using UnityEngine;

// *************
// Script based on ideas from https://connect.unity.com/p/articles-what-i-learned-from-trying-to-make-an-isometric-game-in-unity
// *************

[ExecuteInEditMode]
[RequireComponent(typeof(Renderer))]
public class SpriteOrderer : MonoBehaviour {

    [SerializeField]
    [Tooltip("Where the sprite would be touching the ground if it were a 3D object")]
    private float floorHeight = 0f;

    [SerializeField]
    [Tooltip("If this object is never going to move in-game, this can save a small amount of overhead")]
    private bool isStatic = false;

    private new Renderer renderer;

    void Start()
    {
        renderer = GetComponent<Renderer>();
    }

    void OnEnable()
    {
        renderer = GetComponent<Renderer>();
    }

    void Update ()
    {
        // Some objects never move in the game, so we can save a bit of overhead
        if (isStatic && Application.isPlaying)
            return;

        // In case where renderer was added after script loaded, try to cache it again (for Edit Mode)
        if (renderer == null)
            renderer = GetComponent<Renderer>();

        Vector3 bottomLeft = renderer.bounds.min + (Vector3.up * floorHeight);
        Vector3 bottomRight = renderer.bounds.min + (Vector3.right * renderer.bounds.size.x) + (Vector3.up * floorHeight);
        float yPosWithFloor = ((bottomLeft + bottomRight) / 2).y;
        Vector3 newPos = transform.position;

        newPos.z = yPosWithFloor * 0.01f;
        transform.position = newPos;
    }

    void OnDrawGizmos()
    {
        Gizmos.color = Color.yellow;

        Vector3 bottomLeft = renderer.bounds.min + (Vector3.up * floorHeight);
        Vector3 bottomRight = renderer.bounds.min + (Vector3.right * renderer.bounds.size.x) + (Vector3.up * floorHeight);

        Gizmos.DrawLine(bottomLeft, bottomRight);
    }
}