package de.pixart.messenger.xmpp.jingle;

import android.util.Base64;
import android.util.Log;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;

import de.pixart.messenger.Config;
import de.pixart.messenger.crypto.axolotl.AxolotlService;
import de.pixart.messenger.crypto.axolotl.OnMessageCreatedCallback;
import de.pixart.messenger.crypto.axolotl.XmppAxolotlMessage;
import de.pixart.messenger.entities.Account;
import de.pixart.messenger.entities.Conversation;
import de.pixart.messenger.entities.Conversational;
import de.pixart.messenger.entities.DownloadableFile;
import de.pixart.messenger.entities.Message;
import de.pixart.messenger.entities.Presence;
import de.pixart.messenger.entities.ServiceDiscoveryResult;
import de.pixart.messenger.entities.Transferable;
import de.pixart.messenger.entities.TransferablePlaceholder;
import de.pixart.messenger.parser.IqParser;
import de.pixart.messenger.persistance.FileBackend;
import de.pixart.messenger.services.AbstractConnectionManager;
import de.pixart.messenger.services.XmppConnectionService;
import de.pixart.messenger.utils.CryptoHelper;
import de.pixart.messenger.xml.Element;
import de.pixart.messenger.xmpp.OnIqPacketReceived;
import de.pixart.messenger.xmpp.jingle.stanzas.Content;
import de.pixart.messenger.xmpp.jingle.stanzas.JinglePacket;
import de.pixart.messenger.xmpp.jingle.stanzas.Reason;
import de.pixart.messenger.xmpp.stanzas.IqPacket;
import rocks.xmpp.addr.Jid;

public class JingleConnection implements Transferable {
    private final SimpleDateFormat fileDateFormat = new SimpleDateFormat("yyyyMMdd_HHmmssSSS", Locale.US);

    private JingleConnectionManager mJingleConnectionManager;
    private XmppConnectionService mXmppConnectionService;

    private static final int JINGLE_STATUS_OFFERED = -1;
    protected static final int JINGLE_STATUS_INITIATED = 0;
    protected static final int JINGLE_STATUS_ACCEPTED = 1;
    protected static final int JINGLE_STATUS_FINISHED = 4;
    protected static final int JINGLE_STATUS_TRANSMITTING = 5;
    protected static final int JINGLE_STATUS_FAILED = 99;

    private Content.Version ftVersion = Content.Version.FT_3;

    private int ibbBlockSize = 8192;

    private int mJingleStatus = JINGLE_STATUS_OFFERED;
    private int mStatus = Transferable.STATUS_UNKNOWN;
    private Message message;
    private String sessionId;
    private Account account;
    private Jid initiator;
    private Jid responder;
    private List<JingleCandidate> candidates = new ArrayList<>();
    private ConcurrentHashMap<String, JingleSocks5Transport> connections = new ConcurrentHashMap<>();

    private String transportId;
    private Element fileOffer;
    private DownloadableFile file = null;

    private String contentName;
    private String contentCreator;

    private int mProgress = 0;

    private boolean receivedCandidate = false;
    private boolean sentCandidate = false;

    private boolean acceptedAutomatically = false;
    private boolean cancelled = false;

    private XmppAxolotlMessage mXmppAxolotlMessage;

    private JingleTransport transport = null;

    private OutputStream mFileOutputStream;
    private InputStream mFileInputStream;

    private OnIqPacketReceived responseListener = (account, packet) -> {
        if (packet.getType() != IqPacket.TYPE.RESULT) {
            fail(IqParser.extractErrorMessage(packet));
        }
    };
    private byte[] expectedHash = new byte[0];

    final OnFileTransmissionStatusChanged onFileTransmissionStatusChanged = new OnFileTransmissionStatusChanged() {

        @Override
        public void onFileTransmitted(DownloadableFile file) {
            if (responding()) {
                if (expectedHash.length > 0 && !Arrays.equals(expectedHash, file.getSha1Sum())) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": hashes did not match");
                }
                sendSuccess();
                mXmppConnectionService.getFileBackend().updateFileParams(message);
                mXmppConnectionService.databaseBackend.createMessage(message);
                mXmppConnectionService.markMessage(message, Message.STATUS_RECEIVED);
                if (acceptedAutomatically) {
                    message.markUnread();
                    if (message.getEncryption() == Message.ENCRYPTION_PGP) {
                        account.getPgpDecryptionService().decrypt(message, true);
                    } else {
                        mXmppConnectionService.getFileBackend().updateMediaScanner(file, () -> JingleConnection.this.mXmppConnectionService.getNotificationService().push(message));
                    }
                    Log.d(Config.LOGTAG, "successfully transmitted file:" + file.getAbsolutePath() + " (" + CryptoHelper.bytesToHex(file.getSha1Sum()) + ")");
                    return;
                }
            } else {
                if (ftVersion == Content.Version.FT_5) { //older Conversations will break when receiving a session-info
                    sendHash();
                }
                if (message.getEncryption() == Message.ENCRYPTION_PGP) {
                    account.getPgpDecryptionService().decrypt(message, false);
                }
                if (message.getEncryption() == Message.ENCRYPTION_PGP || message.getEncryption() == Message.ENCRYPTION_DECRYPTED) {
                    file.delete();
                }
            }
            Log.d(Config.LOGTAG, "successfully transmitted file:" + file.getAbsolutePath() + " (" + CryptoHelper.bytesToHex(file.getSha1Sum()) + ")");
            if (message.getEncryption() != Message.ENCRYPTION_PGP) {
                mXmppConnectionService.getFileBackend().updateMediaScanner(file);
            }
        }

