using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;

namespace AiwazAnimator
{
    abstract public class Animation : INotifyPropertyChanged
    {
        public float StartTime { get; set; }
        public float EndTime { get; set; }
        public float StartValue { get; set; }
        public float EndValue { get; set; }

        public Func<float> ValueGetter;
        public Action<float> ValueSetter;
        public Func<string> ValueNamer;
        public float Value
        {
            get { return ValueGetter(); }
            set { ValueSetter(value); OnPropertyChanged("Value"); }
        }

        private float _time;
        public float Time
        {
            get
            {
                return _time;
            }
            set
            {
                if (_time == value)
                    return;
                _time = value;
                OnPropertyChanged("Time");
            }
        }

        public Animation()
        {
            AnimationName = "Erroneous";
        }

        public string ListString
        {
            get
            {
                return string.Format("Type: {0}, Time: [{1}, {2}], Value: [{3}, {4}], Target: {5}", AnimationName, StartTime, EndTime, StartValue, EndValue, ValueNamer());
            }
        }

        public void Animate(float time)
        {
            if (time < StartTime)
            {
                return;
            }
            else if (time > EndTime)
            {
                return;
            }
            float NormalizedTime = (time - StartTime) / (EndTime - StartTime);
            Time = NormalizedTime;
            Value = Calculate(NormalizedTime);
        }

        protected abstract float Calculate(float NormalizedTime);
        public string AnimationName;

        protected virtual void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }
}