/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * 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 com.android.dumprendertree2.forwarder;

import android.util.Log;

import com.android.dumprendertree2.FsUtils;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

/**
 * Worker class for {@link Forwarder}. A ConnectionHandler will be created once the Forwarder
 * accepts an incoming connection, and it will then forward the incoming/outgoing streams to a
 * connection already proxied by adb networking (see also {@link AdbUtils}).
 */
public class ConnectionHandler {

    private static final String LOG_TAG = "ConnectionHandler";

    public static interface OnFinishedCallback {
        public void onFinished();
    }

    private class SocketPipeThread extends Thread {

        private InputStream mInputStream;
        private OutputStream mOutputStream;

        public SocketPipeThread(InputStream inputStream, OutputStream outputStream) {
            mInputStream = inputStream;
            mOutputStream = outputStream;
            setName("SocketPipeThread: " + getName());
        }

        @Override
        public void run() {
            byte[] buffer = new byte[4096];
            int length;
            while (true) {
                try {
                    if ((length = mInputStream.read(buffer)) < 0) {
                        break;
                    }
                    mOutputStream.write(buffer, 0, length);
                } catch (IOException e) {
                    /** This exception means one of the streams is closed */
                    Log.v(LOG_TAG, this.toString(), e);
                    break;
                }
            }

            synchronized (mThreadsRunning) {
                mThreadsRunning--;
                if (mThreadsRunning == 0) {
                    ConnectionHandler.this.stop();
                    mOnFinishedCallback.onFinished();
                }
            }
        }

        @Override
        public String toString() {
            return getName();
        }
    }

    private Integer mThreadsRunning;

    private Socket mFromSocket, mToSocket;
    private SocketPipeThread mFromToPipe, mToFromPipe;
    private InputStream mFromSocketInputStream, mToSocketInputStream;
    private OutputStream mFromSocketOutputStream, mToSocketOutputStream;

    private int mPort;
    private String mRemoteMachineIpAddress;

    private OnFinishedCallback mOnFinishedCallback;

    public ConnectionHandler(String remoteMachineIp, int port, Socket fromSocket, Socket toSocket)
            throws IOException {
        mRemoteMachineIpAddress = remoteMachineIp;
        mPort = port;

        mFromSocket = fromSocket;
        mToSocket = toSocket;

        try {
            mFromSocketInputStream = mFromSocket.getInputStream();
            mToSocketInputStream = mToSocket.getInputStream();
            mFromSocketOutputStream = mFromSocket.getOutputStream();
            mToSocketOutputStream = mToSocket.getOutputStream();
            AdbUtils.configureConnection(mToSocketInputStream, mToSocketOutputStream,
                    mRemoteMachineIpAddress, mPort);
        } catch (IOException e) {
            Log.e(LOG_TAG, "Unable to start ConnectionHandler", e);
            closeStreams();
            throw e;
        }

        mFromToPipe = new SocketPipeThread(mFromSocketInputStream, mToSocketOutputStream);
        mToFromPipe = new SocketPipeThread(mToSocketInputStream, mFromSocketOutputStream);
    }

    public void registerOnConnectionHandlerFinishedCallback(OnFinishedCallback callback) {
        mOnFinishedCallback = callback;
    }

    private void closeStreams() {
        FsUtils.closeInputStream(mFromSocketInputStream);
        FsUtils.closeInputStream(mToSocketInputStream);
        FsUtils.closeOutputStream(mFromSocketOutputStream);
        FsUtils.closeOutputStream(mToSocketOutputStream);
    }

    public void start() {
        /** We have 2 threads running, one for each pipe, that we start here. */
        mThreadsRunning = 2;
        mFromToPipe.start();
        mToFromPipe.start();
    }

    public void stop() {
        shutdown(mFromSocket);
        shutdown(mToSocket);
    }

    private void shutdown(Socket socket) {
        synchronized (mFromToPipe) {
            synchronized (mToFromPipe) {
                /** This will stop the while loop in the run method */
                try {
                    if (!socket.isInputShutdown()) {
                        socket.shutdownInput();
                    }
                } catch (IOException e) {
                    Log.e(LOG_TAG, "mFromToPipe=" + mFromToPipe + " mToFromPipe=" + mToFromPipe, e);
                }
                try {
                    if (!socket.isOutputShutdown()) {
                        socket.shutdownOutput();
                    }
                } catch (IOException e) {
                    Log.e(LOG_TAG, "mFromToPipe=" + mFromToPipe + " mToFromPipe=" + mToFromPipe, e);
                }
                try {
                    if (!socket.isClosed()) {
                        socket.close();
                    }
                } catch (IOException e) {
                    Log.e(LOG_TAG, "mFromToPipe=" + mFromToPipe + " mToFromPipe=" + mToFromPipe, e);
                }
            }
        }
    }
}