) throws IOException {
        byte[] buffer = new byte[1000];
          int c = 0;
          ByteArrayOutputStream bout = new ByteArrayOutputStream();
        while ((c = is.read(buffer)) != -1) {
              bout.write(buffer, 0, c);
          }

          return new String(bout.toByteArray());
    }

    private static String DAV_NS = "DAV:"; //$NON-NLS-1$

    public static Map<String, ResourceProperties> parseListing(String base, InputStream is) throws Exception {
        Map<String, ResourceProperties> res = new HashMap<String, ResourceProperties>();
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        factory.setNamespaceAware(true);
        DocumentBuilder parser = factory.newDocumentBuilder();
        Document doc = parser.parse(is);
        NodeList nl = doc.getElementsByTagNameNS(DAV_NS, "response"); //$NON-NLS-1$
        for (int i = 0; i < nl.getLength(); i++) {
            Element oneElem = (Element)nl.item(i);
            NodeList resName = oneElem.getElementsByTagNameNS(DAV_NS, "href"); //$NON-NLS-1$
            assert(resName.getLength() == 1);
            String bareName = extractOverlap(base, URLDecoder.decode(resName.item(0).getTextContent(), "UTF-8"));
            if (bareName.trim().length() > 0) {
                ResourceProperties props = new ResourceProperties();
                NodeList propList = oneElem.getElementsByTagNameNS(DAV_NS, "resourcetype"); //$NON-NLS-1$
                assert(propList.getLength() == 1);
                NodeList resTypeList = ((Element)propList.item(0)).getElementsByTagNameNS(DAV_NS, "collection"); //$NON-NLS-1$
                assert(resTypeList.getLength() < 2);
                if (resTypeList.getLength() == 1) {
                    props.setDirectory(true);
                }
                propList = oneElem.getElementsByTagNameNS(DAV_NS, "creationdate"); //$NON-NLS-1$
                if (propList.getLength() > 0) {
                    props.setCreationDate(propList.item(0).getTextContent());
                }
                propList = oneElem.getElementsByTagNameNS(DAV_NS, "getlastmodified"); //$NON-NLS-1$
                if (propList.getLength() > 0) {
                    props.setLastModifiedDate(propList.item(0).getTextContent());
                }
                String normBase = base.trim().endsWith("/")?base.trim():base.trim() + "/"; //$NON-NLS-1$ //$NON-NLS-2$
                props.setBase(normBase);
                res.put(bareName, props);
            }
        }
        return res;
    }

    private static String extractOverlap(String base, String extension) {
        String res = null;
        int pos = 0;
        int i = 1;
        boolean done = false;
        while (i < extension.length() && !done) {
            pos = base.lastIndexOf(extension.substring(0, i));
            if (pos == -1) {
                res = extension.substring(i - 1);
                done = true;
            }
            i++;
        }
        // If we got to the end of the loop above but !done,
        // that means the entire extension string matched in
        // base, so remove the entire extension contents
        if (!done) {
            res = ""; //$NON-NLS-1$
        }
        if (res.startsWith("/") && res.length() > 1) { //$NON-NLS-1$
            res = res.substring(1);
        }
//System.out.println("Returning " + res + " from " + base + ", " + extension);
        return res;
    }


    public static String parseISODateFormat(String dateStr) {

        if (dateStr == null)
            return null;

        String val = dateStr;

        try {
            if (dateStr.indexOf('T') == 10 && dateStr.endsWith("Z")) {
                Date date = CREATION_DATE_FORMAT.parse(dateStr);
                val = GUNVOR_TOOLS_DATE_FORMAT.format(date);

            } else if (dateStr.indexOf('T') == 10) {
                Date date = LAST_MODIFIED_DATE_FORMAT.parse(dateStr);
                val = GUNVOR_TOOLS_DATE_FORMAT.format(date);
            }

        }
        catch (ParseException e) {

        }

        return val;
    }
}