package eu.siacs.conversations.xml;

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

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

import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.util.Log;
import android.util.Xml;

public class XmlReader {
	private static final String LOGTAG = "xmppService";
	private XmlPullParser parser;
	private PowerManager.WakeLock wakeLock;
	private InputStream is;

	public XmlReader(WakeLock wakeLock) {
		this.parser = Xml.newPullParser();
		try {
			this.parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES,true);
		} catch (XmlPullParserException e) {
			Log.d(LOGTAG,"error setting namespace feature on parser");
		}
		this.wakeLock = wakeLock;
	}
	
	public void setInputStream(InputStream inputStream) throws IOException {
		if (inputStream==null) {
			throw new IOException();
		}
		this.is = inputStream;
		try {
			parser.setInput(new InputStreamReader(this.is));
		} catch (XmlPullParserException e) {
			throw new IOException("error resetting parser");
		}
	}

	public InputStream getInputStream() throws IOException {
		if (this.is==null) {
			throw new IOException();
		}
		return is;
	}

	public void reset() throws IOException {
		if (this.is==null) {
			throw new IOException();
		}
		try {
			parser.setInput(new InputStreamReader(this.is));
		} catch (XmlPullParserException e) {
			throw new IOException("error resetting parser");
		}
	}
	
	public Tag readTag() throws XmlPullParserException, IOException {
		if (wakeLock.isHeld()) {
			try { wakeLock.release();} catch (RuntimeException re) {}
		}
		try {
			while(this.is != null && parser.next() != XmlPullParser.END_DOCUMENT) {
					wakeLock.acquire();
					if (parser.getEventType() == XmlPullParser.START_TAG) {
						Tag tag = Tag.start(parser.getName());
						for(int i = 0; i < parser.getAttributeCount(); ++i) {
							tag.setAttribute(parser.getAttributeName(i), parser.getAttributeValue(i));
						}
						String xmlns = 	parser.getNamespace();
						if (xmlns!=null) {
							tag.setAttribute("xmlns",xmlns);
						}
						return tag;
					} else if (parser.getEventType() == XmlPullParser.END_TAG) {
						Tag tag = Tag.end(parser.getName());
						return tag;
					} else if (parser.getEventType() == XmlPullParser.TEXT) {
						Tag tag = Tag.no(parser.getText());
						return tag;
					}
				}
			if (wakeLock.isHeld()) {
				try { wakeLock.release();} catch (RuntimeException re) {}
			}
		} catch (ArrayIndexOutOfBoundsException e) {
			throw new IOException("xml parser mishandled ArrayIndexOufOfBounds", e);
		} catch (StringIndexOutOfBoundsException e) {
			throw new IOException("xml parser mishandled StringIndexOufOfBounds", e);
		}
		return null;
	}

	public Element readElement(Tag currentTag) throws XmlPullParserException, IOException {
		Element element = new Element(currentTag.getName());
		element.setAttributes(currentTag.getAttributes());
		Tag nextTag = this.readTag();
		if (nextTag == null) {
			throw new IOException("unterupted mid tag");
		}
		if(nextTag.isNo()) {
			element.setContent(nextTag.getName());
			nextTag = this.readTag();
			if (nextTag == null) {
				throw new IOException("unterupted mid tag");
			}
		}
		while(!nextTag.isEnd(element.getName())) {
			if (!nextTag.isNo()) {
				Element child = this.readElement(nextTag);
				element.addChild(child);
			}
			nextTag = this.readTag();
			if (nextTag == null) {
				throw new IOException("unterupted mid tag");
			}
		}
		return element;
	}
}