#!/usr/bin/env node
// mysql-CLI-compatible shim for harness (CODEX_HARNESS_MYSQL) on hosts without a mysql client.
// Supports the subset harness uses: -h HOST -u USER [-N] [--flags] [DATABASE] [-e SQL | stdin].
import fs from 'node:fs';
import { createRequire } from 'node:module';
import { pathToFileURL } from 'node:url';

export function parseArgs(argv) {
  const opts = { host: '', user: '', database: '', sql: '', noHeaders: false };
  for (let i = 0; i < argv.length; i += 1) {
    const arg = argv[i];
    if (arg === '-h' && i + 1 < argv.length) {
      opts.host = argv[++i];
    } else if (arg === '-u' && i + 1 < argv.length) {
      opts.user = argv[++i];
    } else if (arg === '-N') {
      opts.noHeaders = true;
    } else if (arg === '-e' && i + 1 < argv.length) {
      opts.sql = argv[++i];
    } else if (!arg.startsWith('-') && !opts.database) {
      opts.database = arg;
    }
  }
  return opts;
}

export function resolveMysql2Module(env = process.env, requireFrom = import.meta.url) {
  const explicit = String(env.MEMIND_MYSQL2_MODULE || '').trim();
  if (explicit) return explicit;
  return createRequire(requireFrom).resolve('mysql2/promise');
}

// With rowsAsArray, a row set is an array of rows and each row is an array of scalar cells.
// Multi-statement results are an array of row sets and ResultSetHeader objects.
const isRow = (value) => Array.isArray(value) && value.every((cell) => !Array.isArray(cell));
const isRowSet = (value) => Array.isArray(value) && value.every(isRow);

export function findLastRowSet(result) {
  if (isRowSet(result)) return result;
  if (!Array.isArray(result)) return null;
  for (let i = result.length - 1; i >= 0; i -= 1) {
    if (isRowSet(result[i])) return result[i];
  }
  return null;
}

export function formatRows(rows) {
  if (!rows || rows.length === 0) return '';
  const lines = rows.map((row) => {
    const values = Array.isArray(row) ? row : Object.values(row);
    return values.map((value) => (value == null ? 'NULL' : String(value))).join('\t');
  });
  return `${lines.join('\n')}\n`;
}

async function main() {
  const opts = parseArgs(process.argv.slice(2));
  const sql = opts.sql || fs.readFileSync(0, 'utf8');
  const modulePath = resolveMysql2Module();
  const mysqlModule = await import(pathToFileURL(modulePath).href);
  const mysql = mysqlModule.default ?? mysqlModule;
  const connection = await mysql.createConnection({
    host: opts.host || process.env.CODEX_HARNESS_DB_HOST || '127.0.0.1',
    user: opts.user || process.env.CODEX_HARNESS_DB_USER || 'boot',
    password: process.env.MYSQL_PWD || process.env.CODEX_HARNESS_DB_PASSWORD || '',
    database: opts.database || undefined,
    charset: 'utf8mb4',
    multipleStatements: true,
    rowsAsArray: true,
  });
  try {
    const [result] = await connection.query({ sql, rowsAsArray: true });
    process.stdout.write(formatRows(findLastRowSet(result)));
  } finally {
    await connection.end();
  }
}

if (import.meta.url === pathToFileURL(process.argv[1] ?? '').href) {
  main().catch((error) => {
    process.stderr.write(`${error?.code ? `${error.code}: ` : ''}${error?.message ?? error}\n`);
    process.exit(1);
  });
}