backend/app/models/VersionedModel.js

const Model = require('flitter-orm/src/model/Model');
const uuid = require('uuid/v4');

class VersionedModel extends Model {
    static get schema() {
        return {
            version_archive: [Object],
            version_num: { type: Number, default: 1 },
            version_create_date: { type: Date, default: () => new Date },
            version_user_id: String,
        }
    }

    async version_save(message = undefined, user_id = undefined) {
        await this.new_version(message, user_id)
        return this.save()
    }

    async new_version(message = undefined, user_id = undefined) {
        if ( !this.version_num ) this.version_num = 1
        if ( !this.version_archive ) this.version_archive = []

        this.version_num += 1
        this.version_create_date = new Date()
        this.version_user_id = user_id

        const version_data = await this.cast_to_version_data()
        version_data.version_UUID = uuid()
        version_data.version_message = message

        this.version_archive.push(version_data)
    }

    async cast_to_version_data() {
        const schema = this.constructor.__schema
        const shallow_object = {}
        for ( const prop in schema.schema ) {
            if ( prop in this ) {
                shallow_object[prop] = this[prop]
            }
        }

        const data = await this.__scope_limit_save(schema.cast_to_schema(shallow_object))
        delete data.version_archive
        return data
    }
}

module.exports = exports = VersionedModel