/*
 * Copyright (C) 2014 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 org.surfsite.iconsole;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;

import org.surfsite.iconsole.common.logger.Log;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.UUID;

/**
 * This class does all the work for setting up and managing Bluetooth
 * connections with other devices. It has a thread that listens for
 * incoming connections, a thread for connecting with a device, and a
 * thread for performing data transmissions when connected.
 */
public class BluetoothChatService {
    // Debugging
    private static final String TAG = "BluetoothChatService";
    // Name for the SDP record when creating server socket
    private static final String NAME_SECURE = "BluetoothChatSecure";
    private static final String NAME_INSECURE = "BluetoothChatInsecure";

    // Unique UUID for this application
    private static final UUID SERIAL_PORT_CLASS = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");
    // Member fields
    private final BluetoothAdapter mAdapter;
    private final Handler mHandler;

    private ConnectThread mConnectThread;
    private ConnectedThread mConnectedThread;
    private int mState;
    private int mNewState;

    // Constants that indicate the current connection state
    public static final int STATE_NONE = 0;       // we're doing nothing
    public static final int STATE_LISTEN = 1;     // now listening for incoming connections
    public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
    public static final int STATE_CONNECTED = 3;  // now connected to a remote device

    /**
     * Constructor. Prepares a new BluetoothChat session.
     *
     * @param context The UI Activity Context
     * @param handler A Handler to send messages back to the UI Activity
     */
    public BluetoothChatService(Context context, Handler handler) {
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        mState = STATE_NONE;
        mNewState = mState;
        mHandler = handler;
    }


    /**
     * Update UI title according to the current state of the chat connection
     */
    private synchronized void updateUserInterfaceTitle() {
        mState = getState();
        Log.d(TAG, "updateUserInterfaceTitle() " + mNewState + " -> " + mState);
        mNewState = mState;

        // Give the new state to the Handler so the UI Activity can update
        mHandler.obtainMessage(Constants.MESSAGE_STATE_CHANGE, mNewState, -1).sendToTarget();
    }

    /**
     * Return the current connection state.
     */
    public synchronized int getState() {
        return mState;
    }

    /**
     * Start the chat service. Specifically start AcceptThread to begin a
     * session in listening (server) mode. Called by the Activity onResume()
     */
    public synchronized void start() {
        Log.d(TAG, "start");

        // Cancel any thread attempting to make a connection
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }
        // Update UI title
        updateUserInterfaceTitle();
    }

    /**
     * Start the ConnectThread to initiate a connection to a remote device.
     *
     * @param device The BluetoothDevice to connect
     */
    public synchronized void connect(BluetoothDevice device) {
        Log.d(TAG, "connect to: " + device);

        // Cancel any thread attempting to make a connection
        if (mState == STATE_CONNECTING) {
            if (mConnectThread != null) {
                mConnectThread.cancel();
                mConnectThread = null;
            }
        }

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        // Start the thread to connect with the given device
        mConnectThread = new ConnectThread(device);
        mConnectThread.start();
        // Update UI title
        updateUserInterfaceTitle();
    }

    /**
     * Start the ConnectedThread to begin managing a Bluetooth connection
     *
     * @param socket The BluetoothSocket on which the connection was made
     * @param device The BluetoothDevice that has been connected
     */
    public synchronized void connected(BluetoothSocket socket, BluetoothDevice
            device) {
        Log.d(TAG, "connected");

        // Cancel the thread that completed the connection
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        // Start the thread to manage the connection and perform transmissions
        mConnectedThread = new ConnectedThread(socket);
        mConnectedThread.start();

        // Send the name of the connected device back to the UI Activity
        Message msg = mHandler.obtainMessage(Constants.MESSAGE_DEVICE_NAME);
        Bundle bundle = new Bundle();
        bundle.putString(Constants.DEVICE_NAME, device.getName());
        msg.setData(bundle);
        mHandler.sendMessage(msg);
        // Update UI title
        updateUserInterfaceTitle();
    }

    /**
     * Stop all threads
     */
    public synchronized void stop() {
        Log.d(TAG, "stop");

        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }

        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        mState = STATE_NONE;
        // Update UI title
        updateUserInterfaceTitle();
    }

    /**
     * Write to the ConnectedThread in an unsynchronized manner
     *
     * @param out The bytes to write
     * @see ConnectedThread#write(byte[])
     */
    public void write(byte[] out) {
    }

