sdis1819-t7g02

package channels;

import java.util.ArrayList;

import service.Constants;

public class Message {

        private MessageHeader h;

        private byte[] chunkData;

        int totalLength = 0;

        public Message(byte[] msg) {

                int separation = headerLength(msg);

                if(separation < 0) {

                        throw new IllegalArgumentException("Couldn't find separation.");

                }

                h = new MessageHeader(msg, separation);

                if(!separateChunkData(msg, separation)) {

                        throw new IllegalArgumentException("Invalid message, chuk max size exceeded");

                }

        }

        public Message(byte[] msg, int length) {

                totalLength = length;

                int separation = headerLength(msg);

                if(separation < 0) {

                        throw new IllegalArgumentException("Couldn't find separation.");

                }

                h = new MessageHeader(msg, separation);

                if(!separateChunkData(msg, separation)) {

                        throw new IllegalArgumentException("Invalid message, chuk max size exceeded");

                }

        }

        public void setTotalLength(int l) {

                totalLength = l;

        }

        public Message(MessageHeader h, byte[] chunk) {

                if(chunk.length > Constants.MAX_CHUNK_SIZE) {

                        throw new IllegalArgumentException("Invalid message, chuk max size exceeded");

                }

                this.h = h;

                chunkData = chunk;

        }

        private int headerLength(byte[] msg) {

                int i = 0;

                for(i = 0; i < msg.length-4; i++) {

                        if(msg[i] == Constants.CR && msg[i+1] == Constants.LF && msg[i+2] == Constants.CR && msg[i+3] == Constants.LF) {

                                return i;

                        }

                }

                return -1;

        }

        private boolean separateChunkData(byte[] msg, int separation) {

                int chunkLength = totalLength <= 0 ? msg.length - separation - 4: totalLength - separation - 4;

                if(chunkLength > Constants.MAX_CHUNK_SIZE) {

                        System.out.println("looks to big");

                        return false;

                }

                chunkData = new byte[chunkLength];

                System.arraycopy(msg, separation + 4, chunkData, 0, chunkLength);

                return true;

        }

        public MessageHeader getHeader() {

                return h;

        }

        public byte[] getChunkContent() {

                return chunkData;

        }

        public byte[] toBytes() {

                ArrayList<Byte> messageToBeSent = h.toBytes();

                byte[] toReturn = new byte[messageToBeSent.size() + chunkData.length];

                int index = 0;

                for(Byte b : messageToBeSent) {

                        toReturn[index] = b;

                        index++;

                }

                for(Byte b : chunkData) {

                        toReturn[index] = b;

                        index++;

                }

                return toReturn;

        }

}