        @Override
        public void onFileTransferAborted() {
            JingleConnection.this.sendCancel();
            JingleConnection.this.fail();
        }
    };

    private boolean responding() {
        return responder != null && responder.equals(account.getJid());
    }

    private boolean initiating() {
        return initiator.equals(account.getJid());
    }

    public InputStream getFileInputStream() {
        return this.mFileInputStream;
    }

    public OutputStream getFileOutputStream() throws IOException {
        if (this.file == null) {
            Log.d(Config.LOGTAG, "file object was not assigned");
            return null;
        }
        this.file.getParentFile().mkdirs();
        this.file.createNewFile();
        this.mFileOutputStream = AbstractConnectionManager.createOutputStream(this.file, message.getEncryption() == Message.ENCRYPTION_AXOLOTL);
        return this.mFileOutputStream;
    }

    private OnProxyActivated onProxyActivated = new OnProxyActivated() {

        @Override
        public void success() {
            if (initiator.equals(account.getJid())) {
                Log.d(Config.LOGTAG, "we were initiating. sending file");
                transport.send(file, onFileTransmissionStatusChanged);
            } else {
                transport.receive(file, onFileTransmissionStatusChanged);
                Log.d(Config.LOGTAG, "we were responding. receiving file");
            }
        }

        @Override
        public void failed() {
            Log.d(Config.LOGTAG, "proxy activation failed");
        }
    };

    public JingleConnection(JingleConnectionManager mJingleConnectionManager) {
        this.mJingleConnectionManager = mJingleConnectionManager;
        this.mXmppConnectionService = mJingleConnectionManager
                .getXmppConnectionService();
    }

    public String getSessionId() {
        return this.sessionId;
    }

    public Account getAccount() {
        return this.account;
    }

    public Jid getCounterPart() {
        return this.message.getCounterpart();
    }

    public void deliverPacket(JinglePacket packet) {
        boolean returnResult = true;
        if (packet.isAction("session-terminate")) {
            Reason reason = packet.getReason();
            if (reason != null) {
                if (reason.hasChild("cancel")) {
                    this.fail();
                } else if (reason.hasChild("success")) {
                    this.receiveSuccess();
                } else {
                    this.fail();
                }
            } else {
                this.fail();
            }
        } else if (packet.isAction("session-accept")) {
            returnResult = receiveAccept(packet);
        } else if (packet.isAction("session-info")) {
            returnResult = true;
            Element checksum = packet.getChecksum();
            Element file = checksum == null ? null : checksum.findChild("file");
            Element hash = file == null ? null : file.findChild("hash", "urn:xmpp:hashes:2");
            if (hash != null && "sha-1".equalsIgnoreCase(hash.getAttribute("algo"))) {
                try {
                    this.expectedHash = Base64.decode(hash.getContent(), Base64.DEFAULT);
                } catch (Exception e) {
                    this.expectedHash = new byte[0];
                }
            }
        } else if (packet.isAction("transport-info")) {
            returnResult = receiveTransportInfo(packet);
        } else if (packet.isAction("transport-replace")) {
            if (packet.getJingleContent().hasIbbTransport()) {
                returnResult = this.receiveFallbackToIbb(packet);
            } else {
                returnResult = false;
                Log.d(Config.LOGTAG, "trying to fallback to something unknown"
                        + packet.toString());
            }
        } else if (packet.isAction("transport-accept")) {
            returnResult = this.receiveTransportAccept(packet);
        } else {
            Log.d(Config.LOGTAG, "packet arrived in connection. action was "
                    + packet.getAction());
            returnResult = false;
        }
        IqPacket response;
        if (returnResult) {
            response = packet.generateResponse(IqPacket.TYPE.RESULT);

        } else {
            response = packet.generateResponse(IqPacket.TYPE.ERROR);
        }
        mXmppConnectionService.sendIqPacket(account, response, null);
    }

    public void init(final Message message) {
        if (message.getEncryption() == Message.ENCRYPTION_AXOLOTL) {
            Conversation conversation = (Conversation) message.getConversation();
            conversation.getAccount().getAxolotlService().prepareKeyTransportMessage(conversation, new OnMessageCreatedCallback() {
                @Override
                public void run(XmppAxolotlMessage xmppAxolotlMessage) {
                    if (xmppAxolotlMessage != null) {
                        init(message, xmppAxolotlMessage);
                    } else {
                        fail();
                    }
                }
            });
        } else {
            init(message, null);
        }
    }

    private void init(Message message, XmppAxolotlMessage xmppAxolotlMessage) {
        this.mXmppAxolotlMessage = xmppAxolotlMessage;
        this.contentCreator = "initiator";
        this.contentName = this.mJingleConnectionManager.nextRandomId();
        this.message = message;
        this.account = message.getConversation().getAccount();
        upgradeNamespace();
        this.message.setTransferable(this);
        this.mStatus = Transferable.STATUS_UPLOADING;
        this.initiator = this.account.getJid();
        this.responder = this.message.getCounterpart();
        this.sessionId = this.mJingleConnectionManager.nextRandomId();
        this.transportId = this.mJingleConnectionManager.nextRandomId();
        if (this.candidates.size() > 0) {
            this.sendInitRequest();
        } else {
            this.mJingleConnectionManager.getPrimaryCandidate(account,
                    new OnPrimaryCandidateFound() {

