import type { Kysely } from "kysely";
import { sql } from "kysely";

import { columnExists } from "../dialect-helpers.js";

/**
 * Where a collection's entries live.
 *
 *   _emdash_collections.storage   'db'  (default) rows in the ec_* table
 *                                 'git' JSON files in the site's git repo
 *                                       (content/<collection>/<slug>.json);
 *                                       the ec_* table stays for schema only
 *
 * Git-backed collections are read from and written to the repo directly —
 * saving in the admin is a commit — so seldom-changing, version-worthy
 * content (form definitions, site structure) lives with the site's code,
 * while frequently edited or sensitive data stays in the database.
 */
export async function up(db: Kysely<unknown>): Promise<void> {
	if (!(await columnExists(db, "_emdash_collections", "storage"))) {
		await sql`ALTER TABLE ${sql.ref("_emdash_collections")} ADD COLUMN ${sql.ref("storage")} text NOT NULL DEFAULT 'db'`.execute(
			db,
		);
	}
}

export async function down(_db: Kysely<unknown>): Promise<void> {
	// Forward-only: SQLite can't drop columns portably and 'db' rows are unaffected.
}