// Applies pending Drizzle migrations from ./drizzle. Runs as the schema owner
// (DB_MIGRATE_URL, role `personal`); falls back to DB_URL for local dev.
//
//   bun scripts/db-migrate.ts          apply pending migrations
//   bun scripts/db-migrate.ts --init   record the baseline as applied without running it
//                                      (once, on a database already reorganised by the
//                                      hand-written reorg scripts in db/reorg/)
import { drizzle } from 'drizzle-orm/postgres-js';
import { migrate } from 'drizzle-orm/postgres-js/migrator';
import postgres from 'postgres';

const url = process.env.DB_MIGRATE_URL || process.env.DB_URL;
if (!url) throw new Error('Set DB_MIGRATE_URL (schema owner) or DB_URL');
const init = process.argv.includes('--init');

const client = postgres(url, { max: 1, connect_timeout: 10, onnotice: () => {} });
try {
	const db = drizzle({ client });
	// Safety: never run the baseline on a database that already has data. Existing
	// databases are brought to the baseline by the reviewed reorg scripts and then
	// recorded with --init; only a truly empty database gets the baseline executed.
	const [state] = await client`
		select
			to_regclass('drizzle.__drizzle_migrations') is not null as tracked,
			(select count(*)::int from pg_class c join pg_namespace n on n.oid = c.relnamespace
			 where c.relkind = 'r' and n.nspname not in ('pg_catalog', 'information_schema', 'drizzle')
			   and n.nspname not like 'pg_toast%') as tables`;
	const recorded = state.tracked
		? (await client`select count(*)::int as n from drizzle.__drizzle_migrations`)[0].n
		: 0;
	if (!init && recorded === 0 && state.tables > 0)
		throw new Error(
			`Refusing to run the Drizzle baseline on a non-empty database (${state.tables} tables). ` +
				'Apply the reorg scripts (db/reorg/) and record the baseline with --init first.'
		);
	if (init && state.tables === 0)
		throw new Error('--init on an empty database: run without --init to create the schema');
	const result = await migrate(db, {
		migrationsFolder: new URL('../drizzle', import.meta.url).pathname,
		migrationsSchema: 'drizzle',
		migrationsTable: '__drizzle_migrations',
		...(init ? { init: true } : {})
	});
	if (result && 'exitCode' in result) {
		throw new Error(
			result.exitCode === 'databaseMigrations'
				? '--init refused: migrations are already recorded in this database'
				: '--init refused: more than one local migration exists'
		);
	}
	const [{ n }] = await client`select count(*)::int as n from drizzle.__drizzle_migrations`;
	console.log(`${init ? 'Baseline recorded' : 'Migrations up to date'}; ${n} recorded`);
} finally {
	await client.end();
}