                        @Override
                        public void onPrimaryCandidateFound(boolean success,
                                                            final JingleCandidate candidate) {
                            if (success) {
                                final JingleSocks5Transport socksConnection = new JingleSocks5Transport(
                                        JingleConnection.this, candidate);
                                connections.put(candidate.getCid(),
                                        socksConnection);
                                socksConnection
                                        .connect(new OnTransportConnected() {

                                            @Override
                                            public void failed() {
                                                Log.d(Config.LOGTAG,
                                                        "connection to our own primary candidete failed");
                                                sendInitRequest();
                                            }

                                            @Override
                                            public void established() {
                                                Log.d(Config.LOGTAG,
                                                        "successfully connected to our own primary candidate");
                                                mergeCandidate(candidate);
                                                sendInitRequest();
                                            }
                                        });
                                mergeCandidate(candidate);
                            } else {
                                Log.d(Config.LOGTAG, "no primary candidate of our own was found");
                                sendInitRequest();
                            }
                        }
                    });
        }

    }

    private void upgradeNamespace() {
        Jid jid = this.message.getCounterpart();
        String resource = jid != null ? jid.getResource() : null;
        if (resource != null) {
            Presence presence = this.account.getRoster().getContact(jid).getPresences().getPresences().get(resource);
            ServiceDiscoveryResult result = presence != null ? presence.getServiceDiscoveryResult() : null;
            if (result != null) {
                List<String> features = result.getFeatures();
                if (features.contains(Content.Version.FT_5.getNamespace())) {
                    this.ftVersion = Content.Version.FT_5;
                } else if (features.contains(Content.Version.FT_4.getNamespace())) {
                    this.ftVersion = Content.Version.FT_4;
                }
            }
        }
    }

    public void init(Account account, JinglePacket packet) {
        this.mJingleStatus = JINGLE_STATUS_INITIATED;
        Conversation conversation = this.mXmppConnectionService.findOrCreateConversation(account, packet.getFrom().asBareJid(), false, false);
        this.message = new Message(conversation, "", Message.ENCRYPTION_NONE);
        this.message.setStatus(Message.STATUS_RECEIVED);
        this.mStatus = Transferable.STATUS_OFFER;
        this.message.setTransferable(this);
        final Jid from = packet.getFrom();
        this.message.setCounterpart(from);
        this.account = account;
        this.initiator = packet.getFrom();
        this.responder = this.account.getJid();
        this.sessionId = packet.getSessionId();
        Content content = packet.getJingleContent();
        this.contentCreator = content.getAttribute("creator");
        this.contentName = content.getAttribute("name");
        this.transportId = content.getTransportId();
        this.mergeCandidates(JingleCandidate.parse(content.socks5transport().getChildren()));
        this.ftVersion = content.getVersion();
        if (ftVersion == null) {
            this.sendCancel();
            this.fail();
            return;
        }
        this.fileOffer = content.getFileOffer(this.ftVersion);

        mXmppConnectionService.sendIqPacket(account, packet.generateResponse(IqPacket.TYPE.RESULT), null);

