defmodule ToweropsWeb.Api.V1.InvitationsController do
  @moduledoc "API controller for organization invitations."
  use ToweropsWeb, :controller

  alias Towerops.Organizations

  def index(conn, _params) do
    organization_id = conn.assigns.current_organization_id

    invitations =
      organization_id
      |> Organizations.list_pending_invitations()
      |> Enum.map(&format_invitation/1)

    json(conn, %{data: invitations})
  end

  def create(conn, %{"email" => email, "role" => role}) do
    organization_id = conn.assigns.current_organization_id
    user = conn.assigns[:current_user]

    attrs = %{
      organization_id: organization_id,
      email: email,
      role: role,
      invited_by_id: user && user.id,
      token: Ecto.UUID.generate(),
      expires_at: DateTime.add(DateTime.utc_now(), 7 * 86_400, :second) |> DateTime.truncate(:second)
    }

    case Organizations.create_invitation(attrs) do
      {:ok, invitation} ->
        conn
        |> put_status(:created)
        |> json(%{data: format_invitation(Towerops.Repo.preload(invitation, :invited_by))})

      {:error, changeset} ->
        conn
        |> put_status(:unprocessable_entity)
        |> json(%{errors: translate_errors(changeset)})
    end
  end

  def create(conn, _params) do
    conn |> put_status(:bad_request) |> json(%{error: "Missing 'email' and 'role' parameters"})
  end

  def delete(conn, %{"id" => id}) do
    organization_id = conn.assigns.current_organization_id

    invitation = Towerops.Repo.get!(Towerops.Organizations.Invitation, id)

    if invitation.organization_id == organization_id do
      case Organizations.delete_invitation(invitation) do
        {:ok, _} -> conn |> put_status(:no_content) |> send_resp(204, "")
        {:error, _} -> conn |> put_status(:unprocessable_entity) |> json(%{error: "Could not delete invitation"})
      end
    else
      conn |> put_status(:not_found) |> json(%{error: "Invitation not found"})
    end
  rescue
    Ecto.NoResultsError ->
      conn |> put_status(:not_found) |> json(%{error: "Invitation not found"})
  end

  defp format_invitation(invitation) do
    %{
      id: invitation.id,
      email: invitation.email,
      role: invitation.role,
      expires_at: invitation.expires_at,
      invited_by_email: get_in_loaded(invitation, :invited_by, :email),
      inserted_at: invitation.inserted_at
    }
  end

  defp get_in_loaded(struct, assoc, field) do
    case Map.get(struct, assoc) do
      %Ecto.Association.NotLoaded{} -> nil
      nil -> nil
      loaded -> Map.get(loaded, field)
    end
  end

  defp translate_errors(changeset) do
    Ecto.Changeset.traverse_errors(changeset, fn {msg, opts} ->
      Regex.replace(~r"%{(\w+)}", msg, fn _, key ->
        if String.length(key) <= 50 and String.match?(key, ~r/^[a-z_]+$/) do
          opts |> Keyword.get(String.to_existing_atom(key), key) |> to_string()
        else
          key
        end
      end)
    end)
  end
end