/// <summary>
/// Remove a number of an item from this user.
/// </summary>
/// <param name="user">User from which to remove this/these item(s)</param>
/// <param name="playerInventoryItemId">PlayerInventoryItem "slot" from which to remove items</param>
/// <param name="amount">The amount of this item to remove. Will throw an exception if this is greater than the amount the User currently has</param>
public async Task RemoveItemFromUser(User user, Guid playerInventoryItemId, int amount)
{
PlayerInventoryItem existingInventoryItem = GetInventoryItemById(user, playerInventoryItemId);
// Validate user has an item with this id
if (existingInventoryItem == null)
{
throw new System.ArgumentException($"Cannot remove item from user. User '{user.Id}' has no inventory item with id '{playerInventoryItemId}'");
}
// Validate user has enough of this item to remove
else if (existingInventoryItem.Count < amount)
{
throw new InvalidOperationException($"Cannot remove {amount} of item from user. User '{user.Id}' only has {existingInventoryItem.Count} of item '{playerInventoryItemId}'");
}
// Decrease amount
existingInventoryItem.Count -= amount;
if (existingInventoryItem.Count == 0)
{
// Remove from user entirely
user.Inventory.Remove(existingInventoryItem);
}
// Save changes to DB
this.db.Users.Update(user);
await this.db.SaveChangesAsync();
}
/// <summary>
/// Give the user an item.
/// </summary>
/// <param name="user">User for which to give this item</param>
/// <param name="itemId">Unique ID of the item to give to this user. A PlayerInventoryItem "slot" will be created if one doesn't exist already</param>
public async Task AddItemToUser(User user, Guid itemId, int amount)
{
// Look up item to add (validation)
Item item = this.itemService.GetItemById(itemId);
if (item == null)
{
throw new ArgumentException($"Cannot add item to user. No item exists with id '{itemId}'", nameof(itemId));
}
// See if player already holds this item
PlayerInventoryItem existingInventoryItem = GetInventoryItemByItemId(user, itemId);
if (existingInventoryItem != null)
{
// Update inventory item
existingInventoryItem.Count += amount;
}
else
{
// Create new inventory item
PlayerInventoryItem newInventoryItem = new PlayerInventoryItem
{
Count = amount,
UserId = user.Id,
ItemId = item.Id,
};
user.Inventory.Add(newInventoryItem);
}
// Save changes to DB
this.db.Users.Update(user);
await this.db.SaveChangesAsync();
}
public async Task UserDonateItem(User user, Guid playerInventoryItemId)
{
// @TODO less trips to the database
// Fetch and validate playerInventoryItemId
PlayerInventoryItem playerInventoryItem = this.userService.GetInventoryItemById(user, playerInventoryItemId);
if (playerInventoryItem == null)
{
throw new ArgumentException($"Cannot donate item to taking tree. Player has no item with id '{playerInventoryItemId}'", nameof(playerInventoryItemId));
}
// Remove item from user
await this.userService.RemoveItemFromUser(user, playerInventoryItemId, 1);
// Add item to taking tree
await this.db.TakingTreeInventoryItems.AddAsync(new TakingTreeInventoryItem
{
ItemId = playerInventoryItem.Item.Id,
DonatedById = user.Id,
});
await this.db.SaveChangesAsync();
}