        if (fileOffer != null) {
            Element encrypted = fileOffer.findChild("encrypted", AxolotlService.PEP_PREFIX);
            if (encrypted != null) {
                this.mXmppAxolotlMessage = XmppAxolotlMessage.fromElement(encrypted, packet.getFrom().asBareJid());
            }
            Element fileSize = fileOffer.findChild("size");
            Element fileNameElement = fileOffer.findChild("name");
            if (fileNameElement != null) {
                String[] filename = fileNameElement.getContent()
                        .toLowerCase(Locale.US).toLowerCase().split("\\.");
                String filename_new = fileDateFormat.format(new Date(message.getTimeSent())) + "_" + message.getUuid().substring(0, 4);
                String extension = filename[filename.length - 1];
                if (VALID_IMAGE_EXTENSIONS.contains(extension)) {
                    message.setType(Message.TYPE_IMAGE);
                    message.setRelativeFilePath(filename_new + "." + extension);
                } else if (VALID_CRYPTO_EXTENSIONS.contains(
                        filename[filename.length - 1])) {
                    if (filename.length == 3) {
                        extension = filename[filename.length - 2];
                        if (VALID_IMAGE_EXTENSIONS.contains(extension)) {
                            message.setType(Message.TYPE_IMAGE);
                            message.setRelativeFilePath(filename_new + "." + extension);
                        } else {
                            message.setType(Message.TYPE_FILE);
                        }
                        if (filename[filename.length - 1].equals("otr")) {
                            message.setEncryption(Message.ENCRYPTION_OTR);
                        } else {
                            message.setEncryption(Message.ENCRYPTION_PGP);
                        }
                    }
                } else {
                    message.setType(Message.TYPE_FILE);
                }
                if (message.getType() == Message.TYPE_FILE) {
                    String suffix = "";
                    if (!fileNameElement.getContent().isEmpty()) {
                        String parts[] = fileNameElement.getContent().split("/");
                        suffix = parts[parts.length - 1];
                        if (message.getEncryption() == Message.ENCRYPTION_OTR && suffix.endsWith(".otr")) {
                            suffix = suffix.substring(0, suffix.length() - 4);
                        } else if (message.getEncryption() == Message.ENCRYPTION_PGP && (suffix.endsWith(".pgp") || suffix.endsWith(".gpg"))) {
                            suffix = suffix.substring(0, suffix.length() - 4);
                        }
                    }
                    message.setRelativeFilePath(filename_new + "_" + suffix);
                }
                long size = Long.parseLong(fileSize.getContent());
                message.setBody(Long.toString(size));
                conversation.add(message);
                mJingleConnectionManager.updateConversationUi(true);
                if (mJingleConnectionManager.hasStoragePermission()
                        && size < this.mJingleConnectionManager.getAutoAcceptFileSize()
                        && mXmppConnectionService.isDataSaverDisabled()) {
                    Log.d(Config.LOGTAG, "auto accepting file from " + packet.getFrom());
                    this.acceptedAutomatically = true;
                    this.sendAccept();
                } else {
                    message.markUnread();
                    Log.d(Config.LOGTAG,
                            "not auto accepting new file offer with size: "
                                    + size
                                    + " allowed size:"
                                    + this.mJingleConnectionManager
                                    .getAutoAcceptFileSize());
                    this.mXmppConnectionService.getNotificationService().push(message);
                }
                this.file = this.mXmppConnectionService.getFileBackend().getFile(message, false);
                if (mXmppAxolotlMessage != null) {
                    XmppAxolotlMessage.XmppAxolotlKeyTransportMessage transportMessage = account.getAxolotlService().processReceivingKeyTransportMessage(mXmppAxolotlMessage, false);
                    if (transportMessage != null) {
                        message.setEncryption(Message.ENCRYPTION_AXOLOTL);
                        this.file.setKey(transportMessage.getKey());
                        this.file.setIv(transportMessage.getIv());
                        message.setFingerprint(transportMessage.getFingerprint());
                    } else {
                        Log.d(Config.LOGTAG, "could not process KeyTransportMessage");
                    }
                } else if (message.getEncryption() == Message.ENCRYPTION_OTR) {
                    byte[] key = conversation.getSymmetricKey();
                    if (key == null) {
                        this.sendCancel();
                        this.fail();
                        return;
                    } else {
                        this.file.setKeyAndIv(key);
                    }
                }
                this.file.setExpectedSize(size);
                message.resetFileParams();
                Log.d(Config.LOGTAG, "receiving file: expecting size of " + this.file.getExpectedSize());
            } else {
                this.sendCancel();
                this.fail();
            }
        } else {
            this.sendCancel();
            this.fail();
        }
    }

    private void sendInitRequest() {
        JinglePacket packet = this.bootstrapPacket("session-initiate");
        Content content = new Content(this.contentCreator, this.contentName);
        if (message.isFileOrImage()) {
            content.setTransportId(this.transportId);
            this.file = this.mXmppConnectionService.getFileBackend().getFile(message, false);
            if (message.getEncryption() == Message.ENCRYPTION_OTR) {
                Conversational conversation = this.message.getConversation();
                if (!this.mXmppConnectionService.renewSymmetricKey((Conversation) conversation)) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": could not set symmetric key");
                    cancel();
                }
                Conversation c = (Conversation) this.message.getConversation();
                this.file.setKeyAndIv(c.getSymmetricKey());
                this.file.setExpectedSize((file.getSize() / 16 + 1) * 16);
                content.setFileOffer(this.file, true, this.ftVersion);
            } else if (message.getEncryption() == Message.ENCRYPTION_AXOLOTL) {
                this.file.setKey(mXmppAxolotlMessage.getInnerKey());
                this.file.setIv(mXmppAxolotlMessage.getIV());
                this.file.setExpectedSize(file.getSize() + 16);
                content.setFileOffer(this.file, false, this.ftVersion).addChild(mXmppAxolotlMessage.toElement());
            } else {
                this.file.setExpectedSize(file.getSize());
                content.setFileOffer(this.file, false, this.ftVersion);
            }
            message.resetFileParams();
            try {
                this.mFileInputStream = new FileInputStream(file);
            } catch (FileNotFoundException e) {
                abort();
                return;
            }
            content.setTransportId(this.transportId);
            content.socks5transport().setChildren(getCandidatesAsElements());
            packet.setContent(content);
            this.sendJinglePacket(packet, new OnIqPacketReceived() {

