package de.hs_mannheim.informatik.spreadsheet;

import org.junit.jupiter.api.Test;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import static org.junit.jupiter.api.Assertions.*;

class SpreadsheetTest {

    String[][] cells = {{"1","2"},{"2","4"},{"3","6"}};

    @Test
    void sumTest() {

        double result = 0;

        for(int r = 0; r<cells.length; r++)
            for(int c = 0; c<cells[r].length; c++)
                if(!cells[r][c].isEmpty())
                    result += Double.parseDouble(cells[r][c]);

        assertEquals(18, result);
    }
    @Test
    void productTest() {

        double result = 0;
        int counter = 0;

        for(int r = 0; r<cells.length; r++)
            for(int c = 0; c<cells[r].length; c++)
                if(!cells[r][c].isEmpty())
                    if(counter>0)
                        result *= Double.parseDouble(cells[r][c]);
                    else {
                        result = Double.parseDouble(cells[r][c]);
                        counter++;
                    }
        assertEquals(288,result);
    }
    @Test
    void averageTest() {

        double result = 0;
        int counter = 0;

        for(int r = 0; r<cells.length; r++)
            for(int c = 0; c<cells[r].length; c++)
                if(!cells[r][c].isEmpty()) {
                    result += Double.parseDouble(cells[r][c]);
                    counter++;
                }

        if(result!=0)
            result /= counter;

        assertEquals(3,result);
    }
    @Test
    void standardDeviationTest() {
        ArrayList<String> cellNames = new ArrayList<>();

        double result = 0;
        double avg = 0;
        int counter = 0;
        for(int r = 0; r<cells.length; r++)
            for(int c = 0; c<cells[r].length; c++)
                if(!cells[r][c].isEmpty()){
                    avg += Double.parseDouble(cells[r][c]);
                    counter++;
                    cellNames.add(cells[r][c]);
                }
        avg /= counter;
        //average/ add cell names to list

        ArrayList<String> copyCellNames = new ArrayList<>(cellNames);
        double[] frequency = new double[cellNames.size()];
        Arrays.fill(frequency,1);
        ArrayList<Double> relativeFrequency = new ArrayList<>();
        double mem = 0;

        for(int i = 0; i< cellNames.size(); i++) {
            for(int t = 0; t<cellNames.size(); t++){
                if((t!=i)&&(!cellNames.get(i).isEmpty())&&(cellNames.get(i).equals(cellNames.get(t)))){
                    cellNames.remove(t);
                    frequency[i] ++;
                    t = 0;
                }
            }
        }
        //delete all duplicates

        for(int i = 0; i< cellNames.size(); i++)
            relativeFrequency.add(i,frequency[i]/copyCellNames.size());

        if(cellNames.get(0).isEmpty())
            mem = ((0 - avg)*(0 - avg))
                    * relativeFrequency.get(0);

        else
            mem = ((Double.parseDouble(cellNames.get(0)) - avg)*(Double.parseDouble(cellNames.get(0)) - avg))
                    * relativeFrequency.get(0);

        for(int i = 1; i<cellNames.size(); i++)
            if(cellNames.get(i).isEmpty())
                mem += ((0 - avg)*(0 - avg))
                        * relativeFrequency.get(i);
            else
                mem += ((Double.parseDouble(cellNames.get(i)) - avg)*(Double.parseDouble(cellNames.get(i)) - avg))
                        * relativeFrequency.get(i);
        result = Math.sqrt(mem);

        assertEquals(1.632993161855452,result);
    }
    @Test
    void minTest() {
        ArrayList<String> cellNames = new ArrayList<>();

        for(int r = 0; r< cells.length; r++)
            for(int c = 0; c<cells[r].length; c++)
                if(!cells[r][c].isEmpty())
                    cellNames.add(cells[r][c]);

        double result = Double.parseDouble(cellNames.get(0));
        for(int i = 0; i< cellNames.size(); i++)
            if (result > Double.parseDouble(cellNames.get(i)))
                result = Double.parseDouble(cellNames.get(i));

        assertEquals(1,result);
    }
    @Test
    void maxTest() {
        ArrayList<String> cellNames = new ArrayList<>();

        for(int r = 0; r< cells.length; r++)
            for(int c = 0; c<cells[r].length; c++)
                if(!cells[r][c].isEmpty())
                    cellNames.add(cells[r][c]);

        double result = Double.parseDouble(cellNames.get(0));
        for(int i = 0; i< cellNames.size(); i++)
            if (result < Double.parseDouble(cellNames.get(i)))
                result = Double.parseDouble(cellNames.get(i));

        assertEquals(6,result);
    }
    @Test
    void calculate() throws ArithmeticException {
        Matcher m = Pattern.compile("([A-Z][1-9][0-9]*)|[-+*/]|[0-9]+").matcher("15+"+cells[1][1]+"*5");

        double result = 0;
        double currentOperand = 0;
        String currentOperator = "+";
        boolean firstOperator = true;

        while (m.find()) {
            String s = m.group();

            if (s.matches(("[0-9]+")))
                currentOperand = Double.parseDouble(s);
            else {
                if (!firstOperator) {
                    result = evaluateOperator(result, currentOperand, currentOperator);
                } else {
                    result = currentOperand;
                    firstOperator = false;
                }
                currentOperator = s;
            }
        }

        if (!firstOperator) {
            result = evaluateOperator(result, currentOperand, currentOperator);
        } else
            result = currentOperand;

        assertEquals(95,result);
    }

    private double evaluateOperator(double leftOperand, double rightOperand, String currentOperator) {
        switch (currentOperator) {
            case "+":
                return (leftOperand + rightOperand);
            case "-":
                return (leftOperand - rightOperand);
            case "*":
                return (leftOperand * rightOperand);
            case "/":
                return (leftOperand / rightOperand);
            default:
                throw new IllegalArgumentException("Invalid operator: " + currentOperator);
        }
    }
}