defmodule Microwaveprop.Repo.Migrations.AddSourceToGridTasks do
  use Ecto.Migration

  # `source` splits grid_tasks between HRRR-derived (CONUS) and HRDPS-
  # derived (Canada) work. Rust workers branch on this column to pick the
  # right URL pattern + decoder. Default 'hrrr' so existing rows keep
  # their meaning; HRDPS rows arrive only once HrdpsGridWorker is added
  # to the cron (deferred until the Rust HRDPS branch ships).
  def change do
    alter table(:grid_tasks) do
      add :source, :string, null: false, default: "hrrr"
    end

    # Replace (run_time, forecast_hour, kind) uniqueness with a 4-column
    # key so HRRR and HRDPS analysis/forecast rows for the same cycle can
    # coexist. The index also speeds up `claim_next` filters.
    drop_if_exists unique_index(:grid_tasks, [:run_time, :forecast_hour, :kind])
    create unique_index(:grid_tasks, [:run_time, :forecast_hour, :kind, :source])

    create index(:grid_tasks, [:source])
  end
end