defmodule ToweropsWeb.GraphQL.Resolvers.Site do
  @moduledoc "GraphQL resolvers for site queries and mutations."

  alias Towerops.Repo
  alias Towerops.Sites
  alias Towerops.Sites.Site

  def list(_parent, _args, %{context: %{organization_id: org_id}}) do
    sites = Sites.list_organization_sites(org_id)
    {:ok, sites}
  end

  def list(_parent, _args, _resolution), do: {:error, "Authentication required"}

  def get(_parent, %{id: id}, %{context: %{organization_id: org_id}}) do
    fetch_org_site(id, org_id)
  end

  def get(_parent, _args, _resolution), do: {:error, "Authentication required"}

  def create(_parent, %{input: input}, %{context: %{organization_id: org_id}}) do
    attrs =
      input
      |> Map.new(fn {k, v} -> {to_string(k), v} end)
      |> Map.put("organization_id", org_id)

    case Sites.create_site(attrs) do
      {:ok, site} -> {:ok, site}
      {:error, changeset} -> {:error, format_errors(changeset)}
    end
  end

  def create(_parent, _args, _resolution), do: {:error, "Authentication required"}

  def update(_parent, %{id: id, input: input}, %{context: %{organization_id: org_id}}) do
    with {:ok, site} <- fetch_org_site(id, org_id) do
      attrs = Map.new(input, fn {k, v} -> {to_string(k), v} end)

      case Sites.update_site(site, attrs) do
        {:ok, updated} -> {:ok, updated}
        {:error, changeset} -> {:error, format_errors(changeset)}
      end
    end
  end

  def update(_parent, _args, _resolution), do: {:error, "Authentication required"}

  def delete(_parent, %{id: id}, %{context: %{organization_id: org_id}}) do
    with {:ok, site} <- fetch_org_site(id, org_id) do
      case Sites.delete_site(site) do
        {:ok, _} -> {:ok, %{success: true, message: "Site deleted"}}
        {:error, _} -> {:ok, %{success: false, message: "Could not delete site"}}
      end
    end
  end

  def delete(_parent, _args, _resolution), do: {:error, "Authentication required"}

  defp fetch_org_site(id, org_id) do
    case Repo.get(Site, id) do
      nil -> {:error, "Site not found"}
      %Site{organization_id: ^org_id} = site -> {:ok, site}
      %Site{} -> {:error, "Site not found"}
    end
  end

  defp format_errors(changeset) do
    changeset
    |> Ecto.Changeset.traverse_errors(fn {msg, opts} ->
      Regex.replace(~r"%{(\w+)}", msg, fn _, key ->
        opts |> Keyword.get(String.to_existing_atom(key), key) |> to_string()
      end)
    end)
    |> Enum.map_join("; ", fn {field, messages} -> "#{field}: #{Enum.join(messages, ", ")}" end)
  end
end