defmodule Microwaveprop.Weather.Era5CdsJob do
  @moduledoc """
  Tracks an in-flight ERA5 CDS request submitted by `Era5SubmitWorker` and
  awaiting download+decode by `Era5PollWorker`. Persisting the CDS job IDs
  decouples the Oban worker lifecycle from the 30+ minute CDS queue time,
  so a pod restart resumes polling instead of re-submitting.
  """
  use Ecto.Schema

  import Ecto.Changeset

  @primary_key {:id, :binary_id, autogenerate: true}
  @foreign_key_type :binary_id

  schema "era5_cds_jobs" do
    field :year, :integer
    field :month, :integer
    field :tile_lat, :integer
    field :tile_lon, :integer
    field :single_job_id, :string
    field :pressure_job_id, :string
    field :submitted_at, :utc_datetime
    field :last_polled_at, :utc_datetime
    field :poll_count, :integer, default: 0

    timestamps(type: :utc_datetime)
  end

  @type t :: %__MODULE__{}

  @required_fields ~w(year month tile_lat tile_lon single_job_id pressure_job_id submitted_at)a
  @optional_fields ~w(last_polled_at poll_count)a

  @spec changeset(t() | Ecto.Changeset.t(), map()) :: Ecto.Changeset.t()
  def changeset(job, attrs) do
    job
    |> cast(attrs, @required_fields ++ @optional_fields)
    |> validate_required(@required_fields)
    |> unique_constraint([:year, :month, :tile_lat, :tile_lon],
      name: :era5_cds_jobs_year_month_tile_lat_tile_lon_index,
      error_key: :tile_month
    )
  end
end