duckdb_http.ts

/**
 * DuckDB HTTPServer wrapper (NDJSON parser)
 * Supports Basic Auth + API Key
 *
 * Example server:
 *   curl -u user:pass -H "X-API-Key: secretkey" \
 *     "http://localhost:9999?query=select * from transactions limit 2"
 */

export type RowData = Record<string, any>;

export interface ConnectionOptions {
  baseUrl: string;
  username?: string;
  password?: string;
  apiKey?: string;
}

export class Connection {
  private baseUrl: string;
  private headers: HeadersInit;

  constructor(options: ConnectionOptions) {
    this.baseUrl = options.baseUrl.replace(/\/$/, ''); // strip trailing /
    this.headers = {};

    if (options.username && options.password) {
      const token = Buffer.from(
        `${options.username}:${options.password}`
      ).toString('base64');
      this.headers['Authorization'] = `Basic ${token}`;
    }
    if (options.apiKey) {
      this.headers['X-API-Key'] = options.apiKey;
    }
  }

  private async _getQuery(sql: string): Promise<RowData[]> {
    const url = `${this.baseUrl}?query=${encodeURIComponent(sql)}`;
    const res = await fetch(url, { headers: this.headers });

    if (!res.ok) {
      throw new Error(`DuckDB HTTP error ${res.status}: ${await res.text()}`);
    }

    const text = await res.text();
    const rows: RowData[] = [];

    for (const line of text.split('\n')) {
      if (line.trim() === '') continue;
      try {
        rows.push(JSON.parse(line));
      } catch (e) {
        console.error('Failed to parse NDJSON line:', line, e);
      }
    }

    return rows;
  }

  async all(sql: string): Promise<RowData[]> {
    return this._getQuery(sql);
  }

  async each(sql: string, cb: (row: RowData) => void): Promise<void> {
    const rows = await this._getQuery(sql);
    for (const row of rows) cb(row);
  }

  async exec(sql: string): Promise<void> {
    await this._getQuery(sql);
  }

  async run(sql: string): Promise<void> {
    await this._getQuery(sql);
  }
}

export class Database {
  private options: ConnectionOptions;

  private constructor(options: ConnectionOptions) {
    this.options = options;
  }

  static async connect(options: ConnectionOptions): Promise<Database> {
    const db = new Database(options);
    // health check
    await db.all('SELECT 1');
    return db;
  }

  connect(): Connection {
    return new Connection(this.options);
  }

  async all(sql: string): Promise<RowData[]> {
    return new Connection(this.options).all(sql);
  }

  async exec(sql: string): Promise<void> {
    return new Connection(this.options).exec(sql);
  }
}

// -----------------------------
// Example usage
// -----------------------------
(async () => {
  const db = await Database.connect({
    baseUrl: 'http://localhost:9999',
    apiKey: 'secretkey'
  });

  const rows = await db.all('SELECT * FROM transactions LIMIT 2');
  console.log('Rows:', rows);
})();