defmodule Credo.Service.SourceFileScopes do
  use GenServer

  @table_name __MODULE__

  def start_link(opts \\ []) do
    {:ok, _pid} = GenServer.start_link(__MODULE__, opts, name: __MODULE__)
  end

  def get(filename) do
    GenServer.call(__MODULE__, {:get, filename})
  end

  def put(filename, source) do
    GenServer.call(__MODULE__, {:put, filename, source})
  end

  # callbacks

  def init(_) do
    ets = :ets.new(@table_name, [:named_table, read_concurrency: true])
    {:ok, ets}
  end

  def handle_call({:get, filename}, _from, current_state) do
    case :ets.lookup(@table_name, filename) do
      [{^filename, value}] ->
        {:reply, {:ok, value}, current_state}
      [] ->
        {:reply, :notfound, current_state}
    end
  end

  def handle_call({:put, filename, source}, _from, current_state) do
    :ets.insert(@table_name, {filename, source})
    {:reply, source, current_state}
  end
end