wine-cellar

elixir/wine-cellar/lib/wine_cellar.ex

@@ -0,0 +1,49 @@
+defmodule WineCellar do
+  @colors [
+    white: "Fermented without skin contact.",
+    red: "Fermented with skin contact using dark-colored grapes.",
+    rose: "Fermented with some skin contact, but not enough to qualify as a red wine."
+  ]
+
+  # @cellar [
+  #   white: {"Chardonnay", 2015, "Italy"},
+  #   white: {"Pinot grigio", 2017, "Germany"},
+  #   red: {"Pinot noir", 2016, "France"},
+  #   rose: {"Dornfelder", 2018, "Germany"}
+  # ]
+
+  def explain_colors(), do: @colors
+
+  def filter(cellar, color, opts \\ []) do
+    cellar
+    |> Keyword.get_values(color)
+    |> filter_by_year(opts[:year])
+    |> filter_by_country(opts[:country])
+  end
+
+  # The functions below do not need to be modified.
+
+  defp filter_by_year(wines, year)
+  defp filter_by_year(wines, nil), do: wines
+  defp filter_by_year([], _year), do: []
+
+  defp filter_by_year([{_, year, _} = wine | tail], year) do
+    [wine | filter_by_year(tail, year)]
+  end
+
+  defp filter_by_year([{_, _, _} | tail], year) do
+    filter_by_year(tail, year)
+  end
+
+  defp filter_by_country(wines, country)
+  defp filter_by_country(wines, nil), do: wines
+  defp filter_by_country([], _country), do: []
+
+  defp filter_by_country([{_, _, country} = wine | tail], country) do
+    [wine | filter_by_country(tail, country)]
+  end
+
+  defp filter_by_country([{_, _, _} | tail], country) do
+    filter_by_country(tail, country)
+  end
+end