package eu.siacs.conversations.parser;

import android.util.Log;
import android.util.Pair;

import eu.siacs.conversations.crypto.PgpDecryptionService;
import net.java.otr4j.session.Session;
import net.java.otr4j.session.SessionStatus;

import java.util.ArrayList;
import java.util.Set;

import eu.siacs.conversations.Config;
import eu.siacs.conversations.crypto.axolotl.AxolotlService;
import eu.siacs.conversations.crypto.axolotl.XmppAxolotlMessage;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.entities.Bookmark;
import eu.siacs.conversations.entities.Contact;
import eu.siacs.conversations.entities.Conversation;
import eu.siacs.conversations.entities.Message;
import eu.siacs.conversations.entities.MucOptions;
import eu.siacs.conversations.http.HttpConnectionManager;
import eu.siacs.conversations.services.MessageArchiveService;
import eu.siacs.conversations.services.XmppConnectionService;
import eu.siacs.conversations.utils.CryptoHelper;
import eu.siacs.conversations.xml.Element;
import eu.siacs.conversations.xmpp.OnMessagePacketReceived;
import eu.siacs.conversations.xmpp.chatstate.ChatState;
import eu.siacs.conversations.xmpp.jid.Jid;
import eu.siacs.conversations.xmpp.pep.Avatar;
import eu.siacs.conversations.xmpp.stanzas.MessagePacket;

public class MessageParser extends AbstractParser implements
		OnMessagePacketReceived {
	public MessageParser(XmppConnectionService service) {
		super(service);
	}

	private boolean extractChatState(Conversation conversation, final MessagePacket packet) {
		ChatState state = ChatState.parse(packet);
		if (state != null && conversation != null) {
			final Account account = conversation.getAccount();
			Jid from = packet.getFrom();
			if (from.toBareJid().equals(account.getJid().toBareJid())) {
				conversation.setOutgoingChatState(state);
				if (state == ChatState.ACTIVE || state == ChatState.COMPOSING) {
					mXmppConnectionService.markRead(conversation);
					account.activateGracePeriod();
				}
				return false;
			} else {
				return conversation.setIncomingChatState(state);
			}
		}
		return false;
	}

	private Message parseOtrChat(String body, Jid from, String id, Conversation conversation) {
		String presence;
		if (from.isBareJid()) {
			presence = "";
		} else {
			presence = from.getResourcepart();
		}
		if (body.matches("^\\?OTRv\\d{1,2}\\?.*")) {
			conversation.endOtrIfNeeded();
		}
		if (!conversation.hasValidOtrSession()) {
			conversation.startOtrSession(presence,false);
		} else {
			String foreignPresence = conversation.getOtrSession().getSessionID().getUserID();
			if (!foreignPresence.equals(presence)) {
				conversation.endOtrIfNeeded();
				conversation.startOtrSession(presence, false);
			}
		}
		try {
			conversation.setLastReceivedOtrMessageId(id);
			Session otrSession = conversation.getOtrSession();
			body = otrSession.transformReceiving(body);
			SessionStatus status = otrSession.getSessionStatus();
			if (body == null && status == SessionStatus.ENCRYPTED) {
				mXmppConnectionService.onOtrSessionEstablished(conversation);
				return null;
			} else if (body == null && status == SessionStatus.FINISHED) {
				conversation.resetOtrSession();
				mXmppConnectionService.updateConversationUi();
				return null;
			} else if (body == null || (body.isEmpty())) {
				return null;
			}
			if (body.startsWith(CryptoHelper.FILETRANSFER)) {
				String key = body.substring(CryptoHelper.FILETRANSFER.length());
				conversation.setSymmetricKey(CryptoHelper.hexToBytes(key));
				return null;
			}
			Message finishedMessage = new Message(conversation, body, Message.ENCRYPTION_OTR, Message.STATUS_RECEIVED);
			conversation.setLastReceivedOtrMessageId(null);
			return finishedMessage;
		} catch (Exception e) {
			conversation.resetOtrSession();
			return null;
		}
	}

