import knex, { type Knex } from 'knex';
import ClientPgLite from 'knex-pglite';
import { PGlite } from '@electric-sql/pglite';
import { vector } from '@electric-sql/pglite/vector';

import { destroy, type Services } from '../../utils/utils.services.js';

import { migrationSource } from './migrations/migrations.js';

class DatabaseService {
  #services: Services;
  #instance?: Promise<Knex>;

  constructor(services: Services) {
    this.#services = services;
  }

  #setup = async () => {
    const pglite = new PGlite({
      extensions: { vector },
    });

    const instance = knex({
      client: ClientPgLite,
      dialect: 'postgres',
      connection: () => ({ pglite }) as object,
    });
    await instance.raw(`CREATE EXTENSION IF NOT EXISTS vector`);

    await instance.migrate.latest({
      migrationSource: migrationSource({ services: this.#services }),
    });

    return instance;
  };

  public getInstance = () => {
    if (!this.#instance) {
      this.#instance = this.#setup();
    }
    return this.#instance;
  };

  [destroy] = async () => {
    if (!this.#instance) {
      return;
    }
    const instance = await this.#instance;
    await instance.destroy();
  };
}

export { type TableRows, tableNames } from './migrations/migrations.js';
export { DatabaseService };