const pool = require('../database/postgresql.js');
const axios = require('axios');
const config = require('../config/main.js')();
const logger = require('../logger/main.js');

/**
 * Saves exchange rate of the fiat currency
 * @returns {Object} -
 */
async function save_fiat() {
    if (!config['currency']['collecting']['fiat']) return;

    config['currency']['fiat'].forEach(
        (value) => config['currency']['fiat'].forEach(async (pair) => {
            if(value === pair) return;
            const res = await axios.get(
                `https://duckduckgo.com/js/spice/currency/1/${value}/${pair}`,
                {
                    timeout: 3000,
                });

            const regExp = new RegExp('\\(\\s*(.*)\\s*\\);$', 'mg');
            const data = JSON.parse(Array.from(res.data.matchAll(regExp))[0][1]);

            delete data['terms'];
            delete data['privacy'];

            logger.debug(JSON.stringify(data));

            if (res.status !== 200) {
                logger.error(`DuckDuckGo ended with the status ${res.status}`);
                return;
            }

            const point = data['to'][0]['mid'].toString().indexOf('.') + 4;

            pool.query('SELECT * FROM currency WHERE from_currency = $1 AND conv_currency = $2 AND date = $3',
                    [ value, pair, new Date(data['timestamp']).toLocaleDateString() ]
            ).then(async (db) => {
                if (db['rows'][0]) return;

                await pool.query(`INSERT INTO currency (from_currency, conv_currency, rate, date) VALUES ($1, $2, $3, $4)`,
                    [
                        value,
                        pair,
                        data['to'][0]['mid'].toString().slice(0, point),
                        new Date(data['timestamp']).toLocaleDateString()
                    ]);
            });
        })
    );
}

module.exports = save_fiat;