using System.Collections.Generic;
using UnityEngine;

public class EdgeIndicatorManager : MonoBehaviour
{
    public static EdgeIndicatorManager Instance;

    [Header("References")]
    public MinimapManager minimapManager;
    public RectTransform edgeContainer;
    public EdgeIndicator indicatorPrefab;

    [Header("Settings")]
    public float edgePadding = 18f;
    public float refreshInterval = 1f;

    private readonly Dictionary<EdgeTarget, EdgeIndicator> indicators =
        new Dictionary<EdgeTarget, EdgeIndicator>();

    float timer;

    void Awake()
    {
        Instance = this;
    }

    void Start()
    {
        if (minimapManager == null)
            minimapManager = FindObjectOfType<MinimapManager>();

        RefreshTargets();
    }

    void Update()
    {
        timer += Time.deltaTime;

        if (timer >= refreshInterval)
        {
            timer = 0;
            RefreshTargets();
        }
    }

    void RefreshTargets()
    {
        EdgeTarget[] targets = FindObjectsOfType<EdgeTarget>();

        HashSet<EdgeTarget> currentTargets = new HashSet<EdgeTarget>(targets);

        //-------------------------------------
        // Remove destroyed targets
        //-------------------------------------

        List<EdgeTarget> remove = new List<EdgeTarget>();

        foreach (var pair in indicators)
        {
            if (pair.Key == null || !currentTargets.Contains(pair.Key))
            {
                if (pair.Value != null)
                    Destroy(pair.Value.gameObject);

                remove.Add(pair.Key);
            }
        }

        foreach (var t in remove)
            indicators.Remove(t);

        //-------------------------------------
        // Add new targets
        //-------------------------------------

        foreach (EdgeTarget target in targets)
        {
            if (indicators.ContainsKey(target))
                continue;

            EdgeIndicator arrow =
                Instantiate(indicatorPrefab, edgeContainer);

            arrow.Initialize(
    target,
    edgeContainer,
    edgePadding);

            indicators.Add(target, arrow);
        }
    }
}