// Copyright 2007 The Android Open Source Project
package com.google.wireless.gdata.spreadsheets.parser.xml;

import com.google.wireless.gdata.data.Entry;
import com.google.wireless.gdata.data.Feed;
import com.google.wireless.gdata.data.StringUtils;
import com.google.wireless.gdata.data.XmlUtils;
import com.google.wireless.gdata.parser.ParseException;
import com.google.wireless.gdata.parser.xml.XmlGDataParser;
import com.google.wireless.gdata.spreadsheets.data.ListEntry;
import com.google.wireless.gdata.spreadsheets.data.ListFeed;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import java.io.IOException;
import java.io.InputStream;

/**
 * Parser for non-Atom data in a GData Spreadsheets List-based feed.
 */
public class XmlListGDataParser extends XmlGDataParser {
    /**
     * The rel ID used by the server to identify the URLs for List POSTs
     * (updates)
     */
    private static final String LIST_FEED_POST_REL =
            "http://schemas.google.com/g/2005#post";

    /**
     * Creates a new XmlListGDataParser.
     * 
     * @param is the stream from which to read the data
     * @param xmlParser the XmlPullParser to use to parse the raw XML
     * @throws ParseException if the super-class throws one
     */
    public XmlListGDataParser(InputStream is, XmlPullParser xmlParser)
            throws ParseException {
        super(is, xmlParser);
    }

    /* (non-JavaDoc)
     * Creates a new Entry that can handle the data parsed by this class.
     */
    protected Entry createEntry() {
        return new ListEntry();
    }

    /* (non-JavaDoc)
     * Creates a new Feed that can handle the data parsed by this class.
     */
    protected Feed createFeed() {
        return new ListFeed();
    }

    /* (non-JavaDoc)
     * Callback to handle non-Atom data present in an Atom entry tag.
     */
    protected void handleExtraElementInEntry(Entry entry)
            throws XmlPullParserException, IOException {
        XmlPullParser parser = getParser();
        if (!(entry instanceof ListEntry)) {
            throw new IllegalArgumentException("Expected ListEntry!");
        }
        ListEntry row = (ListEntry) entry;

        String name = parser.getName();
        row.setValue(name, XmlUtils.extractChildText(parser));
    }

    /* (non-JavaDoc)
     * Callback to handle non-Atom data in the feed.
     */
    protected void handleExtraElementInFeed(Feed feed)
            throws XmlPullParserException, IOException {
        XmlPullParser parser = getParser();
        if (!(feed instanceof ListFeed)) {
            throw new IllegalArgumentException("Expected ListFeed!");
        }
        ListFeed listFeed = (ListFeed) feed;

        String name = parser.getName();
        if (!"link".equals(name)) {
            return;
        }

        // lists store column data in the gsx namespace:
        // <gsx:columnheader>data</gsx:columnheader>
        // The columnheader tag names are the scrubbed values of the first row.
        // We extract them all and store them as keys in a Map.
        int numAttrs = parser.getAttributeCount();
        String rel = null;
        String href = null;
        String attrName = null;
        for (int i = 0; i < numAttrs; ++i) {
            attrName = parser.getAttributeName(i);
            if ("rel".equals(attrName)) {
                rel = parser.getAttributeValue(i);
            } else if ("href".equals(attrName)) {
                href = parser.getAttributeValue(i);
            }
        }
        if (!(StringUtils.isEmpty(rel) || StringUtils.isEmpty(href))) {
            if (LIST_FEED_POST_REL.equals(rel)) {
                listFeed.setEditUri(href);
            }
        }
    }
}