/**
 * Copyright (c) 2014 Digi International Inc.,
 * All rights not expressly granted are reserved.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Digi International Inc. 11001 Bren Road East, Minnetonka, MN 55343
 * =======================================================================
 */
package com.digi.xbee.api.packet.raw;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.LinkedHashMap;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.digi.xbee.api.models.XBee16BitAddress;
import com.digi.xbee.api.packet.XBeeAPIPacket;
import com.digi.xbee.api.packet.APIFrameType;
import com.digi.xbee.api.utils.HexUtils;

/**
 * This class represents a TX (Transmit) 16 Request packet. Packet is built 
 * using the parameters of the constructor or providing a valid API payload.
 * 
 * <p>A TX Request message will cause the module to transmit data as an RF 
 * Packet.</p>
 * 
 * @see com.digi.xbee.api.packet.XBeeAPIPacket
 */
public class TX16Packet extends XBeeAPIPacket {

        // Constants.
        private static final int MIN_API_PAYLOAD_LENGTH = 5; // 1 (Frame type) + 1 (frame ID) + 2 (address) + 1 (transmit options)
        
        // Variables.
        private final int transmitOptions;
        
        private final XBee16BitAddress destAddress16;
        
        private byte[] rfData;
        
        private Logger logger;
        
        /**
         * Creates a new {@code TX16Packet} object from the given payload.
         * 
         * @param payload The API frame payload. It must start with the frame type 
         *                corresponding to a TX16 Request packet ({@code 0x01}).
         *                The byte array must be in {@code OperatingMode.API} mode.
         * 
         * @return Parsed TX (transmit) 16 Request packet.
         * 
         * @throws IllegalArgumentException if {@code payload[0] != APIFrameType.TX_16.getValue()} or
         *                                  if {@code payload.length < }{@value #MIN_API_PAYLOAD_LENGTH} or
         *                                  if {@code frameID < 0} or
         *                                  if {@code frameID > 255} or
         *                                  if {@code transmitOptions < 0} or
         *                                  if {@code transmitOptions > 255}.
         * @throws NullPointerException if {@code payload == null}.
         */
        public static TX16Packet createPacket(byte[] payload) {
                if (payload == null)
                        throw new NullPointerException("TX16 Request packet payload cannot be null.");
                
                // 1 (Frame type) + 1 (frame ID) + 2 (address) + 1 (transmit options)
                if (payload.length < MIN_API_PAYLOAD_LENGTH)
                        throw new IllegalArgumentException("Incomplete TX16 Request packet.");
                
                if ((payload[0] & 0xFF) != APIFrameType.TX_16.getValue())
                        throw new IllegalArgumentException("Payload is not a TX16 Request packet.");
                
                // payload[0] is the frame type.
                int index = 1;
                
                // Frame ID byte.
                int frameID = payload[index] & 0xFF;
                index = index + 1;
                
                // 2 bytes of address, starting at 2nd byte.
                XBee16BitAddress destAddress16 = new XBee16BitAddress(payload[index] & 0xFF, payload[index + 1] & 0xFF);
                index = index + 2;
                
                // Transmit options byte.
                int transmitOptions = payload[index] & 0xFF;
                index = index + 1;
                
                // Get data.
                byte[] data = null;
                if (index < payload.length)
                        data = Arrays.copyOfRange(payload, index, payload.length);
                
                return new TX16Packet(frameID, destAddress16, transmitOptions, data);
        }
        
        /**
         * Class constructor. Instantiates a new {@code TX16Packet} object with
         * the given parameters.
         * 
         * @param frameID Frame ID.
         * @param destAddress16 16-bit address of the destination device.
         * @param transmitOptions Bitfield of supported transmission options.
         * @param rfData RF Data that is sent to the destination device.
         * 
         * @throws IllegalArgumentException if {@code frameID < 0} or
         *                                  if {@code frameID > 255} or
         *                                  if {@code transmitOptions < 0} or
         *                                  if {@code transmitOptions > 255}.
         * @throws NullPointerException if {@code destAddress == null}.
         * 
         * @see com.digi.xbee.api.models.XBeeTransmitOptions
         * @see com.digi.xbee.api.models.XBee16BitAddress
         */
        public TX16Packet(int frameID, XBee16BitAddress destAddress16, int transmitOptions, byte[] rfData) {
                super(APIFrameType.TX_16);
                
                if (destAddress16 == null)
                        throw new NullPointerException("16-bit destination address cannot be null.");
                if (frameID < 0 || frameID > 255)
                        throw new IllegalArgumentException("Frame ID must be between 0 and 255.");
                if (transmitOptions < 0 || transmitOptions > 255)
                        throw new IllegalArgumentException("Transmit options must be between 0 and 255.");
                
                this.frameID = frameID;
                this.destAddress16 = destAddress16;
                this.transmitOptions = transmitOptions;
                this.rfData = rfData;
                this.logger = LoggerFactory.getLogger(TX16Packet.class);
        }

        /*
         * (non-Javadoc)
         * @see com.digi.xbee.api.packet.XBeeAPIPacket#getAPIPacketSpecificData()
         */
        @Override
        protected byte[] getAPIPacketSpecificData() {
                ByteArrayOutputStream os = new ByteArrayOutputStream();
                try {
                        os.write(destAddress16.getValue());
                        os.write(transmitOptions);
                        if (rfData != null)
                                os.write(rfData);
                } catch (IOException e) {
                        logger.error(e.getMessage(), e);
                }
                return os.toByteArray();
        }

        /*
         * (non-Javadoc)
         * @see com.digi.xbee.api.packet.XBeeAPIPacket#needsAPIFrameID()
         */
        @Override
        public boolean needsAPIFrameID() {
                return true;
        }
        
        /*
         * (non-Javadoc)
         * @see com.digi.xbee.api.packet.XBeeAPIPacket#isBroadcast()
         */
        @Override
        public boolean isBroadcast() {
                return get16bitDestinationAddress().equals(XBee16BitAddress.BROADCAST_ADDRESS);
        }
        
        /**
         * Returns the 16-bit destination address.
         * 
         * @return The 16-bit destination address.
         * 
         * @see com.digi.xbee.api.models.XBee16BitAddress
         */
        public XBee16BitAddress get16bitDestinationAddress() {
                return destAddress16;
        }
        
        /**
         * Returns the transmit options bitfield.
         * 
         * @return Transmit options bitfield.
         * 
         * @see com.digi.xbee.api.models.XBeeTransmitOptions
         */
        public int getTransmitOptions() {
                return transmitOptions;
        }
        
        /**
         * Sets the RF data to send.
         * 
         * @param rfData RF Data to send.
         */
        public void setRFData(byte[] rfData) {
                this.rfData = rfData;
        }
        
        /**
         * Returns the RF Data to send.
         * 
         * @return RF data to send.
         */
        public byte[] getRFData() {
                return rfData;
        }
        
        /*
         * (non-Javadoc)
         * @see com.digi.xbee.api.packet.XBeeAPIPacket#getAPIPacketParameters()
         */
        @Override
        public LinkedHashMap<String, String> getAPIPacketParameters() {
                LinkedHashMap<String, String> parameters = new LinkedHashMap<String, String>();
                parameters.put("16-bit dest. address", HexUtils.prettyHexString(destAddress16.toString()));
                parameters.put("Options", HexUtils.prettyHexString(HexUtils.integerToHexString(transmitOptions, 1)));
                if (rfData != null)
                        parameters.put("RF data", HexUtils.prettyHexString(HexUtils.byteArrayToHexString(rfData)));
                return parameters;
        }
}