using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace TR
{
	/// <summary>
	/// Description of MainForm.
	/// </summary>
	public partial class MainForm : Form
	{
		public MainForm()
		{
			//
			// The InitializeComponent() call is required for Windows Forms designer support.
			//
			InitializeComponent();
			
			//
			// TODO: Add constructor code after the InitializeComponent() call.
			//	

		}
				
		double operator1 = 0;
		double operator2 = 0;
		char zeichen;
		double ergebnis;
		bool point = false;
		bool special = false;
		double faktor = 10;
		double save1 = 0;
		
		void insert (int number)
		{
			if(special)
			{
				operator1 = 0;
			}
			if(point)
			{
				operator1 += (number / faktor);
				faktor *= 10;
			}
			else
			{
				operator1 *= 10;
				operator1 += number;
			}
			if(zeichen == ' ')
			{
				operator2 = 0;
			}
			string output = System.Convert.ToString(operator1);
			this.textBox1.Text = output;
			special = false;
		
		}
		
		void Add ()
		{
			ergebnis = operator2 + operator1;
			string output = System.Convert.ToString(ergebnis);
			this.textBox1.Text = output;
		}
		
		void Subtract()
		{
			ergebnis = operator2 - operator1;
			string output2 = System.Convert.ToString(ergebnis);
			this.textBox1.Text = output2;
		}
		
		void Multiply ()
		{
			ergebnis = operator2 * operator1;
			string output3 = System.Convert.ToString(ergebnis);
			this.textBox1.Text = output3;
		}
		
		void Divide()
		{
			ergebnis = operator2 / operator1;
			string output4 = System.Convert.ToString(ergebnis);
			this.textBox1.Text = output4;
		}
		
		void Button1Click(object sender, EventArgs e)
		{
			insert(1);
		}
		
		void Button2Click(object sender, EventArgs e)
		{
			insert(2);
		}
		
		void Button3Click(object sender, EventArgs e)
		{
			insert(3);
		}
		
		void Button4Click(object sender, EventArgs e)
		{
			insert(4);
		}
		
		void Button5Click(object sender, EventArgs e)
		{
			insert(5);
		}
		
		void Button6Click(object sender, EventArgs e)
		{
			insert(6);
		}
		
		void Button7Click(object sender, EventArgs e)
		{
			insert(7);
		}
		
		void Button8Click(object sender, EventArgs e)
		{
			insert(8);
		}
		
		void Button9Click(object sender, EventArgs e)
		{
			insert(9);
		}
		
		void Button11Click(object sender, EventArgs e)
		{
			insert(0);
		}
		
		void Button17Click(object sender, EventArgs e)
		{
			operator1 = 0;
			operator2 = 0;
			ergebnis = 0;
			point = false;
			special = false;
			faktor = 10;
			this.textBox1.Text = "0";
		}
		
		void Button16Click(object sender, EventArgs e)
		{
			if(operator1 == 0)
			{
				
			}
			else if(zeichen == '+')
			{
				operator2 += operator1;
				string output = System.Convert.ToString(operator2);
				this.textBox1.Text = output;
			}
			else if(operator2 == 0)
			{
				operator2 = operator1;
			}
			else
			{
				switch(zeichen)
				{
				case '-':	
					Subtract();
					break;
				case '*':	
					Multiply();
					break;
				case '/':	
					Divide();
					break;
				default:
					break;				
				}
				operator2 = ergebnis;
				ergebnis = 0;
			}
			operator1 = 0;
			point = false;
			special = false;
			faktor = 10;
			zeichen = '+';
		}
		
		void Button15Click(object sender, EventArgs e)
		{
			if(operator1 == 0)
			{
				
			}
			else if(zeichen == '-')
			{
				operator2 -= operator1;
				string output = System.Convert.ToString(operator2);
				this.textBox1.Text = output;
			}
			else if(operator2 == 0)
			{
				operator2 = operator1;
			}
			else
			{
				switch(zeichen)
				{
				case '+':	
					Add();
					break;
				case '*':	
					Multiply();
					break;
				case '/':	
					Divide();
					break;
				default:
					break;				
				}
				operator2 = ergebnis;
				ergebnis = 0;
			}
			operator1 = 0;
			point = false;
			special = false;
			faktor = 10;
			zeichen = '-';
		}
		
		void Button14Click(object sender, EventArgs e)
		{
			if(operator1 == 0)
			{
				
			}
			else if(zeichen == '*')
			{
				operator2 *= operator1;
				string output = System.Convert.ToString(operator2);
				this.textBox1.Text = output;
			}
			else if(operator2 == 0)
			{
				operator2 = operator1;
			}
			else
			{
				switch(zeichen)
				{
				case '+':	
					Add();
					break;
				case '-':	
					Subtract();
					break;
				case '/':	
					Divide();
					break;
				default:
					break;				
				}
				operator2 = ergebnis;
				ergebnis = 0;
			}
			operator1 = 0;
			point = false;
			special = false;
			faktor = 10;
			zeichen = '*';
		}
		
		void Button13Click(object sender, EventArgs e)
		{
			if(operator1 == 0)
			{
				
			}
			else if(zeichen == '/')
			{
				operator2 /= operator1;
				string output = System.Convert.ToString(operator2);
				this.textBox1.Text = output;
			}
			else if(operator2 == 0)
			{
				operator2 = operator1;
			}
			else
			{
				switch(zeichen)
				{
				case '+':	
					Add();
					break;
				case '-':	
					Subtract();
					break;
				case '*':	
					Multiply();
					break;
				default:
					break;				
				}
				operator2 = ergebnis;
				ergebnis = 0;
			}
			operator1 = 0;
			point = false;
			special = false;
			faktor = 10;
			zeichen = '/';
		}
		
