import { BaseSchema } from '@adonisjs/lucid/schema'

/**
 * What inspection learns about a file (content type, archive listing) lives
 * in file_details, on the NVMe, instead of in `files` (LOG.md 2026-10-08 (14)).
 * `files` sits on the HDD and was updated after its insert by every probe:
 * a new row version on a random page and an entry in each of its indexes
 * (3.7M updates against 49.5M inserts in a day, 27% HOT). Its rows are now
 * only inserted (and moved between releases or renamed, rarely).
 * The existing values are copied by `files:move-details` after this deploy;
 * a later migration drops the columns.
 */
export default class extends BaseSchema {
  async up() {
    // The foreign key locks `files` briefly: take the lock first, so it can't deadlock with writers.
    await this.db.rawQuery(`SET LOCAL lock_timeout = '60s'`)
    await this.db.rawQuery(`LOCK TABLE files IN SHARE ROW EXCLUSIVE MODE`)
    await this.db.rawQuery(`
      CREATE TABLE IF NOT EXISTS file_details (
        file_id bigint PRIMARY KEY REFERENCES files (id) ON DELETE CASCADE,
        content_type varchar(16),
        archive jsonb)`)
  }

  async down() {
    await this.db.rawQuery(`DROP TABLE IF EXISTS file_details`)
  }
}