defmodule ArcadiaCloud.Sync.ProjectsWorker do
  @moduledoc """
  Sync of DigitalOcean Projects → cloud_projects table.

  Two-pass:
    1. Upsert every DO project locally (purpose derives from name pattern).
    2. For each known project, fetch its resource memberships and update
       cloud_resources.cloud_project_id + tenant_id accordingly.

  Tenant attribution: a DO project named `tenant-<uuid>` maps to that
  tenant. `skyai-internal` is the platform tenant (tenant_id = nil).
  Everything else has tenant_id = nil and is operator-classified later.
  """

  use Oban.Worker, queue: :cloud_sync_full, max_attempts: 3

  import Ecto.Query

  alias ArcadiaCloud.Cloud
  alias ArcadiaCloud.Cloud.CloudResource
  alias ArcadiaCloud.DigitalOcean.Client
  alias ArcadiaCloud.Repo

  @impl Oban.Worker
  def perform(_job) do
    with {:ok, do_projects} <- Client.list_projects() do
      Enum.each(do_projects, &sync_project/1)
      attribute_resources(do_projects)
      :ok
    end
  end

  defp sync_project(do_project) do
    Cloud.ensure_project(%{
      provider: "digitalocean",
      provider_id: do_project["id"],
      name: do_project["name"],
      purpose: derive_purpose(do_project["name"]),
      metadata: %{
        do_purpose: do_project["purpose"],
        environment: do_project["environment"],
        description: do_project["description"],
        is_default: do_project["is_default"]
      }
    })
  end

  defp derive_purpose("skyai-internal"), do: "skyai-infra"
  defp derive_purpose("tenant-" <> _rest), do: "tenant-workload"
  defp derive_purpose(_), do: "shared-services"

  # ---- attribution ----------------------------------------------------------

  defp attribute_resources(do_projects) do
    Enum.each(do_projects, fn do_project ->
      local = Cloud.get_project_by_provider("digitalocean", do_project["id"])

      if local do
        case Client.list_project_resources(do_project["id"]) do
          {:ok, resources} -> attribute_urns(resources, local)
          _ -> :noop
        end
      end
    end)
  end

  defp attribute_urns(urns, %{id: project_id} = local) do
    tenant_id = tenant_id_for(local)

    Enum.each(urns, fn %{"urn" => urn} ->
      case parse_urn(urn) do
        {kind, provider_id} -> update_resource_attribution(kind, provider_id, project_id, tenant_id)
        _ -> :skip
      end
    end)
  end

  defp update_resource_attribution(kind, provider_id, project_id, tenant_id) do
    from(r in CloudResource,
      where:
        r.provider == "digitalocean" and r.kind == ^kind and r.provider_id == ^provider_id and
          is_nil(r.deleted_at)
    )
    |> Repo.update_all(set: [cloud_project_id: project_id, tenant_id: tenant_id])
  end

  # "do:droplet:567897199" → {"droplet", "567897199"}
  defp parse_urn("do:" <> rest) do
    case String.split(rest, ":", parts: 2) do
      [kind, id] -> {normalize_kind(kind), id}
      _ -> nil
    end
  end

  defp parse_urn(_), do: nil

  # DO URN uses singular common nouns; our cloud_resources.kind names some
  # things more explicitly to disambiguate (e.g. dns_zone vs dns_record).
  defp normalize_kind("domain"), do: "dns_zone"
  defp normalize_kind("space"), do: "spaces_bucket"
  defp normalize_kind(other), do: other

  defp tenant_id_for(%{name: "tenant-" <> tenant_uuid}), do: tenant_uuid
  defp tenant_id_for(_), do: nil
end