using UnityEngine;

namespace OctoCore.Components
{
public class OctoCharacterAnimation : MonoBehaviour
{
    [SerializeField] private Animator animator;
    [SerializeField] private float walkSpeed = 8;
    [SerializeField] private float runSpeed = 15;
    [SerializeField, Range(1, 10)] private int sampling = 5;

    private bool backward;
    private float backwardSmooth;
    private float sideSmooth;
    private float smoothSpeed;
    private Vector4[] positions;
    private Vector3 lastStep;
    private Vector3 direction;

    private float step = .1f;

    void OnDrawGizmos()
    {
        Gizmos.color = Color.cyan;
        Gizmos.DrawRay(transform.position + Vector3.up, transform.forward);

        Gizmos.color = Color.red;
        Gizmos.DrawRay(transform.position + Vector3.up, direction);
    }

    void OnEnable()
    {
        positions = new Vector4[sampling + 1];
        for (int i = 0; i < sampling; i++)
        {
            positions[i] = transform.position;
            positions[i].z = .002f;
        }

        direction = transform.forward;
    }

    void Update()
    {
        if (lastStep != transform.position && Vector3.Distance(lastStep, transform.position) > step)
        {
            Vector3 offset = (lastStep - transform.position).normalized * step;
            lastStep = transform.position + offset;
        }

        direction = Vector3.Lerp(direction, (transform.position - lastStep).normalized, Time.deltaTime * 10);

        float speed = GetSpeed();
        smoothSpeed = Mathf.Lerp(smoothSpeed, speed, Time.deltaTime * 10);

        float move = Mathf.Clamp01(smoothSpeed / walkSpeed);
        float run = Mathf.Clamp01((smoothSpeed - walkSpeed) / (runSpeed - walkSpeed));

        float dot = Vector3.Dot(transform.forward, direction.normalized);
        Vector3 crs = Vector3.Cross(transform.forward, direction.normalized);

        backward = dot < 0;
        backwardSmooth = Mathf.Lerp(backwardSmooth, backward ? 1 : 0, Time.deltaTime * 10);

        sideSmooth = Mathf.Lerp(sideSmooth, (1 - Mathf.Abs(dot)) * Mathf.Sign(transform.InverseTransformDirection(crs).y) * direction.magnitude, Time.deltaTime * 20);

        run *= 1 - backwardSmooth;
        run *= 1 - Mathf.Abs(sideSmooth);

        //Debug.Log(dot);

        animator.SetFloat("move", Mathf.Sqrt(move));
        animator.SetFloat("run", run);
        animator.SetFloat("backward", backwardSmooth);
        animator.SetFloat("side", sideSmooth);
    }

    float GetSpeed()
    {
        float offset = 0;
        float delta = 0;

        for (int i = 0; i < positions.Length - 1; i++)
        {
            offset += Vector3.Distance(positions[i], positions[i + 1]);
            delta += positions[i].w;
        }

        for (int i = positions.Length - 1; i > 0; i--)
            positions[i] = positions[i - 1];

        positions[0] = transform.position;
        positions[0].w = Time.deltaTime;

        if (offset > 0 && delta > 0)
            return offset / (delta / 3.6f);
        else return 0;
    }
}

}