	private Message parseAxolotlChat(Element axolotlMessage, Jid from, String id, Conversation conversation, int status) {
		Message finishedMessage = null;
		AxolotlService service = conversation.getAccount().getAxolotlService();
		XmppAxolotlMessage xmppAxolotlMessage = XmppAxolotlMessage.fromElement(axolotlMessage, from.toBareJid());
		XmppAxolotlMessage.XmppAxolotlPlaintextMessage plaintextMessage = service.processReceivingPayloadMessage(xmppAxolotlMessage);
		if(plaintextMessage != null) {
			finishedMessage = new Message(conversation, plaintextMessage.getPlaintext(), Message.ENCRYPTION_AXOLOTL, status);
			finishedMessage.setAxolotlFingerprint(plaintextMessage.getFingerprint());
			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(finishedMessage.getConversation().getAccount())+" Received Message with session fingerprint: "+plaintextMessage.getFingerprint());
		}

		return finishedMessage;
	}

	private Message parsePGPChat(final Conversation conversation, String pgpEncrypted, int status) {
		final Message message = new Message(conversation, pgpEncrypted, Message.ENCRYPTION_PGP, status);
		PgpDecryptionService pgpDecryptionService = conversation.getAccount().getPgpDecryptionService();
		pgpDecryptionService.add(message);
		return message;
	}

	private class Invite {
		Jid jid;
		String password;
		Invite(Jid jid, String password) {
			this.jid = jid;
			this.password = password;
		}

		public boolean execute(Account account) {
			if (jid != null) {
				Conversation conversation = mXmppConnectionService.findOrCreateConversation(account, jid, true);
				if (!conversation.getMucOptions().online()) {
					conversation.getMucOptions().setPassword(password);
					mXmppConnectionService.databaseBackend.updateConversation(conversation);
					mXmppConnectionService.joinMuc(conversation);
					mXmppConnectionService.updateConversationUi();
				}
				return true;
			}
			return false;
		}
	}

	private Invite extractInvite(Element message) {
		Element x = message.findChild("x", "http://jabber.org/protocol/muc#user");
		if (x != null) {
			Element invite = x.findChild("invite");
			if (invite != null) {
				Element pw = x.findChild("password");
				return new Invite(message.getAttributeAsJid("from"), pw != null ? pw.getContent(): null);
			}
		} else {
			x = message.findChild("x","jabber:x:conference");
			if (x != null) {
				return new Invite(x.getAttributeAsJid("jid"),x.getAttribute("password"));
			}
		}
		return null;
	}

	private static String extractStanzaId(Element packet, Jid by) {
		for(Element child : packet.getChildren()) {
			if (child.getName().equals("stanza-id")
					&& "urn:xmpp:sid:0".equals(child.getNamespace())
					&& by.equals(child.getAttributeAsJid("by"))) {
				return child.getAttribute("id");
			}
		}
		return null;
	}

	private void parseEvent(final Element event, final Jid from, final Account account) {
		Element items = event.findChild("items");
		String node = items == null ? null : items.getAttribute("node");
		if ("urn:xmpp:avatar:metadata".equals(node)) {
			Avatar avatar = Avatar.parseMetadata(items);
			if (avatar != null) {
				avatar.owner = from.toBareJid();
				if (mXmppConnectionService.getFileBackend().isAvatarCached(avatar)) {
					if (account.getJid().toBareJid().equals(from)) {
						if (account.setAvatar(avatar.getFilename())) {
							mXmppConnectionService.databaseBackend.updateAccount(account);
						}
						mXmppConnectionService.getAvatarService().clear(account);
						mXmppConnectionService.updateConversationUi();
						mXmppConnectionService.updateAccountUi();
					} else {
						Contact contact = account.getRoster().getContact(from);
						contact.setAvatar(avatar);
						mXmppConnectionService.getAvatarService().clear(contact);
						mXmppConnectionService.updateConversationUi();
						mXmppConnectionService.updateRosterUi();
					}
				} else {
					mXmppConnectionService.fetchAvatar(account, avatar);
				}
			}
		} else if ("http://jabber.org/protocol/nick".equals(node)) {
			Element i = items.findChild("item");
			Element nick = i == null ? null : i.findChild("nick", "http://jabber.org/protocol/nick");
			if (nick != null && nick.getContent() != null) {
				Contact contact = account.getRoster().getContact(from);
				contact.setPresenceName(nick.getContent());
				mXmppConnectionService.getAvatarService().clear(account);
				mXmppConnectionService.updateConversationUi();
				mXmppConnectionService.updateAccountUi();
			}
		} else if (AxolotlService.PEP_DEVICE_LIST.equals(node)) {
			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account)+"Received PEP device list update from "+ from + ", processing...");
			Element item = items.findChild("item");
			Set<Integer> deviceIds = mXmppConnectionService.getIqParser().deviceIds(item);
			AxolotlService axolotlService = account.getAxolotlService();
			axolotlService.registerDevices(from, deviceIds);
			mXmppConnectionService.updateAccountUi();
		}
	}

