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

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        private Bitmap b1, b2;
        private double alphaChannel=1;
        //public int outWidth=700;
        //public int outHeight=700;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            this.MaximizeBox = false;
            this.KeyPreview = true;
            picLeft.Click += new EventHandler(LoadImage);
            picRight.Click += new EventHandler(LoadImage);
            btnBlending.Enabled = false;
            btnBlending.Click += new EventHandler(Blending);
            trbBlendingFactor.ValueChanged += new EventHandler(trbBlendingFactor_ValueChanged);
            lblOpacity.Text = alphaChannel.ToString();
        }

        private void Form1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode==Keys.F12)
            {
                Rectangle bounds = Screen.GetBounds(Point.Empty);
                Bitmap bitmap = new Bitmap(bounds.Width, bounds.Height);
                Graphics g = Graphics.FromImage(bitmap);

                g.CopyFromScreen(Point.Empty, Point.Empty, bounds.Size);

                if (b1==null)
                {
                    b1 = bitmap;
                    picLeft.Image = b1;
                }
                else
                {
                    b2 = bitmap;
                    picRight.Image = b2;
                    btnBlending.Enabled = true;
                }

            }

        }


        private void LoadImage(object sender, EventArgs e)
        {
            PictureBox pic = sender as PictureBox;

            OpenFileDialog dialog = new OpenFileDialog();
            dialog.Filter = "Image files | *.BMP; *.JPG; *.PNG";
            dialog.Multiselect = false;

            DialogResult d = dialog.ShowDialog();
            if (d==DialogResult.OK)
            {
                string path = dialog.FileName;

                switch(pic.Name)
                {
                    case "picLeft":
                        {
                            b1 = new Bitmap(path);
                            pic.Image = b1;
                        }
                        break;
                    case "picRight":
                        {
                            b2 = new Bitmap(path);
                            pic.Image = b2;
                        }
                        break;
                    //default:
                    //    {

                    //    }
                    //    break;
                }
                if (b1!=null && b2!=null)
                {
                    btnBlending.Enabled = true;
                    //prgBlendingProgress.Maximum = outWidth * outHeight;
                }
            }
            else if (d != DialogResult.Cancel)
            {
                MessageBox.Show("Bad file","Bad file",MessageBoxButtons.OK,MessageBoxIcon.Error);
            }
        }
        private void Blending(object sender, EventArgs e)
        {
            prgBlendingProgress.Visible = true;
            lblInProgress.Visible = true;

            //back_w.WorkerSupportsCancellation = true;


            if (back_w.IsBusy==false)
            {
                back_w.DoWork += new DoWorkEventHandler(Blend);
                back_w.RunWorkerCompleted += new RunWorkerCompletedEventHandler(BlendDone);
                back_w.WorkerReportsProgress = true;
                back_w.ProgressChanged += new ProgressChangedEventHandler((object s, ProgressChangedEventArgs ea) => prgBlendingProgress.Value = ea.ProgressPercentage);
                back_w.RunWorkerAsync();
            }
            else
            {
                back_w2.DoWork += new DoWorkEventHandler(Blend);
                back_w2.RunWorkerCompleted += new RunWorkerCompletedEventHandler(BlendDone);
                back_w2.WorkerReportsProgress = true;
                back_w2.ProgressChanged += new ProgressChangedEventHandler((object s, ProgressChangedEventArgs ea) => prgBlendingProgress.Value = ea.ProgressPercentage);
                back_w2.RunWorkerAsync();
            }

        }

        private void trbBlendingFactor_ValueChanged(object sender, EventArgs e)
        {
            alphaChannel = (double)trbBlendingFactor.Value / (double)trbBlendingFactor.Maximum;
            lblOpacity.Text = (alphaChannel).ToString();

        }

        private void Blend(object sender, DoWorkEventArgs e)
        {
            int outWidth = Math.Min(picLeft.Image.Width, picRight.Image.Width);
            int outHeight = Math.Min(picLeft.Image.Height, picRight.Image.Height);
            Bitmap result = new Bitmap(outWidth,outHeight);

            Bitmap bb1 = new Bitmap(b1);
            Bitmap bb2 = new Bitmap(b2);

            for (int i = 0; i < outWidth; i++)
            {
                Thread.Sleep(10);
                back_w.ReportProgress(100*i/outWidth);
                for (int j = 0; j < outHeight; j++)
                {
                    Color leftC = bb1.GetPixel(i, j);
                    Color rightC = bb2.GetPixel(i, j);
                    Color c = Color.FromArgb(
                        255,
                        (int)(alphaChannel * leftC.R + (1 - alphaChannel) * rightC.R),
                        (int)(alphaChannel * leftC.G + (1 - alphaChannel) * rightC.G),
                        (int)(alphaChannel * leftC.B + (1 - alphaChannel) * rightC.B)
                        );

                    result.SetPixel(i, j, c);
                   // prgBlendingProgress.PerformStep();
                }
            }

            Form resultForm = new Form
            {
                Width = outWidth+50,//picLeft.Width,
                Height = outHeight+50//picLeft.Height
            };
            PictureBox pictureBox = new PictureBox
            {
                Width = outWidth,//picLeft.Width,
                Height = outHeight,//picLeft.Height,
                //SizeMode = PictureBoxSizeMode.StretchImage,
                Image = result
            };

            resultForm.Controls.Add(pictureBox);
            //resultForm.Show();

            BeginInvoke(new Action(() => resultForm.Show()));


        }
        private void BlendDone(object sender, RunWorkerCompletedEventArgs e)
        {
            lblInProgress.Visible = false;
            prgBlendingProgress.Visible = false;
        }
    }
}