@spec empty?(t()) :: boolean()

Checks whether an account is empty (no balance).

Examples

iex> Bookk.Account.new(fixture_account_head(:cash), Decimal.new(0))
iex> |> Bookk.Account.empty?()
true

iex> Bookk.Account.new(fixture_account_head(:cash), Decimal.new(10))
iex> |> Bookk.Account.empty?()
false

@spec merge([t(), ...]) :: t()

Merges a non-empty set of accounts into one (account head MUST be the same).

Examples

iex> a = Bookk.Account.new(fixture_account_head(:cash), Decimal.new(5))
iex> b = Bookk.Account.new(fixture_account_head(:cash), Decimal.new(15))
iex> c = Bookk.Account.new(fixture_account_head(:cash), Decimal.new(30))
iex> Bookk.Account.merge([a, b, c])
Bookk.Account.new(fixture_account_head(:cash), Decimal.new(50))

If you try to merge an empty list of accounts, an error will be raised.

@spec merge(t(), t()) :: t()

Merges two accounts into one (account head MUST be the same).

Examples

iex> a = Bookk.Account.new(fixture_account_head(:cash), Decimal.new(5))
iex> b = Bookk.Account.new(fixture_account_head(:cash), Decimal.new(15))
iex> Bookk.Account.merge(a, b)
Bookk.Account.new(fixture_account_head(:cash), Decimal.new(20))

It raises if the account head is different:

iex> a = Bookk.Account.new(fixture_account_head(:cash), Decimal.new(5))
iex> b = Bookk.Account.new(fixture_account_head(:deposits), Decimal.new(15))
iex> Bookk.Account.merge(a, b)
** (FunctionClauseError) no function clause matching in Bookk.Account.merge/2

@spec new(Bookk.AccountHead.t(), balance :: Decimal.t()) :: t()

Creates a new account from a Bookk.AccountHead.

Examples

If no initial balance is provided in the second argument, then balance will be set to zero:

iex> head = fixture_account_head(:cash)
iex> Bookk.Account.new(head)
%Bookk.Account{
  head: fixture_account_head(:cash),
  balance: Decimal.new(0)
}

If an initial balance is provided in the second argument, then balance will be set to it:

iex> head = fixture_account_head(:cash)
iex> Bookk.Account.new(head, Decimal.new(50))
%Bookk.Account{
  head: fixture_account_head(:cash),
  balance: Decimal.new(50)
}

@spec post(t(), Bookk.Operation.t()) :: t()

Calculates de delta amount for the operation then adds it the account's balance. See Bookk.Operation.to_delta_amount/1 for more information on delta amount.

Examples

iex> class = %Bookk.AccountClass{natural_balance: :debit}
iex> head = %Bookk.AccountHead{class: class}
iex> account = Bookk.Account.new(head)
iex>
iex> op = debit(head, Decimal.new(25))
iex>
iex> Bookk.Account.post(account, op)
%Bookk.Account{
  head: %Bookk.AccountHead{class: %Bookk.AccountClass{natural_balance: :debit}},
  balance: Decimal.new(25)
}

The account's head must match the head in the operation, otherwise an error is raised:

iex> head_a = %Bookk.AccountHead{name: "a"}
iex> head_b = %Bookk.AccountHead{name: "b"}
iex>
iex> account = Bookk.Account.new(head_a)
iex> op = debit(head_b, Decimal.new(25))
iex>
iex> Bookk.Account.post(account, op)
** (FunctionClauseError) no function clause matching in Bookk.Account.post/2