using UnityEngine;

public class uGUIMarkerDrawer:MonoBehaviour
{
    private static uGUIMarkerDrawer instance;
    public RectTransform container;
    public GameObject prefab;

    private Canvas canvas;

    private Camera worldCamera
    {
        get
        {
            if (canvas.renderMode == RenderMode.ScreenSpaceOverlay) return null;
            return canvas.worldCamera;
        }
    }

    private void OnEnable()
    {
        instance = this;
        canvas = container.GetComponentInParent<Canvas>();
    }

    private void Start()
    {
        OnlineMapsControlBase.instance.markerDrawer = new Drawer(OnlineMapsControlBase.instance);
    }

    public class Drawer : OnlineMapsMarker2DDrawer
    {
        private OnlineMapsControlBase control;

        public Drawer(OnlineMapsControlBase control)
        {
            this.control = control;

            control.OnDrawMarkers += OnDrawMarkers;
        }

        public override void Dispose()
        {
            control.OnDrawMarkers -= OnDrawMarkers;
            control = null;
        }

        private void OnDrawMarkers()
        {
            double tlx, tly, brx, bry;
            map.GetCorners(out tlx, out tly, out brx, out bry);

            foreach (OnlineMapsMarker marker in OnlineMapsMarkerManager.instance.items)
            {
                DrawMarker(marker, tlx, tly, brx, bry);
            }
        }

        private void DrawMarker(OnlineMapsMarker marker, double tlx, double tly, double brx, double bry)
        {
            double px, py;
            marker.GetPosition(out px, out py);
            GameObject markerInstance = marker["instance"] as GameObject;

            if (px < tlx || px > brx || py < bry || py > tly)
            {
                if (markerInstance != null)
                {
                    OnlineMapsUtils.Destroy(markerInstance);
                    marker["instance"] = null;
                }
                return;
            }

            if (markerInstance == null)
            {
                marker["instance"] = markerInstance = Instantiate(instance.prefab);
                (markerInstance.transform as RectTransform).SetParent(instance.container);
                markerInstance.transform.localScale = Vector3.one;
            }

            Vector2 screenPosition = control.GetScreenPosition(px, py);
            RectTransform markerRectTransform = markerInstance.transform as RectTransform;

            screenPosition.y += markerRectTransform.rect.height / 2;

            Vector2 point;
            RectTransformUtility.ScreenPointToLocalPointInRectangle(markerRectTransform.parent as RectTransform, screenPosition, instance.worldCamera, out point);
            markerRectTransform.localPosition = point;
        }
    }
}