	private boolean handleErrorMessage(Account account, MessagePacket packet) {
		if (packet.getType() == MessagePacket.TYPE_ERROR) {
			Jid from = packet.getFrom();
			if (from != null) {
				Element error = packet.findChild("error");
				String text = error == null ? null : error.findChildContent("text");
				if (text != null) {
					Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": sending message to "+ from+ " failed - " + text);
				} else if (error != null) {
					Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": sending message to "+ from+ " failed - " + error);
				}
				Message message = mXmppConnectionService.markMessage(account,
						from.toBareJid(),
						packet.getId(),
						Message.STATUS_SEND_FAILED);
				if (message != null && message.getEncryption() == Message.ENCRYPTION_OTR) {
					message.getConversation().endOtrIfNeeded();
				}
			}
			return true;
		}
		return false;
	}

	@Override
	public void onMessagePacketReceived(Account account, MessagePacket original) {
		if (handleErrorMessage(account, original)) {
			return;
		}
		final MessagePacket packet;
		Long timestamp = null;
		final boolean isForwarded;
		boolean isCarbon = false;
		String serverMsgId = null;
		final Element fin = original.findChild("fin", "urn:xmpp:mam:0");
		if (fin != null) {
			mXmppConnectionService.getMessageArchiveService().processFin(fin,original.getFrom());
			return;
		}
		final Element result = original.findChild("result","urn:xmpp:mam:0");
		final MessageArchiveService.Query query = result == null ? null : mXmppConnectionService.getMessageArchiveService().findQuery(result.getAttribute("queryid"));
		if (query != null && query.validFrom(original.getFrom())) {
			Pair<MessagePacket, Long> f = original.getForwardedMessagePacket("result", "urn:xmpp:mam:0");
			if (f == null) {
				return;
			}
			timestamp = f.second;
			packet = f.first;
			isForwarded = true;
			serverMsgId = result.getAttribute("id");
			query.incrementTotalCount();
		} else if (query != null) {
			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": received mam result from invalid sender");
			return;
		} else if (original.fromServer(account)) {
			Pair<MessagePacket, Long> f;
			f = original.getForwardedMessagePacket("received", "urn:xmpp:carbons:2");
			f = f == null ? original.getForwardedMessagePacket("sent", "urn:xmpp:carbons:2") : f;
			packet = f != null ? f.first : original;
			if (handleErrorMessage(account, packet)) {
				return;
			}
			timestamp = f != null ? f.second : null;
			isCarbon = f != null;
			isForwarded = isCarbon;
		} else {
			packet = original;
			isForwarded = false;
		}

		if (timestamp == null) {
			timestamp = AbstractParser.getTimestamp(packet, System.currentTimeMillis());
		}
		final String body = packet.getBody();
		final Element mucUserElement = packet.findChild("x", "http://jabber.org/protocol/muc#user");
		final String pgpEncrypted = packet.findChildContent("x", "jabber:x:encrypted");
		final Element axolotlEncrypted = packet.findChild(XmppAxolotlMessage.CONTAINERTAG, AxolotlService.PEP_PREFIX);
		int status;
		final Jid counterpart;
		final Jid to = packet.getTo();
		final Jid from = packet.getFrom();
		final String remoteMsgId = packet.getId();

		if (from == null) {
			Log.d(Config.LOGTAG,"no from in: "+packet.toString());
			return;
		}
		
		boolean isTypeGroupChat = packet.getType() == MessagePacket.TYPE_GROUPCHAT;
		boolean isProperlyAddressed = (to != null ) && (!to.isBareJid() || account.countPresences() == 1);
		boolean isMucStatusMessage = from.isBareJid() && mucUserElement != null && mucUserElement.hasChild("status");
		if (packet.fromAccount(account)) {
			status = Message.STATUS_SEND;
			counterpart = to != null ? to : account.getJid();
		} else {
			status = Message.STATUS_RECEIVED;
			counterpart = from;
		}

