/**
 *
 * Copyright 2003-2006 Jive Software.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jivesoftware.smackx.filetransfer;

import org.jivesoftware.smack.SmackException;
import org.jivesoftware.smack.SmackException.IllegalStateChangeException;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.XMPPException.XMPPErrorException;
import org.jivesoftware.smack.packet.XMPPError;

import java.io.*;

/**
 * Handles the sending of a file to another user. File transfer's in jabber have
 * several steps and there are several methods in this class that handle these
 * steps differently.
 *
 * @author Alexander Wenckus
 *
 */
public class OutgoingFileTransfer extends FileTransfer {

        private static int RESPONSE_TIMEOUT = 60 * 1000;
    private NegotiationProgress callback;

    /**
     * Returns the time in milliseconds after which the file transfer
     * negotiation process will timeout if the other user has not responded.
     *
     * @return Returns the time in milliseconds after which the file transfer
     *         negotiation process will timeout if the remote user has not
     *         responded.
     */
    public static int getResponseTimeout() {
        return RESPONSE_TIMEOUT;
    }

        /**
         * Sets the time in milliseconds after which the file transfer negotiation
         * process will timeout if the other user has not responded.
         *
         * @param responseTimeout
         *            The timeout time in milliseconds.
         */
        public static void setResponseTimeout(int responseTimeout) {
                RESPONSE_TIMEOUT = responseTimeout;
        }

        private OutputStream outputStream;

        private String initiator;

        private Thread transferThread;

        protected OutgoingFileTransfer(String initiator, String target,
                        String streamID, FileTransferNegotiator transferNegotiator) {
                super(target, streamID, transferNegotiator);
                this.initiator = initiator;
        }

        protected void setOutputStream(OutputStream stream) {
                if (outputStream == null) {
                        this.outputStream = stream;
                }
        }

        /**
         * Returns the output stream connected to the peer to transfer the file. It
         * is only available after it has been successfully negotiated by the
         * {@link StreamNegotiator}.
         *
         * @return Returns the output stream connected to the peer to transfer the
         *         file.
         */
        protected OutputStream getOutputStream() {
                if (getStatus().equals(FileTransfer.Status.negotiated)) {
                        return outputStream;
                } else {
                        return null;
                }
        }

        /**
         * This method handles the negotiation of the file transfer and the stream,
         * it only returns the created stream after the negotiation has been completed.
         *
         * @param fileName
         *            The name of the file that will be transmitted. It is
         *            preferable for this name to have an extension as it will be
         *            used to determine the type of file it is.
         * @param fileSize
         *            The size in bytes of the file that will be transmitted.
         * @param description
         *            A description of the file that will be transmitted.
         * @return The OutputStream that is connected to the peer to transmit the
         *         file.
         * @throws XMPPException
         *             Thrown if an error occurs during the file transfer
         *             negotiation process.
         * @throws SmackException if there was no response from the server.
         */
        public synchronized OutputStream sendFile(String fileName, long fileSize,
                        String description) throws XMPPException, SmackException {
                if (isDone() || outputStream != null) {
                        throw new IllegalStateException(
                                        "The negotation process has already"
                                                        + " been attempted on this file transfer");
                }
                try {
                        setFileInfo(fileName, fileSize);
                        this.outputStream = negotiateStream(fileName, fileSize, description);
                } catch (XMPPErrorException e) {
                        handleXMPPException(e);
                        throw e;
                }
                return outputStream;
        }

        /**
         * This methods handles the transfer and stream negotiation process. It
         * returns immediately and its progress will be updated through the
         * {@link NegotiationProgress} callback.
         *
         * @param fileName
         *            The name of the file that will be transmitted. It is
         *            preferable for this name to have an extension as it will be
         *            used to determine the type of file it is.
         * @param fileSize
         *            The size in bytes of the file that will be transmitted.
         * @param description
         *            A description of the file that will be transmitted.
         * @param progress
         *            A callback to monitor the progress of the file transfer
         *            negotiation process and to retrieve the OutputStream when it
         *            is complete.
         */
        public synchronized void sendFile(final String fileName,
                        final long fileSize, final String description,
                        final NegotiationProgress progress)
    {
        if(progress == null) {
            throw new IllegalArgumentException("Callback progress cannot be null.");
        }
        checkTransferThread();
                if (isDone() || outputStream != null) {
                        throw new IllegalStateException(
                                        "The negotation process has already"
                                                        + " been attempted for this file transfer");
                }
        setFileInfo(fileName, fileSize);
        this.callback = progress;
        transferThread = new Thread(new Runnable() {
                        public void run() {
                                try {
                                        OutgoingFileTransfer.this.outputStream = negotiateStream(
                                                        fileName, fileSize, description);
                    progress.outputStreamEstablished(OutgoingFileTransfer.this.outputStream);
                }
                catch (XMPPErrorException e) {
                                        handleXMPPException(e);
                                }
                catch (Exception e) {
                    setException(e);
                }
                        }
                }, "File Transfer Negotiation " + streamID);
                transferThread.start();
        }

