using System.Collections.Generic;
using UnityEngine;

[DisallowMultipleComponent]
public sealed class MapTargetController : MonoBehaviour
{
    [Header("Target Settings")]
    [SerializeField, Min(0)] private int targetCount = 5;
    [SerializeField, Min(0f)] private float targetMovementSpeed = 1f;

    private readonly List<MapTarget> targets = new();
    private MapCoordinateSystem coordinateSystem;
    private MapTarget targetPrefab;
    private Transform targetParent;
    private bool isConfigured;

    public IReadOnlyList<MapTarget> Targets => targets;
    public int TargetCount => targetCount;
    public float TargetMovementSpeed => targetMovementSpeed;

    private void OnValidate()
    {
        targetCount = Mathf.Max(0, targetCount);
        targetMovementSpeed = Mathf.Max(0f, targetMovementSpeed);
    }

    public void Configure(
        MapCoordinateSystem newCoordinateSystem,
        MapTarget newTargetPrefab,
        Transform newTargetParent)
    {
        coordinateSystem = newCoordinateSystem;
        targetPrefab = newTargetPrefab;
        targetParent = newTargetParent != null ? newTargetParent : transform;
        isConfigured = coordinateSystem != null &&
                       coordinateSystem.HasValidCorners() &&
                       targetPrefab != null;
    }

    public void CreateAndPlaceTargets()
    {
        if (!isConfigured)
        {
            Debug.LogWarning("Target system is not configured.", this);
            return;
        }

        RegisterExistingTargets();

        while (targets.Count < targetCount)
        {
            MapTarget target = Instantiate(targetPrefab, targetParent);
            target.name = $"Target_{targets.Count + 1}";
            targets.Add(target);
        }

        while (targets.Count > targetCount)
        {
            int lastIndex = targets.Count - 1;
            MapTarget target = targets[lastIndex];
            targets.RemoveAt(lastIndex);

            if (target != null)
                Destroy(target.gameObject);
        }

        for (int index = 0; index < targets.Count; index++)
        {
            MapTarget target = targets[index];
            if (target == null)
                continue;

            target.Configure(
                coordinateSystem,
                GetRandomCoordinates(),
                targetMovementSpeed,
                Random.insideUnitCircle.normalized);
            target.SetVisualsVisible(false);
        }
    }

    public void SetTargetVisualsVisible(bool isVisible)
    {
        foreach (MapTarget target in targets)
        {
            if (target != null)
                target.SetVisualsVisible(isVisible);
        }
    }

    public MapTarget GetTarget(int index)
    {
        return index >= 0 && index < targets.Count ? targets[index] : null;
    }

    private void RegisterExistingTargets()
    {
        targets.Clear();
        MapTarget[] existingTargets = targetParent.GetComponentsInChildren<MapTarget>(true);

        foreach (MapTarget target in existingTargets)
        {
            if (target != null && !targets.Contains(target))
                targets.Add(target);
        }
    }

    private static Vector2 GetRandomCoordinates()
    {
        float maximum = MapCoordinateSystem.CoordinateMaximum;
        return new Vector2(Random.Range(0f, maximum), Random.Range(0f, maximum));
    }
}