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

public class CameraCtrl : MonoBehaviour {

    public Camera[] SyncedCameras;
    public float Radius = 5;
    public float theta = 0;
    public float phi = 0;

    private const float angleSpeed = 0.005f;
    private const float radiusSpeed = 0.1f;
    private const float radiusFar = 100;
    private const float radiusNear = 0.1f;
    private const float phiLimit = Mathf.PI * 0.45f;

    // Use this for initialization
    void Start () {
        mouseLeftPressed = false;
        mouseRightPressed = false;
        UpdateCameras();
	}

	// Update is called once per frame
	void Update ()
    {
        bool cameraDirty = false;
        if ((Input.GetMouseButton(0) == true) || (Input.GetMouseButton(1) == true))
        {
            //Mouse left - rotation
            if (Input.GetMouseButton(0) == true)
            {
                if (mouseLeftPressed == false)
                {
                    mouseLeftPressed = true;
                }
                else
                {
                    float mouseDeltaX = Input.mousePosition.x - mouseLastX;
                    float mouseDeltaY = Input.mousePosition.y - mouseLastY;
                    theta += mouseDeltaX * angleSpeed;
                    if (theta > Mathf.PI) theta -= 2 * Mathf.PI;
                    if (theta < -Mathf.PI) theta += 2 * Mathf.PI;
                    phi += - mouseDeltaY * angleSpeed;
                    if (phi > phiLimit) phi = phiLimit;
                    if (phi < -phiLimit) phi = -phiLimit;
                    cameraDirty = true;
                }
            } else
            {
                mouseLeftPressed = false;
            }

            //Mouse right button -Zooming (radius)
            if (Input.GetMouseButton(1) == true)
            {
                if (mouseRightPressed == false)
                {
                    mouseRightPressed = true;
                }
                else
                {
                    float mouseDeltaY = Input.mousePosition.y - mouseLastY;
                    Radius += - mouseDeltaY * radiusSpeed;
                    if (Radius < radiusNear) Radius = radiusNear;
                    if (Radius > radiusFar) Radius = - radiusFar;
                    cameraDirty = true;
                }
            }
        }

        if (cameraDirty) UpdateCameras();
        mouseLastX = Input.mousePosition.x;
        mouseLastY = Input.mousePosition.y;
    }

    void UpdateCameras()
    {
        Vector3 CameraPos = new Vector3(Mathf.Sin(theta),
                                        Mathf.Tan(phi),
                                        Mathf.Cos(theta));
        CameraPos.Normalize();
        CameraPos *= Radius;

        foreach (Camera cam in SyncedCameras)
        {
            cam.transform.position = CameraPos;
            cam.transform.LookAt(Vector3.zero);
        }
    }

    bool mouseLeftPressed, mouseRightPressed;
    float mouseLastX, mouseLastY;

}