using Unity.Mathematics;
using UnityEditor;
using UnityEditor.EditorTools;
using UnityEditor.Splines;
using UnityEngine;
using UnityEngine.Splines;

namespace Unity.Splines.Examples
{
    [EditorTool("Width Tool", typeof(LoftRoadBehaviour))]
    public class WidthTool : SplineDataToolBase<float>, IDrawSelectedHandles
    {
        GUIContent m_IconContent;
        public override GUIContent toolbarIcon => m_IconContent;

        bool m_DisableHandles = false;

        void OnEnable()
        {
            m_IconContent = new GUIContent()
            {
                image = Resources.Load<Texture2D>("Icons/WidthTool"),
                text = "Width Tool",
                tooltip = "Adjust the width of the created road mesh."
            };
        }

        public override void OnToolGUI(EditorWindow window)
        {
            var splineDataTarget = target as LoftRoadBehaviour;
            if (splineDataTarget == null || splineDataTarget.Container == null)
                return;

            Handles.color = Color.blue;
            m_DisableHandles = false;

            var splines = splineDataTarget.Container.Splines;
            for (var i = 0; i < splines.Count; i++)
            {
                if (i < splineDataTarget.Widths.Count)
                {
                    var nativeSpline = new NativeSpline(splines[i], splineDataTarget.Container.transform.localToWorldMatrix);

                    Undo.RecordObject(splineDataTarget, "Modifying Widths SplineData");

                    // User defined handles to manipulate width
                    DrawDataPoints(nativeSpline, splineDataTarget.Widths[i]);

                    // Using the out-of the box behaviour to manipulate indexes
                    nativeSpline.DataPointHandles(splineDataTarget.Widths[i], false, i);
                }
            }
        }

        public void OnDrawHandles()
        {
            var splineDataTarget = target as LoftRoadBehaviour;
            if (ToolManager.IsActiveTool(this) || splineDataTarget.Container == null)
                return;

            Color color = Color.blue;
            color.a = 0.5f;
            Handles.color = color;
            m_DisableHandles = true;

            var splines = splineDataTarget.Container.Splines;
            for (var i = 0; i < splines.Count; i++)
            {
                if (i < splineDataTarget.Widths.Count)
                {
                    var nativeSpline = new NativeSpline(splines[i], splineDataTarget.Container.transform.localToWorldMatrix);
                    DrawDataPoints(nativeSpline, splineDataTarget.Widths[i]);
                }
            }
        }

        protected override bool DrawDataPoint(
            Vector3 position,
            Vector3 tangent,
            Vector3 up,
            float inValue,
            out float outValue)
        {
            int id1 = m_DisableHandles ? -1 : GUIUtility.GetControlID(FocusType.Passive);
            int id2 = m_DisableHandles ? -1 : GUIUtility.GetControlID(FocusType.Passive);

            outValue = 0f;
            if (tangent == Vector3.zero)
                return false;

            if (Event.current.type == EventType.MouseUp
                && Event.current.button != 0
                && (GUIUtility.hotControl == id1 || GUIUtility.hotControl == id2))
            {
                Event.current.Use();
                return false;
            }

            var handleColor = Handles.color;
            if (GUIUtility.hotControl == id1 || GUIUtility.hotControl == id2)
                handleColor = Handles.selectedColor;
            else if (GUIUtility.hotControl == 0 && (HandleUtility.nearestControl == id1 || HandleUtility.nearestControl == id2))
                handleColor = Handles.preselectionColor;

            var normalDirection = math.normalize(math.cross(tangent, up));

            var extremity1 = position - inValue * (Vector3)normalDirection;
            var extremity2 = position + inValue * (Vector3)normalDirection;
            Vector3 val1, val2;
            using (new Handles.DrawingScope(handleColor))
            {
                if (Event.current.type == EventType.Repaint)
                    Handles.DrawLine(extremity1, extremity2);

                val1 = Handles.Slider(id1, extremity1, normalDirection,
                    k_HandleSize * .5f * HandleUtility.GetHandleSize(position), CustomHandleCap, 0);
                val2 = Handles.Slider(id2, extremity2, normalDirection,
                    k_HandleSize * .5f * HandleUtility.GetHandleSize(position), CustomHandleCap, 0);
            }

            if (GUIUtility.hotControl == id1 && math.abs((val1 - extremity1).magnitude) > 0)
            {
                outValue = math.abs((val1 - position).magnitude);
                return true;
            }

            if (GUIUtility.hotControl == id2 && math.abs((val2 - extremity2).magnitude) > 0)
            {
                outValue = math.abs((val2 - position).magnitude);
                return true;
            }

            return false;
        }

        public void CustomHandleCap(int controlID, Vector3 position, Quaternion rotation, float size, EventType eventType)
        {
            if (m_DisableHandles) // If disabled, do nothing unless it's a repaint event
            {
                if (Event.current.type == EventType.Repaint)
                    Handles.CubeHandleCap(controlID, position, rotation, size, eventType);
            }
            else
                Handles.CubeHandleCap(controlID, position, rotation, size, eventType);
        }
    }
}