defmodule Microwaveprop.Propagation.GridTask do
  @moduledoc """
  Schema for the `grid_tasks` table — a cross-language shared queue between
  Elixir's `PropagationGridWorker` (seeder) and the Rust `prop-grid-rs`
  worker (consumer).

  **This schema does NOT own the table.** The table is created by Ecto
  migrations but rows are written by Elixir seeders (`GridTaskEnqueuer`)
  and consumed/updated by Rust via direct SQL (`SELECT ... FOR UPDATE
  SKIP LOCKED`). No Ecto changeset is provided — the schema exists
  purely for compile-time field-name checking on Ecto queries, so that
  `from(t in GridTask, where: t.status == "queued")` catches typos
  (`t.stauts`) that are invisible in the legacy `from(t in "grid_tasks", ...)`
  string-table queries.
  """

  use Ecto.Schema

  @type t :: %__MODULE__{}

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

  schema "grid_tasks" do
    field :run_time, :utc_datetime
    field :forecast_hour, :integer
    field :valid_time, :utc_datetime
    field :status, :string, default: "queued"
    field :attempt, :integer, default: 0
    field :claimed_at, :utc_datetime_usec
    field :completed_at, :utc_datetime_usec
    field :error, :string
    field :kind, :string, default: "forecast"
    field :source, :string, default: "hrrr"

    timestamps(type: :utc_datetime)
  end
end