package eg.edu.alexu.csd.oop.calculator;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class operation  implements  Calculator {
    static  int theEnd=0;
    private double firstValued;
    private double secondValued;
    private int operator; // 1 for add  2 for substruction 3 for multiplication 4 for division
    private String result;
    private Boolean error;
    private String errorM = "";
    private String cuF;
    //private static String[] LastArray = new String[5];
    private static String[] ArrayHere = new String[5];
    private  static int sizeArrayHere=0;
   // private static int sizeOfOpreation;

    operation() {
        operator = 0;
        result = "";
        error = false;
       // for (int i = 0; i < 5; i++) LastArray[i] = "";
       // sizeOfOpreation=0;
        //load();
    }

    @Override
    public void input(String s) {
        String sp = "^(-?[0-9]*?|[0-9]*?\\.[0-9]*?)([+\\-*/])(-?[0-9]*?|[0-9]*?\\.[0-9]*)(=.)?";
        Pattern pattern = Pattern.compile(sp);
        Matcher matcher = pattern.matcher(s);

        if (matcher.matches()) {
            cuF = s;
            String v = matcher.group(1);
            String v2 = matcher.group(2);
            String v3 = matcher.group(3);
            if(v.length()==0||v3.length()==0){
                error = true;
                errorM = "Wrong Input";
                return;
            }
            String p2 = "[0-9]*?\\.[0-9]*?";

                firstValued = Double.parseDouble(v);
                secondValued = Double.parseDouble(v3);

            switch (v2) {
                case "+":
                    operator = 1;
                    break;
                case "-":
                    operator = 2;
                    break;
                case "*":
                    operator = 3;
                    break;
                case "/":
                    if ( secondValued == 0) {
                        error = true;
                        errorM = "Can't divide by 0";
                    } else operator = 4;
                    break;
            }
        } else {
            error = true;
            errorM = "Wrong Input";
        }

    }


    @Override
    public String getResult() {
        if (!error) {
            double r = op(firstValued, secondValued);
                result=Double.toString(r);
                sA();
               // save();
              // save();
                return result;
        } else {
            return errorM;
        }
    }

    private void sA() {
        if(sizeArrayHere<5){
            ArrayHere[sizeArrayHere++]=cuF;
           // System.out.println(ArrayHere[sizeArrayHere-1]);
            return;
        }
        for(int i=0;i<4;i++){
            ArrayHere[i]=ArrayHere[i+1];
        }
        ArrayHere[4]=cuF;
    }



//    public int getSize(){
//        return sizeOfOpreation;
//    }
//    public String getElement(int x){
//        return LastArray[x-1] ;
//    }




    private double op(double firstValued, double secondValued) {
        if (operator == 1) return firstValued + secondValued;
        if (operator == 2) return firstValued - secondValued;
        if (operator == 3) return firstValued * secondValued;
        else return firstValued / secondValued;
    }


    @Override
    public String current() {
        if(theEnd==-1)return null;
        return LastArray[theEnd];
    }

    @Override
    public String prev() {

        if(theEnd==0||theEnd==-1)return null;
        return LastArray[--theEnd];

    }

    @Override
    public String next() {

        if(theEnd==sizeOfOpreation-1||theEnd==-1)return null;
        return LastArray[++theEnd];
    }

    @Override
    public void save()  {
//          if(sizeOfOpreation<5){
//              LastArray[sizeOfOpreation++]=currenthere();
//          }else {
//              for(int i=0;i<4;i++){
//                  LastArray[i]=LastArray[i+1];
//              }
//              LastArray[4]=currenthere();
//          }
        PrintWriter  printWriter  = null;
        try {
            printWriter = new PrintWriter(new File("read.txt"));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        for(int i=0;i<sizeArrayHere;i++) {
              printWriter.println(ArrayHere[i]);
          }
        printWriter.flush();
    }


    private String currentheree() {
        return cuF+"="+result;
    }

    @Override
    public void load() {
        theEnd=0;
        sizeOfOpreation=0;
        try {
            Scanner scanner = new Scanner(new File("read.txt"));
            int i=0;
            while (scanner.hasNextLine()) {
                String line = scanner.nextLine();
                if(!line.matches(".*?[0-9].*?"))break;
                LastArray[i++]=line;
                sizeOfOpreation++;
                theEnd++;
            }
            theEnd--;
        } catch (FileNotFoundException e) {
            System.out.println(e.getMessage());
        }
    }

}