                @Override
                public void onIqPacketReceived(Account account, IqPacket packet) {
                    if (packet.getType() == IqPacket.TYPE.RESULT) {
                        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": other party received offer");
                        if (mJingleStatus == JINGLE_STATUS_OFFERED) {
                            mJingleStatus = JINGLE_STATUS_INITIATED;
                            mXmppConnectionService.markMessage(message, Message.STATUS_OFFERED);
                        } else {
                            Log.d(Config.LOGTAG, "received ack for offer when status was " + mJingleStatus);
                        }
                    } else {
                        fail(IqParser.extractErrorMessage(packet));
                    }
                }
            });

        }
    }

    private void sendHash() {
        JinglePacket packet = this.bootstrapPacket("session-info");
        packet.addChecksum(file.getSha1Sum(), ftVersion.getNamespace());
        this.sendJinglePacket(packet);
    }

    private List<Element> getCandidatesAsElements() {
        List<Element> elements = new ArrayList<>();
        for (JingleCandidate c : this.candidates) {
            if (c.isOurs()) {
                elements.add(c.toElement());
            }
        }
        return elements;
    }

    private void sendAccept() {
        mJingleStatus = JINGLE_STATUS_ACCEPTED;
        this.mStatus = Transferable.STATUS_DOWNLOADING;
        this.mJingleConnectionManager.updateConversationUi(true);
        this.mJingleConnectionManager.getPrimaryCandidate(this.account, new OnPrimaryCandidateFound() {
            @Override
            public void onPrimaryCandidateFound(boolean success, final JingleCandidate candidate) {
                final JinglePacket packet = bootstrapPacket("session-accept");
                final Content content = new Content(contentCreator, contentName);
                content.setFileOffer(fileOffer, ftVersion);
                content.setTransportId(transportId);
                if (success && candidate != null && !equalCandidateExists(candidate)) {
                    final JingleSocks5Transport socksConnection = new JingleSocks5Transport(
                            JingleConnection.this,
                            candidate);
                    connections.put(candidate.getCid(), socksConnection);
                    socksConnection.connect(new OnTransportConnected() {

                        @Override
                        public void failed() {
                            Log.d(Config.LOGTAG, "connection to our own primary candidate failed");
                            content.socks5transport().setChildren(getCandidatesAsElements());
                            packet.setContent(content);
                            sendJinglePacket(packet);
                            connectNextCandidate();
                        }

                        @Override
                        public void established() {
                            Log.d(Config.LOGTAG, "connected to primary candidate");
                            mergeCandidate(candidate);
                            content.socks5transport().setChildren(getCandidatesAsElements());
                            packet.setContent(content);
                            sendJinglePacket(packet);
                            connectNextCandidate();
                        }
                    });
                } else {
                    Log.d(Config.LOGTAG, "did not find a primary candidate for ourself");
                    content.socks5transport().setChildren(getCandidatesAsElements());
                    packet.setContent(content);
                    sendJinglePacket(packet);
                    connectNextCandidate();
                }
            }
        });
    }

    private JinglePacket bootstrapPacket(String action) {
        JinglePacket packet = new JinglePacket();
        packet.setAction(action);
        packet.setFrom(account.getJid());
        packet.setTo(this.message.getCounterpart());
        packet.setSessionId(this.sessionId);
        packet.setInitiator(this.initiator);
        return packet;
    }

    private void sendJinglePacket(JinglePacket packet) {
        mXmppConnectionService.sendIqPacket(account, packet, responseListener);
    }

    private void sendJinglePacket(JinglePacket packet, OnIqPacketReceived callback) {
        mXmppConnectionService.sendIqPacket(account, packet, callback);
    }

    private boolean receiveAccept(JinglePacket packet) {
        Content content = packet.getJingleContent();
        mergeCandidates(JingleCandidate.parse(content.socks5transport()
                .getChildren()));
        this.mJingleStatus = JINGLE_STATUS_ACCEPTED;
        mXmppConnectionService.markMessage(message, Message.STATUS_UNSEND);
        this.connectNextCandidate();
        return true;
    }

    private boolean receiveTransportInfo(JinglePacket packet) {
        Content content = packet.getJingleContent();
        if (content.hasSocks5Transport()) {
            if (content.socks5transport().hasChild("activated")) {
                if ((this.transport != null) && (this.transport instanceof JingleSocks5Transport)) {
                    onProxyActivated.success();
                } else {
                    String cid = content.socks5transport().findChild("activated").getAttribute("cid");
                    Log.d(Config.LOGTAG, "received proxy activated (" + cid
                            + ")prior to choosing our own transport");
                    JingleSocks5Transport connection = this.connections.get(cid);
                    if (connection != null) {
                        connection.setActivated(true);
                    } else {
                        Log.d(Config.LOGTAG, "activated connection not found");
                        this.sendCancel();
                        this.fail();
                    }
                }
                return true;
            } else if (content.socks5transport().hasChild("proxy-error")) {
                onProxyActivated.failed();
                return true;
            } else if (content.socks5transport().hasChild("candidate-error")) {
                Log.d(Config.LOGTAG, "received candidate error");
                this.receivedCandidate = true;
                if (mJingleStatus == JINGLE_STATUS_ACCEPTED && this.sentCandidate) {
                    this.connect();
                }
                return true;
            } else if (content.socks5transport().hasChild("candidate-used")) {
                String cid = content.socks5transport()
                        .findChild("candidate-used").getAttribute("cid");
                if (cid != null) {
                    Log.d(Config.LOGTAG, "candidate used by counterpart:" + cid);
                    JingleCandidate candidate = getCandidate(cid);
                    if (candidate == null) {
                        Log.d(Config.LOGTAG, "could not find candidate with cid=" + cid);
                        return false;
                    }
                    candidate.flagAsUsedByCounterpart();
                    this.receivedCandidate = true;
                    if (mJingleStatus == JINGLE_STATUS_ACCEPTED && this.sentCandidate) {
                        this.connect();
                    } else {
                        Log.d(Config.LOGTAG, "ignoring because file is already in transmission or we haven't sent our candidate yet status=" + mJingleStatus + " sentCandidate=" + Boolean.toString(sentCandidate));
                    }
                    return true;
                } else {
                    return false;
                }
            } else {
                return false;
            }
        } else {
            return true;
        }
    }

