using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SpawnInLineFromRotationHelper : MonoBehaviour {

    public Vector3 startingRotation;
    public int numMidPoints = 5;
    public float distance = 5f;

    [Header("Prefabs")]
    public GameObject startPrefab;
    public GameObject midPrefab;
    public GameObject endPrefab;

    List<GameObject> spawnedObjs = new List<GameObject>();

    void Update () {
        for(int i = 0; i < spawnedObjs.Count; i++)
        {
            Destroy(spawnedObjs[i]);
        }
        spawnedObjs.Clear();
        Quaternion myRotation = Quaternion.Euler(startingRotation); //Convert to quat for the problems sake
        SpawnInLineFromRotation(transform.position, myRotation);
        Debug.DrawRay(transform.position, myRotation * Vector3.forward);
    }

    void SpawnInLineFromRotation(Vector3 startPoint, Quaternion rotation)
    {
        Vector3 forward = rotation * Vector3.forward;

        //Start point
        GameObject startObj = (GameObject)Instantiate(startPrefab, startPoint, rotation);
        spawnedObjs.Add(startObj);

        float stepSize = distance / (float)(numMidPoints + 1);

        //Start at 1, add 2 to numMidPoints, and end 1 early to make step size calculation easier
        for(int i = 0; i < numMidPoints; i++)
        {
            Vector3 pos = startPoint + (forward * stepSize * (float)(i+1));
            GameObject midObj = (GameObject)Instantiate(midPrefab, pos, rotation);
            spawnedObjs.Add(midObj);
        }

        //End point
        GameObject endObj = (GameObject)Instantiate(endPrefab, startPoint + (forward * distance), rotation);
        spawnedObjs.Add(endObj);
    }
}