using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
using Screenshot.Windows;

namespace Screenshot.Forms
{
    /// <summary>
    /// Repre
    /// </summary>
    public sealed partial class SnippetDialog : Form
    {
        [Browsable(false)]
        public Rectangle SelectedArea { get; private set; }
        public Rectangle AbsoluteSelectedArea { get; private set; }

        private Point _startLocation;
        private Point _startLocationAbsolut;

        private bool _shouldDraw;
        private readonly Color _selectionColor = Color.FromArgb(50, 255, 99, 71);

        public SnippetDialog()
        {
            InitializeComponent();
            Bounds = SystemInformation.VirtualScreen;
            BackgroundImage = ScreenshotProvider.TakeScreenshot(Bounds);

            _startLocation = Cursor.Position;
        }

        protected override void OnMouseDown(MouseEventArgs e)
        {
            // No need for code guard here
            if (e.Button == MouseButtons.Left)
            {
                _startLocation = e.Location;
                _shouldDraw = true;
                NativeMethods.POINT p;
                NativeMethods.GetCursorPos(out p);
                _startLocationAbsolut = new Point(p.X, p.Y);
            }
        }

        protected override void OnMouseMove(MouseEventArgs e)
        {
            NativeMethods.POINT p;
            NativeMethods.GetCursorPos(out p);

            SelectedArea = new Rectangle(
                Math.Min(_startLocation.X, e.X),
                Math.Min(_startLocation.Y, e.Y),
                Math.Abs(_startLocation.X - e.X),
                Math.Abs(_startLocation.Y - e.Y));

            AbsoluteSelectedArea = new Rectangle(
                Math.Min(_startLocationAbsolut.X, p.X),
                Math.Min(_startLocationAbsolut.Y, p.Y),
                Math.Abs(_startLocationAbsolut.X - p.X),
                Math.Abs(_startLocationAbsolut.Y - p.Y));

            if (_shouldDraw)
            {
                Invalidate();
            }
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            // 50 alpha so we can see behind it
            e.Graphics.FillRectangle(new SolidBrush(_selectionColor), SelectedArea);
            e.Graphics.DrawRectangle(Pens.Black, SelectedArea);
        }

        protected override void OnMouseUp(MouseEventArgs e)
        {
            DialogResult = DialogResult.OK;
        }

        protected override void OnKeyDown(KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Escape)
            {
                DialogResult = DialogResult.Cancel;
            }
        }
    }
}