dsql-admin/dsql-app/package-shared/functions/backend/dbHandler.js

// @ts-check

const fs = require("fs");
const serverError = require("./serverError");

const mysql = require("serverless-mysql");
const path = require("path");

const SSL_DIR = "/app/ssl";

const connection = mysql({
    config: {
        host: process.env.DSQL_DB_HOST,
        user: process.env.DSQL_DB_USERNAME,
        password: process.env.DSQL_DB_PASSWORD,
        database: process.env.DSQL_DB_NAME,
        charset: "utf8mb4",
        ssl: {
            ca: fs.readFileSync(`${SSL_DIR}/ca-cert.pem`),
        },
    },
});

// const connection = mysql.createConnection({
//     host: process.env.DSQL_DB_HOST,
//     user: process.env.DSQL_DB_USERNAME,
//     password: process.env.DSQL_DB_PASSWORD,
//     database: process.env.DSQL_DB_NAME,
//     charset: "utf8mb4",
// });

// connection.on("error", (err) => {
//     console.log("CONNECTION STATE: ", connection.state);
//     console.log(err.message);
// });

// connection.on("connect", () => {
//     console.log("CONNECTION ACTIVE: ", connection.state);
// });

// connection.on("end", () => {
//     console.log("CONNECTION DISCONNECTED: ", connection.state);
// });

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/**
 * Main DB Handler Function
 * ==============================================================================
 * @async
 *
 * @param {any} args
 * @returns {Promise<object|null>}
 */
module.exports = async function dbHandler(...args) {
    process.env.NODE_ENV?.match(/dev/) &&
        fs.appendFileSync(
            "./.tmp/sqlQuery.sql",
            args[0] + "\n" + Date() + "\n\n\n",
            "utf8"
        );

    /**
     * Declare variables
     *
     * @description Declare "results" variable
     */
    let results;

    /**
     * Fetch from db
     *
     * @description Fetch data from db if no cache
     */
    try {
        results = await new Promise((resolve, reject) => {
            // @ts-ignore
            connection.query(...args, (error, result, fields) => {
                if (error) {
                    resolve({ error: error.message });
                } else {
                    resolve(result);
                }
            });

            // connection.on("error", (err) => {
            //     console.log("CONNECTION STATE: ", connection.state);
            //     console.log(err.message);
            // });

            // connection.on("connect", () => {
            //     console.log("CONNECTION ACTIVE: ", connection.state);
            // });

            // connection.on("end", () => {
            //     console.log("CONNECTION DISCONNECTED: ", connection.state);
            // });

            /** ********************* Clean up */
        });

        await connection.end();

        // connection.query(...args, (error, result, fields) => {
        //     if (error) {
        //         resolve({ error: error.message });
        //     } else {
        //         resolve(result);
        //     }

        //     connection.end()
        // });
        // connectionPool.query(...args, (error, result, fields) => {
        //     if (error) {
        //         resolve({ error: error.message });
        //     } else {
        //         resolve(result);
        //     }
        // });

        // connectionPool.getConnection(function (err, connection) {
        //     if (err) {
        //         resolve({ error: err.message });
        //         connection.release();
        //         return;
        //     }

        //     connection.query(...args, (error, result, fields) => {
        //         if (error) {
        //             resolve({ error: error.message });
        //         } else {
        //             resolve(result);
        //         }

        //         connection.release();
        //     });
        // });
    } catch (/** @type {any} */ error) {
        fs.appendFileSync(
            "./.tmp/dbErrorLogs.txt",
            JSON.stringify(error, null, 4) + "\n" + Date() + "\n\n\n",
            "utf8"
        );

        results = null;

        serverError({
            component: "dbHandler",
            message: error.message,
        });

        // try {
        //     connection.end();
        // } catch (error) {
        //     console.log("ERROR in dbHandler Function =>", error.message);
        // }
    }

    /**
     * Return results
     *
     * @description Return results add to cache if "req" param is passed
     */
    if (results) {
        return JSON.parse(JSON.stringify(results));
    } else {
        return null;
    }
};