using System.Collections.Generic;
using UnityEngine;

public class MarkerDrawer : MonoBehaviour
{
    public GameObject prefab;
    [SerializeField] private int Reach = 17;

    /// <summary>
    /// Coefficient of scaling of markers for zoom = 20.
    /// It can be a constant or be pre-calculated depending on your needs.
    /// </summary>
    private static float coof = 256;

    private OnlineMapsTileSetControl control;
    private Drawer newDrawe;

    private void Start()
    {
        control = OnlineMapsTileSetControl.instance;
        newDrawe = new Drawer(control, prefab);

        control.markerDrawer = newDrawe;
        control.OnMapClick += OnClick;
    }

    private void OnDisable()
    {
        control.OnMapClick -= OnClick;
    }

    private void OnClick()
    {
        double lng, lat;
        control.GetCoords(out lng, out lat);
        DrawRect(lng, lat);
    }

    private void DrawRect(double lng, double lat)
    {
        double nlng, nlat;
        float dist = Mathf.Sqrt(2 * (2 * Reach) * (2 * Reach)) / 1000;
        OnlineMapsUtils.GetCoordinateInDistance(lng, lat, dist / 2, 45, out nlng, out nlat);
        double blng, blat;
        OnlineMapsUtils.GetCoordinateInDistance(lng, lat, dist / 2, 225, out blng, out blat);

        var marker = OnlineMapsMarkerManager.instance.Create(lng, lat);
        marker.SetPosition(lng, lat);
        marker.scale = 1 / Mathf.Pow(2, 19 - OnlineMaps.instance.floatZoom);

        List<Vector2> points = new List<Vector2>();
        points.Add(new Vector2((float)blng, (float)blat));
        points.Add(new Vector2((float)blng, (float)nlat));
        points.Add(new Vector2((float)nlng, (float)nlat));
        points.Add(new Vector2((float)nlng, (float)blat));
        points.Add(new Vector2((float)blng, (float)blat));
        OnlineMapsDrawingElementManager.instance.Add(new OnlineMapsDrawingLine(points));
    }

    public class Drawer : OnlineMapsMarker2DDrawer
    {
        private OnlineMapsTileSetControl control;
        private GameObject prefab;

        public Drawer(OnlineMapsTileSetControl control, GameObject _prefab)
        {
            this.control = control;
            prefab = _prefab;
            control.OnDrawMarkers += OnDrawMarkers;

            // control.OnMapZoom will not work when changing the zoom using the inspector.
            map.OnChangeZoom += OnZoom;
        }

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

        private void OnZoom()
        {
            float scale = 1 / Mathf.Pow(2, 19 - map.floatZoom);
            foreach (var marker in OnlineMapsMarkerManager.instance.items)
            {
                marker.scale = scale;
            }
        }

        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 (marker.scale < 0.01f || 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(prefab);
                markerInstance.transform.SetParent(control.transform);
            }

            float scale = coof * marker.scale;

            markerInstance.transform.localScale = new Vector3(scale, scale, scale);
            double lng, lat;
            marker.GetPosition(out lng, out lat);
            markerInstance.transform.position = control.GetWorldPosition(lng, lat);
        }
    }
}