using PetCompanion.Models;
using PetCompanion.Repositories;

namespace PetCompanion.Services
{
    public class PetInventoryService
    {
        private readonly PetInventoryRepository _inventoryRepository;
        private readonly PetRepository _petRepository;
        private readonly GameItemsRepository _gameItemsRepository;

        public PetInventoryService(
            PetInventoryRepository inventoryRepository,
            PetRepository petRepository,
            GameItemsRepository gameItemsRepository)
        {
            _inventoryRepository = inventoryRepository;
            _petRepository = petRepository;
            _gameItemsRepository = gameItemsRepository;
        }

        public async Task<Inventory> GetInventory(string petId, string userId)
        {
            var pet = _petRepository.GetPetById(petId, userId);
            if (pet == null)
                throw new Exception("Pet not found");

            return await _inventoryRepository.GetPetInventory(petId);
        }

        public async Task<Inventory> CreateInventory(string petId)
        {
            var inventory = new Inventory
            {
                PetId = petId,
                Capacity = 20,
                Items = new List<InventoryItem>()
            };

            await _inventoryRepository.SaveInventory(inventory);
            return inventory;
        }

        public async Task<Pet> UseItem(string petId, string userId, int itemId)
        {
            var pet = _petRepository.GetPetById(petId, userId);
            if (pet == null)
                throw new Exception("Pet not found");

            var inventory = await _inventoryRepository.GetPetInventory(petId);
            var item = inventory.Items.FirstOrDefault(i => i.GameItemId == itemId);

            if (item == null || item.Quantity <= 0)
                throw new Exception("Item not found in inventory");

            item.Quantity--;
            if (item.Quantity <= 0)
                inventory.Items.Remove(item);

            await _inventoryRepository.SaveInventory(inventory);
            return _petRepository.UpdatePet(pet);
        }

        public async Task<Pet> EquipItem(string petId, string userId, int itemId)
        {
            var pet = _petRepository.GetPetById(petId, userId);
            if (pet == null)
                throw new Exception("Pet not found");

            var inventory = await _inventoryRepository.GetPetInventory(petId);
            var item = inventory.Items.FirstOrDefault(i => i.GameItemId == itemId);

            if (item == null || item.Quantity <= 0)
                throw new Exception("Item not found in inventory");

            if (item.GameItem.Type != ItemType.Equipment)
                throw new Exception("Item is not equipment");

            var equippedItems = await _inventoryRepository.GetEquippedItems(petId);
            if (equippedItems.ContainsKey(item.GameItem.EquipTarget))
            {
                await UnequipItem(petId, userId, item.GameItem.EquipTarget);
            }

            item.Quantity--;
            if (item.Quantity <= 0)
                inventory.Items.Remove(item);

            await _inventoryRepository.SaveInventory(inventory);
            return _petRepository.UpdatePet(pet);
        }

        public async Task<Pet> UnequipItem(string petId, string userId, ItemEquipTarget equipTarget)
        {
            var pet = _petRepository.GetPetById(petId, userId);
            if (pet == null)
                throw new Exception("Pet not found");

            var equippedItems = await _inventoryRepository.GetEquippedItems(petId);
            if (!equippedItems.ContainsKey(equipTarget))
                return pet;

            var itemId = equippedItems[equipTarget];
            var item = _gameItemsRepository.GetById(itemId);

            if (item != null)
            {
                var inventory = await _inventoryRepository.GetPetInventory(petId);
                var inventoryItem = inventory.Items.FirstOrDefault(i => i.GameItemId == itemId);

                if (inventoryItem != null)
                    inventoryItem.Quantity++;
                else
                    inventory.Items.Add(new InventoryItem
                    {
                        GameItemId = itemId,
                        Quantity = 1,
                        GameItem = item,
                        InventoryId = pet.Id
                    });

                await _inventoryRepository.SaveInventory(inventory);
            }

            return _petRepository.UpdatePet(pet);
        }

        public async Task<Pet> DropItem(string petId, string userId, int itemId)
        {
            var pet = _petRepository.GetPetById(petId, userId);
            if (pet == null)
                throw new Exception("Pet not found");

            var inventory = await _inventoryRepository.GetPetInventory(petId);
            if (inventory == null)
                throw new Exception("Inventory not found");

            var item = inventory.Items.FirstOrDefault(i => i.GameItemId == itemId);
            if (item == null || item.Quantity <= 0)
                throw new Exception("Item not found in inventory");

            item.Quantity--;
            if (item.Quantity <= 0)
                inventory.Items.Remove(item);

            await _inventoryRepository.SaveInventory(inventory);
            return pet;
        }

        public async Task<Pet> AddItemToPet(string petId, string userId, int itemId, int quantity)
        {
            var pet = _petRepository.GetPetById(petId, userId);
            if (pet == null)
                throw new Exception("Pet not found");

            var gameItem = _gameItemsRepository.GetById(itemId);
            if (gameItem == null)
                throw new Exception("Item not found");

            var inventory = await _inventoryRepository.GetPetInventory(petId);
            if (inventory == null)
                throw new Exception("Inventory not found");

            var existingItem = inventory.Items.FirstOrDefault(i => i.GameItemId == itemId);
            if (existingItem != null)
            {
                existingItem.Quantity += quantity;
            }
            else
            {
                inventory.Items.Add(new InventoryItem
                {
                    GameItemId = itemId,
                    Quantity = quantity,
                    GameItem = gameItem,
                    InventoryId = inventory.PetId
                });
            }

            await _inventoryRepository.SaveInventory(inventory);
            return pet;
        }
    }
}