defmodule Microwaveprop.Workers.NarrFetchWorker do
  @moduledoc """
  Fetches one NCEP NARR profile from NCEI via `NarrClient.fetch_profile_at/2`
  and inserts it as a `NarrProfile` row.

  Covers pre-2014 contacts where the HRRR archive doesn't reach. Replaces
  the retired ERA5/CDS pipeline. NARR fetches are per-point (one analysis
  hour, one location), so this worker does the fetch + insert directly —
  no downstream batch worker, no routing.

  Jobs are unique on `{lat, lon, valid_time}` so duplicate enrichment
  requests collapse. `valid_time` MUST already be snapped to a NARR
  3-hourly analysis slot (00/03/06/09/12/15/18/21 UTC on the hour) by the
  caller — the worker raises `ArgumentError` otherwise via
  `NarrClient.url_for/1`.

  See `docs/plans/2026-04-15-merra2-historical-backfill.md` for the full
  architecture.
  """
  use Oban.Worker,
    queue: :narr,
    max_attempts: 3,
    unique: [
      period: :infinity,
      states: [:available, :scheduled, :executing, :retryable]
    ]

  import Ecto.Query

  alias Microwaveprop.Repo
  alias Microwaveprop.Weather.NarrClient
  alias Microwaveprop.Weather.NarrProfile

  require Logger

  @impl Oban.Worker
  def perform(%Oban.Job{args: %{"lat" => lat, "lon" => lon, "valid_time" => valid_time_str}}) do
    {:ok, valid_time, _} = DateTime.from_iso8601(valid_time_str)

    rlat = Float.round(lat * 4) / 4
    rlon = Float.round(lon * 4) / 4

    if has_narr_profile?(rlat, rlon, valid_time) do
      :ok
    else
      fetch_and_insert(rlat, rlon, valid_time)
    end
  end

  defp fetch_and_insert(rlat, rlon, valid_time) do
    case NarrClient.fetch_profile_at(valid_time, {rlat, rlon}) do
      {:ok, attrs} ->
        _ = insert_profile(attrs, rlat, rlon, valid_time)
        :ok

      {:error, reason} = error ->
        Logger.warning(
          "NARR: fetch_profile_at failed for #{rlat},#{rlon} @ #{DateTime.to_iso8601(valid_time)}: #{inspect(reason)}"
        )

        error
    end
  end

  defp insert_profile(attrs, rlat, rlon, valid_time) do
    now = DateTime.truncate(DateTime.utc_now(), :second)

    row =
      attrs
      |> Map.put(:lat, rlat)
      |> Map.put(:lon, rlon)
      |> Map.put(:valid_time, valid_time)
      |> Map.put(:inserted_at, now)
      |> Map.put(:updated_at, now)

    Repo.insert_all(NarrProfile, [row],
      on_conflict: :nothing,
      conflict_target: [:lat, :lon, :valid_time]
    )
  end

  defp has_narr_profile?(lat, lon, valid_time) do
    # NARR is exact 3-hourly, so the time window can be tight (±15 min).
    # Lat/lon tolerance matches the 0.25° dedup granularity.
    dlat = 0.13
    dlon = 0.13
    time_start = DateTime.add(valid_time, -900, :second)
    time_end = DateTime.add(valid_time, 900, :second)

    NarrProfile
    |> where(
      [p],
      p.lat >= ^(lat - dlat) and p.lat <= ^(lat + dlat) and
        p.lon >= ^(lon - dlon) and p.lon <= ^(lon + dlon) and
        p.valid_time >= ^time_start and p.valid_time <= ^time_end
    )
    |> Repo.exists?()
  end
end