src/models/SystemConfig.js

const mongoose = require('mongoose');

const systemConfigSchema = new mongoose.Schema(
  {
    paintCalculator: {
      windowDeduction: { type: Number, default: 1.5 },
      doorDeduction: { type: Number, default: 2.0 },
      defaultCoats: { type: Number, default: 2 },
    },
    admin: {
      passwordMinLength: { type: Number, default: 12 },
      passwordExpiryDays: { type: Number, default: 90 },
      bcryptSaltRounds: { type: Number, default: 12 },
    },
  },
  { timestamps: true }
);

// Ensure only one config document exists
systemConfigSchema.statics.getConfig = async function () {
  let config = await this.findOne();
  if (!config) {
    config = await this.create({});
  }
  return config;
};

module.exports = mongoose.model('SystemConfig', systemConfigSchema);