import { MongoClient, Db } from "mongodb";
import { setDb } from "./index";
import { validateConfig, validateMongoUri } from "../utils/validation";

class WebsitalkMongoDBClient {
  private client: MongoClient | null = null;
  private db: Db | null = null;
  private readonly defaultDbName = "website-talk";

  async connect(uri?: string, dbName?: string): Promise<void> {
    if (this.client) {
      return;
    }

    const mongodbUri = uri || process.env.MONGO_URI || process.env.MONGODB_URI;
    validateConfig("MONGO_URI", mongodbUri);
    validateMongoUri(mongodbUri!);

    try {
      this.client = new MongoClient(mongodbUri!);
      await this.client.connect();
      const targetDbName =
        dbName || process.env.WEBSITALK_DB_NAME || this.defaultDbName;
      this.db = this.client.db(targetDbName);
      setDb(this.db);
      console.info(`[core-db] Website Talk MongoDB connected: ${targetDbName}`);
    } catch (error) {
      console.error("[core-db] Website Talk connection failed", error);
      throw error;
    }
  }

  async disconnect(): Promise<void> {
    if (this.client) {
      try {
        await this.client.close();
        this.client = null;
        this.db = null;
        console.info("Website Talk MongoDB disconnected successfully");
      } catch (error) {
        console.error("[core-db] Website Talk disconnection failed", error);
        throw error;
      }
    }
  }

  getDb(): Db {
    if (!this.db) {
      throw new Error(
        "Website Talk database not initialized. Call connect() first.",
      );
    }
    return this.db;
  }

  isConnected(): boolean {
    return this.client !== null && this.client !== undefined;
  }
}

export const websitalkMongodbClient = new WebsitalkMongoDBClient();