import java.util.Arrays;
import java.util.Random;

public class Hash {


    public static void main(String[] args){
        String test = transactionHashGenerator(2, 8, 456.32);

        System.out.println(test); //115G8RSldAs7EFSr50lvv@nophml
                                //11 - ключ
                                //[7] l - ид первого
                                //[15] r - ид второго
                                // @ - divider
                                // nophml - значение транзакции
        System.out.println(bitNumber(2));
        System.out.println(bitNumber(8));
        System.out.println(bitNumber(456.3));
        System.out.println(makeSmallHash(456.3));
        System.out.println(makeSmallHash(456.30));
        System.out.println(makeSmallHash(456.32));
        System.out.println(String.valueOf(decryptor(test)));
    }

    public static String transactionHashGenerator(int idHost, int idDestination, double value){
        // TODO: принимает id отправителя и получателя, расширяет хэш на нужное количество разрядов, переводит каждый разряд id'шников в знак и вставляет на определённую позицию в хэше
        int symbolCount = bitNumber(idHost) + bitNumber(idDestination) + 20;
        char[] hash = new char[symbolCount];
        char[] valueHash = makeSmallHash(value);
        //final Random rand = new Random();
        char[] host = makeSmallHash(idHost); //
        char[] destination = makeSmallHash(idDestination);
        final Random rand = new Random();
        //String str = "";

        hash[0] = (char) (bitNumber(idHost) + 48);
        hash[1] = (char) (bitNumber(idDestination) + 48);
        if (hash[0] == '1' && hash[1] == '1'){

            for (int i = 2; i < 7; i++){
                int ranNum = rand.nextInt(3);
                if(ranNum == 0){
                    hash[i] = (char) randInt(65, 90);
                }
                else if(ranNum == 1){
                    hash[i] = (char) randInt(97, 122);
                }
                else{
                    hash[i] = (char) randInt(48, 57);
                }
            }
            hash[7] = host[0];
            for (int i = 8; i < 15; i++){
                int ranNum = rand.nextInt(3);
                if(ranNum == 0){
                    hash[i] = (char) randInt(65, 90);
                }
                else if(ranNum == 1){
                    hash[i] = (char) randInt(97, 122);
                }
                else{
                    hash[i] = (char) randInt(48, 57);
                }
            }
            hash[15] = destination[0];
            for (int i = 16; i < symbolCount - 1; i++){
                int ranNum = rand.nextInt(3);
                if(ranNum == 0){
                    hash[i] = (char) randInt(65, 90);
                }
                else if(ranNum == 1){
                    hash[i] = (char) randInt(97, 122);
                }
                else{
                    hash[i] = (char) randInt(48, 57);
                }
            }
            hash[symbolCount - 1] = '@';

            return new String(hash) + new String(valueHash);
        }
        else {
            return "lol";
        }


        /*
        str += hash[0];
        str += hash[1];
        if (hash[0] == '1' && hash[1] == '1'){
            str += setHashChars(2, 7, hash);
            hash[7] = host[0];
            str += hash[7];
            str += setHashChars(8, 15, hash);
            hash[15] = destination[0];
            str += hash[15];
            str += setHashChars(16, symbolCount, hash);

            return str;

        } else if(hash[0] == '2' && hash[1] == '2'){
            str += setHashChars(2, 4, hash);
            hash[4] = host[0];
            hash[5] = host[1];
            str += hash[4];
            str += hash[5];
            str += setHashChars(6, 18, hash);
            hash[18] = destination[0];
            hash[19] = destination[1];
            str += hash[18];
            str += hash[19];
            str += setHashChars(20, symbolCount, hash);

            return str;
        } else {
            return "pistrun";
        }
        */
    }

    public static char[] decryptor(String str){
        char[] arr = str.toCharArray();
        char[] arr2 = new char[str.length()];
        int[] preResult = new int[str.length()];
        for(int i = str.indexOf('@') + 1; i<str.length(); i++){
            preResult[i] = arr[i] - 58;
            arr2[i] = (char) preResult[i];
        }
        if(arr[0] == '1' && arr[1] == '1'){
            preResult[0] = arr[7] - 58;
            preResult[1] = arr[15] - 58;
            arr2[0] = (char) preResult[0];
            arr2[1] = (char) preResult[1];
            return arr2;
        }
        else{
            arr2[0] = 25200;
            arr2[1] = 25200;

            return arr2;
        }
    }

    public static String setHashChars(int start, int end, char[] hash){
        final Random rand = new Random();
        for (int i = start; i < end; i++){
            int ranNum = rand.nextInt(3);
            if(ranNum == 0){
                hash[i] = (char) randInt(65, 90);
            }
            else if(ranNum == 1){
                hash[i] = (char) randInt(97, 122);
            }
            else{
                hash[i] = (char) randInt(48, 57);
            }
        }
        return new String(hash);
    }

    public static int randInt(int min, int max) {
        Random r = new Random();
        return r.nextInt(max - min) + min;
    }

    public static int bitNumber(int n){
        return (int) Math.log10(n) + 1;
    }

    public static int bitNumber(double n){
        return (int) Math.log10(n) + 1;
    }

    public static char[] makeSmallHash(double n){
        String temp = Double.toString(n);

        int[] newGuess = new int[temp.length()];
        for (int i = 0; i < temp.length(); i++)
        {
            newGuess[i] = temp.charAt(i) + 58;
        }
        char[] hash = new char[newGuess.length];
        for(int i = 0; i<newGuess.length; i++){
            hash[i] = (char) newGuess[i];
        }

        return hash;
    }

    public static char[] makeSmallHash(int n){
        String temp = Integer.toString(n);

        int[] newGuess = new int[temp.length()];
        for (int i = 0; i < temp.length(); i++)
        {
            newGuess[i] = temp.charAt(i) + 58;
        }
        char[] hash = new char[newGuess.length];
        for(int i = 0; i<newGuess.length; i++){
            hash[i] = (char) newGuess[i];
        }

        return hash;
    }

}