		Invite invite = extractInvite(packet);
		if (invite != null && invite.execute(account)) {
			return;
		}

		if (extractChatState(mXmppConnectionService.find(account, counterpart.toBareJid()), packet)) {
			mXmppConnectionService.updateConversationUi();
		}

		if ((body != null || pgpEncrypted != null || axolotlEncrypted != null) && !isMucStatusMessage) {
			Conversation conversation = mXmppConnectionService.findOrCreateConversation(account, counterpart.toBareJid(), isTypeGroupChat, query);
			if (isTypeGroupChat) {
				if (counterpart.getResourcepart().equals(conversation.getMucOptions().getActualNick())) {
					status = Message.STATUS_SEND_RECEIVED;
					if (mXmppConnectionService.markMessage(conversation, remoteMsgId, status)) {
						return;
					} else if (remoteMsgId == null || Config.IGNORE_ID_REWRITE_IN_MUC) {
						Message message = conversation.findSentMessageWithBody(packet.getBody());
						if (message != null) {
							mXmppConnectionService.markMessage(message, status);
							return;
						}
					}
				} else {
					status = Message.STATUS_RECEIVED;
				}
			}
			Message message;
			if (body != null && body.startsWith("?OTR")) {
				if (!isForwarded && !isTypeGroupChat && isProperlyAddressed) {
					message = parseOtrChat(body, from, remoteMsgId, conversation);
					if (message == null) {
						return;
					}
				} else {
					message = new Message(conversation, body, Message.ENCRYPTION_NONE, status);
				}
			} else if (pgpEncrypted != null) {
				message = parsePGPChat(conversation, pgpEncrypted, status);
			} else if (axolotlEncrypted != null) {
				message = parseAxolotlChat(axolotlEncrypted, from, remoteMsgId, conversation, status);
				if (message == null) {
					return;
				}
			} else {
				message = new Message(conversation, body, Message.ENCRYPTION_NONE, status);
			}

			if (serverMsgId == null) {
				serverMsgId = extractStanzaId(packet, isTypeGroupChat ? conversation.getJid().toBareJid() : account.getServer());
			}

			message.setCounterpart(counterpart);
			message.setRemoteMsgId(remoteMsgId);
			message.setServerMsgId(serverMsgId);
			message.setCarbon(isCarbon);
			message.setTime(timestamp);
			message.markable = packet.hasChild("markable", "urn:xmpp:chat-markers:0");
			if (conversation.getMode() == Conversation.MODE_MULTI) {
				Jid trueCounterpart = conversation.getMucOptions().getTrueCounterpart(counterpart.getResourcepart());
				message.setTrueCounterpart(trueCounterpart);
				if (trueCounterpart != null) {
					updateLastseen(timestamp, account, trueCounterpart, false);
				}
				if (!isTypeGroupChat) {
					message.setType(Message.TYPE_PRIVATE);
				}
			} else {
				updateLastseen(timestamp, account, packet.getFrom(), true);
			}
			boolean checkForDuplicates = query != null
					|| (isTypeGroupChat && packet.hasChild("delay","urn:xmpp:delay"))
					|| message.getType() == Message.TYPE_PRIVATE;
			if (checkForDuplicates && conversation.hasDuplicateMessage(message)) {
				Log.d(Config.LOGTAG,"skipping duplicate message from "+message.getCounterpart().toString()+" "+message.getBody());
				return;
			}

			conversation.add(message);

			if (query == null || query.getWith() == null) { //either no mam or catchup
				if (status == Message.STATUS_SEND || status == Message.STATUS_SEND_RECEIVED) {
					mXmppConnectionService.markRead(conversation);
					if (query == null) {
						account.activateGracePeriod();
					}
				} else {
					message.markUnread();
				}
			}

			if (query != null) {
				query.incrementMessageCount();
			} else {
				mXmppConnectionService.updateConversationUi();
			}

			if (mXmppConnectionService.confirmMessages() && remoteMsgId != null && !isForwarded && !isTypeGroupChat) {
				ArrayList<String> receiptsNamespaces = new ArrayList<>();
				if (packet.hasChild("markable", "urn:xmpp:chat-markers:0")) {
					receiptsNamespaces.add("urn:xmpp:chat-markers:0");
				}
				if (packet.hasChild("request", "urn:xmpp:receipts")) {
					receiptsNamespaces.add("urn:xmpp:receipts");
				}
				if (receiptsNamespaces.size() > 0) {
					MessagePacket receipt = mXmppConnectionService.getMessageGenerator().received(account,
							packet,
							receiptsNamespaces,
							packet.getType());
					mXmppConnectionService.sendMessagePacket(account, receipt);
				}
			}

