defmodule BirdyChatWeb.Api.Messages.Controller do
  use BirdyChatWeb, :controller

  def create(conn, params) do
    case BirdyChat.Message.validate(params) do
      {:ok, changeset} ->
        case BirdyChat.Message.find_peer(changeset.changes) do
          {:ok, :local} ->
            case BirdyChat.MessageWriter.write(changeset.changes) do
              :ok ->
                conn
                |> put_status(:created)
                |> render(:create, message: changeset.changes)
            end

          {:ok, peer_name} ->
            BirdyChatWeb.ServerChannel.broadcast!(peer_name, changeset.changes)

            conn
            |> put_status(:created)
            |> render(:create, message: changeset.changes)

          {:error, :not_found} ->
            changeset =
              changeset
              |> Ecto.Changeset.add_error(:to, "Unknown 'to' server")

            conn
            |> put_status(:unprocessable_entity)
            |> render(:error, changeset: changeset)
        end

      {:error, changeset} ->
        conn
        |> put_status(:unprocessable_entity)
        |> render(:error, changeset: changeset)
    end
  end
end