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

/**
 * is_readable_name(): also judge the stem without an unknown short
 * extension, so `326678d1d07ef12a.bin` counts as random (CONCEPT.md D22).
 */
export default class extends BaseSchema {
  async up() {
    this.defer(async (db) => {
      await db.rawQuery(`
        CREATE OR REPLACE FUNCTION is_readable_name(name text) RETURNS boolean IMMUTABLE LANGUAGE sql AS $$
          WITH s AS (SELECT regexp_replace(name_stem(name), '\\.[A-Za-z0-9]{1,4}$', '') AS stem)
          SELECT name IS NOT NULL AND NOT (
            (stem ~ '^[A-Za-z0-9]{16,}$' AND stem ~ '[a-z]' AND stem ~ '[A-Z]'
              AND (stem ~ '\\d' OR length(regexp_replace(stem, '[^A-Z]', '', 'g')) >= 6))
            OR stem ~* '^[0-9a-f]{16,}$')
          FROM s
        $$`)
    })
  }

  async down() {}
}