repo.ex

defmodule Foobot.Repo do

  # use JSON and some awesomesauce to make a database of sorts.
  # in-memory it will be just a map...
  # on disk JSON
  # reads simply read all the data, writes do the write & also write
  # a copy to disk
  require Logger

  @repo :repo_registry
  def init(filepath) do
    Registry.start_link(keys: :unique, name: @repo)
    setup_db(filepath)
  end

  ##############################################################################
  # Events and their stuff
  def events() do
    [{_pid, data}] = Registry.lookup(@repo, :data)
    data[:events]
  end

  def add_event(event, ts \\ nil) do
    # Should come in as "YYYY-MM-DD 24:MM:SS"
    ts = if ts, do: ts, else: Timex.format!(Timex.now, "%F %T", :strftime)
    IO.puts "WTF1?!?!?!"
    Registry.update_value(@repo, :data,
      fn old ->
        # IO.puts "?!?!?!?!?"
        # [{_pid, data}] = old
        # IO.puts "old: #{old} data: #{data}"
        # put_in(data, [:events], [[ts, event] | data[:events]])
        old
      end)
    # write_db()
    # :ok
  end

  ##############################################################################
  # Setup & persistence functions
  defp setup_db(file) do
    Registry.register(@repo, :db_file, file)
    Registry.register(@repo, :data, %{})
    read_disk_db()
  end

  def read_disk_db() do
    case Registry.lookup(@repo, :db_file) do
      [{_pid, db_file}] ->
        case File.read(db_file) do
          {:ok, data} ->
            Registry.update_value(@repo, :data,
              fn _ ->
                {:ok, data} = JSX.decode(data, [{:labels, :atom}])
                data
              end)
          {:error, err} -> Logger.error "Error reading file: #{err}"
        end
      _ -> Logger.error "No DB File for Repo"
    end
  end

  defp write_db() do
    case Registry.lookup(@repo, :db_file) do
      [{_pid, db_file}] ->
        [{_pid, data}] = Registry.lookup(@repo, :data)
        {:ok, json} = JSX.encode data
        {:ok, json} = JSX.prettify json # makin it perdy
        case File.write(db_file, json) do
          :ok -> Logger.info "Wrote to DB File"
          {:error, err} -> Logger.error "Error writing file: #{err}"
        end
      _ -> Logger.error "No DB file for Repo"
    end
  end

end