using UnityEngine;
using UnityEditor;
using System.Collections.Generic;

namespace Cinemachine.Editor
{
    [CustomEditor(typeof(CinemachineTransposer))]
    [CanEditMultipleObjects]
    internal sealed class CinemachineTransposerEditor : BaseEditor<CinemachineTransposer>
    {
        /// <summary>Get the property names to exclude in the inspector.</summary>
        /// <param name="excluded">Add the names to this list</param>
        protected override void GetExcludedPropertiesInInspector(List<string> excluded)
        {
            base.GetExcludedPropertiesInInspector(excluded);

            switch (Target.m_BindingMode)
            {
                default:
                case CinemachineTransposer.BindingMode.LockToTarget:
                    if (Target.m_AngularDampingMode == CinemachineTransposer.AngularDampingMode.Euler)
                        excluded.Add(FieldPath(x => x.m_AngularDamping));
                    else
                    {
                        excluded.Add(FieldPath(x => x.m_PitchDamping));
                        excluded.Add(FieldPath(x => x.m_YawDamping));
                        excluded.Add(FieldPath(x => x.m_RollDamping));
                    }
                    break;
                case CinemachineTransposer.BindingMode.LockToTargetNoRoll:
                    excluded.Add(FieldPath(x => x.m_RollDamping));
                    excluded.Add(FieldPath(x => x.m_AngularDamping));
                    excluded.Add(FieldPath(x => x.m_AngularDampingMode));
                    break;
                case CinemachineTransposer.BindingMode.LockToTargetWithWorldUp:
                    excluded.Add(FieldPath(x => x.m_PitchDamping));
                    excluded.Add(FieldPath(x => x.m_RollDamping));
                    excluded.Add(FieldPath(x => x.m_AngularDamping));
                    excluded.Add(FieldPath(x => x.m_AngularDampingMode));
                    break;
                case CinemachineTransposer.BindingMode.LockToTargetOnAssign:
                case CinemachineTransposer.BindingMode.WorldSpace:
                    excluded.Add(FieldPath(x => x.m_PitchDamping));
                    excluded.Add(FieldPath(x => x.m_YawDamping));
                    excluded.Add(FieldPath(x => x.m_RollDamping));
                    excluded.Add(FieldPath(x => x.m_AngularDamping));
                    excluded.Add(FieldPath(x => x.m_AngularDampingMode));
                    break;
                case CinemachineTransposer.BindingMode.SimpleFollowWithWorldUp:
                    excluded.Add(FieldPath(x => x.m_XDamping));
                    excluded.Add(FieldPath(x => x.m_PitchDamping));
                    excluded.Add(FieldPath(x => x.m_YawDamping));
                    excluded.Add(FieldPath(x => x.m_RollDamping));
                    excluded.Add(FieldPath(x => x.m_AngularDamping));
                    excluded.Add(FieldPath(x => x.m_AngularDampingMode));
                    break;
            }
            if (Target.HideOffsetInInspector)
                excluded.Add(FieldPath(x => x.m_FollowOffset));
        }

        public override void OnInspectorGUI()
        {
            BeginInspector();
            bool needWarning = false;
            for (int i = 0; !needWarning && i < targets.Length; ++i)
                needWarning = (targets[i] as CinemachineTransposer).FollowTarget == null;
            if (needWarning)
                EditorGUILayout.HelpBox(
                    "Transposer requires a Follow Target.  Change Body to Do Nothing if you don't want a Follow target.",
                    MessageType.Warning);
            DrawRemainingPropertiesInInspector();
        }

        /// Process a position drag from the user.
        /// Called "magically" by the vcam editor, so don't change the signature.
        public void OnVcamPositionDragged(Vector3 delta)
        {
            if (Target.FollowTarget != null)
            {
                Undo.RegisterCompleteObjectUndo(Target, "Camera drag");
                Quaternion targetOrientation = Target.GetReferenceOrientation(Target.VcamState.ReferenceUp);
                Vector3 localOffset = Quaternion.Inverse(targetOrientation) * delta;
                Target.m_FollowOffset += localOffset;
                Target.m_FollowOffset = Target.EffectiveOffset;
            }
        }

        [DrawGizmo(GizmoType.Active | GizmoType.Selected, typeof(CinemachineTransposer))]
        static void DrawTransposerGizmos(CinemachineTransposer target, GizmoType selectionType)
        {
            if (target.IsValid  & !target.HideOffsetInInspector)
            {
                Color originalGizmoColour = Gizmos.color;
                Gizmos.color = CinemachineCore.Instance.IsLive(target.VirtualCamera)
                    ? CinemachineSettings.CinemachineCoreSettings.ActiveGizmoColour
                    : CinemachineSettings.CinemachineCoreSettings.InactiveGizmoColour;

                Vector3 up = Vector3.up;
                CinemachineBrain brain = CinemachineCore.Instance.FindPotentialTargetBrain(target.VirtualCamera);
                if (brain != null)
                    up = brain.DefaultWorldUp;
                Vector3 targetPos = target.FollowTargetPosition;
                Vector3 desiredPos = target.GetTargetCameraPosition(up);
                Gizmos.DrawLine(targetPos, desiredPos);
                //Gizmos.DrawWireSphere(desiredPos, HandleUtility.GetHandleSize(desiredPos) / 20);
                Gizmos.color = originalGizmoColour;
            }
        }
    }
}