			if (message.getStatus() == Message.STATUS_RECEIVED
					&& conversation.getOtrSession() != null
					&& !conversation.getOtrSession().getSessionID().getUserID()
					.equals(message.getCounterpart().getResourcepart())) {
				conversation.endOtrIfNeeded();
			}

			if (message.getEncryption() == Message.ENCRYPTION_NONE || mXmppConnectionService.saveEncryptedMessages()) {
				mXmppConnectionService.databaseBackend.createMessage(message);
			}
			final HttpConnectionManager manager = this.mXmppConnectionService.getHttpConnectionManager();
			if (message.trusted() && message.treatAsDownloadable() != Message.Decision.NEVER && manager.getAutoAcceptFileSize() > 0) {
				manager.createNewDownloadConnection(message);
			} else if (!message.isRead()) {
				if (query == null) {
					mXmppConnectionService.getNotificationService().push(message);
				} else if (query.getWith() == null) { // mam catchup
					mXmppConnectionService.getNotificationService().pushFromBacklog(message);
				}
			}
		} else { //no body
			if (isTypeGroupChat) {
				Conversation conversation = mXmppConnectionService.find(account, from.toBareJid());
				if (packet.hasChild("subject")) {
					if (conversation != null && conversation.getMode() == Conversation.MODE_MULTI) {
						conversation.setHasMessagesLeftOnServer(conversation.countMessages() > 0);
						String subject = packet.findChildContent("subject");
						conversation.getMucOptions().setSubject(subject);
						final Bookmark bookmark = conversation.getBookmark();
						if (bookmark != null && bookmark.getBookmarkName() == null) {
							if (bookmark.setBookmarkName(subject)) {
								mXmppConnectionService.pushBookmarks(account);
							}
						}
						mXmppConnectionService.updateConversationUi();
						return;
					}
				}

				if (conversation != null && isMucStatusMessage) {
					for (Element child : mucUserElement.getChildren()) {
						if (child.getName().equals("status")
								&& MucOptions.STATUS_CODE_ROOM_CONFIG_CHANGED.equals(child.getAttribute("code"))) {
							mXmppConnectionService.fetchConferenceConfiguration(conversation);
						}
					}
				}
			}
		}

		Element received = packet.findChild("received", "urn:xmpp:chat-markers:0");
		if (received == null) {
			received = packet.findChild("received", "urn:xmpp:receipts");
		}
		if (received != null && !packet.fromAccount(account)) {
			mXmppConnectionService.markMessage(account, from.toBareJid(), received.getAttribute("id"), Message.STATUS_SEND_RECEIVED);
		}
		Element displayed = packet.findChild("displayed", "urn:xmpp:chat-markers:0");
		if (displayed != null) {
			if (packet.fromAccount(account)) {
				Conversation conversation = mXmppConnectionService.find(account,counterpart.toBareJid());
				if (conversation != null) {
					mXmppConnectionService.markRead(conversation);
				}
			} else {
				updateLastseen(timestamp, account, packet.getFrom(), true);
				final Message displayedMessage = mXmppConnectionService.markMessage(account, from.toBareJid(), displayed.getAttribute("id"), Message.STATUS_SEND_DISPLAYED);
				Message message = displayedMessage == null ? null : displayedMessage.prev();
				while (message != null
						&& message.getStatus() == Message.STATUS_SEND_RECEIVED
						&& message.getTimeSent() < displayedMessage.getTimeSent()) {
					mXmppConnectionService.markMessage(message, Message.STATUS_SEND_DISPLAYED);
					message = message.prev();
				}
			}
		}

		Element event = packet.findChild("event", "http://jabber.org/protocol/pubsub#event");
		if (event != null) {
			parseEvent(event, from, account);
		}

		String nick = packet.findChildContent("nick", "http://jabber.org/protocol/nick");
		if (nick != null) {
			Contact contact = account.getRoster().getContact(from);
			contact.setPresenceName(nick);
		}
	}
}
