using System;
using System.Collections;
using UnityEngine;
using UnityEngine.Assertions;

[RequireComponent(typeof(ProjectileSpawner))]
public class ProjectileTower : Tower
{
    [SerializeField, Range(0.01f, 20f)] private float attackSecondsDelay = 1f;
    [SerializeField] private ProjectilePattern[] projectileSequence;
    [SerializeField] private GameObject barrel;

    private ProjectileSpawner projectileSpawner;

    public Vector3 AimDirection => transform.TransformVector(transform.InverseTransformVector(horizontalArc.ToKnobVector) + transform.InverseTransformVector(verticalArc.ToKnobVector));

    protected override void Awake()
    {
        base.Awake();

        projectileSpawner = GetComponent<ProjectileSpawner>();
        Assert.IsNotNull(projectileSpawner);

        horizontalArc.Value.AddListener(UpdateBarrelRotation);
        verticalArc.Value.AddListener(UpdateBarrelRotation);

        UpdateBarrelRotation();
        StartCoroutine(AttackLoop());
    }

    protected override void OnDestroy()
    {
        horizontalArc.Value.RemoveListener(UpdateBarrelRotation);
        verticalArc.Value.RemoveListener(UpdateBarrelRotation);
    }

    private IEnumerator AttackLoop()
    {
        do {
            yield return new WaitForSeconds(attackSecondsDelay);
            UpdateBarrelRotation();
            Debug.DrawRay(transform.position, horizontalArc.ToKnobVector, Color.red, attackSecondsDelay);
            Debug.DrawRay(transform.position, verticalArc.ToKnobVector, Color.green, attackSecondsDelay);
            Debug.DrawRay(transform.position, AimDirection, Color.yellow, attackSecondsDelay);
            projectileSpawner.RunBulletSequence(transform.position, transform.up, AimDirection, projectileSequence);
        } while (true);
    }

    private void UpdateBarrelRotation(float unused) => UpdateBarrelRotation();

    // Rotate barrel to match rotation
    private void UpdateBarrelRotation()
    {
        barrel.transform.rotation = Quaternion.Euler(verticalArc.Value, horizontalArc.Value, 0f);
    }
}