    private void connect() {
        final JingleSocks5Transport connection = chooseConnection();
        this.transport = connection;
        if (connection == null) {
            Log.d(Config.LOGTAG, "could not find suitable candidate");
            this.disconnectSocks5Connections();
            if (initiating()) {
                this.sendFallbackToIbb();
            }
        } else {
            this.mJingleStatus = JINGLE_STATUS_TRANSMITTING;
            if (connection.needsActivation()) {
                if (connection.getCandidate().isOurs()) {
                    final String sid;
                    if (ftVersion == Content.Version.FT_3) {
                        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": use session ID instead of transport ID to activate proxy");
                        sid = getSessionId();
                    } else {
                        sid = getTransportId();
                    }
                    Log.d(Config.LOGTAG, "candidate "
                            + connection.getCandidate().getCid()
                            + " was our proxy. going to activate");
                    IqPacket activation = new IqPacket(IqPacket.TYPE.SET);
                    activation.setTo(connection.getCandidate().getJid());
                    activation.query("http://jabber.org/protocol/bytestreams")
                            .setAttribute("sid", sid);
                    activation.query().addChild("activate")
                            .setContent(this.getCounterPart().toString());
                    mXmppConnectionService.sendIqPacket(account, activation,
                            new OnIqPacketReceived() {

                                @Override
                                public void onIqPacketReceived(Account account,
                                                               IqPacket packet) {
                                    if (packet.getType() != IqPacket.TYPE.RESULT) {
                                        onProxyActivated.failed();
                                    } else {
                                        onProxyActivated.success();
                                        sendProxyActivated(connection.getCandidate().getCid());
                                    }
                                }
                            });
                } else {
                    Log.d(Config.LOGTAG,
                            "candidate "
                                    + connection.getCandidate().getCid()
                                    + " was a proxy. waiting for other party to activate");
                }
            } else {
                if (initiating()) {
                    Log.d(Config.LOGTAG, "we were initiating. sending file");
                    connection.send(file, onFileTransmissionStatusChanged);
                } else {
                    Log.d(Config.LOGTAG, "we were responding. receiving file");
                    connection.receive(file, onFileTransmissionStatusChanged);
                }
            }
        }
    }

    private JingleSocks5Transport chooseConnection() {
        JingleSocks5Transport connection = null;
        for (Entry<String, JingleSocks5Transport> cursor : connections
                .entrySet()) {
            JingleSocks5Transport currentConnection = cursor.getValue();
            // Log.d(Config.LOGTAG,"comparing candidate: "+currentConnection.getCandidate().toString());
            if (currentConnection.isEstablished()
                    && (currentConnection.getCandidate().isUsedByCounterpart() || (!currentConnection
                    .getCandidate().isOurs()))) {
                // Log.d(Config.LOGTAG,"is usable");
                if (connection == null) {
                    connection = currentConnection;
                } else {
                    if (connection.getCandidate().getPriority() < currentConnection
                            .getCandidate().getPriority()) {
                        connection = currentConnection;
                    } else if (connection.getCandidate().getPriority() == currentConnection
                            .getCandidate().getPriority()) {
                        // Log.d(Config.LOGTAG,"found two candidates with same priority");
                        if (initiating()) {
                            if (currentConnection.getCandidate().isOurs()) {
                                connection = currentConnection;
                            }
                        } else {
                            if (!currentConnection.getCandidate().isOurs()) {
                                connection = currentConnection;
                            }
                        }
                    }
                }
            }
        }
        return connection;
    }

    private void sendSuccess() {
        JinglePacket packet = bootstrapPacket("session-terminate");
        Reason reason = new Reason();
        reason.addChild("success");
        packet.setReason(reason);
        this.sendJinglePacket(packet);
        this.disconnectSocks5Connections();
        this.mJingleStatus = JINGLE_STATUS_FINISHED;
        this.message.setStatus(Message.STATUS_RECEIVED);
        this.message.setTransferable(null);
        this.mXmppConnectionService.updateMessage(message, false);
        this.mJingleConnectionManager.finishConnection(this);
    }

    private void sendFallbackToIbb() {
        Log.d(Config.LOGTAG, account.getJid().asBareJid()+ ": sending fallback to ibb");
        JinglePacket packet = this.bootstrapPacket("transport-replace");
        Content content = new Content(this.contentCreator, this.contentName);
        this.transportId = this.mJingleConnectionManager.nextRandomId();
        content.setTransportId(this.transportId);
        content.ibbTransport().setAttribute("block-size",
                Integer.toString(this.ibbBlockSize));
        packet.setContent(content);
        this.sendJinglePacket(packet);
    }

