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

/**
 * Per-release totals for browsing and sorting (CONCEPT.md D22). A trigger on
 * `files` keeps `releases.file_count` and `releases.size` current, whichever
 * code path assigns files to releases.
 */
export default class extends BaseSchema {
  async up() {
    this.schema.alterTable('files', (table) => {
      table.bigInteger('size')
    })
    this.schema.alterTable('releases', (table) => {
      table.integer('file_count').notNullable().defaultTo(0).index()
      table.bigInteger('size').notNullable().defaultTo(0).index()
    })
    this.defer(async (db) => {
      await db.rawQuery(`
        UPDATE files f SET size = s.size
        FROM (SELECT id, (SELECT coalesce(sum((v->>'size')::bigint), 0) FROM jsonb_each(message_ids) e(k, v)) AS size FROM files) s
        WHERE s.id = f.id`)
      await db.rawQuery(`
        UPDATE releases r SET file_count = t.n, size = t.size
        FROM (SELECT release_id, count(*) AS n, coalesce(sum(size), 0) AS size FROM files
              WHERE release_id IS NOT NULL GROUP BY release_id) t
        WHERE t.release_id = r.id`)
      await db.rawQuery(`
        CREATE OR REPLACE FUNCTION files_release_totals() RETURNS trigger LANGUAGE plpgsql AS $$
        BEGIN
          IF TG_OP IN ('UPDATE', 'DELETE') AND OLD.release_id IS NOT NULL THEN
            UPDATE releases SET file_count = file_count - 1, size = size - coalesce(OLD.size, 0) WHERE id = OLD.release_id;
          END IF;
          IF TG_OP IN ('UPDATE', 'INSERT') AND NEW.release_id IS NOT NULL THEN
            UPDATE releases SET file_count = file_count + 1, size = size + coalesce(NEW.size, 0) WHERE id = NEW.release_id;
          END IF;
          RETURN NULL;
        END $$`)
      await db.rawQuery(`
        CREATE TRIGGER files_release_totals
        AFTER INSERT OR DELETE OR UPDATE OF release_id, size ON files
        FOR EACH ROW EXECUTE FUNCTION files_release_totals()`)
    })
  }

  async down() {
    this.defer(async (db) => {
      await db.rawQuery('DROP TRIGGER IF EXISTS files_release_totals ON files')
      await db.rawQuery('DROP FUNCTION IF EXISTS files_release_totals()')
    })
    this.schema.alterTable('releases', (table) => {
      table.dropColumn('size')
      table.dropColumn('file_count')
    })
    this.schema.alterTable('files', (table) => table.dropColumn('size'))
  }
}