lib/monfari/types/amount.ex

@@ -0,0 +1,48 @@
+defmodule Monfari.Types.Amount do
+  use Ecto.Type
+  def type, do: :string
+
+  defstruct [:sign, :whole, :part, :currency]
+
+  @re ~r/^(-?)([0-9]+)\.([0-9]{2}) ([A-Z]{3})$/
+
+  def cast(str) when is_binary(str) do
+    case Regex.run(@re, str, capture: :all_but_first) do
+      [sign, whole, part, currency] ->
+        {:ok,
+         %__MODULE__{
+           sign: %{"" => 1, "-" => -1}[sign],
+           whole: String.to_integer(whole),
+           part: String.to_integer(part),
+           currency: currency
+         }}
+
+      nil ->
+        :error
+    end
+  end
+
+  def cast(%__MODULE__{} = val), do: val
+
+  def load(str) when is_binary(str), do: cast(str)
+
+  def dump(%__MODULE__{sign: sign, whole: whole, part: part, currency: currency}) do
+    sign = %{-1 => "-", 1 => ""}[sign]
+    {:ok, "#{sign}#{whole}.#{part} #{currency}"}
+  end
+
+  def dump(_), do: :error
+
+  def value(%__MODULE__{sign: sign, whole: whole, part: part}), do: sign * (whole * 100 + part)
+
+  def from_value(value, currency) do
+    sign = if value >= 0 do 1 else -1 end
+    whole = div(abs(value), 100)
+    part = rem(abs(value), 100)
+    %__MODULE__{sign: sign, whole: whole, part: part, currency: currency}
+  end
+
+  def add(%__MODULE__{currency: currency} = lhs, %__MODULE__{currency: currency} = rhs) do
+    from_value(value(lhs) + value(rhs), currency)
+  end
+end

lib/monfari/types/transaction.ex

@@ -0,0 +1,32 @@
+defmodule Monfari.Schema.Transaction do
+  use Ecto.Schema
+
+  defmodule Effects do
+    use Ecto.Type
+
+    alias Monfari.Types.Amount
+
+    def type, do: {:map, Amount}
+
+    def cast(%{} = s), do: s |> Enum.map(fn {key, value} ->
+      
+    end) |> Enum.into(%{})
+
+  end
+
+  @primary_key {:id, Needle.ULID, autogenerate: true}
+  @foreign_key_type Needle.ULID
+  @derive Jason.Encoder
+
+  schema "transactions" do
+    field :notes, :string
+    field :effects, Effects
+  end
+
+  defmodule Commands.Create do
+  end
+  defmodule Commands.Update do
+  end
+  defmodule Commands.Delete do
+  end
+end