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;
using System.IO;

namespace WindowsFormsApp18
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btn_load_Click(object sender, EventArgs e)
        {
            OpenFileDialog loadDialog = new OpenFileDialog();
            loadDialog.Filter = "txt files (*.txt)|*.txt";
            if (loadDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                textBox1.Clear();
                StreamReader file = new StreamReader(loadDialog.OpenFile());

                string write;
                while((write = file.ReadLine()) != null)
                {
                    textBox1.AppendText(write + "\n");
                }

                file.Close();

            }
        }

        private void btn_save_Click(object sender, EventArgs e)
        {

            SaveFileDialog saveDialog = new SaveFileDialog();
            saveDialog.Filter = "txt files (*.txt)|*.txt";
            if (saveDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                StreamWriter file = new StreamWriter(saveDialog.OpenFile());

                foreach(string text in textBox1.Lines)
                {
                    file.WriteLine(text);
                    file.Flush();
                }
                file.Close();

            }
            textBox1.Clear();

        }

        private void btn_calculate_Click(object sender, EventArgs e)
        {

            List<string> output = new List<string>();

            foreach(string text in textBox1.Lines)
            {

                /*if (text.Any(char.IsDigit))
                {
                    output.Add(text)
                    return;
                }*/

                double a, b;
                char c;
                string[] znak = text.Split(new Char[] { ' ' });

                a = Double.Parse(znak[0]);
                b = Double.Parse(znak[2]);
                c = Char.Parse(znak[1]);
                switch (c)
                {
                    case '+': output.Add( a.ToString() + " + " + b.ToString() + " = " + (a + b).ToString() + "\n" ); break;
                    case '*': output.Add( a.ToString() + " * " + b.ToString() + " = " + (a * b).ToString() + "\n"); break;
                    case '-': output.Add( a.ToString() + " - " + b.ToString() + " = " + (a - b).ToString() + "\n"); break;
                    case '/': output.Add( a.ToString() + " / " + b.ToString() + " = " + (a / b).ToString() + "\n"); break;
                    case '^': output.Add( a.ToString() + " ^ " + b.ToString() + " = " + (Math.Pow(a,b)).ToString() + "\n"); break;
                }

            }

            textBox1.Clear();

            foreach(string text in output)
            {
                textBox1.AppendText(text);
            }

        }

        private void btn_transform_Click(object sender, EventArgs e)
        {

            List<string> output = new List<string>();

            foreach(string text in textBox1.Lines)
            {
                output.Add(text.ToLower());
            }

            textBox1.Clear();

            foreach(string text in output)
            {
                textBox1.AppendText(text + "\n");
            }

        }
    }
}