//### Particles Static Bezier Flow Inspector
//Provides a Unity Editor UI for `ParticlesStaticBezierFlowController`
//
//License information: [ASSET STORE TERMS OF SERVICE AND EULA](https://unity3d.com/legal/as_terms)
//
//Developed by [MathArtCode](https://www.assetstore.unity3d.com/en/#!/search/page=1/sortby=popularity/query=publisher:8738) team, 2015

using Assets.Editor.BezierCurvedParticlesFlow.Utilities;
using Assets.Scripts.BezierCurvedParticlesFlow;
using UnityEditor;
using UnityEngine;

#if !UNITY_3_5
namespace Assets.Editor.BezierCurvedParticlesFlow {
#endif
    // ReSharper disable once UnusedMember.Global
    [CustomEditor( typeof( ParticlesStaticBezierFlowController ) )]
    public sealed class ParticlesStaticBezierFlowInspector: UnityEditor.Editor {


        private ParticlesStaticBezierFlowController _flowController;

        private CurveDrawingHelper _curveDrawingHelperObject;
        private CurveDrawingHelper CurveDrawingHelper {
            get {
                if ( _curveDrawingHelperObject == null ) {
                    _curveDrawingHelperObject =
                        new CurveDrawingHelper( this, _flowController.gameObject, _flowController.BezierLogic );
                    CurveDrawingHelper.OnChangeInitiated += OnChangeStarted;
                    CurveDrawingHelper.OnChangeCommit += OnChangeCommit;
                }
                return _curveDrawingHelperObject;
            }
        }

        //Draws inspector interface
        public override void OnInspectorGUI() {
            _flowController = target as ParticlesStaticBezierFlowController;

            if ( _flowController == null ) {
                Debug.LogError( "Spline was not found" );
                return;
            }

            EditorGUI.BeginChangeCheck();
            if ( CurveDrawingHelper.SelectedIndex >= 0 && CurveDrawingHelper.SelectedIndex < _flowController.BezierLogic.ControlPointCount ) {
                DrawSelectedPointInspector();
            }

            if ( GUILayout.Button( "Add Point" ) ) {
                OnChangeStarted("Add Point");
                _flowController.BezierLogic.AddPoint();
                OnChangeCommit();
            }

            var usePositions = GUILayout.Toggle(_flowController.UsePositions, "Use Positions");
            if ( usePositions != _flowController.UsePositions ) {
                OnChangeStarted("Use Positions changed" );
                _flowController.UsePositions = usePositions;
                OnChangeCommit();
            }

            var useVelocities = GUILayout.Toggle( _flowController.UseVelocities, "Use Velocities" );
            if ( useVelocities != _flowController.UseVelocities ) {
                OnChangeStarted("Use Velocities changed" );
                _flowController.UseVelocities = useVelocities;
                OnChangeCommit();
            }


            var samplesCount = EditorGUILayout.IntField( "Segments count", _flowController.SamplesCount );
            if ( samplesCount != _flowController.SamplesCount ) {
               OnChangeStarted("Segments count changed");
                _flowController.SamplesCount = samplesCount;
                OnChangeCommit();
            }

#if UNITY_3_5
            EditorGUILayout.HelpBox("You shall set this to the same value \"Particle System->Game Object->Max Particles\" is set. \nThis field is editable only for Unity 3.", MessageType.Warning);
            var maxParticles = EditorGUILayout.IntField( "Max Particles", _flowController.MaxParticles );
            if ( maxParticles != _flowController.MaxParticles ) {
                OnChangeStarted( "Max Particles count changed" );
                _flowController.MaxParticles = maxParticles;
                OnChangeCommit();
            }
#endif

        }

        //Draws currently selected curve point Editor Inspector UI
        private void DrawSelectedPointInspector() {
            GUILayout.Label("Selected Point");
            EditorGUI.BeginChangeCheck();
            var point = EditorGUILayout.Vector3Field( "Position", _flowController.BezierLogic.GetControlPoint( CurveDrawingHelper.SelectedIndex) );
            if (EditorGUI.EndChangeCheck()) {
                OnChangeStarted("Move Point");
                _flowController.BezierLogic.SetControlPoint( CurveDrawingHelper.SelectedIndex, point );
                OnChangeCommit();
            }
            EditorGUI.BeginChangeCheck();
        }

        // Draws curve on in Scene window
        // ReSharper disable once UnusedMember.Local
        // ReSharper disable once InconsistentNaming
        private void OnSceneGUI() {
            _flowController = target as ParticlesStaticBezierFlowController;
            CurveDrawingHelper.OnSceneGUI();
        }

        // Registers editor action checkpoint
        private void OnChangeStarted(string label) {
#if UNITY_3_5
            Undo.RegisterUndo( _flowController, label );
#else
            Undo.RecordObject( _flowController, label);
#endif
        }

        // Registers commits new checkpoint
        private void OnChangeCommit() {
            _flowController.Rasterize();
            EditorUtility.SetDirty(_flowController);
        }
    }
#if !UNITY_3_5
}
#endif