Database/models/comments.js

const mongoose = require('mongoose');

const commentSchema = new mongoose.Schema(
    {
        user: {
            type: mongoose.Schema.Types.ObjectId,
            ref: 'User',
        },
        createdAt: {
            type: Date,
            default: Date.now,
        },
        comment: {
            type: String,
            required: [true, 'Comment is required'],
        },
        likes: [
            {
                type: mongoose.Schema.Types.ObjectId,
                ref: 'User',
            },
        ],
        post: {
            type: mongoose.Schema.Types.ObjectId,
            ref: 'Post',
        },
        // reply: [
        //   {
        //     user: {
        //       type: mongoose.Schema.Types.ObjectId,
        //       ref: 'User',
        //     },
        //     comment: {
        //       type: String,
        //     },
        //     like: [
        //       {
        //         type: mongoose.Schema.Types.ObjectId,
        //         ref: 'Profile',
        //       },
        //     ],
        //   },
        // ],
    },
    {
        toJSON: { virtuals: true },
        toObject: { virtuals: true },
    }
);

// commentSchema.virtual('replies', {
//             ref: 'Reply',
//             localField: '_id',
//             foreignField: 'comment'

// })

commentSchema.pre(/^find/, function (next) {
    this.find()
        .populate('user')
        .populate({
            path: 'likes',
            select: 'username user name photo _id',
        });

    next();
});

const Comment = mongoose.model('Comment', commentSchema);
module.exports = Comment;