// Unity C# reference source
// Copyright (c) Unity Technologies. For terms of use, see
// https://unity3d.com/legal/licenses/Unity_Reference_Only_License

using System;
using UnityEditorInternal;
using UnityEngine;
using System.Collections.Generic;

namespace UnityEditor
{
    internal class RotationCurveInterpolation
    {
        public struct State
        {
            public bool allAreNonBaked;
            public bool allAreBaked;
            public bool allAreRaw;
            public bool allAreRotations;
        }

        public static char[] kPostFix = { 'x', 'y', 'z', 'w' };

        public enum Mode { Baked, NonBaked, RawQuaternions, RawEuler, Undefined }

        public static Mode GetModeFromCurveData(EditorCurveBinding data)
        {
            if (AnimationWindowUtility.IsTransformType(data.type) && data.propertyName.StartsWith("localEulerAngles"))
            {
                if (data.propertyName.StartsWith("localEulerAnglesBaked"))
                    return Mode.Baked;
                else if (data.propertyName.StartsWith("localEulerAnglesRaw"))
                    return Mode.RawEuler;
                else
                    return Mode.NonBaked;
            }
            else if (AnimationWindowUtility.IsTransformType(data.type) && data.propertyName.StartsWith("m_LocalRotation"))
                return Mode.RawQuaternions;

            return Mode.Undefined;
        }

        // Extracts the interpolation state for the selection from the clip
        public static State GetCurveState(AnimationClip clip, EditorCurveBinding[] selection)
        {
            State state;
            state.allAreRaw = true;
            state.allAreNonBaked = true;
            state.allAreBaked = true;
            state.allAreRotations = true;

            foreach (EditorCurveBinding data in selection)
            {
                Mode mode = GetModeFromCurveData(data);
                state.allAreBaked &= (mode == Mode.Baked);
                state.allAreNonBaked &= (mode == Mode.NonBaked);
                state.allAreRaw &= mode == (Mode.RawEuler);
                state.allAreRotations &= mode != (Mode.Undefined);
            }

            return state;
        }

        public static char ExtractComponentCharacter(string name)
        {
            return name[name.Length - 1];
        }

        public static string GetPrefixForInterpolation(Mode newInterpolationMode)
        {
            if (newInterpolationMode == Mode.Baked)
                return "localEulerAnglesBaked";
            else if (newInterpolationMode == Mode.NonBaked)
                return "localEulerAngles";
            else if (newInterpolationMode == Mode.RawEuler)
                return "localEulerAnglesRaw";
            else if (newInterpolationMode == Mode.RawQuaternions)
                return "m_LocalRotation";
            else
                return null;
        }

        internal static EditorCurveBinding[] ConvertRotationPropertiesToDefaultInterpolation(AnimationClip clip, EditorCurveBinding[] selection)
        {
            var mode = clip.legacy ? Mode.Baked : Mode.RawEuler;
            return ConvertRotationPropertiesToInterpolationType(selection, mode);
        }

        internal static EditorCurveBinding[] ConvertRotationPropertiesToInterpolationType(EditorCurveBinding[] selection, Mode newInterpolationMode)
        {
            if (selection.Length != 4)
                return selection;

            if (GetModeFromCurveData(selection[0]) == Mode.RawQuaternions)
            {
                EditorCurveBinding[] newCurves = new EditorCurveBinding[3];
                newCurves[0] = selection[0];
                newCurves[1] = selection[1];
                newCurves[2] = selection[2];

                string prefix = GetPrefixForInterpolation(newInterpolationMode);
                newCurves[0].propertyName = prefix + ".x";
                newCurves[1].propertyName = prefix + ".y";
                newCurves[2].propertyName = prefix + ".z";

                return newCurves;
            }
            else
                return selection;
        }

        static EditorCurveBinding[] GenerateTransformCurveBindingArray(string path, string property, Type type, int count)
        {
            EditorCurveBinding[] bindings = new EditorCurveBinding[count];
            for (int i = 0; i < count; i++)
                bindings[i] = EditorCurveBinding.FloatCurve(path, type, property + kPostFix[i]);
            return bindings;
        }

        static public EditorCurveBinding[] RemapAnimationBindingForAddKey(EditorCurveBinding binding, AnimationClip clip)
        {
            if (!AnimationWindowUtility.IsTransformType(binding.type))
            {
                return null;
            }
            else if (binding.propertyName.StartsWith("m_LocalPosition."))
            {
                if (binding.type == typeof(Transform))
                    return GenerateTransformCurveBindingArray(binding.path, "m_LocalPosition.", binding.type, 3);
                else
                    return null;
            }
            else if (binding.propertyName.StartsWith("m_LocalScale."))
                return GenerateTransformCurveBindingArray(binding.path, "m_LocalScale.", binding.type, 3);
            else if (binding.propertyName.StartsWith("m_LocalRotation"))
            {
                return SelectRotationBindingForAddKey(binding, clip);
            }
            else
                return null;
        }

        static public EditorCurveBinding[] RemapAnimationBindingForRotationAddKey(EditorCurveBinding binding, AnimationClip clip)
        {
            if (!AnimationWindowUtility.IsTransformType(binding.type))
            {
                return null;
            }
            else if (binding.propertyName.StartsWith("m_LocalRotation"))
            {
                return SelectRotationBindingForAddKey(binding, clip);
            }
            else
                return null;
        }

