import { readdir, readFile } from 'node:fs/promises';
import { basename, dirname, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';
import { loadConfig } from './config.js';
import { getPool, closePool, quoteIdentifier, withTransaction } from './db.js';

const here = dirname(fileURLToPath(import.meta.url));

async function resolveMigrationsDir(): Promise<string> {
  const candidates = [
    resolve(here, '../migrations'),
    resolve(process.cwd(), 'control-plane/migrations')
  ];
  for (const candidate of candidates) {
    try {
      await readdir(candidate);
      return candidate;
    } catch {
      // The compiled layout does not copy SQL files into dist; continue with
      // the project-root source migration directory.
    }
  }
  throw new Error('迁移目录不存在。');
}

export async function migrateDatabase(): Promise<string[]> {
  const config = loadConfig();
  const migrationsDir = await resolveMigrationsDir();
  await getPool(config).query(`CREATE SCHEMA IF NOT EXISTS ${quoteIdentifier(config.DATABASE_SCHEMA)}`);
  await getPool(config).query(`
    CREATE TABLE IF NOT EXISTS schema_migrations (
      version text PRIMARY KEY,
      applied_at timestamptz NOT NULL DEFAULT now()
    )
  `);
  const files = (await readdir(migrationsDir))
    .filter((file) => /^\d+_.+\.sql$/.test(file))
    .sort();
  const applied: string[] = [];
  for (const file of files) {
    const version = basename(file, '.sql');
    const result = await withTransaction(config, async (client) => {
      const existing = await client.query('SELECT 1 FROM schema_migrations WHERE version = $1', [version]);
      if (existing.rowCount) return false;
      const sql = await readFile(resolve(migrationsDir, file), 'utf8');
      await client.query(sql);
      await client.query('INSERT INTO schema_migrations (version) VALUES ($1)', [version]);
      return true;
    });
    if (result) applied.push(version);
  }
  return applied;
}

if (process.argv[1] && resolve(process.argv[1]) === resolve(fileURLToPath(import.meta.url))) {
  migrateDatabase()
    .then((applied) => {
      console.log(JSON.stringify({ ok: true, applied }));
    })
    .catch((error) => {
      console.error(JSON.stringify({ ok: false, error: error.message || String(error) }));
      process.exitCode = 1;
    })
    .finally(() => closePool());
}