using LibMMD.Model;

namespace LibMMD.Motion
{
    public class MotionPlayer
    {
        public MotionPlayer(MmdMotion motion, Poser poser)
        {
            _motion = motion;
            _poser = poser;
            var model = poser.Model;
            _translationScaler = new MmdMotionTranslationScaler(model);
            _bindings = new MmdMotionBindingMap(motion, model);
            _grooveFallback = new MmdGrooveFallback(
                motion, poser, _translationScaler, _bindings.GrooveFallbackCenterIndex);
            _morphWeightCalculator = new MmdMorphWeightCalculator(motion, _bindings.Morphs);
            poser.ResetIkEnabled();
        }

        public void SeekFrame(int frame)
        {
            foreach (var entry in _bindings.Ik)
                _poser.SetIkEnabled(entry.Value, _motion.GetIkEnabled(entry.Key, frame));
            foreach (var entry in _bindings.Morphs)
            {
                _poser.SetMorphPose(entry.Value, _motion.GetMorphPose(entry.Key, frame));
            }
            foreach (var entry in _bindings.Bones)
            {
                _poser.SetBonePose(entry.Value,
                    _translationScaler.Apply(entry.Value, _motion.GetBonePose(entry.Key, frame)));
            }
            _grooveFallback.ApplyFrame(frame);
        }

        public void SeekTime(double time)
        {
            var frame = time * 30.0;
            foreach (var entry in _bindings.Ik)
                _poser.SetIkEnabled(entry.Value, _motion.GetIkEnabled(entry.Key, frame));
            foreach (var entry in _bindings.Morphs)
            {
                _poser.SetMorphPose(entry.Value, _motion.GetMorphPose(entry.Key, time));
            }
            foreach (var entry in _bindings.Bones)
            {
                _poser.SetBonePose(entry.Value,
                    _translationScaler.Apply(entry.Value, _motion.GetBonePose(entry.Key, time)));
            }
            _grooveFallback.ApplyTime(time);
        }

        // Effective weight per vertex-type morph (indexed by model.Morphs index), with group
        // morphs recursively expanded into their leaf vertex morphs. Used to drive Unity
        // BlendShape weights (SkinnedMeshRenderer.SetBlendShapeWeight) instead of rewriting
        // vertex positions directly.
        public void CalculateMorphWeights(MmdModel model, double time, float[] output)
        {
            _morphWeightCalculator.Calculate(model, time, output);
        }
        
        public double GetMotionTimeLength()
        {
            return _motion.Length * 30.0;
        }

        public int GetMotionFrameLength()
        {
            return _motion.Length;
        }

        private readonly MmdMotion _motion;
        private readonly Poser _poser;
        private readonly MmdMotionTranslationScaler _translationScaler;
        private readonly MmdMotionBindingMap _bindings;
        private readonly MmdGrooveFallback _grooveFallback;
        private readonly MmdMorphWeightCalculator _morphWeightCalculator;
    }
}