defmodule Microwaveprop.Weather.Iemre do
  @moduledoc false

  import Ecto.Query

  alias Microwaveprop.Radio
  alias Microwaveprop.Radio.Contact
  alias Microwaveprop.Repo
  alias Microwaveprop.Weather.IemreObservation
  alias Microwaveprop.Weather.ProfileLookup

  # Delegates to ProfileLookup
  defdelegate iemre_for_contact(contact), to: ProfileLookup
  defdelegate iemre_for_path(contact), to: ProfileLookup
  defdelegate find_nearest_iemre(lat, lon, timestamp), to: ProfileLookup
  defdelegate round_to_iemre_grid(lat, lon), to: ProfileLookup

  @spec upsert_iemre_observation(map()) :: {:ok, IemreObservation.t()} | {:error, Ecto.Changeset.t()}
  def upsert_iemre_observation(attrs) do
    %IemreObservation{}
    |> IemreObservation.changeset(attrs)
    |> Repo.insert(
      on_conflict: :nothing,
      conflict_target: [:lat, :lon, :date]
    )
  end

  @spec has_iemre_observation?(float(), float(), Date.t()) :: boolean()
  def has_iemre_observation?(lat, lon, date) do
    IemreObservation
    |> where([i], i.lat == ^lat and i.lon == ^lon and i.date == ^date)
    |> Repo.exists?()
  end

  @doc """
  Flip `contacts.iemre_status` from `:queued` to `:complete` for every
  contact whose path points all have an `iemre_observations` row at
  the rounded grid cell for the QSO's UTC date.

  Per-contact check (via the existing helpers); kept in Elixir because
  `contact_path_points/1` produces 1–3 points depending on whether
  `pos2` is set, and rounding to the 0.125° IEMRE grid per point in
  pure SQL is awkward. Queue sizes are small (<20 stuck at steady
  state).
  """
  @spec reconcile_iemre_statuses() :: {:ok, non_neg_integer()}
  def reconcile_iemre_statuses do
    queued =
      Contact
      |> where([c], c.iemre_status == :queued and not is_nil(c.pos1))
      |> Repo.all()

    to_complete =
      Enum.filter(queued, fn c ->
        date = DateTime.to_date(c.qso_timestamp)

        c
        |> Radio.contact_path_points()
        |> Enum.all?(fn {lat, lon} ->
          {rlat, rlon} = round_to_iemre_grid(lat, lon)
          has_iemre_observation?(rlat, rlon, date)
        end)
      end)

    if to_complete == [] do
      {:ok, 0}
    else
      ids = Enum.map(to_complete, & &1.id)
      _ = Radio.set_enrichment_status!(ids, :iemre_status, :complete)
      {:ok, length(to_complete)}
    end
  end
end