using System;

using System.Drawing;

using System.Drawing.Imaging;

using System.Windows.Forms;

using System.Collections.Generic;

namespace Assistance {

    public class MainWindow : Form {

        static public void Main() { Application.Run(new MainWindow()); }

		Bitmap bitmap = new Bitmap(1, 1);

		Workarea workarea = new Workarea();

		bool dragging = false;

		ActivePoint activePoint;

		Point offset;

		Point cursor;

		Track track = null;

		public MainWindow() {

			Paint += onPaint;

			MouseMove += onMouseMove;

			MouseDown += onMouseDown;

			MouseUp += onMouseUp;

			KeyDown += onKeyDown;

            WindowState = FormWindowState.Maximized;

        }

		protected override void OnPaintBackground(PaintEventArgs e) { }

        public void onPaint(Object sender, PaintEventArgs e) {

			if (bitmap.Size != ClientSize)

				bitmap = new Bitmap(ClientSize.Width, ClientSize.Height);

			Graphics g = Graphics.FromImage(bitmap);

			g.Clear(Color.White);

            draw(g);

			g.Flush();

			e.Graphics.DrawImageUnscaled(bitmap, 0, 0);

        }

		public Point windowToWorkarea(Point p) {

			return new Point(p.x - ClientSize.Width/2.0, p.y - ClientSize.Height/2.0);

		}

		public Point workareaToWindow(Point p) {

			return new Point(p.x + ClientSize.Width/2.0, p.y + ClientSize.Height/2.0);

		}

		private void beginDrag() {

			endDragAndTrack();

			dragging = true;

			offset = activePoint.position - cursor;

			activePoint.bringToFront();

		}

		private void beginTrack() {

			endDragAndTrack();

			track = new Track();

		}

		private void endDragAndTrack() {

			dragging = false;

			offset = new Point();

			if (track != null)

				workarea.paintTrack(track);

			track = null;

		}

		public void onKeyDown(Object sender, KeyEventArgs e) {

			switch(e.KeyCode) {

			case Keys.D1:

				new VanishingPoint(workarea, cursor);

				break;

			case Keys.D2:

				new Grid(workarea, cursor);

				break;

			case Keys.Delete:

				if (activePoint != null)

					activePoint.assistant.remove();

				endDragAndTrack();

				break;

			}

			endDragAndTrack();

			Invalidate();

		}

		public void onMouseDown(Object sender, MouseEventArgs e) {

			cursor = windowToWorkarea(new Point(e.Location.X, e.Location.Y));

			if (e.Button == MouseButtons.Left) {

				activePoint = workarea.findPoint(cursor);

				if (activePoint != null) {

					beginDrag();

				} else {

					beginTrack();

					track.points.Add(cursor);

				}

			}

			Invalidate();

		}

		public void onMouseUp(Object sender, MouseEventArgs e) {

			cursor = windowToWorkarea(new Point(e.X, e.Y));

			if (e.Button == MouseButtons.Left)

				endDragAndTrack();

			if (!dragging && track == null)

				activePoint = workarea.findPoint(cursor);

			Invalidate();

		}

		public void onMouseMove(Object sender, MouseEventArgs e) {

			cursor = windowToWorkarea(new Point(e.Location.X, e.Location.Y));

			if (dragging) {

				activePoint.assistant.onMovePoint(activePoint, cursor + offset);

			} else

			if (track != null) {

				track.points.Add(cursor);

			} else {

				activePoint = workarea.findPoint(cursor);

			}

			Invalidate();

        }

        public void draw(Graphics g) {

			g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

			g.TranslateTransform(ClientSize.Width/2, ClientSize.Height/2);

			workarea.draw(g, activePoint, cursor + offset, track);

        }

    }

}