const Collection = require('../../util/Collection.js');

class TransactionHandler {

    constructor(client) {

        this.client = client;
        this.transactions = new Collection();

    }

    send(message, options = {}) {

        /** Message structure
         *  {
         *      provider: string, -- mongodb or mariadb
         *      request: {
         *          type: string, -- The function to use from this class, ex. findOne
         *          collection: string, -- Which collection to query from
         *          query: { }, -- Actual search query
         *          data: { } -- If the operation is to update or insert something, this is what to insert
         *      }
         *  }
         */

        return new Promise((resolve, reject) => {
            
            const id = this.transactionID;
            this.transactions.set(id, { id, resolve, reject });

            process.send({ _storage: true, transactionID: id, ...message, ...options });

        });

    }

    _receive(message) {

        if(!message.transactionID) return undefined;
        const transaction = this.transactions.get(message.transactionID);
        
        if(!transaction) return undefined;
        
        if(message.error) transaction.reject(message.message);
        else transaction.resolve(message.result);

        return this.transactions.delete(message.transactionID);

    }

    get transactionID() {
        return `${[ this.client.shard.ids ]}-${Date.now().toString(36)}`;
    }

}

module.exports = TransactionHandler;