CREATE TYPE IF NOT EXISTS asset_variant_kind AS ENUM (
  'thumb',
  'poster',
  'video_mp4'
);

CREATE TABLE IF NOT EXISTS asset_variants (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  asset_id uuid NOT NULL REFERENCES assets(id) ON DELETE CASCADE,
  kind asset_variant_kind NOT NULL,
  size int NOT NULL,
  key text NOT NULL,
  mime_type text NOT NULL,
  width int,
  height int,
  created_at timestamptz NOT NULL DEFAULT now(),
  UNIQUE(asset_id, kind, size)
);

CREATE INDEX IF NOT EXISTS asset_variants_asset_id_idx ON asset_variants(asset_id);