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

namespace DanieleMarotta.RiversongCodeShowcase
{
    [Service(typeof(IUnlocksService))]
    [InitializeAfter(typeof(HouseTierCountTrackingSystem))]
    public class UnlocksManagerSystem : GameSystem, IInitializable, IDisposable, IUnlocksService
    {
        [InjectService]
        private IGameDatabase _gameDatabase;

        [InjectService]
        private ISignalBus _signalBus;

        [InjectService]
        private IEntityCollection _entityCollection;

        [InjectService]
        private World _world;

        private List<UnlockDefinition> _unlocks;

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

        public UniTask InitializeAsync()
        {
            _unlocks = _gameDatabase.OfType<UnlockDefinition>();

            foreach (var unlock in _unlocks)
                if (unlock.Building)
                    _world.UnlocksState.AddBuildingUnlock(unlock.Building, unlock.RuntimeId);

            _signalBus.Subscribe<WorldReadySignal>(OnWorldReady);
            _signalBus.Subscribe<BuildingCreatedSignal>(OnBuildingCreated);
            _signalBus.Subscribe<BuildingUpgradedSignal>(OnBuildingUpgraded);

            return UniTask.CompletedTask;
        }

        public void Dispose()
        {
            _signalBus.Unsubscribe<WorldReadySignal>(OnWorldReady);
            _signalBus.Unsubscribe<BuildingCreatedSignal>(OnBuildingCreated);
            _signalBus.Unsubscribe<BuildingUpgradedSignal>(OnBuildingUpgraded);
        }

        private void OnWorldReady(WorldReadySignal signal)
        {
            _ = GrantFreeUnlocksWithDelayAsync();
        }

        private async UniTask GrantFreeUnlocksWithDelayAsync()
        {
            await UniTask.WaitForSeconds(2, true);

            foreach (var unlock in _unlocks)
                if (unlock.Conditions.Count <= 0)
                    Unlock(unlock);
        }

        private void OnBuildingCreated(BuildingCreatedSignal signal)
        {
            TryUnlockAvailableUnlocks();
        }

        private void OnBuildingUpgraded(BuildingUpgradedSignal signal)
        {
            TryUnlockAvailableUnlocks();
        }

        private void TryUnlockAvailableUnlocks()
        {
            foreach (var unlock in _unlocks)
                if (CanUnlock(unlock))
                    Unlock(unlock);
        }

        private bool CanUnlock(UnlockDefinition unlock)
        {
            if (_world.UnlocksState.Unlocked.Contains(unlock.RuntimeId)) return false;

            foreach (var condition in unlock.Conditions)
                if (!IsConditionSatisfied(condition))
                    return false;

            return true;
        }

        public void Unlock(UnlockDefinition unlock)
        {
            if (!_world.UnlocksState.Unlocked.Add(unlock.RuntimeId)) return;

            switch (unlock.Type)
            {
                case UnlockType.UnlockBuilding:
                    UnlockBuilding(unlock);
                    break;

                case UnlockType.None:
                default:
                    throw new ArgumentOutOfRangeException();
            }

            _signalBus.Raise(new UnlockUnlockedSignal(unlock));
        }

        public void UnlockAll()
        {
            foreach (var unlock in _unlocks) Unlock(unlock);
        }

        private void UnlockBuilding(UnlockDefinition unlock)
        {
            var unlocksState = _world.UnlocksState;
            var unlockedId = unlock.Building.RuntimeId;

            unlocksState.UnlockedBuildings.Add(unlockedId);
            unlocksState.TeasedBuildings.Remove(unlockedId);

            foreach (var teased in unlock.TeasedBuildings)
            {
                if (unlocksState.UnlockedBuildings.Contains(teased.RuntimeId)) continue;

                unlocksState.TeasedBuildings.Add(teased.RuntimeId);
            }
        }

        private bool IsConditionSatisfied(UnlockCondition condition)
        {
            switch (condition.Type)
            {
                case UnlockConditionType.BuildingPlaced:
                    foreach (Building building in _entityCollection.GetInternalEntityList(typeof(Building)))
                        if (building.Definition.RuntimeId == condition.Building.RuntimeId)
                            return true;
                    return false;

                case UnlockConditionType.HouseCountAtTierOrAbove:
                    var houseCount = 0;
                    var houseCountsByTier = _world.PopulationState.HouseCountsByTier;
                    for (var i = condition.MinHouseTierIndex; i < WorldPopulationState.MaxBuildingTier; i++) houseCount += houseCountsByTier[i];

                    return houseCount >= condition.HouseCount;

                case UnlockConditionType.None:
                default:
                    throw new ArgumentOutOfRangeException();
            }
        }
    }
}