KapitalRechner-Advanced

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Kapitalrechner_3
{
    public partial class Form_1 : Form
    {
        public Form_1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            ClearAll(this);
        }

        private void button_exit_Click(object sender, EventArgs e)
        {
            Environment.Exit(0);
        }

        private void button_Clipboard_Click(object sender, EventArgs e)
        {
            string clip = "";
            foreach (string line in listBox_out.Items)
            {
                clip += line.Replace(" ", string.Empty);
                clip += Environment.NewLine;
            }

            try
            {
                Clipboard.SetText(clip);
            }
            catch
            {
                label_info.Text = "Data is null";
                return;
            }

            label_info.Text = "Copied";
        }

        void ClearAll(Control con)
        {
            ClearList();

            foreach (Control c in con.Controls)
            {
                if (c is TextBox)
                    ((TextBox)c).Clear();
                else
                    ClearAll(c);
            }
        }

        void ClearList()
        {
            listBox_out.Items.Clear();
        }

        private void button_clearAll_Click(object sender, EventArgs e)
        {
            ClearAll(this);
            textBox_k0.Focus();
        }

        private void button_clearList_Click(object sender, EventArgs e)
        {
            ClearList();
        }

        float GetDays(DateTime startD, DateTime endD)
        {
            float days = 0;

            days = (30 - startD.Date.Day) + 30 * ((endD.Date.Month + (endD.Date.Year - startD.Date.Year) * 12) - startD.Date.Month - 1) - 1 + endD.Date.Day;

            return days;
        }

        float GetYears(DateTime startD, DateTime endD)
        {
            float years = 0;

            years = (endD.Date.Year - startD.Date.Year) - 1;
            if (years < 0)
            {
                years = 0;
            }


            Console.WriteLine("Years: " + years);
            return years;
        }

        float GetDaysFirst(DateTime startD, DateTime endD)
        {
            float days = 0;

            days = (30 - startD.Date.Day) + 30 * (12 - startD.Date.Month - 1);

            Console.WriteLine("First Days: " + days);
            return days;
        }

        float GetDaysLast(DateTime startD, DateTime endD)
        {
            float days = 0;

            days = 30 * endD.Date.Month + endD.Date.Day;

            Console.WriteLine("Last Days: " + days);
            return days;
        }

        private void button_go_Click(object sender, EventArgs e)
        {
            ClearList();

            button_go.Enabled = false;

            double k0 = 0;
            double n = 0;
            double p = 0;
            double peff = 0;

            double pFormular = 0;

            DateTime startDate;
            DateTime endDate;

            double kFirst = 0;
            double kMiddle = 0;
            double kLast = 0;

            double kAll = 0;

            try
            {
                startDate = dateTimePicker_start.Value.Date;
                endDate = dateTimePicker_end.Value.Date;

                k0 = Convert.ToDouble(textBox_k0.Text);
                p = Convert.ToDouble(textBox_p.Text);
            }
            catch
            {
                label_info.Text = "Check your input";
                return;
            }

            try
            {
                n = Convert.ToDouble(textBox_n.Text);
            }
            catch
            {
                try
                {
                    n = Convert.ToDouble(new DataTable().Compute(textBox_n.Text, null));
                }
                catch
                {
                    try
                    {
                        n = GetDays(startDate, endDate);
                        textBox_n.Text = n + " / 360";
                    }
                    catch
                    {
                        label_info.Text = "Check your input";
                        return;
                    }
                }
            }

            //Peff
            peff = p * 0.75;
            textBox_peff.Text = peff.ToString();

            //Check if Peff should be used
            if (checkBox_usePeff.Checked)
            {
                pFormular = peff / 100;
            }
            else
            {
                pFormular = p / 100;
            }

            //Display day difference
            label_days.Text = n.ToString();

            //First Action:
            kFirst = k0 * (1 + pFormular * (GetDaysFirst(startDate, endDate) / 360));

            //Second Action:
            kMiddle = kFirst * Math.Pow(1 + pFormular, (GetYears(startDate, endDate)));

            //Last Action:
            kLast = kMiddle * (1 + pFormular * (GetDaysLast(startDate, endDate) / 360));

            kAll = kFirst + kMiddle + kLast;

            if (startDate.Date.Year == endDate.Date.Year)
            {
                kAll = k0 * (1 + pFormular * (GetDays(startDate, endDate) / 360));

                kFirst = 0;
                kMiddle = 0;
                kLast = 0;
            }

            //Display output
            listBox_out.Items.Add("K" + startDate.Date.Year.ToString() + ":\t" + kFirst);
            listBox_out.Items.Add("K" + (startDate.Date.Year + GetYears(startDate, endDate)) + ":\t" + kMiddle);
            listBox_out.Items.Add("K" + endDate.Date.Year.ToString() + ":\t" + kLast);
            listBox_out.Items.Add("Kall:\t" + kAll);

            button_go.Enabled = true;
        }
    }
}