        private void checkTransferThread() {
                if (transferThread != null && transferThread.isAlive() || isDone()) {
                        throw new IllegalStateException(
                                        "File transfer in progress or has already completed.");
                }
        }

    /**
         * This method handles the stream negotiation process and transmits the file
         * to the remote user. It returns immediately and the progress of the file
         * transfer can be monitored through several methods:
         *
         * <UL>
         * <LI>{@link FileTransfer#getStatus()}
         * <LI>{@link FileTransfer#getProgress()}
         * <LI>{@link FileTransfer#isDone()}
         * </UL>
         *
     * @param file the file to transfer to the remote entity.
     * @param description a description for the file to transfer.
         * @throws SmackException
         *             If there is an error during the negotiation process or the
         *             sending of the file.
         */
        public synchronized void sendFile(final File file, final String description)
                        throws SmackException {
                checkTransferThread();
                if (file == null || !file.exists() || !file.canRead()) {
                        throw new IllegalArgumentException("Could not read file");
                } else {
                        setFileInfo(file.getAbsolutePath(), file.getName(), file.length());
                }

                transferThread = new Thread(new Runnable() {
                        public void run() {
                                try {
                                        outputStream = negotiateStream(file.getName(), file
                                                        .length(), description);
                                } catch (XMPPErrorException e) {
                                        handleXMPPException(e);
                                        return;
                                }
                catch (Exception e) {
                    setException(e);
                }
                                if (outputStream == null) {
                                        return;
                                }

                if (!updateStatus(Status.negotiated, Status.in_progress)) {
                                        return;
                                }

                                InputStream inputStream = null;
                                try {
                                        inputStream = new FileInputStream(file);
                                        writeToStream(inputStream, outputStream);
                                } catch (FileNotFoundException e) {
                                        setStatus(FileTransfer.Status.error);
                                        setError(Error.bad_file);
                                        setException(e);
                                } catch (SmackException e) {
                                        setStatus(FileTransfer.Status.error);
                                        setException(e);
                                } finally {
                                        try {
                                                if (inputStream != null) {
                                                        inputStream.close();
                                                }

                                                outputStream.flush();
                                                outputStream.close();
                                        } catch (IOException e) {
                        /* Do Nothing */
                                        }
                                }
                updateStatus(Status.in_progress, FileTransfer.Status.complete);
                                }

                }, "File Transfer " + streamID);
                transferThread.start();
        }

    /**
         * This method handles the stream negotiation process and transmits the file
         * to the remote user. It returns immediately and the progress of the file
         * transfer can be monitored through several methods:
         *
         * <UL>
         * <LI>{@link FileTransfer#getStatus()}
         * <LI>{@link FileTransfer#getProgress()}
         * <LI>{@link FileTransfer#isDone()}
         * </UL>
         *
     * @param in the stream to transfer to the remote entity.
     * @param fileName the name of the file that is transferred
     * @param fileSize the size of the file that is transferred
     * @param description a description for the file to transfer.
         */
        public synchronized void sendStream(final InputStream in, final String fileName, final long fileSize, final String description){
                checkTransferThread();

                setFileInfo(fileName, fileSize);
                transferThread = new Thread(new Runnable() {
                        public void run() {
                //Create packet filter
                try {
                                        outputStream = negotiateStream(fileName, fileSize, description);
                                } catch (XMPPErrorException e) {
                                        handleXMPPException(e);
                                        return;
                                }
                catch (Exception e) {
                    setException(e);
                }
                                if (outputStream == null) {
                                        return;
                                }

                if (!updateStatus(Status.negotiated, Status.in_progress)) {
                                        return;
                                }
                                try {
                                        writeToStream(in, outputStream);
                                } catch (SmackException e) {
                                        setStatus(FileTransfer.Status.error);
                                        setException(e);
                                } finally {
                                        try {
                                                if (in != null) {
                                                        in.close();
                                                }

