aiom/src/core/experiment.js

A Framework for interdependent (mcmc-like) behavioral experiments

const express = require('express');
const path = require('path');
const fs = require('fs');
const fileUpload = require('express-fileupload');
const cors = require('cors');
const errorHandler = require('../middleware/errorHandler');
const { ExperimentConfig } = require('./config');

class Experiment {
    constructor(options = {}) {
        this.paint_AIOM_in_CLI();
        this.experimentPath = options.experimentPath || process.cwd();
        this.config = new ExperimentConfig(this.experimentPath);
        this.experiment = this.config.get('experiment');
        this.app = express();
        this.setupMiddleware();
        this.setupResources();
        this.setupBasicRoutes();
        this.setupExperimentRoutes();
        this.setupOrderedExp();
    }

    paint_AIOM_in_CLI() {
        console.log(`
         █████╗ ██╗ ██████╗ ███╗   ███╗
        ██╔══██╗██║██╔═══██╗████╗ ████║
        ███████║██║██║   ██║██╔████╔██║
        ██╔══██║██║██║   ██║██║╚██╔╝██║
        ██║  ██║██║╚██████╔╝██║ ╚═╝ ██║
        ╚═╝  ╚═╝╚═╝ ╚═════╝ ╚═╝     ╚═╝                
        `);
    }
    
    setupMiddleware() {
        this.app.use(cors());
        this.app.use(express.json());
        this.app.use(express.urlencoded({ extended: true }));
        this.app.use(require('cookie-parser')());
        this.app.use(fileUpload({
            limits: { fileSize: 50 * 1024 * 1024 }, // 50MB limit
            useTempFiles: false,
            createParentPath: true
        }));
        this.app.use(errorHandler);
    }

    setupResources() {
        // Serve package static files --- css styles, js scripts, etc.
        const packageStatic = path.join(__dirname, '..', 'static');
        this.app.use('/pkg-static', express.static(packageStatic));

        // Serve experiment static files --- custom text, stimuli, etc.
        const customTextDir = path.join(this.experimentPath, 'custom_text');
        this.app.use('/exp-static', express.static(customTextDir));
        this.app.use('/exp-production-example', express.static(path.join(this.experimentPath, 'static', 'stimuli', 'production_example')));
    }
    
    setupBasicRoutes() {
        // Base routes that all experiments need
        this.app.get('/', this.renderTemplate_prolific.bind(this, 'index'));
        this.app.get('/consent', this.renderTemplate.bind(this, 'consent'));
        this.app.get('/instruction', this.renderTemplate.bind(this, 'instruction'));
        // this.app.get('/waitingroom', this.renderTemplate.bind(this, 'waitingroom'));
        this.app.get("/early_stop", this.renderTemplate_prolific.bind(this, 'early_stop'));
        this.app.get('/complete_redirect', this.handleCompleteRedirect.bind(this));
    }
    
    setupExperimentRoutes() {
        const { api_router } = require('./api');
        this.api_handler = new api_router(this.app, this.config, this.experimentPath);
    }

    setupOrderedExp() {
        const task_order = this.config.getArray('task_order');
        this.app.get("/experiment/:stage", (req, res) => {
            const stage = req.params.stage;
            if (stage === 'begin') {
                this.sendTask(task_order[0], req, res);
            } else if (task_order.includes(stage)) {
                const currentIndex = task_order.indexOf(stage);
                if (currentIndex < task_order.length - 1) {
                    this.sendTask(task_order[currentIndex + 1], req, res);
                } else {
                    this.renderTemplate_prolific('thanks', req, res);
                }
            } else {
                // Handle invalid stage
                console.error(`Invalid stage requested: ${stage}`);
                res.status(404).send('Stage not found');
            }
        });
    }

    sendTask(task, req, res) {
        const templatePath = task === 'main' ?
            this.getTemplatePath(this.experiment, 'experiment') :
            this.getTemplatePath(task);
        res.sendFile(templatePath);
    }

    handleCompleteRedirect(req, res) {
        if (this.config.getBoolean('prolific')) {
            require('../controllers/addon/prolific_Controller').complete_redirect(req, res);
        } else {
            res.status(200).json({ success: true });
        }
    }
    
    renderTemplate(templateName, req, res) {
        const templatePath = this.getTemplatePath(templateName);
        res.sendFile(templatePath);
    }

    renderTemplate_prolific(templateName, req, res) {
        const templatePath = this.config.getBoolean('prolific') ? 
            this.getTemplatePath(templateName + '-prolific') :
            this.getTemplatePath(templateName);
        res.sendFile(templatePath);
    }
    
    getTemplatePath(templateName, fileCat='base') {
        // First check experiment directory
        const expTemplate = path.join(this.experimentPath, 'public', fileCat, `${templateName}.html`);
        // if not exist, Fall back to package template
        return fs.existsSync(expTemplate) ? expTemplate : 
            path.join(__dirname, '..', 'templates', fileCat, `${templateName}.html`);
    }
    
    async start(port = 3000) {
        try {
            const { pool } = require('./database');
            const result = await pool.query('SELECT NOW() as current_time, version() as pg_version');
            console.log('✅ Database connected successfully');
            console.log(`📅 Server time: ${result.rows[0].current_time}`);
            console.log(`🐘 PostgreSQL version: ${result.rows[0].pg_version.split(' ')[0]}`);
        } catch (error) {
            console.error('❌ Database initialization failed:', error.message);
            throw error;
        }
        return this.app.listen(port, () => {
            console.log(`🧪 Experiment type: ${this.config.get('experiment')}`);
            const test_url = this.config.getBoolean('prolific')
            ? `🌐 Server: http://localhost:${port}/?PROLIFIC_PID=test${Math.floor(Math.random()*10000)}&STUDY_ID=test${Math.floor(Math.random()*10000)}&SESSION_ID=test${Math.floor(Math.random()*10000)}`
            : `🌐 Server: http://localhost:${port}`;
            console.log(test_url);
        });
    }
}

module.exports = { Experiment };