/**
 * Drizzle ORM Database Client for Turso/libSQL.
 *
 * Provides the configured drizzle instance and convenience helpers.
 * Reads DATABASE_URL and DATABASE_TOKEN from environment.
 */

import { sql } from "drizzle-orm";
import { drizzle, type LibSQLDatabase } from "drizzle-orm/libsql";
import { createClient } from "@libsql/client";
import * as schema from "./schema";

export type {
  PlantRow,
  PlantInsert,
  DiseaseRow,
  DiseaseInsert,
  FlaggedContentRow,
  FlaggedContentInsert,
} from "./schema";

export { schema };

let _db: LibSQLDatabase<typeof schema> | null = null;
let _client: ReturnType<typeof createClient> | null = null;

/** Get or create the Drizzle database instance (singleton). */
export function getDb(): LibSQLDatabase<typeof schema> {
  if (_db) return _db;

  const url = process.env.DATABASE_URL;
  const token = process.env.DATABASE_TOKEN;

  if (!url) {
    throw new Error(
      "DATABASE_URL is not set. Check your .env.development or .env.production file.",
    );
  }
  if (!token) {
    throw new Error(
      "DATABASE_TOKEN is not set. Check your .env.development or .env.production file.",
    );
  }

  _client = createClient({ url, authToken: token });
  _db = drizzle(_client, { schema });
  return _db;
}

/** Check database connectivity. */
export async function checkConnection(): Promise<boolean> {
  try {
    const db = getDb();
    const result = await db.run(sql`SELECT 1 AS ok`);
    return result.rowsAffected >= 0;
  } catch (err) {
    console.error("[DB] Connection failed:", err);
    return false;
  }
}

/** Close the client connection. */
export function closeDb() {
  if (_client) {
    _client.close();
    _client = null;
    _db = null;
  }
}