models/Document.js

const mongoose = require('mongoose');

const documentSchema = new mongoose.Schema(
  {
    fileId: {
      type: mongoose.Schema.Types.ObjectId,
      required: true,
      unique: true,
      index: true,
    },
    filename: {
      type: String,
      required: true,
      trim: true,
    },
    originalName: {
      type: String,
      required: true,
      trim: true,
    },
    mimeType: {
      type: String,
      required: true,
      trim: true,
    },
    size: {
      type: Number,
      required: true,
      min: 0,
    },
    category: {
      type: String,
      default: 'general',
      trim: true,
    },
    description: {
      type: String,
      default: '',
      trim: true,
    },
    uploadedBy: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'AdminUser',
      default: null,
    },
  },
  { timestamps: true }
);

documentSchema.index({ createdAt: -1 });
documentSchema.index({ category: 1, createdAt: -1 });

module.exports = mongoose.model('Document', documentSchema);