using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;

namespace sharpcapture
{
    public partial class ScreenshotWindow : Form
    {
        private const float PEN_WIDTH = 2f;
        private Bitmap capturedBitmap;
        float zoom = 1;

        public Bitmap CapturedBitmap
        {
            get { return capturedBitmap; }
            set
            {
                capturedBitmap = value;

                int maxWidth = Screen.PrimaryScreen.Bounds.Width;
                int maxHeight = Screen.PrimaryScreen.Bounds.Height;

                int width = capturedBitmap.Width;
                int height = capturedBitmap.Height;

                if ((width / maxWidth) >= 1 || (height / maxHeight) >= 1)
                {
                    // Allow for 10% of space as well
                    Zoom = (float)Math.Min(
                        maxWidth / (1.1 * width),
                        maxHeight / (1.1 * height));
                }
                else
                {
                    Zoom = 1;
                }
            }
        }

        public float Zoom
        {
            get { return zoom; }
            set {
                zoom = value;

                SetClientSizeCore((int)(capturedBitmap.Width * zoom), (int)(capturedBitmap.Height * zoom) + toolStrip.Height);
                Invalidate();
            }
        }

        BufferedGraphicsContext context;
        BufferedGraphics buffer;

        private Point? firstPoint;

        // Mouse coordinates
        int mouseX;
        int mouseY;        

        public ScreenshotWindow(Bitmap capturedBitmap)
        {
            InitializeComponent();

            InitializaGraphics();
            
            CapturedBitmap = capturedBitmap;
            CopyToClipboard();            
        }

        private void InitializaGraphics()
        {
            context = new BufferedGraphicsContext();
            buffer = context.Allocate(this.toolStripContainer.ContentPanel.CreateGraphics(), this.DisplayRectangle);
        }

        private void CopyToClipboard()
        {
            Clipboard.SetDataObject(capturedBitmap, true);
        }

        private void SaveScreenshot()
        {
            SaveFileDialog saveScreenshot = new SaveFileDialog();
            saveScreenshot.Filter = "PNG Image|*.png|JPEG Image|*.jpg|Bitmap Image|*.bmp|Gif Image|*.gif";
            if (capturedBitmap != null && saveScreenshot.ShowDialog() == DialogResult.OK)
            {
                capturedBitmap.Save(saveScreenshot.FileName);
            }
        }

        private void exitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Exit();
        }

        private void Exit()
        {
            context.Dispose();

            Close();
        }

        private void MainWindow_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Escape)
            {
                Exit();
            }
            else if (e.Control && e.KeyCode == Keys.S)
            {
                SaveScreenshot();
            }
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            if (capturedBitmap != null)
            {
                if (zoom != 1)
                {
                    buffer.Graphics.InterpolationMode = InterpolationMode.NearestNeighbor;
                    buffer.Graphics.DrawImage(
                        capturedBitmap,
                        new Rectangle(0, toolStrip.Height, (int)(capturedBitmap.Size.Width * zoom), (int)(capturedBitmap.Size.Height * zoom) + toolStrip.Height),
                        new Rectangle(0, 0, capturedBitmap.Size.Width, capturedBitmap.Size.Height),
                        GraphicsUnit.Pixel);
                }
                // Avoid distorsion
                else
                {
                    buffer.Graphics.DrawImage(
                        capturedBitmap,
                        new Rectangle(0, 0, capturedBitmap.Size.Width, capturedBitmap.Size.Height),
                        new Rectangle(0, 0, capturedBitmap.Size.Width, capturedBitmap.Size.Height),
                        GraphicsUnit.Pixel);
                }
            }

            if (firstPoint.HasValue && toolStrip.Visible)
            {
                DrawShape(buffer.Graphics, firstPoint.Value, new Point(mouseX, mouseY), true);
            }

            buffer.Render();
        }

        private void DrawShape(Graphics g, Point p1, Point p2, bool temp)
        {
            Color color = temp ? Color.FromArgb(128, btnPicker.BackColor) : btnPicker.BackColor;
            Pen pen = new Pen(color, PEN_WIDTH);

