defmodule SyntropyWeb.Api.WebhookController do
  @moduledoc """
  REST management of webhook endpoint registrations and delivery logs.
  """

  use SyntropyWeb, :controller

  import SyntropyWeb.Api.ControllerHelpers

  alias Syntropy.Webhooks.Registry, as: WebhookRegistry

  @doc "GET /api/webhooks — list registrations with recent delivery attempts."
  def index(conn, _params) do
    data =
      WebhookRegistry.list()
      |> Enum.map(fn {webhook, deliveries} -> webhook_json(webhook, deliveries) end)

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

  @doc "POST /api/webhooks — register an endpoint. Returns the secret once."
  def create(conn, params) do
    case WebhookRegistry.register(params) do
      {:ok, webhook} ->
        conn
        |> put_status(:created)
        |> json(%{data: Map.put(webhook_json(webhook, []), :secret, webhook.secret)})

      {:error, errors} ->
        invalid_request(conn, "Webhook registration is invalid.", errors)
    end
  end

  @doc "PATCH /api/webhooks/:id — pause or resume deliveries."
  def update(conn, %{"id" => id} = params) do
    case Map.get(params, "active") do
      active when is_boolean(active) ->
        case WebhookRegistry.set_active(id, active) do
          {:ok, webhook} -> json(conn, %{data: webhook_json(webhook, [])})
          {:error, :not_found} -> not_found(conn, "Webhook", id)
        end

      _other ->
        invalid_request(conn, "Webhook update is invalid.", [
          %{field: "active", message: "must be a boolean"}
        ])
    end
  end

  @doc "DELETE /api/webhooks/:id — remove a registration."
  def delete(conn, %{"id" => id}) do
    case WebhookRegistry.remove(id) do
      :ok -> json(conn, %{data: %{id: id, removed: true}})
      {:error, :not_found} -> not_found(conn, "Webhook", id)
    end
  end

  defp webhook_json(webhook, deliveries) do
    %{
      id: webhook.id,
      url: webhook.url,
      events: webhook.events,
      active: webhook.active,
      masked_secret: mask_secret(webhook.secret),
      inserted_at: DateTime.to_iso8601(webhook.inserted_at),
      recent_deliveries: Enum.map(deliveries, &delivery_json/1)
    }
  end

  defp delivery_json(delivery) do
    %{
      event_id: delivery.event_id,
      status: delivery.status,
      http_status: delivery.http_status,
      attempts: delivery.attempts,
      error: delivery.error,
      delivered_at: DateTime.to_iso8601(delivery.delivered_at)
    }
  end

  defp mask_secret(secret) do
    "••••" <> String.slice(secret, -4, 4)
  end
end