using System;
using System.Reflection;
using UnityEditor;
using UnityEditor.Animations;
using UnityEngine;
using Object = UnityEngine.Object;
using Random = UnityEngine.Random;

// ReSharper disable once CheckNamespace
namespace AnimatorAsCode.V1
{
    internal static class AacInternals
    {
        internal const string AutoGeneratedPrefix = "zAutogenerated/";
        // The legacy prefix is preserved, because we need to still be able to clean up
        // assets generated using that legacy prefix from previous versions.
        internal const string AutoGeneratedLegacyPrefix = "zAutogenerated__";

        internal static AnimatorController NewAnimatorController(AacConfiguration component, string suffix)
        {
            var animatorController = new AnimatorController();
            animatorController.name = Internal_GenerateAnimationName(component, suffix); // FIXME animation name conflict
            animatorController.hideFlags = HideFlags.None;
            component.ContainerProvider.SaveAsPersistenceRequired(animatorController);
            return animatorController;
        }

        internal static AnimationClip NewClip(AacConfiguration component, string suffix)
        {
            return RegisterClip(component, suffix, new AnimationClip());
        }
        
        internal static AnimationClip RegisterClip(AacConfiguration component, string suffix, AnimationClip clip)
        {
            clip.name = Internal_GenerateAnimationName(component, suffix);
            clip.hideFlags = HideFlags.None;
            component.ContainerProvider.SaveAsRegular(clip);
            return clip;
        }

        internal static BlendTree NewBlendTreeAsRaw(AacConfiguration component, string suffix)
        {
            var clip = new BlendTree();
            clip.name = Internal_GenerateAnimationName(component, suffix);
            clip.hideFlags = HideFlags.None;
            component.ContainerProvider.SaveAsRegular(clip);
            return clip;
        }

        internal static T DuplicateAssetIntoContainer<T>(AacConfiguration component, T assetToDuplicate) where T : Object
        {
            var duplicated = (T)Object.Instantiate(assetToDuplicate);
            duplicated.name = Internal_GenerateAnimationName(component, assetToDuplicate.name);
            duplicated.hideFlags = HideFlags.None;
            component.ContainerProvider.SaveAsRegular(duplicated);
            return duplicated;
        }

        private static string Internal_GenerateAnimationName(AacConfiguration component, string middle)
        {
            return AutoGeneratedPrefix + component.AssetKey + "__" + middle + "_" + Random.Range(0, Int32.MaxValue); // FIXME animation name conflict
        }

        internal static AvatarMask NewAvatarMask(AacConfiguration component, string fullLayerName)
        {
            var avatarMask = new AvatarMask();
            avatarMask.name = AutoGeneratedPrefix + component.AssetKey + "_" + fullLayerName + "__AvatarMask";
            avatarMask.hideFlags = HideFlags.None;
            component.ContainerProvider.SaveAsRegular(avatarMask);
            return avatarMask;
        }

        internal static EditorCurveBinding Binding(AacConfiguration component, Type type, Transform transform, string propertyName)
        {
            return new EditorCurveBinding
            {
                path = ResolveRelativePath(component.AnimatorRoot, transform),
                type = type,
                propertyName = propertyName
            };
        }

        internal static void SetCurve(AnimationClip clip, EditorCurveBinding binding, AnimationCurve curve)
        {
            // https://forum.unity.com/threads/new-animationclip-property-names.367288/#post-2384172
            clip.SetCurve(binding.path, binding.type, binding.propertyName, curve);
        }

        internal static AnimationCurve OneFrame(float desiredValue)
        {
            return AnimationCurve.Constant(0f, 1 / 60f, desiredValue);
        }

        internal static AnimationCurve ConstantSeconds(float seconds, float desiredValue)
        {
            return AnimationCurve.Constant(0f, seconds, desiredValue);
        }

        internal static string ResolveRelativePath(Transform avatar, Transform item)
        {
            if (avatar == item)
            {
                // TODO: Is this correct??
                return "";
            }
            
            if (item.parent != avatar && item.parent != null)
            {
                return ResolveRelativePath(avatar, item.parent) + "/" + item.name;
            }

            return item.name;
        }

        internal static EditorCurveBinding ToSubBinding(EditorCurveBinding binding, string suffix)
        {
            return new EditorCurveBinding {path = binding.path, type = binding.type, propertyName = binding.propertyName + "." + suffix};
        }

        internal static void NoUndo<T>(T obj, Action action)
        {
            try
            {
                UndoDisable(obj);
                action.Invoke();
            }
            finally
            {
                UndoEnable(obj);
            }
        }

        internal static TResult NoUndo<T, TResult>(T obj, Func<TResult> action)
        {
            try
            {
                UndoDisable(obj);
                return action.Invoke();
            }
            finally
            {
                UndoEnable(obj);
            }
        }

        private static void UndoDisable<T>(T state)
        {
            GetPushUndoProperty<T>().SetValue(state, false);
        }

        private static void UndoEnable<T>(T state)
        {
            GetPushUndoProperty<T>().SetValue(state, true);
        }

        private static PropertyInfo GetPushUndoProperty<T>()
        {
            return typeof(T)
                .GetProperty("pushUndo", BindingFlags.Instance | BindingFlags.NonPublic);
        }
    }
}