// Originally from:
// https://github.com/fauna/netlify-faunadb-todomvc/blob/master/scripts/bootstrap-fauna-database.js

const faunadb = require('faunadb')
const config = require('./config.js')
const q = faunadb.query

/* idempotent function to create the necessary collections in your Fauna database */
function ensureFaunaCollections(fauna_server_secret) {
    if (!fauna_server_secret) {
        console.log('Missing first argument: fauna_server_secret. Try with:')
        console.log()
        console.log('node ensure-fauna-collections.js fnYourFaunaSecretHere')
        console.log()
        console.log('You can create fauna DB keys here: https://dashboard.fauna.com/db/keys')
        return false
    }

    const client = new faunadb.Client({
        secret: fauna_server_secret
    })

    console.log('Creating the collections...')
    return client.query(
            q.CreateCollection({
                name: config.COLLECTION_NAME,
            })
        )
        .then(() => client.query(
            q.CreateIndex({
                name: config.INDEX_NAME,
                source: q.Collection(config.COLLECTION_NAME),
                values: [
                    {field: ['data', 'expires_at']},
                    {field: ['ref']},
                ],
            })
        ))
        .then(console.log.bind(console))
        .catch((e) => {
            if (e.message === 'instance already exists') {
                console.log("collection already created... skipping. You're good to go!");
            } else if (e.message === 'unauthorized') {
                e.message = 'unauthorized: missing or invalid fauna_server_secret, or not enough permissions';
                throw e
            } else {
                throw e
            }
        })
}

if (require.main === module) {
    ensureFaunaCollections.apply(this, process.argv.slice(2))
        .then((result) => console.log(result))
        .catch((error) => console.error(error))
}

module.exports = ensureFaunaCollections;