community_garden

elixir/community-garden/lib/community_garden.ex

@@ -0,0 +1,38 @@
+# Use the Plot struct as it is provided
+defmodule Plot do
+  @enforce_keys [:plot_id, :registered_to]
+  defstruct [:plot_id, :registered_to]
+end
+
+defmodule CommunityGarden do
+  def start(),
+    do: Agent.start(fn -> %{index: 0, plots: []} end)
+
+  def list_registrations(pid),
+    do: Agent.get(pid, fn %{plots: plots} -> plots end)
+
+  def register(pid, register_to),
+    do:
+      Agent.get_and_update(pid, fn %{plots: plots, index: counter} ->
+        index = counter + 1
+        plot = %Plot{plot_id: index, registered_to: register_to}
+        {plot, %{plots: [plot | plots], index: index}}
+      end)
+
+  def release(pid, plot_id),
+    do:
+      Agent.cast(pid, fn %{plots: plots} = state ->
+        %{state | plots: Enum.reject(plots, fn element -> compare(element, plot_id) end)}
+      end)
+
+  def get_registration(pid, plot_id) do
+    list_registrations(pid)
+    |> Enum.find(
+      {:not_found, "plot is unregistered"},
+      fn element -> compare(element, plot_id) end
+    )
+  end
+
+  defp compare(%Plot{plot_id: element_id}, plot_id) when element_id == plot_id, do: true
+  defp compare(_element, _plot_id), do: false
+end