import mongoose from "mongoose";

declare global { var mongoose: { conn: mongoose.Mongoose | null; promise: Promise<mongoose.Mongoose> | null } }
let cached = global.mongoose;

if (!cached) { cached = global.mongoose = { conn: null, promise: null } }

export async function connectDB() {
    if (cached.conn) return cached.conn;
    if (!process.env.MONGODB_URI) { throw new Error("Please define MONGODB_URI in your environment variables") }
    if (!cached.promise) { cached.promise = mongoose.connect(process.env.MONGODB_URI).then((mongoose) => mongoose) }
    cached.conn = await cached.promise;
    return cached.conn;
}