using System;
using System.Collections.Generic;
using System.Windows.Forms;
using CodeImp.DoomBuilder.Editing;
using CodeImp.DoomBuilder.Geometry;
using CodeImp.DoomBuilder.Map;
using CodeImp.DoomBuilder.Windows;

namespace CodeImp.DoomBuilder.BuilderModes.ClassicModes
{
    [EditMode(DisplayName = "Snap Map Elements to Grid",
              SwitchAction = "snapvertstogrid",
              AllowCopyPaste = false,
              Optional = false,
              Volatile = true)]
    public class SnapVerticesMode : BaseClassicMode
    {
        public SnapVerticesMode() {
            // We have no destructor
            GC.SuppressFinalize(this);
        }
        
        // Mode engages
        public override void OnEngage() {
            base.OnEngage();

            //get selection
			General.Map.Map.ClearAllMarks(false);
            General.Map.Map.MarkAllSelectedGeometry(true, false, true, false, false);
            List<Vertex> verts = General.Map.Map.GetMarkedVertices(true);

            //nothing selected?
            if (verts.Count == 0) {
	            //check things
	            List<Thing> things = General.Map.Map.GetMarkedThings(true);
	            if (things.Count == 0) {
		            General.Interface.DisplayStatus(StatusType.Warning, "Select some map elements first!");
		            base.OnCancel();
		            General.Editing.ChangeMode(General.Editing.PreviousStableMode.Name);
	            } else {
		            snapThings(things);
	            }
            } else {
				snapVertices(verts);
            }
        }

		private void snapVertices(List<Vertex> verts) {
			// Make undo for the snapping
			General.Map.UndoRedo.CreateUndo("Snap vertices");

			int snappedCount = 0;

			//snap them all!
			foreach(Vertex v in verts) {
				Vector2D pos = v.Position;
				v.SnapToGrid();

				if(v.Position.x != pos.x || v.Position.y != pos.y)
					snappedCount++;
			}

			//done
			General.Interface.DisplayStatus(StatusType.Info, "Snapped " + snappedCount + " vertices.");
			base.OnAccept();
			General.Editing.ChangeMode(General.Editing.PreviousStableMode.Name);
		}

		private void snapThings(List<Thing> things) {
			// Make undo for the snapping
			General.Map.UndoRedo.CreateUndo("Snap things");

			int snappedCount = 0;

			//snap them all!
			foreach(Thing t in things) {
				Vector2D pos = t.Position;
				t.SnapToGrid();

				if(t.Position.x != pos.x || t.Position.y != pos.y)
					snappedCount++;
			}

			//done
			General.Interface.DisplayStatus(StatusType.Info, "Snapped " + snappedCount + " things.");
			base.OnAccept();
			General.Editing.ChangeMode(General.Editing.PreviousStableMode.Name);
		}

        // Disenagaging
        public override void OnDisengage() {
            base.OnDisengage();
            Cursor.Current = Cursors.AppStarting;

            if (!cancelled) {
                // Update cached values
                General.Map.Map.Update();
                // Map is changed
                General.Map.IsChanged = true;
            }

            // Done
            Cursor.Current = Cursors.Default;
        }
    }
}