using Patagames.Pdf.Net.Controls.WinForms;
using System;
using Patagames.Pdf.Net;
using System.Drawing;
using System.Windows.Forms;
using Patagames.Pdf.Enums;

namespace ExamplesWinForms
{
	public class MyPdfViewer : PdfViewer
	{
		PointF _startPt = new PointF(0, 0);
		PointF _curPt = new PointF(0, 0);
		int _shapshotPage = -1;
		bool _isSelectionStarted = false;

		protected override void OnMouseDown(MouseEventArgs e)
		{
			base.OnMouseDown(e);

			_shapshotPage = PointInPage(e.Location);
			if (_shapshotPage >= 0)
			{
				_startPt = ClientToPage(_shapshotPage, e.Location);
				_curPt = _startPt;
				_isSelectionStarted = true;
			}

		}

		protected override void OnMouseUp(MouseEventArgs e)
		{
			base.OnMouseUp(e);
			_isSelectionStarted = false;
		}

		protected override void OnMouseMove(MouseEventArgs e)
		{
			base.OnMouseMove(e);
			if (_isSelectionStarted)
			{
				int pageIdx = PointInPage(e.Location);
				if (pageIdx != _shapshotPage)
					return;

				_curPt = ClientToPage(_shapshotPage, e.Location);
				Invalidate();
			}
		}

		protected override void OnPaint(PaintEventArgs e)
		{
			base.OnPaint(e);
			if (_shapshotPage >= 0)
			{
				var pt1 = PageToClient(_shapshotPage, _startPt);
				var pt2 = PageToClient(_shapshotPage, _curPt);
				int left = Math.Min(pt1.X, pt2.X);
				int top = Math.Min(pt1.Y, pt2.Y);
				int right = Math.Max(pt1.X, pt2.X);
				int bottom = Math.Max(pt1.Y, pt2.Y);
				e.Graphics.DrawRectangle(Pens.Red, left, top, right - left, bottom - top);
			}
		}

		private void NormalizeSnapshotPoints(out PointF leftTop, out PointF rightBotton)
		{
			leftTop = new PointF(
				Math.Min(_startPt.X, _curPt.X),
				Math.Max(_startPt.Y, _curPt.Y));
			rightBotton = new PointF(
				Math.Max(_startPt.X, _curPt.X),
				Math.Min(_startPt.Y, _curPt.Y));
		}

		internal Image TakeShapshot(int width)
		{
			//The rectangle on a page in PDF coordinates which should be snapshoted.
			PointF leftTop;
			PointF rightBottom;
			NormalizeSnapshotPoints(out leftTop, out rightBottom);

			//Calculate the scale
			double k = width / (rightBottom.X - leftTop.X);

			//Calculate image height
			int height = (int)((leftTop.Y - rightBottom.Y) * k);

			//The current page of loaded document.
			var page = CurrentPage;

			using (var bmp = new PdfBitmap(width, height, true))
			{
				//Calculate the offset
				int devX, devY;
				page.PageToDevice(0, 0, (int)(page.Width * k), (int)(page.Height * k), PageRotate.Normal, leftTop.X, leftTop.Y, out devX, out devY);

				//Render part of page into bitmap;
				CurrentPage.Render(bmp, -devX, -devY, (int)(page.Width * k), (int)(page.Height * k),  PageRotate.Normal, RenderFlags.FPDF_LCD_TEXT);

				return new Bitmap(bmp.Image);
			}

		}
	}
}