using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using pdftron.PDF.Tools;
using pdftron.PDF;
using System.Windows.Controls;
using System.Windows;
using System.Windows.Shapes;
using System.Diagnostics;

namespace PDFViewWPFCS
{
    class CalibrationTool
    {
        private PDFViewWPF _PDFView;
        private System.Windows.Shapes.Rectangle _Rect;
        private bool _Dragging = false;
        private System.Windows.Point _DownPoint;
        private System.Windows.Point _MovePoint;
        private Canvas _DrawingCanvas;
        private int _PageNumber = -1;


        public CalibrationTool(PDFViewWPF view)
        {
            _PDFView = view;
            // Set ToolMode to custom, so that the PDFViewWPD doesn't try to do anything.
            _PDFView.SetToolMode(PDFViewWPF.ToolMode.e_custom);

            _DrawingCanvas = _PDFView.GetCanvas();

            // Subscribing to this canvas works, subscribing directly to PDFViewWPF doesn't.
            _DrawingCanvas.MouseLeftButtonDown += _PDFView_MouseLeftButtonDown;
            _DrawingCanvas.MouseMove += _PDFView_MouseMove;
            _DrawingCanvas.PreviewMouseLeftButtonUp += _PDFView_PreviewMouseLeftButtonUp;
        }

        void _PDFView_PreviewMouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
        {
            Debug.WriteLine("Done dragging");

            // Now, translate these coordinates to page coordinates

            double downX = _DownPoint.X;
            double downY = _DownPoint.Y;

            // Convert from screen point to page point.
            Debug.WriteLine("before: {0}, {1}", downX, downY);
            _PDFView.ConvScreenPtToPagePt(ref downX, ref downY, _PageNumber);
            Debug.WriteLine("after: {0}, {1}", downX, downY);

            // Do the same with MovePoint

            _Dragging = false;
            _DrawingCanvas.Children.Remove(_Rect);

            

            Close();
        }

        void _PDFView_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
        {
            if (_Dragging)
            {
                Debug.WriteLine("Dragging");
                // check page bounds etc...


                _MovePoint = e.GetPosition(_PDFView);
                _Rect.Width = Math.Abs(_MovePoint.X - _DownPoint.X);
                _Rect.Height = Math.Abs(_MovePoint.Y - _DownPoint.Y);
                
            }
        }

        void _PDFView_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
        {
            Debug.WriteLine("mouse down");
            _Dragging = true;
            _DownPoint = e.GetPosition(_PDFView);

            // Which page are we on
            _PageNumber = _PDFView.GetPageNumberFromScreenPt(_DownPoint.X, _DownPoint.Y);

            // You will want to build a crop box here
            pdftron.PDF.Page page = _PDFView.GetDoc().GetPage(_PageNumber);
            pdftron.PDF.Rect rect = page.GetCropBox();
            // convert this to screen points using _PDFView.ConvPagePtToScreenPt


            _Rect = new System.Windows.Shapes.Rectangle();
            _Rect.Fill = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromArgb(100, 255, 0, 0));
            _DrawingCanvas.Children.Add(_Rect);
            _Rect.SetValue(Canvas.LeftProperty, _DownPoint.X + _PDFView.GetHScrollPos());
            _Rect.SetValue(Canvas.TopProperty, _DownPoint.Y + _PDFView.GetVScrollPos());
            
        }

        private void Close()
        {
            // unsubscribe events here


            // Restore the toolMode to pan
            _PDFView.SetToolMode(PDFViewWPF.ToolMode.e_pan);
        }

    }
}