        static private EditorCurveBinding[] SelectRotationBindingForAddKey(EditorCurveBinding binding, AnimationClip clip)
        {
            EditorCurveBinding testBinding = binding;
            testBinding.propertyName = "localEulerAnglesBaked.x";
            if (AnimationUtility.GetEditorCurve(clip, testBinding) != null)
                return GenerateTransformCurveBindingArray(binding.path, "localEulerAnglesBaked.", binding.type, 3);
            else
            {
                testBinding.propertyName = "localEulerAngles.x";
                if (AnimationUtility.GetEditorCurve(clip, testBinding) != null)
                {
                    return GenerateTransformCurveBindingArray(binding.path, "localEulerAngles.", binding.type, 3);
                }
                else
                {
                    testBinding.propertyName = "localEulerAnglesRaw.x";
                    if (clip.legacy && AnimationUtility.GetEditorCurve(clip, testBinding) == null)
                        return GenerateTransformCurveBindingArray(binding.path, "localEulerAnglesBaked.", binding.type, 3);

                    return GenerateTransformCurveBindingArray(binding.path, "localEulerAnglesRaw.", binding.type, 3);
                }
            }
        }

        static public EditorCurveBinding RemapAnimationBindingForRotationCurves(EditorCurveBinding curveBinding, AnimationClip clip)
        {
            if (!AnimationWindowUtility.IsTransformType(curveBinding.type))
                return curveBinding;

            // Convert rotation binding to valid editor curve binding.
            // Only a single rotation binding (RawEuler, Baked or NonBaked) should be allowed in one clip.
            // RawQuaternions should be converted to appropriate euler bindings if available.
            Mode mode = GetModeFromCurveData(curveBinding);
            if (mode != Mode.Undefined)
            {
                string suffix = curveBinding.propertyName.Split('.')[1];

                EditorCurveBinding newBinding = curveBinding;

                if (mode != Mode.NonBaked)
                {
                    newBinding.propertyName = GetPrefixForInterpolation(Mode.NonBaked) + "." + suffix;
                    AnimationCurve curve = AnimationUtility.GetEditorCurve(clip, newBinding);
                    if (curve != null)
                        return newBinding;
                }

                if (mode != Mode.Baked)
                {
                    newBinding.propertyName = GetPrefixForInterpolation(Mode.Baked) + "." + suffix;
                    AnimationCurve curve = AnimationUtility.GetEditorCurve(clip, newBinding);
                    if (curve != null)
                        return newBinding;
                }

                if (mode != Mode.RawEuler)
                {
                    newBinding.propertyName = GetPrefixForInterpolation(Mode.RawEuler) + "." + suffix;
                    AnimationCurve curve = AnimationUtility.GetEditorCurve(clip, newBinding);
                    if (curve != null)
                        return newBinding;
                }

                return curveBinding;
            }
            else
                return curveBinding;
        }

        internal static void SetInterpolation(AnimationClip clip, EditorCurveBinding[] curveBindings, Mode newInterpolationMode)
        {
            Undo.RegisterCompleteObjectUndo(clip, "Rotation Interpolation");

            if (clip.legacy && newInterpolationMode == Mode.RawEuler)
            {
                Debug.LogWarning("Warning, Euler Angles interpolation mode is not fully supported for Legacy animation clips. If you mix clips using Euler Angles interpolation with clips using other interpolation modes (using Animation.CrossFade, Animation.Blend or other methods), you will get erroneous results. Use with caution.", clip);
            }
            List<EditorCurveBinding> newCurvesBindings = new List<EditorCurveBinding>();
            List<AnimationCurve> newCurveDatas = new List<AnimationCurve>();
            List<EditorCurveBinding> oldCurvesBindings = new List<EditorCurveBinding>();

            foreach (EditorCurveBinding curveBinding in curveBindings)
            {
                Mode currentMode = GetModeFromCurveData(curveBinding);

                if (currentMode == Mode.Undefined)
                    continue;

                if (currentMode == Mode.RawQuaternions)
                {
                    Debug.LogWarning("Can't convert quaternion curve: " + curveBinding.propertyName);
                    continue;
                }

                AnimationCurve curve = AnimationUtility.GetEditorCurve(clip, curveBinding);

                if (curve == null)
                    continue;

                string newPropertyPath = GetPrefixForInterpolation(newInterpolationMode) + '.' + ExtractComponentCharacter(curveBinding.propertyName);

                EditorCurveBinding newBinding = new EditorCurveBinding();
                newBinding.propertyName = newPropertyPath;
                newBinding.type = curveBinding.type;
                newBinding.path = curveBinding.path;
                newCurvesBindings.Add(newBinding);
                newCurveDatas.Add(curve);

                EditorCurveBinding removeCurve = new EditorCurveBinding();
                removeCurve.propertyName = curveBinding.propertyName;
                removeCurve.type = curveBinding.type;
                removeCurve.path = curveBinding.path;
                oldCurvesBindings.Add(removeCurve);
            }

            Undo.RegisterCompleteObjectUndo(clip, "Rotation Interpolation");

            foreach (EditorCurveBinding binding in oldCurvesBindings)
                AnimationUtility.SetEditorCurve(clip, binding, null);

            foreach (EditorCurveBinding binding in newCurvesBindings)
                AnimationUtility.SetEditorCurve(clip, binding, newCurveDatas[newCurvesBindings.IndexOf(binding)]);
        }
    }
}
