@spec empty() :: t()

Produces a empty naive state.

@spec get_ledger(t(), String.t()) :: Bookk.Ledger.t()

Get's a ledger from the state by its name. If the ledger doesn't exist in the state yet, then a new empty ledger will be returned.

Examples

Returns an empty ledger when requested ledger doesn't exist in state:

iex> Bookk.NaiveState.get_ledger(%Bookk.NaiveState{}, "acme")
%Bookk.Ledger{name: "acme"}

Returns the ledger when it exists in state:

iex> state = %Bookk.NaiveState{
iex>   ledgers_by_name: %{
iex>     "foo" => %Bookk.Ledger{
iex>       accounts_by_name: %{
iex>         "cash" => %Bookk.Account{}
iex>       }
iex>     }
iex>   }
iex> }
iex>
iex> Bookk.NaiveState.get_ledger(state, "foo")
%Bookk.Ledger{
  accounts_by_name: %{
    "cash" => %Bookk.Account{}
  }
}

@spec new([Bookk.Ledger.t()]) :: t()

Produces a new state struct from a set of ledgers.

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

Posts a Bookk.InterledgerEntry to the state, appling changes in balance to multiple accounts accross multiple ledgers.

Examples

iex> import Bookk.Notation, only: [journalize!: 2]
iex>
iex> user_id = "123"
iex> deposited_amount = 500_00
iex>
iex> journal_entry =
iex>   journalize! using: TestChartOfAccounts do
iex>     on ledger(:acme) do
iex>       debit account(:cash), deposited_amount
iex>       credit account({:unspent_cash, {:user, user_id}}), deposited_amount
iex>     end
iex>
iex>     on ledger({:user, user_id}) do
iex>       debit account(:cash), deposited_amount
iex>       credit account(:deposits), deposited_amount
iex>     end
iex>   end
iex>
iex> Bookk.NaiveState.empty()
iex> |> Bookk.NaiveState.post(journal_entry)
%Bookk.NaiveState{
  ledgers_by_name: %{
    "acme" => %Bookk.Ledger{
      name: "acme",
      accounts_by_name: %{
        fixture_account_head(:cash).name => %Bookk.Account{
          head: fixture_account_head(:cash),
          balance: 500_00
        },
        fixture_account_head({:unspent_cash, {:user, "123"}}).name => %Bookk.Account{
          head: fixture_account_head({:unspent_cash, {:user, "123"}}),
          balance: 500_00
        }
      }
    },
    "user(123)" => %Bookk.Ledger{
      name: "user(123)",
      accounts_by_name: %{
        fixture_account_head(:cash).name => %Bookk.Account{
          head: fixture_account_head(:cash),
          balance: 500_00
        },
        fixture_account_head(:deposits).name => %Bookk.Account{
          head: fixture_account_head(:deposits),
          balance: 500_00
        }
      }
    }
  }
}