dsi-icl/optimise

/*eslint no-console: "off"*/
import dbcon from './db-connection';
// import fs from 'fs';

// Current level of the DB
// This field is to be updated with subsequent versions of the DB
const CURRENT_VERSION = 1;

export async function migrate() {

    const db = await dbcon().then(client => client.db());

    // // Verify the OPT_KV configuration table exists
    const isIntitialized = await db.collections().then(cols => cols.filter(col => col.collectionName === 'OPT_SYNC_KV')).then(res => res.length > 0);
    let stepVersion = 0;

    if (!isIntitialized) {
        // If not create it and initialize CURRENT_VERSION
        await db.createCollection('OPT_SYNC_KV');
        await db.collection('OPT_SYNC_KV').insertOne({
            key: 'CURRENT_VERSION',
            value: '0',
            created_at: (new Date()).getTime(),
            updated_at: (new Date()).getTime()
        });
    } else {
        // Otherwise fetch the CURRENT_VERSION
        const stepVersionResult = await db.collection('OPT_SYNC_KV').findOne({
            key: 'CURRENT_VERSION'
        });

        if (stepVersionResult !== undefined && stepVersionResult.value !== undefined)
            stepVersion = parseInt(stepVersionResult.value) || 0;
    }


    if (stepVersion !== CURRENT_VERSION) {

        if (CURRENT_VERSION < stepVersion)
            return Promise.reject(new Error('The existing database was created with a newer version of Optimise ! Please upgrade before using Optimise !'));

        // For every table file launch the update for sequential version up
        while (stepVersion < CURRENT_VERSION) {
            stepVersion++;
            // TODO: Jump from version to version
        }

        // Finally set the CURRENT_VERSION to the current level
        await db.collection('OPT_SYNC_KV').updateOne({ key: 'CURRENT_VERSION' }, {
            $set: {
                value: `${stepVersion}`,
                updated_at: (new Date()).getTime()
            }
        }, { upsert: true });
    }

    return dbcon;
}

export function erase() {
    return new Promise((resolve, reject) => {
        if (process.env.NODE_ENV !== 'test') {
            // if (process.env.NODE_ENV === 'development') console.log('Removing database file ...');
            // let filename = dbcon().client.config.connection.filename;
            try {
                // if (fs.existsSync(filename))
                //     fs.unlinkSync(filename);
            } catch (err) {
                return reject(err);
            }
        }
        return resolve();
    });
}

export default {
    migrate,
    erase
};