                                                outputStream.flush();
                                                outputStream.close();
                                        } catch (IOException e) {
                        /* Do Nothing */
                                        }
                                }
                updateStatus(Status.in_progress, FileTransfer.Status.complete);
                                }

                }, "File Transfer " + streamID);
                transferThread.start();
        }

        private void handleXMPPException(XMPPErrorException e) {
                XMPPError error = e.getXMPPError();
                if (error != null) {
                        String condition = error.getCondition();
                        if (XMPPError.Condition.forbidden.equals(condition)) {
                                setStatus(Status.refused);
                                return;
                        }
            else if (XMPPError.Condition.bad_request.equals(condition)) {
                                setStatus(Status.error);
                                setError(Error.not_acceptable);
            }
            else {
                setStatus(FileTransfer.Status.error);
            }
        }

        setException(e);
        }

        /**
         * Returns the amount of bytes that have been sent for the file transfer. Or
         * -1 if the file transfer has not started.
         * <p>
         * Note: This method is only useful when the {@link #sendFile(File, String)}
         * method is called, as it is the only method that actually transmits the
         * file.
         *
         * @return Returns the amount of bytes that have been sent for the file
         *         transfer. Or -1 if the file transfer has not started.
         */
        public long getBytesSent() {
                return amountWritten;
        }

        private OutputStream negotiateStream(String fileName, long fileSize,
                        String description) throws SmackException, XMPPException {
                // Negotiate the file transfer profile

        if (!updateStatus(Status.initial, Status.negotiating_transfer)) {
            throw new IllegalStateChangeException();
        }
                StreamNegotiator streamNegotiator = negotiator.negotiateOutgoingTransfer(
                                getPeer(), streamID, fileName, fileSize, description,
                                RESPONSE_TIMEOUT);

                if (streamNegotiator == null) {
                        setStatus(Status.error);
                        setError(Error.no_response);
                        return null;
                }

        // Negotiate the stream
        if (!updateStatus(Status.negotiating_transfer, Status.negotiating_stream)) {
            throw new IllegalStateChangeException();
        }
                outputStream = streamNegotiator.createOutgoingStream(streamID,
                initiator, getPeer());

        if (!updateStatus(Status.negotiating_stream, Status.negotiated)) {
            throw new IllegalStateChangeException();
                }
                return outputStream;
        }

        public void cancel() {
                setStatus(Status.cancelled);
        }

    @Override
    protected boolean updateStatus(Status oldStatus, Status newStatus) {
        boolean isUpdated = super.updateStatus(oldStatus, newStatus);
        if(callback != null && isUpdated) {
            callback.statusUpdated(oldStatus, newStatus);
        }
        return isUpdated;
    }

    @Override
    protected void setStatus(Status status) {
        Status oldStatus = getStatus();
        super.setStatus(status);
        if(callback != null) {
            callback.statusUpdated(oldStatus, status);
        }
    }

    @Override
    protected void setException(Exception exception) {
        super.setException(exception);
        if(callback != null) {
            callback.errorEstablishingStream(exception);
        }
    }

    /**
         * A callback class to retrieve the status of an outgoing transfer
         * negotiation process.
         *
         * @author Alexander Wenckus
         *
         */
        public interface NegotiationProgress {

                /**
                 * Called when the status changes
         *
         * @param oldStatus the previous status of the file transfer.
         * @param newStatus the new status of the file transfer.
         */
                void statusUpdated(Status oldStatus, Status newStatus);

                /**
                 * Once the negotiation process is completed the output stream can be
                 * retrieved.
         *
         * @param stream the established stream which can be used to transfer the file to the remote
         * entity
                 */
                void outputStreamEstablished(OutputStream stream);

        /**
         * Called when an exception occurs during the negotiation progress.
         *
         * @param e the exception that occurred.
         */
        void errorEstablishingStream(Exception e);
    }

}