using System.Collections;
using System.Collections.Generic;
using uc.Spline;
using UnityEngine;

public class IronHorse : MonoBehaviour {

    [SerializeField]
    private IronHorseDataHolder ironHorseHolder;

    public BezierSplineComponent m_bezierSpline;
    [SerializeField]
    public float targetSpeed;
    public Ease.Easing m_ease;
    public bool playOnStart = true;

    public float speedSmooth { set { speed_smooth = value; } }
    private float speed_smooth = 0.1f;
    float m_speed = 1;
    float m_position = 0;
    BaseSpline.SplineIterator m_iter;

    public float initialPosition = 0;

    public float Progress
    {
        get { if(m_bezierSpline != null) return m_position / m_bezierSpline.Spline.Length; return 0; }
    }

    // Use this for initialization
    IEnumerator Start ()
    {
        while (m_bezierSpline == null)
            yield return null;

        m_iter = m_bezierSpline.Spline.GetIterator();
        m_iter.SetTransform(m_bezierSpline.transform);

        if (ironHorseHolder)
        {
            targetSpeed = ironHorseHolder.TargetSpeed;
            speed_smooth = ironHorseHolder.SpeedSmooth;
            m_ease = ironHorseHolder.ease;
        }
        if(initialPosition != 0)
            m_position = initialPosition;


        if (playOnStart)
            Play();
    }

    // Update is called once per frame
    void Update()
    {
        if (m_bezierSpline == null || m_iter == null)
            return;

        m_speed = Mathf.Lerp(m_speed, targetSpeed, speed_smooth);

        if(isPlaying)
            m_position += m_speed * Time.deltaTime;

        float position = Ease.EaseByType(m_ease, 0, m_bezierSpline.Spline.Length, m_position / m_bezierSpline.Spline.Length);
        m_iter.SetOffset(position);

        transform.position = m_iter.GetPosition();

        Vector3 tangent = m_iter.GetTangent();
        if(tangent != Vector3.zero)
            transform.localRotation = Quaternion.LookRotation(tangent);
    }

    bool isPlaying = false;
    public void Play()
    {
        isPlaying = true;
    }

    public void Pause()
    {
        isPlaying = false;
    }

    public void Stop()
    {
        Pause();
        m_position = initialPosition;
    }

    void OnDrawGizmos()
    {
        if (m_iter == null)
            return;
        Gizmos.matrix = transform.localToWorldMatrix;
        Gizmos.color = Color.black;
        float fov = 30;
        float near = 0;
        float far = 10;
        float aspect = 2;
        Gizmos.DrawFrustum(Vector3.zero, fov, far, near, aspect);
        Gizmos.DrawLine(Vector3.zero, Vector3.forward * far);
    }
}