    /**
     * Indicate that the connection attempt failed and notify the UI Activity.
     */
    private void connectionFailed() {
        // Send a failure message back to the Activity
        Message msg = mHandler.obtainMessage(Constants.MESSAGE_TOAST);
        Bundle bundle = new Bundle();
        bundle.putString(Constants.TOAST, "Unable to connect device");
        msg.setData(bundle);
        mHandler.sendMessage(msg);

        mState = STATE_NONE;
        // Update UI title
        updateUserInterfaceTitle();

        // Start the service over to restart listening mode
        BluetoothChatService.this.start();
    }

    /**
     * Indicate that the connection was lost and notify the UI Activity.
     */
    private void connectionLost() {
        // Send a failure message back to the Activity
        Message msg = mHandler.obtainMessage(Constants.MESSAGE_TOAST);
        Bundle bundle = new Bundle();
        bundle.putString(Constants.TOAST, "Device connection was lost");
        msg.setData(bundle);
        mHandler.sendMessage(msg);

        mState = STATE_NONE;
        // Update UI title
        updateUserInterfaceTitle();

        // Start the service over to restart listening mode
        BluetoothChatService.this.start();
    }

    /**
     * This thread runs while attempting to make an outgoing connection
     * with a device. It runs straight through; the connection either
     * succeeds or fails.
     */
    private class ConnectThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;

        public ConnectThread(BluetoothDevice device) {
            mmDevice = device;
            BluetoothSocket tmp = null;

            // Get a BluetoothSocket for a connection with the
            // given BluetoothDevice
            try {
                tmp = device.createRfcommSocketToServiceRecord(SERIAL_PORT_CLASS);
            } catch (IOException e) {
                Log.e(TAG, "Socket Type: create() failed", e);
            }
            mmSocket = tmp;
            mState = STATE_CONNECTING;
        }

        public void run() {
            Log.i(TAG, "BEGIN mConnectThread");
            setName("ConnectThread");

            // Always cancel discovery because it will slow down a connection
            mAdapter.cancelDiscovery();

            // Make a connection to the BluetoothSocket
            try {
                // This is a blocking call and will only return on a
                // successful connection or an exception
                mmSocket.connect();
            } catch (IOException e) {
                // Close the socket
                try {
                    mmSocket.close();
                } catch (IOException e2) {
                    Log.e(TAG, "unable to close() socket during connection failure", e2);
                }
                connectionFailed();
                return;
            }

            // Reset the ConnectThread because we're done
            synchronized (BluetoothChatService.this) {
                mConnectThread = null;
            }

            // Start the connected thread
            connected(mmSocket, mmDevice);
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "close() of socket failed", e);
            }
        }
    }

    /**
     * This thread runs during a connection with a remote device.
     * It handles all incoming and outgoing transmissions.
     */
    private class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;
        private final IConsole mmIConsole;

        public ConnectedThread(BluetoothSocket socket) {
            Log.d(TAG, "create ConnectedThread");
            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            // Get the BluetoothSocket input and output streams
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
                Log.e(TAG, "temp sockets not created", e);
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;
            mState = STATE_CONNECTED;

            mmIConsole = new IConsole(mmInStream, mmOutStream, new IConsole.DataListener() {
                @Override
                public void onData(IConsole.Data data) {
                    Log.i(TAG, "mConnectedThread: " + data.toString());
                    /* print */
                }

                @Override
                public void onError(Exception e) {
                    Log.e(TAG, "mConnectedThread Error: ", e);

                    if (e instanceof IOException)
                        connectionLost();
                }
            }, new IConsole.DebugListener() {
                @Override
                public void onRead(byte[] buffer) {
                    if (buffer.length > 0) {
                        String hexbuf = IConsole.byteArrayToHex(Arrays.copyOfRange(buffer, 0, buffer.length)) + '\n';

                        // Send the obtained bytes to the UI Activity
                        mHandler.obtainMessage(Constants.MESSAGE_READ, hexbuf.length(), -1, hexbuf.getBytes())
                                .sendToTarget();
                    }
                }

                @Override
                public void onWrite(byte[] buffer) {
                    String hexbuf = IConsole.byteArrayToHex(buffer) + '\n';

                    // Share the sent message back to the UI Activity
                    mHandler.obtainMessage(Constants.MESSAGE_WRITE, -1, -1, hexbuf.getBytes())
                            .sendToTarget();
                }
            });
        }

        public void run() {
            Log.i(TAG, "BEGIN mConnectedThread");

            while (mState == STATE_CONNECTED) {
                if (!mmIConsole.processIO())
                    break;
            }
        }

        public boolean setLevel(int level) {
            return mmIConsole.setLevel(level);
        }

        public void cancel() {
            mmIConsole.stop();

            try {
                mmSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "close() of connect socket failed", e);
            }
        }
    }
}