import { drizzle } from 'drizzle-orm/postgres-js';
import postgres from 'postgres';

import * as schema from './schema';

const connectionString = process.env.DATABASE_URL!;

// Connection pool for queries.
//
// `statement_timeout` and `idle_in_transaction_session_timeout` are set
// per-connection via `connection.options` (postgres.js exposes the
// startup-parameter list there). Without these, a slow query or a
// transaction left open by a crashed handler holds a connection slot
// indefinitely and eventually exhausts the pool (max=20). The 30s
// statement cap is well above expected query latency; tune up if a
// legitimate report needs longer.
//
// `max_lifetime` recycles connections every 30 minutes so any
// per-connection state drift (prepared statements, GUCs) doesn't
// accumulate forever.
const queryClient = postgres(connectionString, {
  max: 20,
  idle_timeout: 20,
  connect_timeout: 10,
  max_lifetime: 60 * 30,
  connection: {
    // ms values per postgres.js types; these become Postgres GUC settings
    // applied at session start.
    statement_timeout: 30_000,
    idle_in_transaction_session_timeout: 10_000,
  },
});

export const db = drizzle(queryClient, {
  schema,
  logger: process.env.NODE_ENV === 'development',
});

/** Close the underlying connection pool. Used by the vitest teardown so
 *  the parent process can exit cleanly. */
export async function closeDb(): Promise<void> {
  await queryClient.end({ timeout: 5 });
}

export type Database = typeof db;