DROP TABLE IF EXISTS pay_purchases;
CREATE TABLE subscriptions_old (
  id          INTEGER PRIMARY KEY AUTOINCREMENT,
  user_id     INTEGER NOT NULL,
  plan_id     INTEGER NOT NULL,
  expires_at  DATETIME NOT NULL,
  source      TEXT NOT NULL CHECK (source IN ('trial','code')),
  created_at  DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (user_id) REFERENCES users(id),
  FOREIGN KEY (plan_id) REFERENCES plans(id)
);
INSERT INTO subscriptions_old (id, user_id, plan_id, expires_at, source, created_at)
  SELECT id, user_id, plan_id, expires_at, source, created_at FROM subscriptions;
DROP TABLE subscriptions;
ALTER TABLE subscriptions_old RENAME TO subscriptions;
CREATE INDEX idx_subs_user_exp ON subscriptions (user_id, expires_at);