defmodule Ledger do @doc """ Format the given entries given a currency and locale """ @type currency :: :usd | :eur @type locale :: :en_US | :nl_NL @type entry :: %{amount_in_cents: integer(), date: Date.t(), description: String.t()} @spec format_entries(currency(), locale(), list(entry())) :: String.t() def format_entries(currency, locale, entries) do header = if locale == :en_US do "Date | Description | Change \n" else "Datum | Omschrijving | Verandering \n" end if entries == [] do header else entries = Enum.sort(entries, fn a, b -> cond do a.date.day < b.date.day -> true a.date.day > b.date.day -> false a.description < b.description -> true a.description > b.description -> false true -> a.amount_in_cents <= b.amount_in_cents end end) |> Enum.map(fn entry -> format_entry(currency, locale, entry) end) |> Enum.join("\n") header <> entries <> "\n" end end defp format_entry(currency, locale, entry) do year = entry.date.year |> to_string() month = entry.date.month |> to_string() |> String.pad_leading(2, "0") day = entry.date.day |> to_string() |> String.pad_leading(2, "0") date = if locale == :en_US do month <> "/" <> day <> "/" <> year <> " " else day <> "-" <> month <> "-" <> year <> " " end number = if locale == :en_US do decimal = entry.amount_in_cents |> abs |> rem(100) |> to_string() |> String.pad_leading(2, "0") whole = if abs(div(entry.amount_in_cents, 100)) < 1000 do abs(div(entry.amount_in_cents, 100)) |> to_string() else to_string(div(abs(div(entry.amount_in_cents, 100)), 1000)) <> "," <> to_string(rem(abs(div(entry.amount_in_cents, 100)), 1000)) end whole <> "." <> decimal else decimal = entry.amount_in_cents |> abs |> rem(100) |> to_string() |> String.pad_leading(2, "0") whole = if abs(div(entry.amount_in_cents, 100)) < 1000 do abs(div(entry.amount_in_cents, 100)) |> to_string() else to_string(div(abs(div(entry.amount_in_cents, 100)), 1000)) <> "." <> to_string(rem(abs(div(entry.amount_in_cents, 100)), 1000)) end whole <> "," <> decimal end amount = if entry.amount_in_cents >= 0 do if locale == :en_US do " #{if(currency == :eur, do: "€", else: "$")}#{number} " else " #{if(currency == :eur, do: "€", else: "$")} #{number} " end else if locale == :en_US do " (#{if(currency == :eur, do: "€", else: "$")}#{number})" else " #{if(currency == :eur, do: "€", else: "$")} -#{number} " end end |> String.pad_leading(14, " ") description = if entry.description |> String.length() > 26 do " " <> String.slice(entry.description, 0, 22) <> "..." else " " <> String.pad_trailing(entry.description, 25, " ") end date <> "|" <> description <> " |" <> amount end end