		void Button18Click(object sender, EventArgs e)
		{
			switch(zeichen)
			{
				case '+':	
					Add();
					break;
				case '-':	
					Subtract();
					break;
				case '*':	
					Multiply();
					break;
				case '/':	
					Divide();
					break;
				default:
					break;
			}
			operator2 = ergebnis;
			ergebnis = 0;
			operator1 = 0;
			point = false;
			special = false;
			faktor = 10;
			zeichen = ' ';
		}
		
		void Button10Click(object sender, EventArgs e)
		{
			point = true;
		}
		
		void Button12Click(object sender, EventArgs e)
		{
			string output1 = this.textBox1.Text;
			ergebnis = System.Convert.ToDouble(output1);
			ergebnis = 1 / ergebnis;
			string output2 = System.Convert.ToString(ergebnis);
			this.textBox1.Text = output2;
			operator1 = ergebnis;
			point = false;
			special = true;
			faktor = 10;
		}
		
		void Button23Click(object sender, EventArgs e)
		{
			string output1 = this.textBox1.Text;
			ergebnis = System.Convert.ToDouble(output1);
			ergebnis -= 2 * ergebnis;
			string output2 = System.Convert.ToString(ergebnis);
			this.textBox1.Text = output2;
			operator1 = ergebnis;
			point = false;
			special = true;
			faktor = 10;
		}
		
		void Button19Click(object sender, EventArgs e)
		{
			string output1 = this.textBox1.Text;
			ergebnis = System.Convert.ToDouble(output1);
			ergebnis = Math.Sqrt(ergebnis);
			string output2 = System.Convert.ToString(ergebnis);
			this.textBox1.Text = output2;
			operator1 = ergebnis;
			point = false;
			special = true;
			faktor = 10;
		}
		
		void Button20Click(object sender, EventArgs e)
		{
			string output1 = this.textBox1.Text;
			ergebnis = System.Convert.ToDouble(output1);
			ergebnis *= ergebnis;
			string output2 = System.Convert.ToString(ergebnis);
			this.textBox1.Text = output2;
			operator1 = ergebnis;
			point = false;
			special = true;
			faktor = 10;
		}
		
		void Button24Click(object sender, EventArgs e)
		{
			string output1 = this.textBox1.Text;
			ergebnis = System.Convert.ToDouble(output1);
			ergebnis = Math.PI;
			string output2 = System.Convert.ToString(ergebnis);
			this.textBox1.Text = output2;
			operator1 = ergebnis;
			point = false;
			special = true;
			faktor = 10;
		}
		
		void Button21Click(object sender, EventArgs e)
		{
			string output = this.textBox1.Text;
			save1 = System.Convert.ToDouble(output); 
		}
		
		void Button22Click(object sender, EventArgs e)
		{
			if(save1 != 0)
			{
				string output = System.Convert.ToString(save1);
				this.textBox1.Text = output;
				operator1 = save1;
				special = true;
			}
		}
		
		void MainFormFormClosing(object sender, FormClosingEventArgs e)
		{
			e.Cancel = MessageBox.Show("Sind sicher dass sie Beenden möchten?",
			                           "Warning",
			                           MessageBoxButtons.YesNo,
			                           MessageBoxIcon.Warning) == DialogResult.No;
		}
		
		void MainFormKeyDown(object sender, KeyEventArgs e)
		{
			if(e.KeyCode == Keys.F1)
			{
				MessageBox.Show("Created by Samuel ©",
                "Info",
                MessageBoxButtons.OK,
                MessageBoxIcon.Asterisk);
			}
			if(e.KeyCode == Keys.Back)
			{
				operator1 = 0;
				point = false;
				this.textBox1.Text ="";
			}
			if(e.KeyCode == Keys.NumPad0)
			{
				button11.Select();
				button11.PerformClick();
			}
			if(e.KeyCode == Keys.NumPad1)
			{
				button1.Select();
				button1.PerformClick();
			}
			if(e.KeyCode == Keys.NumPad2)
			{
				button2.Select();
				button2.PerformClick();
			}
			if(e.KeyCode == Keys.NumPad3)
			{
				button3.Select();
				button3.PerformClick();
			}
			if(e.KeyCode == Keys.NumPad4)
			{
				button4.Select();
				button4.PerformClick();
			}
			if(e.KeyCode == Keys.NumPad5)
			{
				button5.Select();
				button5.PerformClick();
			}
			if(e.KeyCode == Keys.NumPad6)
			{
				button6.Select();
				button6.PerformClick();
			}
			if(e.KeyCode == Keys.NumPad7)
			{
				button7.Select();
				button7.PerformClick();
			}
			if(e.KeyCode == Keys.NumPad8)
			{
				button8.Select();
				button8.PerformClick();
			}
			if(e.KeyCode == Keys.NumPad9)
			{
				button9.Select();
				button9.PerformClick();
			}
			if(e.KeyCode == Keys.Add)
			{
				button16.Select();
				button16.PerformClick();
			}
			if(e.KeyCode == Keys.Subtract)
			{
				button15.Select();
				button15.PerformClick();
			}
			if(e.KeyCode == Keys.Multiply)
			{
				button14.Select();
				button14.PerformClick();
			}
			if(e.KeyCode == Keys.Divide)
			{
				button13.Select();
				button13.PerformClick();
			}
			if(e.KeyCode == Keys.Delete)
			{
				button17.Select();
				button17.PerformClick();
			}
			if(e.KeyCode == Keys.Decimal)
			{
				button10.Select();
				button10.PerformClick();
			}
			if(e.KeyCode == Keys.Escape)
			{
				this.Close();
			}
			if(e.KeyCode == Keys.Enter)
			{
				button18.Select();
				button18.PerformClick();
			}
		}
	}
}