using MegaKoop.Game.Networking;
using Steamworks;
using UnityEngine;

namespace MegaKoop.Game.Vfx
{
    [DefaultExecutionOrder(-50)]
    public class ProjectileImpactVfxService : MonoBehaviour
    {
        private const float MinLifetime = 0.5f;

        private static ProjectileImpactVfxService instance;

        private SteamCoopNetworkManager networkManager;
        private bool isRegistered;
        private ProjectileImpactVfxSettings settings;

        public static ProjectileImpactVfxService Instance
        {
            get
            {
                if (instance == null)
                {
                    instance = FindObjectOfType<ProjectileImpactVfxService>();
                    if (instance == null)
                    {
                        var go = new GameObject(nameof(ProjectileImpactVfxService));
                        instance = go.AddComponent<ProjectileImpactVfxService>();
                    }
                }

                return instance;
            }
        }

        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.AfterSceneLoad)]
        private static void AutoCreate()
        {
            _ = Instance;
        }

        public static void ReportImpact(ProjectileImpactKind kind, Vector3 position, Vector3 normal)
        {
            Instance.InternalReportImpact(kind, position, normal);
        }

        private void Awake()
        {
            if (instance != null && instance != this)
            {
                Destroy(gameObject);
                return;
            }

            instance = this;
            DontDestroyOnLoad(gameObject);
            LoadSettings();
        }

        private void OnEnable()
        {
            TryBindNetworkManager();
        }

        private void Update()
        {
            TryBindNetworkManager();
        }

        private void OnDisable()
        {
            UnregisterHandler();
        }

        private void OnDestroy()
        {
            if (instance == this)
            {
                instance = null;
            }

            UnregisterHandler();
        }

        private void LoadSettings()
        {
            if (settings != null)
            {
                return;
            }

            settings = ProjectileImpactVfxSettings.LoadFromResources();
            if (settings == null)
            {
                Debug.LogWarning($"[ProjectileImpactVfxService] Could not locate Resources/{ProjectileImpactVfxSettings.ResourcePath}. Impact particles will be skipped.");
            }
        }

        private void TryBindNetworkManager()
        {
            var current = SteamCoopNetworkManager.Instance;
            if (current != networkManager)
            {
                UnregisterHandler();
                networkManager = current;
            }

            if (networkManager != null && !isRegistered)
            {
                networkManager.RegisterHandler(NetworkMessageType.ProjectileImpact, HandleImpactMessage);
                isRegistered = true;
            }
        }

        private void UnregisterHandler()
        {
            if (isRegistered && networkManager != null)
            {
                networkManager.UnregisterHandler(NetworkMessageType.ProjectileImpact, HandleImpactMessage);
            }

            isRegistered = false;
        }

        private void HandleImpactMessage(NetworkMessage message)
        {
            ProjectileImpactMessage impact = ProjectileImpactMessage.Deserialize(message.Payload);
            SpawnImpact(impact.Kind, impact.Position, impact.Normal);
        }

        private void InternalReportImpact(ProjectileImpactKind kind, Vector3 position, Vector3 normal)
        {
            SpawnImpact(kind, position, normal);

            TryBindNetworkManager();
            if (networkManager == null || !networkManager.IsHost)
            {
                return;
            }

            var impactMessage = new ProjectileImpactMessage(kind, position, normal);
            byte[] payload = ProjectileImpactMessage.Serialize(impactMessage);
            networkManager.SendToAll(NetworkMessageType.ProjectileImpact, payload, EP2PSend.k_EP2PSendUnreliableNoDelay);
        }

        private void SpawnImpact(ProjectileImpactKind kind, Vector3 position, Vector3 normal)
        {
            LoadSettings();
            if (settings == null)
            {
                return;
            }

            GameObject prefab = kind switch
            {
                ProjectileImpactKind.Hero => settings.HeroImpactPrefab,
                ProjectileImpactKind.Enemy => settings.EnemyImpactPrefab,
                _ => null
            };

            if (prefab == null)
            {
                return;
            }

            Quaternion rotation = normal.sqrMagnitude > 0.001f ? Quaternion.LookRotation(normal) : Quaternion.identity;
            GameObject instance = Instantiate(prefab, position, rotation);
            float lifetime = EstimateLifetime(instance);
            if (lifetime > 0f)
            {
                Destroy(instance, lifetime);
            }
        }

        private float EstimateLifetime(GameObject effectInstance)
        {
            float fallback = settings != null ? settings.FallbackLifetime : 4f;
            ParticleSystem[] particleSystems = effectInstance.GetComponentsInChildren<ParticleSystem>();
            if (particleSystems == null || particleSystems.Length == 0)
            {
                return Mathf.Max(MinLifetime, fallback);
            }

            float maxLifetime = fallback;
            foreach (ParticleSystem system in particleSystems)
            {
                var main = system.main;
                if (main.loop)
                {
                    maxLifetime = Mathf.Max(maxLifetime, fallback);
                    continue;
                }

                float candidate = main.duration + main.startLifetime.constantMax;
                if (candidate <= 0f)
                {
                    candidate = fallback;
                }

                maxLifetime = Mathf.Max(maxLifetime, candidate);
            }

            return Mathf.Max(MinLifetime, maxLifetime);
        }
    }
}