// A presentation's theme, whether or not the model produced a structured deck.
//
// The theme lived only inside the deck JSON, so a presentation that fell back
// to markdown slides — 28 of the 41 in production — had nowhere to keep one,
// and "change template" answered that it had no layout to change. The column
// holds the author's choice for every presentation; a deck's own theme field
// is kept in step with it.

exports.up = pgm => pgm.sql(`
  ALTER TABLE user_resources ADD COLUMN IF NOT EXISTS theme TEXT;
  UPDATE user_resources SET theme = deck->>'theme' WHERE theme IS NULL AND deck IS NOT NULL AND deck->>'theme' IS NOT NULL;
`);

exports.down = pgm => pgm.sql(`
  ALTER TABLE user_resources DROP COLUMN IF EXISTS theme;
`);