using System;
using System.Collections.Generic;
using Cysharp.Threading.Tasks;
using UnityEngine;

namespace DanieleMarotta.RiversongCodeShowcase
{
    [GameSystemGroup(typeof(WorldGenSystemGroup))]
    [InitializeAfter(typeof(WorldCreationSystem))]
    public class WorldGenerationOperationsSystem : GameSystem, IInitializable, IDisposable
    {
        [InjectService]
        private World _world;

        [InjectService]
        private ISignalBus _signalBus;

        private readonly List<IWorldGeneratorOperation> _operations = new();

        public WorldGenerationOperationsSystem(IServiceLocator serviceLocator) : base(serviceLocator)
        {
        }

        public UniTask InitializeAsync()
        {
            _operations.Add(new MapDataInitializationOperation());
            _operations.Add(new TerrainMaterialsInitializationOperation());
            _operations.Add(new TerrainGeneratorOperation());
            _operations.Add(new TreeResourcesGeneratorOperation());
            _operations.Add(new StoneResourcesGeneratorOperation());
            _operations.Add(new FreeProductStacksGeneratorOperation());
            _operations.Add(new CritterHerdsGeneratorOperation());

            foreach (var operation in _operations) ServiceLocator.Inject(operation);

            _signalBus.Subscribe<GameStartedSignal>(OnGameStarted);

            return UniTask.CompletedTask;
        }

        public void Dispose()
        {
            _signalBus.Unsubscribe<GameStartedSignal>(OnGameStarted);
        }

        private void OnGameStarted(GameStartedSignal signal)
        {
            ExecuteOperationsAsync().Forget(Debug.LogException);
        }

        private async UniTask ExecuteOperationsAsync()
        {
            _world.Seed = Environment.TickCount;

            foreach (var operation in _operations) await operation.Execute(_world);

            var generationCompletedCallbacks = new List<IOnWorldGenerationCompletedCallback>();
            _signalBus.Raise(new WorldGenerationCompletedSignal(generationCompletedCallbacks));
            foreach (var callback in generationCompletedCallbacks) await callback.OnWorldGenerationCompletedAsync(_world);

            _signalBus.Raise(new WorldReadySignal());
        }
    }
}