using UnityEngine;
using UnityEditor;
using System.Collections.Generic;
using Cinemachine.Utility;
using System.IO;

namespace Cinemachine.Editor
{
    [CustomEditor(typeof(CinemachineBrain))]
    public sealed class CinemachineBrainEditor : BaseEditor<CinemachineBrain>
    {
        EmbeddeAssetEditor<CinemachineBlenderSettings> m_BlendsEditor;
        bool mEventsExpanded = false;

        protected override List<string> GetExcludedPropertiesInInspector()
        {
            List<string> excluded = base.GetExcludedPropertiesInInspector();
            excluded.Add(FieldPath(x => x.m_CameraCutEvent));
            excluded.Add(FieldPath(x => x.m_CameraActivatedEvent));
            excluded.Add(FieldPath(x => x.m_CustomBlends));
            return excluded;
        }

        private void OnEnable()
        {
            m_BlendsEditor = new EmbeddeAssetEditor<CinemachineBlenderSettings>(
                    FieldPath(x => x.m_CustomBlends), this);
            m_BlendsEditor.OnChanged = (CinemachineBlenderSettings b) =>
                {
                    UnityEditorInternal.InternalEditorUtility.RepaintAllViews();
                };
        }

        private void OnDisable()
        {
            if (m_BlendsEditor != null)
                m_BlendsEditor.OnDisable();
        }

        public override void OnInspectorGUI()
        {
            BeginInspector();

            // Show the active camera and blend
            GUI.enabled = false;
            ICinemachineCamera vcam = Target.ActiveVirtualCamera;
            Transform activeCam = (vcam != null && vcam.VirtualCameraGameObject != null)
                ? vcam.VirtualCameraGameObject.transform : null;
            EditorGUILayout.ObjectField("Live Camera", activeCam, typeof(Transform), true);
            EditorGUILayout.DelayedTextField(
                "Live Blend", Target.ActiveBlend != null
                ? Target.ActiveBlend.Description : string.Empty);
            GUI.enabled = true;

            // Normal properties
            DrawRemainingPropertiesInInspector();

            // Blender
            m_BlendsEditor.DrawEditorCombo(
                "Create New Blender Asset",
                Target.gameObject.name + " Blends", "asset", string.Empty,
                "Custom Blends", false);

            mEventsExpanded = EditorGUILayout.Foldout(mEventsExpanded, "Events", true);
            if (mEventsExpanded)
            {
                EditorGUILayout.PropertyField(FindProperty(x => x.m_CameraCutEvent));
                EditorGUILayout.PropertyField(FindProperty(x => x.m_CameraActivatedEvent));
            }
            serializedObject.ApplyModifiedProperties();
        }

        [DrawGizmo(GizmoType.Selected | GizmoType.NonSelected, typeof(CinemachineBrain))]
        private static void DrawBrainGizmos(CinemachineBrain brain, GizmoType drawType)
        {
            if (brain.OutputCamera != null && brain.m_ShowCameraFrustum)
            {
                DrawCameraFrustumGizmo(
                    brain, LensSettings.FromCamera(brain.OutputCamera), 
                    brain.transform.localToWorldMatrix, 
                    Color.white); // GML why is this color hardcoded?
            }
        }

        internal static void DrawCameraFrustumGizmo(
            CinemachineBrain brain, LensSettings lens, 
            Matrix4x4 transform, Color color)
        {
            float aspect = 1;
            bool ortho = false;
            if (brain != null)
            {
                aspect = brain.OutputCamera.aspect;
                ortho = brain.OutputCamera.orthographic;
            }

            Matrix4x4 originalMatrix = Gizmos.matrix;
            Color originalGizmoColour = Gizmos.color;
            Gizmos.color = color;
            Gizmos.matrix = transform;
            if (ortho)
            {
                Vector3 size = new Vector3(
                        aspect * lens.OrthographicSize * 2, 
                        lens.OrthographicSize * 2, 
                        lens.NearClipPlane + lens.FarClipPlane);
                Gizmos.DrawWireCube(
                    new Vector3(0, 0, (size.z / 2) + lens.NearClipPlane), size);
            }
            else
            {
                Gizmos.DrawFrustum(
                        Vector3.zero, lens.FieldOfView,
                        lens.FarClipPlane, lens.NearClipPlane, aspect);
            }
            Gizmos.matrix = originalMatrix;
            Gizmos.color = originalGizmoColour;
        }

        [DrawGizmo(GizmoType.Active | GizmoType.InSelectionHierarchy | GizmoType.Pickable, typeof(CinemachineVirtualCameraBase))]
        public static void DrawVirtualCameraBaseGizmos(CinemachineVirtualCameraBase vcam, GizmoType selectionType)
        {
            // Don't draw gizmos on hidden stuff
            if ((vcam.gameObject.hideFlags & (HideFlags.HideInHierarchy | HideFlags.HideInInspector)) != 0)
                return;

            if (vcam.ParentCamera != null && (selectionType & GizmoType.Active) == 0)
                return;

            CameraState state = vcam.State;
            Gizmos.DrawIcon(state.FinalPosition, kGizmoFileName, true);

            DrawCameraFrustumGizmo(
                CinemachineCore.Instance.FindPotentialTargetBrain(vcam),
                state.Lens,
                Matrix4x4.TRS(
                    state.FinalPosition,
                    UnityQuaternionExtensions.Normalized(state.FinalOrientation), Vector3.one),
                CinemachineCore.Instance.IsLive(vcam)
                    ? CinemachineSettings.CinemachineCoreSettings.ActiveGizmoColour
                    : CinemachineSettings.CinemachineCoreSettings.InactiveGizmoColour);
        }

        static string kGizmoFileName = "Packages/com.unity.cinemachine/Gizmos/cm_logo.png";
    }
}
