// Learning Hub is retired. My Resources generates better slides from a typed
// deck, and the articles and quizzes live in the quiz app.
//
// The content was exported before this ran — every article as markdown plus a
// full SQL dump of all five tables — to ops-backups/learning-hub-export-*.
// That export is the restore path; this migration is not reversible in any
// useful sense, because down() can recreate the shape but never the rows.
//
// generated_image_links goes with it: it existed only to say which Learning Hub
// content an image was published in, and it was the sole reason a generated
// image could ever be read by someone who did not make it. Images are now
// owner-only, which is both simpler and stricter.

exports.up = async function (pgm) {
  // Order matters only for readability — CASCADE handles the dependencies.
  pgm.sql('DROP TABLE IF EXISTS generated_image_links CASCADE');
  pgm.sql('DROP TABLE IF EXISTS learning_progress CASCADE');
  pgm.sql('DROP TABLE IF EXISTS learning_options CASCADE');
  pgm.sql('DROP TABLE IF EXISTS learning_questions CASCADE');
  pgm.sql('DROP TABLE IF EXISTS learning_content CASCADE');
  pgm.sql('DROP TABLE IF EXISTS learning_categories CASCADE');

  // The workflow enum on image jobs. Any rows for the retired workflow go with
  // it: those images belonged to Learning Hub content that no longer exists.
  pgm.sql("DELETE FROM generated_image_jobs WHERE workflow = 'learning_hub'");
  pgm.sql('ALTER TABLE generated_image_jobs DROP CONSTRAINT IF EXISTS generated_image_jobs_workflow_check');
  pgm.sql("ALTER TABLE generated_image_jobs ADD CONSTRAINT generated_image_jobs_workflow_check " +
          "CHECK (workflow = ANY (ARRAY['clinical_assistant'::text, 'my_resources'::text]))");

  // Settings that only ever addressed Learning Hub.
  pgm.sql("DELETE FROM app_settings WHERE key LIKE 'learning_hub.%'");
};

exports.down = async function (pgm) {
  // The shape, not the content. Restoring the rows means loading the export.
  pgm.sql('ALTER TABLE generated_image_jobs DROP CONSTRAINT IF EXISTS generated_image_jobs_workflow_check');
  pgm.sql("ALTER TABLE generated_image_jobs ADD CONSTRAINT generated_image_jobs_workflow_check " +
          "CHECK (workflow = ANY (ARRAY['clinical_assistant'::text, 'learning_hub'::text, 'my_resources'::text]))");
};