using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using static UnityEditor.PlayerSettings;

public class CameraMovement : MonoBehaviour
{
    [Header("Speeds")]
    public float MovementSpeed = 50.0f;
    public float RotationSpeed = 60.0f;
    public float TiltSpeed = 30f;
    public float ZoomSpeed = 1.0f;

    [Header("Bounds")]
    public Vector3 CameraMinimumBound = new Vector3(-100, 1, -250);
    public Vector3 CameraMaximumBound = new Vector3(100, 25, 250);
    public float EdgeScrollThreshold = 5.0f;
    public float MinFOV = 25f;
    public float MaxFOV = 100f;
    public float MinTilt = -75f;
    public float MaxTilt = 75f;

    private bool hasElevationAxis = true;
    private bool hasRotationAxis = true;
    private bool hasTiltAxis = true;
    
    // Start is called before the first frame update
    private Camera cam;
    private float tiltAngle;

    void Start()
    {
        cam = GetComponent<Camera>();
        tiltAngle = this.transform.localEulerAngles.x;
        if(cam == null) {
            Debug.Log("Attach the CameraMovement script to your scene's main Camera object.");
        }
        // Has the Elevation axis been created?
        try {
            Input.GetAxis("Elevation");
        } catch {
            Debug.Log("Elevation axis is missing");
            hasElevationAxis = false;
        }
        // has the Rotation
        try {
            Input.GetAxis("Rotation");
        }
        catch {
            Debug.Log("Rotation axis is missing");
            hasRotationAxis = false;
        }
        try {
            Input.GetAxis("Tilt");
        }
        catch {
            Debug.Log("Tilt axis is missing");
            hasTiltAxis = false;
        }
    }

    // Update is called once per frame
    void Update()
    {
        if(cam != null) {
            KeyboardMovement();
            MouseMovement();        
        }
    }

    private void MouseMovement() {

        if(Input.GetMouseButton(2)) // Middle mouse (scroll wheel) held down
        {


            float mouseY = Input.GetAxis("Mouse Y");
            tiltAngle -= mouseY * TiltSpeed * Time.deltaTime;
            tiltAngle = Mathf.Clamp(tiltAngle, MinTilt, MaxTilt);
            transform.localRotation = Quaternion.Euler(tiltAngle, this.transform.localEulerAngles.y, 0f);
            return;

        }

        // Move camera when mouse is near the screen edge
        Vector3 currentPosition = this.transform.position;
        Vector3 mouse = Input.mousePosition;

        if(mouse.x >= Screen.width - EdgeScrollThreshold)
            currentPosition.x -= MovementSpeed * Time.deltaTime;
        if(mouse.x <= EdgeScrollThreshold)
            currentPosition.x += MovementSpeed * Time.deltaTime;
        if(mouse.y >= Screen.height - EdgeScrollThreshold)
            currentPosition.z -= MovementSpeed * Time.deltaTime; // assuming top-down scroll on Z
        if(mouse.y <= EdgeScrollThreshold)
            currentPosition.z += MovementSpeed * Time.deltaTime;
        this.transform.position = currentPosition;

        // Zoom camera by changing its focal length
        float zoomAmount = Input.mouseScrollDelta.y * ZoomSpeed * Time.deltaTime;
        cam.fieldOfView -= zoomAmount;
        cam.fieldOfView = Mathf.Clamp(cam.fieldOfView, MinFOV, MaxFOV);

        // Tilt camera when middle mouse is depressed



    }

    private void KeyboardMovement() {
        // Move the camerar
        Vector3 movement = new Vector3(0, 0, 0);
        movement.x -= Input.GetAxis("Horizontal");
        movement.z -= Input.GetAxis("Vertical");
        if(hasElevationAxis) movement.y += Input.GetAxis("Elevation");

        movement *= MovementSpeed;
        this.transform.Translate(movement * Time.deltaTime, Space.World);

        // Clamp camera position within bounds
        Vector3 currentPosition = this.transform.position;
        currentPosition.x = Mathf.Clamp(currentPosition.x, CameraMinimumBound.x, CameraMaximumBound.x);
        currentPosition.y = Mathf.Clamp(currentPosition.y, CameraMinimumBound.y, CameraMaximumBound.y);
        currentPosition.z = Mathf.Clamp(currentPosition.z, CameraMinimumBound.z, CameraMaximumBound.z);
        this.transform.position = currentPosition;

        // Rotate camera left/right (relative to world)
        Vector3 rotation = new Vector3(0, 0, 0);
        if(hasRotationAxis) rotation.y = Input.GetAxis("Rotation");
        rotation = rotation * RotationSpeed;
        this.transform.Rotate(rotation * Time.deltaTime, Space.World);

        // Tilt camera up/down (relative to self)
        if(hasTiltAxis) tiltAngle = tiltAngle - Input.GetAxis("Tilt") * TiltSpeed * Time.deltaTime;
        tiltAngle = Mathf.Clamp(tiltAngle, MinTilt, MaxTilt);

        this.transform.rotation = Quaternion.Euler(tiltAngle, this.transform.localEulerAngles.y, 0);

    }
}