package eu.siacs.conversations.parser;

import java.util.List;

import net.java.otr4j.session.Session;
import net.java.otr4j.session.SessionStatus;
import android.util.Log;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.entities.Conversation;
import eu.siacs.conversations.entities.Message;
import eu.siacs.conversations.services.XmppConnectionService;
import eu.siacs.conversations.xml.Element;
import eu.siacs.conversations.xmpp.stanzas.MessagePacket;

public class MessageParser {

	protected static final String LOGTAG = "xmppService";
	private XmppConnectionService mXmppConnectionService;

	public MessageParser(XmppConnectionService service) {
		this.mXmppConnectionService = service;
	}

	public Message parseChat(MessagePacket packet, Account account) {
		String[] fromParts = packet.getFrom().split("/");
		Conversation conversation = mXmppConnectionService
				.findOrCreateConversation(account, fromParts[0], false);
		conversation.setLatestMarkableMessageId(getMarkableMessageId(packet));
		String pgpBody = getPgpBody(packet);
		if (pgpBody != null) {
			return new Message(conversation, packet.getFrom(), pgpBody,
					Message.ENCRYPTION_PGP, Message.STATUS_RECIEVED);
		} else {
			return new Message(conversation, packet.getFrom(),
					packet.getBody(), Message.ENCRYPTION_NONE,
					Message.STATUS_RECIEVED);
		}
	}

	public Message parseOtrChat(MessagePacket packet, Account account) {
		boolean properlyAddressed = (packet.getTo().split("/").length == 2)
				|| (account.countPresences() == 1);
		String[] fromParts = packet.getFrom().split("/");
		Conversation conversation = mXmppConnectionService
				.findOrCreateConversation(account, fromParts[0], false);
		String body = packet.getBody();
		if (!conversation.hasValidOtrSession()) {
			if (properlyAddressed) {
				Log.d("xmppService",
						"starting new otr session with "
								+ packet.getFrom()
								+ " because no valid otr session has been found");
				conversation.startOtrSession(
						mXmppConnectionService.getApplicationContext(),
						fromParts[1], false);
			} else {
				Log.d("xmppService", account.getJid()
						+ ": ignoring otr session with " + fromParts[0]);
				return null;
			}
		} else {
			String foreignPresence = conversation.getOtrSession()
					.getSessionID().getUserID();
			if (!foreignPresence.equals(fromParts[1])) {
				conversation.resetOtrSession();
				if (properlyAddressed) {
					Log.d("xmppService",
							"replacing otr session with " + packet.getFrom());
					conversation.startOtrSession(
							mXmppConnectionService.getApplicationContext(),
							fromParts[1], false);
				} else {
					return null;
				}
			}
		}
		try {
			Session otrSession = conversation.getOtrSession();
			SessionStatus before = otrSession.getSessionStatus();
			body = otrSession.transformReceiving(body);
			SessionStatus after = otrSession.getSessionStatus();
			if ((before != after) && (after == SessionStatus.ENCRYPTED)) {
				Log.d(LOGTAG, "otr session etablished");
				List<Message> messages = conversation.getMessages();
				for (int i = 0; i < messages.size(); ++i) {
					Message msg = messages.get(i);
					if ((msg.getStatus() == Message.STATUS_UNSEND)
							&& (msg.getEncryption() == Message.ENCRYPTION_OTR)) {
						MessagePacket outPacket = mXmppConnectionService
								.prepareMessagePacket(account, msg, otrSession);
						msg.setStatus(Message.STATUS_SEND);
						mXmppConnectionService.databaseBackend
								.updateMessage(msg);
						account.getXmppConnection()
								.sendMessagePacket(outPacket);
					}
				}
				mXmppConnectionService.updateUi(conversation, false);
			} else if ((before != after) && (after == SessionStatus.FINISHED)) {
				conversation.resetOtrSession();
				Log.d(LOGTAG, "otr session stoped");
			}
			// isEmpty is a work around for some weird clients which send emtpty
			// strings over otr
			if ((body == null) || (body.isEmpty())) {
				return null;
			}
			conversation.setLatestMarkableMessageId(getMarkableMessageId(packet));
			return new Message(conversation, packet.getFrom(), body,
					Message.ENCRYPTION_OTR, Message.STATUS_RECIEVED);
		} catch (Exception e) {
			conversation.resetOtrSession();
			return null;
		}
	}

	public Message parseGroupchat(MessagePacket packet, Account account) {
		int status;
		String[] fromParts = packet.getFrom().split("/");
		Conversation conversation = mXmppConnectionService
				.findOrCreateConversation(account, fromParts[0], true);
		if (packet.hasChild("subject")) {
			conversation.getMucOptions().setSubject(
					packet.findChild("subject").getContent());
			mXmppConnectionService.updateUi(conversation, false);
			return null;
		}
		if ((fromParts.length == 1)) {
			return null;
		}
		String counterPart = fromParts[1];
		if (counterPart.equals(conversation.getMucOptions().getNick())) {
			if (mXmppConnectionService.markMessage(conversation,
					packet.getId(), Message.STATUS_SEND)) {
				return null;
			} else {
				status = Message.STATUS_SEND;
			}
		} else {
			status = Message.STATUS_RECIEVED;
		}
		String pgpBody = getPgpBody(packet);
		conversation.setLatestMarkableMessageId(getMarkableMessageId(packet));
		if (pgpBody == null) {
			return new Message(conversation, counterPart, packet.getBody(),
					Message.ENCRYPTION_NONE, status);
		} else {
			return new Message(conversation, counterPart, pgpBody,
					Message.ENCRYPTION_PGP, status);
		}
	}

	public Message parseCarbonMessage(MessagePacket packet, Account account) {
		int status;
		String fullJid;
		Element forwarded;
		if (packet.hasChild("received")) {
			forwarded = packet.findChild("received").findChild("forwarded");
			status = Message.STATUS_RECIEVED;
		} else if (packet.hasChild("sent")) {
			forwarded = packet.findChild("sent").findChild("forwarded");
			status = Message.STATUS_SEND;
		} else {
			return null;
		}
		if (forwarded == null) {
			return null;
		}
		Element message = forwarded.findChild("message");
		if ((message == null) || (!message.hasChild("body")))
			return null; // either malformed or boring
		if (status == Message.STATUS_RECIEVED) {
			fullJid = message.getAttribute("from");
		} else {
			fullJid = message.getAttribute("to");
		}
		String[] parts = fullJid.split("/");
		Conversation conversation = mXmppConnectionService
				.findOrCreateConversation(account, parts[0], false);
		conversation.setLatestMarkableMessageId(getMarkableMessageId(packet));
		String pgpBody = getPgpBody(message);
		if (pgpBody != null) {
			return new Message(conversation, fullJid, pgpBody,
					Message.ENCRYPTION_PGP, status);
		} else {
			String body = message.findChild("body").getContent();
			return new Message(conversation, fullJid, body,
					Message.ENCRYPTION_NONE, status);
		}
	}

	public void parseError(MessagePacket packet, Account account) {
		String[] fromParts = packet.getFrom().split("/");
		mXmppConnectionService.markMessage(account, fromParts[0],
				packet.getId(), Message.STATUS_SEND_FAILED);
	}

	private String getPgpBody(Element message) {
		Element child = message.findChild("x", "jabber:x:encrypted");
		if (child == null) {
			return null;
		} else {
			return child.getContent();
		}
	}
	
	private String getMarkableMessageId(Element message) {
		if (message.hasChild("markable", "urn:xmpp:chat-markers:0")) {
			return message.getAttribute("id");
		} else {
			return null;
		}
	}
}