            int x = Math.Min(p1.X, p2.X);
            int y = Math.Min(p1.Y, p2.Y);
            int width = Math.Abs(p1.X - p2.X);
            int height = Math.Abs(p1.Y - p2.Y);

            if (Control.ModifierKeys == Keys.Control)
            {
                // Align horizontally
                if (width > height)
                {
                    p2.Y = p1.Y;
                }
                // Align vertically
                else
                {
                    p2.X = p1.X;
                }
                height = width;
            }

            if (!temp) firstPoint = null;

            if (btnLine.Checked)
            {
                g.DrawLine(pen, p1, p2);
            }
            else if (btnPath.Checked)
            {
                g.DrawLine(pen, p1, p2);
                if (!temp) firstPoint = p2;
            }
            else if (btnRect.Checked)
            {
                g.DrawRectangle(pen, new Rectangle(x, y, width, height));
            }
            else if (btnEllipse.Checked)
            {
                g.DrawEllipse(pen, new Rectangle(x, y, width, height));
            }
            else if (btnFilledRect.Checked)
            {
                g.FillRectangle(new SolidBrush(color), new Rectangle(x, y, width, height));
            }
            else if (btnFilledEllipse.Checked)
            {
                g.FillEllipse(new SolidBrush(color), new Rectangle(x, y, width, height));
            }
        }

        private void ScreenshotWindow_MouseMove(object sender, MouseEventArgs e)
        {
            mouseX = e.X;
            mouseY = e.Y;

            if (firstPoint != null)
            {
                Invalidate();
            }
        }

        protected override void OnPaintBackground(PaintEventArgs e)
        {
            // NOOP
            //base.OnPaintBackground(e);
        }

        private void MainWindow_Resize(object sender, EventArgs e)
        {
            InitializaGraphics();
        }

        private void saveButton_Click(object sender, EventArgs e)
        {
            SaveScreenshot();
        }

        private void toolStripButton_Click(object sender, EventArgs e)
        {
            if (sender == btnPicker)
            {
                colorDialog.Color = btnPicker.BackColor;
                if (colorDialog.ShowDialog(this) == DialogResult.OK)
                {
                    btnPicker.BackColor = colorDialog.Color;
                }
            }
            else if (sender == btnZoomMore)
            {
                if (zoom < 1) zoom *= 2;
                else Zoom++;

            }
            else if (sender == btnZoomLess)
            {
                if (zoom > 0.25)
                {
                    if (zoom > 1) zoom--;
                    else Zoom /= 2;
                }
            }
            else
            {
                btnLine.Checked = false;
                btnPath.Checked = false;
                btnRect.Checked = false;
                btnEllipse.Checked = false;
                btnFilledRect.Checked = false;
                btnFilledEllipse.Checked = false;

                ((ToolStripButton)sender).Checked = true;
            }
        }

        private void zoomComboBox_SelectedIndexChanged(object sender, EventArgs e)
        {
            switch (toolStripComboBox1.SelectedIndex)
            {
                case 0:
                    Zoom = 0.25f;
                    break;
                case 1:
                    Zoom = 0.5f;
                    break;
                case 2:
                    Zoom = 0.75f;
                    break;
                case 3:
                    Zoom = 1;
                    break;
                case 4:
                    Zoom = 1.5f;
                    break;
                // >= 200%
                default:
                    Zoom = toolStripComboBox1.SelectedIndex - 3;
                    break;
            }
        }

        private void ScreenshotWindow_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                if (firstPoint == null)
                {
                    firstPoint = new Point(e.X, e.Y);
                }
                else
                {
                    Graphics g = Graphics.FromImage(capturedBitmap);
                    //DrawShape(g, new Point((int)(firstPoint.Value.X / zoom), (int)(firstPoint.Value.Y / zoom)), new Point((int)(e.X / zoom), (int)(e.Y / zoom)), false);
                    DrawShape(g, new Point(firstPoint.Value.X, firstPoint.Value.Y), new Point(e.X, e.Y), false);
                    Invalidate();
                    CopyToClipboard();
                }
            }
            if (e.Button == MouseButtons.Right)
            {
                if (firstPoint != null)
                {
                    firstPoint = null;
                    Invalidate();
                }
            }
        }
    }
}