DemoUtils

package main;

import java.io.File;
import java.util.Arrays;

import DataTypes.Message;

public class DemoUtils {

    public static short ByteToShort(byte byte1, byte byte2) {
        return (short) (byte2<<8 | byte1 & 0xFF);
    }

    public static float ByteToFloat(byte byte1, byte byte2, byte byte3, byte byte4) {
        return Float.intBitsToFloat(byte4<<24 | (byte3&0xFF)<<16 | (byte2&0xFF)<<8 | byte1 & 0xFF);
    }

    public static float ByteToFloat(byte[] bytes, int start) {
        return ByteToFloat(bytes[start], bytes[start+1], bytes[start+2], bytes[start+3]);
    }

    public static int ByteToInt(byte byte1, byte byte2, byte byte3, byte byte4) {
        return (byte4<<24 | (byte3&0xFF)<<16 | (byte2&0xFF)<<8 | byte1 & 0xFF);
    }

    public static int ByteToInt(byte[] bytes, int start) {
        return ByteToInt(bytes[start], bytes[start+1], bytes[start+2], bytes[start+3]);
    }

    public static String ByteToHex (byte[] bytes) {
        String output = "";
        for (int i = 0; i < bytes.length; i++) {
            output=output.concat(String.format("%02x",bytes[i]));
        }
        return output;
    }

    public static String ByteToHex (byte bytes) {
        return String.format("%02x",bytes);
    }

    public static String ByteToLongHex (byte bytes) {
        return String.format("%#04x",bytes);
    }

    //get a message from byte[] at bytenumber
    public static Message getMessage(byte[] demo, int bytenumber) {
        short messagelength = (short)(DemoUtils.ByteToShort(demo[bytenumber], demo[bytenumber+1]) + 2);
        Message message = new Message(bytenumber, Arrays.copyOfRange(demo, bytenumber, bytenumber+messagelength));
        return message;
    }

    //give the location of the first instance of BYTE in data. Starts searching at data[start] to skip unwanted instances of BYTE.
    public static int findByte(byte[] data, int start, byte BYTE) {
        try {
            for (int i = 0; i  + start < data.length; i++) {
                if (data[i + start] == BYTE) {
                    return (i + start);
                }
            }
            throw new Exception ("Couldn't find X"+ BYTE + "X");
        } catch (Exception e) {
            e.printStackTrace();
            return 0;
        }
    }

    //give the location of the first instance of a zerobyte in data[].Starts searching at data[start] to skip unwanted zerobytes.
    public static int findZeroByte (byte[] data, int start) {
        return findByte (data, start, (byte) 0x00);
    }

    //get Bytes from data[start] to data[end]
    public static byte[] getBytes(byte[] data, int start, int end) {
        byte[] output  = new byte[end - start];
        for (int i = 0; i < output.length;i++) {
            output[i] = data[i+start];
        }
        return output;
    }

    //get Bytes from data[start] until it finds BYTE
    public static byte[] getBytes(byte[] data, int start, byte BYTE) {
        return getBytes(data, start, findByte(data, start, BYTE));
    }

    //get Bytes from data[0] until it finds BYTE
    public static byte[] getBytes(byte[] data, byte BYTE) {
        return getBytes(data, 0, BYTE);
    }

    //get Bytes from data[0] until it finds a zerobyte 0x00
    public static byte[] getBytesBeforeZeroByte(byte[] data, int start) {
        return getBytes(data, start, findByte(data, start, (byte) 0x00));
    }

    //get Bytes from data[0] until it finds a zerobyte 0x00 and return it as string
    public static String getStringBeforeZeroByte(byte[] data, int start) {
        return new String(getBytesBeforeZeroByte(data, start));
    }

    //check if a File ends with .PRdemo
    public static boolean isCorrectFile(File demofile) {
        int i = demofile.toString().lastIndexOf(".");
        return (i > 0 && demofile.toString().substring(i).equals(".PRdemo"));
    }

}