using System;
using UnityEngine;

public class TilesetWithSegments : MonoBehaviour
{
    private const int MaxSegments = 128;
    private static readonly Vector4[] segments = new Vector4[MaxSegments * 2];
    private static readonly int segmentsId = Shader.PropertyToID("_Segments");
    private static readonly int countSegmentsId = Shader.PropertyToID("_CountSegments");
    private static readonly int thicknessId = Shader.PropertyToID("_SegmentsThickness");
    private static readonly int colorId = Shader.PropertyToID("_SegmentsColor");
    
    public OnlineMaps map;
    public float thickness = 50; // world points
    public Color color = Color.red;
    
    private OnlineMapsTileSetControl control;
    private OnlineMapsMarker marker1;
    private OnlineMapsMarker marker2;

    private void Start()
    {
        if (!map) map = OnlineMaps.instance;
        control = map.control as OnlineMapsTileSetControl;
        if (!control) throw new Exception("You must use the Tileset control.");
        
        map.OnMapUpdated += OnMapUpdated;
        marker1 = map.markerManager.Create(-10, 0, "M1");
        marker1.SetDraggable();
        marker2 = map.markerManager.Create(10, 0, "M2");
        marker2.SetDraggable();
    }

    private void OnMapUpdated()
    {
        Vector3 p1 = control.GetWorldPosition(marker1.position);
        Vector3 p2 = control.GetWorldPosition(marker2.position);

        segments[0] = new Vector4(p1.x, p1.z);
        segments[1] = new Vector4(p2.x, p2.z);
        
        Shader.SetGlobalVectorArray(segmentsId, segments);
        Shader.SetGlobalInt(countSegmentsId, 1);
        Shader.SetGlobalFloat(thicknessId, thickness);
        Shader.SetGlobalColor(colorId, color);
    }
}