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

public class RTSCamera : MonoBehaviour
{
    //Component Assignment
    Camera cam;

    [Header("Camera Variables")]
    public float panSpeed = 5;
    public float rotateSpeed = 50;
    public float rotateAmount = 50;

    float panDetect = 15f;
    Quaternion cameraRotation;
    float minCameraHeight = 2f;
    float maxCameraHeight = 10f;


    private void Start()
    {
        //Initialise Component
        cam = GetComponentInChildren<Camera>();
        cameraRotation = cam.transform.rotation;
    }

    private void Update()
    {
        MoveCamera();
        RotateCamera();

        if(Input.GetKeyDown(KeyCode.Space))
        {
            cam.transform.rotation = cameraRotation;
        }
    }

    void MoveCamera() //Handles basic panning
    {
        float moveX = cam.transform.position.x;
        float moveY = cam.transform.position.y;
        float moveZ = cam.transform.position.z;

        float xPos = Input.mousePosition.x;
        float yPos = Input.mousePosition.y;

        if (Input.GetKey(KeyCode.A) || (xPos > 0 && xPos < panDetect))
        {
            moveX -= panSpeed * Time.deltaTime;
        }
        else if (Input.GetKey(KeyCode.D) || (xPos < Screen.width && xPos > Screen.width - panDetect))
        {
            moveX += panSpeed * Time.deltaTime;
        }

        if (Input.GetKey(KeyCode.W) || yPos < Screen.height && yPos > Screen.height - panDetect)
        {
            moveZ += panSpeed * Time.deltaTime;
        }
        else if (Input.GetKey(KeyCode.S) || yPos > 0 && yPos < panSpeed)
        {
            moveZ -= panSpeed * Time.deltaTime;
        }

        //Camera Height
        moveY -= Input.GetAxis("Mouse ScrollWheel") * (panSpeed * 20 * Time.deltaTime);
        moveY = Mathf.Clamp(moveY, minCameraHeight, maxCameraHeight);

        Vector3 newPos = new Vector3(moveX, moveY, moveZ);
        cam.transform.position = newPos;
    }

    void RotateCamera()
    {
        Vector3 origin = cam.transform.eulerAngles;
        Vector3 destination = origin;

        if (Input.GetMouseButton(2)) //Hold MiddleMouse to Rotate
        {
            destination.x -= Input.GetAxis("Mouse Y") * rotateAmount * Time.deltaTime;
            destination.y += Input.GetAxis("Mouse X") * rotateAmount * Time.deltaTime;
        }

        if (destination != origin)
        {
            cam.transform.eulerAngles = Vector3.MoveTowards(origin, destination, rotateSpeed * Time.deltaTime);
        }
    }
}