apple-picker/Assets/Scripts/AppleTree.cs

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

public class AppleTree : MonoBehaviour
{
    [Header("Set in Inspector")]
    // Prefab for instantiating apples
    public GameObject applePrefab;
    public GameObject rottenApplePrefab;
    // Speed at which the AppleTree moves
    public float speed = 1f;
    // Distance where AppleTree turns around
    public float leftAndRightEdge = 10f;
    // Chance that the AppleTree will change directions
    public float chanceToChangeDirections = 0.1f;
    // Rate at which Apples will be instantiated
    public float secondsBetweenAppleDrops = 1f;
    // Rate at which RottenApples will be instantiated
    public float secondsBetweenRottenAppleDrops = 3f;
    // Start is called before the first frame update
    void Start()
    {
        // Dropping apples every second
        Invoke("DropApple", 2f);
        // Dropping rotten apples every 3 seconds
        Invoke("DropRottenApple", 2f);
    }

    void DropApple() {
        GameObject apple = Instantiate<GameObject>(applePrefab);
        apple.transform.position = transform.position;
        Invoke("DropApple", secondsBetweenAppleDrops);
    }

    void DropRottenApple() {
        GameObject rottenApple = Instantiate<GameObject>(rottenApplePrefab);
        rottenApple.transform.position = transform.position;
        Invoke("DropRottenApple", secondsBetweenRottenAppleDrops);
    }

    // Update is called once per frame
    void Update()
    {
        // Basic Movement
        Vector3 pos = transform.position;
        pos.x += speed * Time.deltaTime;
        transform.position = pos;
        // Changing Direction
        if (pos.x < -leftAndRightEdge) {
            speed = Mathf.Abs(speed);
        } else if (pos.x > leftAndRightEdge) {
            speed = -Mathf.Abs(speed);
        } 
    }

    // Update exactly 50 times per second
    void FixedUpdate() 
    {
        if (Random.value < chanceToChangeDirections) {
            speed *= -1;
        }
    }
}