using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AddressableAssets;

namespace Jovian.EncounterSystem {
    /// <summary>id → encounter cache. Editor auto-repopulates on asset changes; runtime must call <see cref="PopulateEncounters"/>.</summary>
    [CreateAssetMenu(fileName = "EncounterRegistry", menuName = "Jovian/Encounter System/Encounter Registry")]
    public class EncounterRegistry : ScriptableObject {
        public EncountersCollection[] encounterCollections = Array.Empty<EncountersCollection>();

        private readonly Dictionary<string, IEncounter> encounters = new();

        public Dictionary<string, IEncounter> GetEncounters() => encounters;

        public void RegisterEncounter(IEncounter encounter) {
            var id = encounter?.EncounterDefinition?.internalId;
            if(string.IsNullOrEmpty(id)) {
                return;
            }
            encounters.TryAdd(id, encounter);
        }

        public void UnregisterEncounter(IEncounter encounter) {
            var id = encounter?.EncounterDefinition?.internalId;
            if(string.IsNullOrEmpty(id)) {
                return;
            }
            encounters.Remove(id);
        }

        public void ClearEncounters() {
            encounters.Clear();
        }

        public void PopulateEncounters() {
            if(encounterCollections == null) {
                return;
            }

            for(int c = 0; c < encounterCollections.Length; c++) {
                var collection = encounterCollections[c];
                if(collection?.encounterTables == null) {
                    continue;
                }

                for(int t = 0; t < collection.encounterTables.Length; t++) {
                    var table = collection.encounterTables[t];
                    if(table?.encounters == null) {
                        continue;
                    }

                    for(int i = 0; i < table.encounters.Count; i++) {
                        RegisterEncounter(table.encounters[i]);
                    }
                }
            }
        }
    }

#if UNITY_EDITOR
    /// <summary>Rebuilds the registry (Addressables key "EncounterRegistry") on any asset import/move/delete.</summary>
    public class EncounterRegister : UnityEditor.AssetPostprocessor {
        private static EncounterRegistry registryCache;

        private static void OnPostprocessAllAssets(string[] importedAssets, string[] deletedAssets, string[] movedAssets, string[] movedFromAssetPaths) {
            registryCache ??= Addressables.LoadAssetAsync<EncounterRegistry>("EncounterRegistry").WaitForCompletion();
            registryCache.ClearEncounters();
            registryCache.PopulateEncounters();
        }
    }
#endif
}