    OnTransportConnected onIbbTransportConnected = new OnTransportConnected() {
        @Override
        public void failed() {
            Log.d(Config.LOGTAG, "ibb open failed");
        }

        @Override
        public void established() {
            JingleConnection.this.transport.send(file, onFileTransmissionStatusChanged);
        }
    };

    private boolean receiveFallbackToIbb(JinglePacket packet) {
        Log.d(Config.LOGTAG, "receiving fallack to ibb");
        String receivedBlockSize = packet.getJingleContent().ibbTransport()
                .getAttribute("block-size");
        if (receivedBlockSize != null) {
            int bs = Integer.parseInt(receivedBlockSize);
            if (bs > this.ibbBlockSize) {
                this.ibbBlockSize = bs;
            }
        }
        this.transportId = packet.getJingleContent().getTransportId();
        this.transport = new JingleInbandTransport(this, this.transportId, this.ibbBlockSize);
        JinglePacket answer = bootstrapPacket("transport-accept");
        Content content = new Content("initiator", "a-file-offer");
        content.setTransportId(this.transportId);
        content.ibbTransport().setAttribute("block-size", this.ibbBlockSize);
        answer.setContent(content);


        if (initiating()) {
            this.sendJinglePacket(answer, new OnIqPacketReceived() {
                @Override
                public void onIqPacketReceived(Account account, IqPacket packet) {
                    if (packet.getType() == IqPacket.TYPE.RESULT) {
                        Log.d(Config.LOGTAG, account.getJid().asBareJid() + " recipient ACKed our transport-accept. creating ibb");
                        transport.connect(onIbbTransportConnected);
                    }
                }
            });
        } else {
            this.transport.receive(file, onFileTransmissionStatusChanged);
            this.sendJinglePacket(answer);
        }
        return true;
    }

    private boolean receiveTransportAccept(JinglePacket packet) {
        if (packet.getJingleContent().hasIbbTransport()) {
            String receivedBlockSize = packet.getJingleContent().ibbTransport()
                    .getAttribute("block-size");
            if (receivedBlockSize != null) {
                int bs = Integer.parseInt(receivedBlockSize);
                if (bs > this.ibbBlockSize) {
                    this.ibbBlockSize = bs;
                }
            }
            this.transport = new JingleInbandTransport(this, this.transportId, this.ibbBlockSize);

            //might be receive instead if we are not initiating
            if (initiating()) {
                this.transport.connect(onIbbTransportConnected);
            } else {
                this.transport.receive(file, onFileTransmissionStatusChanged);
            }
            return true;
        } else {
            return false;
        }
    }

    private void receiveSuccess() {
        if (initiating()) {
            this.mJingleStatus = JINGLE_STATUS_FINISHED;
            this.mXmppConnectionService.markMessage(this.message, Message.STATUS_SEND_RECEIVED);
            this.disconnectSocks5Connections();
            if (this.transport instanceof JingleInbandTransport) {
                this.transport.disconnect();
            }
            this.message.setTransferable(null);
            this.mJingleConnectionManager.finishConnection(this);
        } else {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": received session-terminate/success while responding");
        }
    }

    public void cancel() {
        this.cancelled = true;
        abort();
    }

    public void abort() {
        this.disconnectSocks5Connections();
        if (this.transport instanceof JingleInbandTransport) {
            this.transport.disconnect();
        }
        this.sendCancel();
        this.mJingleConnectionManager.finishConnection(this);
        if (responding()) {
            this.message.setTransferable(new TransferablePlaceholder(Transferable.STATUS_FAILED));
            if (this.file != null) {
                file.delete();
            }
            this.mJingleConnectionManager.updateConversationUi(true);
        } else {
            this.mXmppConnectionService.markMessage(this.message, Message.STATUS_SEND_FAILED, cancelled ? Message.ERROR_MESSAGE_CANCELLED : null);
            this.message.setTransferable(null);
        }
    }

    private void fail() {
        fail(null);
    }

    private void fail(String errorMessage) {
        this.mJingleStatus = JINGLE_STATUS_FAILED;
        this.disconnectSocks5Connections();
        if (this.transport instanceof JingleInbandTransport) {
            this.transport.disconnect();
        }
        FileBackend.close(mFileInputStream);
        FileBackend.close(mFileOutputStream);
        if (this.message != null) {
            if (responding()) {
                this.message.setTransferable(new TransferablePlaceholder(Transferable.STATUS_FAILED));
                if (this.file != null) {
                    file.delete();
                }
                this.mJingleConnectionManager.updateConversationUi(true);
            } else {
                this.mXmppConnectionService.markMessage(this.message,
                        Message.STATUS_SEND_FAILED,
                        cancelled ? Message.ERROR_MESSAGE_CANCELLED : errorMessage);
                this.message.setTransferable(null);
            }
        }
        this.mJingleConnectionManager.finishConnection(this);
    }

