defmodule ToweropsWeb.Api.V1.AgentsController do
  @moduledoc "API controller for agent tokens."
  use ToweropsWeb, :controller

  alias Towerops.Agents

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

    agents =
      organization_id
      |> Agents.list_organization_agent_tokens()
      |> Enum.map(&format_agent/1)

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

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

    case Agents.create_agent_token(organization_id, name) do
      {:ok, agent_token, raw_token} ->
        conn
        |> put_status(:created)
        |> json(%{data: Map.put(format_agent(agent_token), :token, raw_token)})

      {: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 'name' parameter"})
  end

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

    agent = Agents.get_agent_token!(id)

    if agent.organization_id == organization_id do
      device_count = Agents.count_assigned_devices(id)

      json(conn, %{
        data:
          format_agent(agent)
          |> Map.put(:device_count, device_count)
      })
    else
      conn |> put_status(:not_found) |> json(%{error: "Agent not found"})
    end
  rescue
    Ecto.NoResultsError ->
      conn |> put_status(:not_found) |> json(%{error: "Agent not found"})
  end

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

    agent = Agents.get_agent_token!(id)

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

  defp format_agent(agent) do
    %{
      id: agent.id,
      name: agent.name,
      enabled: agent.enabled,
      last_seen_at: agent.last_seen_at,
      last_ip: agent.last_ip,
      metadata: agent.metadata,
      inserted_at: agent.inserted_at
    }
  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