ckn.backend/core/Backend.js

CKN Framework for Backend

import {Log} from "ckn.core";
import express from "express";
import fileUpload from "express-fileupload";
import bodyParser from "body-parser";
import {Session} from "./Session.js";

class Backend {
    constructor() {
        this.rootPhysicalPath = process.cwd();
        this.log = new Log("CKN", "BACKEND");
        this.port = 5900;
        this.server = express();
        this.server.disable('x-powered-by');
        this.server.use(fileUpload());
        this.server.use(bodyParser.json({limit: '100mb'}));
        this.server.use(bodyParser.urlencoded({limit: '50mb', extended: false}));
        this.server.set('view engine', 'ejs');
        this.modules = [];
        this.themes = [];
    }

    async start() {
        this.log.info("Server has been starting.");
        this.middlewares = this.middlewares.sort((a, b) => a.priority - b.priority);
        await this.#executeMiddlewareOnStartingServerState(() => {
            let result = new Promise(resolve => {
                try {
                    this.server.listen(this.port, () => {
                        this.log.info("Server has been listened on port = " + this.port);
                        resolve();
                    });
                } catch (err) {
                    this.log.error(err);
                }
            });
            result.then(() => {
                this.log.info("Server is started.");
            });
        });
    }

    async get(url, handler) {
        url = url.replaceAll("\\","/");
        this.server.get(url, async (req, res) => {
            this.log.info("GET:", url);
            let session = new Session(req, res);
            session.backend = this;
            await this.#executeMiddlewareOnInitialSession(session, () => {
                handler(session);
            });
        });
    }

    async post(url, handler) {
        url = url.replaceAll("\\","/");
        this.server.post(url, async (req, res) => {
            this.log.info("POST:", url);
            let session = new Session(req, res);
            await this.#executeMiddlewareOnInitialSession(session, () => {
                handler(session);
            });
        });
    }

    async put(url, handler) {
        url = url.replaceAll("\\","/");
        this.server.put(url, async (req, res) => {
            this.log.info("PUT:", url);
            let session = new Session(req, res);
            await this.#executeMiddlewareOnInitialSession(session, () => {
                handler(session);
            });
        });
    }

    async patch(url, handler) {
        url = url.replaceAll("\\","/");
        this.server.patch(url, async (req, res) => {
            this.log.info("PATCH:", url);
            let session = new Session(req, res);
            await this.#executeMiddlewareOnInitialSession(session, () => {
                handler(session);
            });
        });
    }

    async delete(url, handler) {
        this.server.delete(url, async (req, res) => {
            url = url.replaceAll("\\","/");
            this.log.info("DELETE:", url);
            let session = new Session(req, res);
            await this.#executeMiddlewareOnInitialSession(session, () => {
                handler(session);
            });
        });
    }

    middlewares = [];

    use(middleware) {
        if (this.middlewares.where(s => s.constructor.name === middleware.constructor.name).length == 0) {
            this.middlewares.push(middleware);
        }
    }

    async #executeMiddlewareOnStartingServerState(next) {
        let run = () => {
            if (run.index == this.middlewares.length) {
                next();
            } else {
                run.index++;
                this.middlewares[run.index - 1].onStartingServer(this, run);
            }
        }
        run.index = 0;
        run();
    }

    async #executeMiddlewareOnInitialSession(session, next) {
        let run = () => {
            if (run.index == this.middlewares.length) {
                next();
            } else {
                run.index++;
                this.middlewares[run.index - 1].onInitialSession(this, session, run);
            }
        }
        run.index = 0;
        run();
    }
}

export {Backend}