    private void sendCancel() {
        JinglePacket packet = bootstrapPacket("session-terminate");
        Reason reason = new Reason();
        reason.addChild("cancel");
        packet.setReason(reason);
        this.sendJinglePacket(packet);
    }

    private void connectNextCandidate() {
        for (JingleCandidate candidate : this.candidates) {
            if ((!connections.containsKey(candidate.getCid()) && (!candidate
                    .isOurs()))) {
                this.connectWithCandidate(candidate);
                return;
            }
        }
        this.sendCandidateError();
    }

    private void connectWithCandidate(final JingleCandidate candidate) {
        final JingleSocks5Transport socksConnection = new JingleSocks5Transport(
                this, candidate);
        connections.put(candidate.getCid(), socksConnection);
        socksConnection.connect(new OnTransportConnected() {

            @Override
            public void failed() {
                Log.d(Config.LOGTAG,
                        "connection failed with " + candidate.getHost() + ":"
                                + candidate.getPort());
                connectNextCandidate();
            }

            @Override
            public void established() {
                Log.d(Config.LOGTAG,
                        "established connection with " + candidate.getHost()
                                + ":" + candidate.getPort());
                sendCandidateUsed(candidate.getCid());
            }
        });
    }

    private void disconnectSocks5Connections() {
        Iterator<Entry<String, JingleSocks5Transport>> it = this.connections
                .entrySet().iterator();
        while (it.hasNext()) {
            Entry<String, JingleSocks5Transport> pairs = it.next();
            pairs.getValue().disconnect();
            it.remove();
        }
    }

    private void sendProxyActivated(String cid) {
        JinglePacket packet = bootstrapPacket("transport-info");
        Content content = new Content(this.contentCreator, this.contentName);
        content.setTransportId(this.transportId);
        content.socks5transport().addChild("activated")
                .setAttribute("cid", cid);
        packet.setContent(content);
        this.sendJinglePacket(packet);
    }

    private void sendCandidateUsed(final String cid) {
        JinglePacket packet = bootstrapPacket("transport-info");
        Content content = new Content(this.contentCreator, this.contentName);
        content.setTransportId(this.transportId);
        content.socks5transport().addChild("candidate-used").setAttribute("cid", cid);
        packet.setContent(content);
        this.sentCandidate = true;
        if ((receivedCandidate) && (mJingleStatus == JINGLE_STATUS_ACCEPTED)) {
            connect();
        }
        this.sendJinglePacket(packet);
    }

    private void sendCandidateError() {
        JinglePacket packet = bootstrapPacket("transport-info");
        Content content = new Content(this.contentCreator, this.contentName);
        content.setTransportId(this.transportId);
        content.socks5transport().addChild("candidate-error");
        packet.setContent(content);
        this.sentCandidate = true;
        if (receivedCandidate && mJingleStatus == JINGLE_STATUS_ACCEPTED) {
            connect();
        }
        this.sendJinglePacket(packet);
    }

    public int getJingleStatus() {
        return this.mJingleStatus;
    }

    private boolean equalCandidateExists(JingleCandidate candidate) {
        for (JingleCandidate c : this.candidates) {
            if (c.equalValues(candidate)) {
                return true;
            }
        }
        return false;
    }

    private void mergeCandidate(JingleCandidate candidate) {
        for (JingleCandidate c : this.candidates) {
            if (c.equals(candidate)) {
                return;
            }
        }
        this.candidates.add(candidate);
    }

    private void mergeCandidates(List<JingleCandidate> candidates) {
        for (JingleCandidate c : candidates) {
            mergeCandidate(c);
        }
    }

    private JingleCandidate getCandidate(String cid) {
        for (JingleCandidate c : this.candidates) {
            if (c.getCid().equals(cid)) {
                return c;
            }
        }
        return null;
    }

    public void updateProgress(int i) {
        this.mProgress = i;
        mJingleConnectionManager.updateConversationUi(false);
    }

    public String getTransportId() {
        return this.transportId;
    }

    public Content.Version getFtVersion() {
        return this.ftVersion;
    }

    interface OnProxyActivated {
        void success();

        void failed();
    }

    public boolean hasTransportId(String sid) {
        return sid.equals(this.transportId);
    }

    public JingleTransport getTransport() {
        return this.transport;
    }

    public boolean start() {
        if (account.getStatus() == Account.State.ONLINE) {
            if (mJingleStatus == JINGLE_STATUS_INITIATED) {
                new Thread(new Runnable() {

                    @Override
                    public void run() {
                        sendAccept();
                    }
                }).start();
            }
            return true;
        } else {
            return false;
        }
    }

    @Override
    public int getStatus() {
        return this.mStatus;
    }

    @Override
    public long getFileSize() {
        if (this.file != null) {
            return this.file.getExpectedSize();
        } else {
            return 0;
        }
    }

    @Override
    public int getProgress() {
        return this.mProgress;
    }

    public AbstractConnectionManager getConnectionManager() {
        return this.mJingleConnectionManager;
    }
}