using UnityEngine;

public class ShipControls : MonoBehaviour {
    public Camera m_camera;

    Rigidbody m_ridigBody;

    Vector3 m_initialPosition;
    Vector3 m_initialForce;

    Vector3 m_thrust;
    Vector3 m_strafe;

    float   m_strafeMag;
    float   m_thrustMag;
    float   m_stabliseMag;
    ForceMode m_forceMode;


    void Start() {
        Cursor.lockState = CursorLockMode.Locked;
        m_ridigBody = GetComponent<Rigidbody>();

        m_initialPosition = m_ridigBody.transform.position;
        m_initialForce = Vector3.zero;

        m_thrust = Vector3.zero;
        m_strafe = Vector3.zero;

        m_thrustMag = 50.0f;
        m_strafeMag = 25.0f;
        m_stabliseMag = 75.0f;

        m_forceMode = ForceMode.Acceleration;
    }

    void Update() {
        // update the movement vectors every frame
        m_thrust = getThrust();
        m_strafe = getStrafe();

        Debug.Log(m_thrust);

        // do everything else input related on every frame too
        processInput();
    }

    void FixedUpdate() {
        // // the ship being propelled forward
        m_ridigBody.AddForce(m_thrust, m_forceMode);

        // moving side to side
        m_ridigBody.AddForce(m_strafe, m_forceMode);

        // add relative force?

        // rotating towards the camera's orientation
        // not being done by a force because of strange behaviour
        // needs investigation
        float step = m_stabliseMag * Time.fixedDeltaTime;
        m_ridigBody.rotation = Quaternion.RotateTowards(transform.rotation, m_camera.transform.rotation, step);
    }

    Vector3 getThrust() {
        // thrust
        if (Input.GetMouseButton(0))
            return m_camera.transform.TransformDirection(Vector3.forward) * m_thrustMag;

        // brake
        if (Input.GetMouseButton(1))
            return m_camera.transform.TransformDirection(Vector3.back) * m_thrustMag;

        return Vector3.zero;
    }

    // 2D strafing
    // TODO add multiplier
    // combine
    Vector3 getStrafe() {
        Vector3 strafe = new Vector3(0.0f, 0.0f, 0.0f);

        if (Input.GetKey(KeyCode.W))
            strafe += m_strafeMag * m_camera.transform.TransformDirection(Vector3.up);
        if (Input.GetKey(KeyCode.S))
            strafe += m_strafeMag * m_camera.transform.TransformDirection(Vector3.down);

        if (Input.GetKey(KeyCode.A))
            strafe += m_strafeMag * m_camera.transform.TransformDirection(Vector3.left);

        if (Input.GetKey(KeyCode.D))
            strafe += m_strafeMag * m_camera.transform.TransformDirection(Vector3.right);

        return strafe;
    }

    void processInput() {
        if (Input.GetKey(KeyCode.Space))
            Respawn();

        if (Input.GetKey(KeyCode.Alpha1))
            m_forceMode = ForceMode.Acceleration;
        if (Input.GetKey(KeyCode.Alpha2))
            m_forceMode = ForceMode.Impulse;
        if (Input.GetKey(KeyCode.Alpha3))
            m_forceMode = ForceMode.Force;
        if (Input.GetKey(KeyCode.Alpha4))
            m_forceMode = ForceMode.VelocityChange;
    }

    void Respawn() {
        m_thrust = new Vector3(0.0f, 0.0f, 0.0f);
        transform.position = m_initialPosition;
        m_ridigBody.transform.forward = m_initialForce;
        m_ridigBody.velocity = new Vector3(0f, 0f, 0f);
        m_camera.transform.eulerAngles = Vector3.forward;

    }

    void OnDrawGizmosSelected() {
        Gizmos.color = Color.red;
        Vector3 direction = m_camera.transform.TransformDirection(Vector3.up) * 10;
        Gizmos.DrawRay(transform.position, direction);

        Gizmos.color = Color.green;
        Vector3 right = m_camera.transform.TransformDirection(Vector3.right) * 10;
        Gizmos.DrawRay(transform.position, right);

        Gizmos.color = Color.yellow;
        Vector3 forward = m_camera.transform.TransformDirection(Vector3.forward) * 10;
        Gizmos.DrawRay(transform.position, forward);
    }
}