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

public class ShipController : MonoBehaviour {
    public float speed = 10.0f;

    // The clamp margins
    public float
        clampMarginMinX = 10.0f,
        clampMarginMaxX = 10.0f,
        clampMarginMinY = 10.0f,
        clampMarginMaxY = 10.0f,

    // The minimum and maximum values which the object can go

        m_clampMinX,
        m_clampMaxX,
        m_clampMinY,
        m_clampMaxY;

    private void Start()
    {
        // Get the minimum and maximum position values according to the screen size represented by the main camera.
        m_clampMinX = Camera.main.ScreenToWorldPoint(new Vector2(0 + clampMarginMinX, 0)).x;
        m_clampMaxX = Camera.main.ScreenToWorldPoint(new Vector2(Screen.width - clampMarginMaxX, 0)).x;
        m_clampMinY = Camera.main.ScreenToWorldPoint(new Vector2(0, 0 + clampMarginMinY)).y;
        m_clampMaxY = Camera.main.ScreenToWorldPoint(new Vector2(0, Screen.height + clampMarginMaxY)).y;
    }

    private void Update()
    {
        Vector3 direction = Vector3.zero;

        // Going left
        if (Input.GetKey(KeyCode.A))
        {
            direction = Vector2.right * -1;
        }

        // Going right
        else if (Input.GetKey(KeyCode.D))
        {
            direction = Vector2.right;
        }

        if (transform.position.x < m_clampMinX)
        {
            // If the object position tries to exceed the left screen bound clamp the min x position to 0.
            // The maximum x position won't be clamped so the object can move to the right.
            direction.x = Mathf.Clamp(direction.x, 0, Mathf.Infinity);
        }

        if (transform.position.x > m_clampMaxX)
        {
            // Same goes here
            direction.x = Mathf.Clamp(direction.x, Mathf.NegativeInfinity, 0);
        }

        transform.position += direction * (Time.deltaTime * speed);
    }

}