Back-End Services

Overview

The back-end services of PDeck form the core of the application, handling business logic, data processing, and integration with external services. These services work together to provide a robust and scalable foundation for the task management and prioritization system.

Key Components

Authentication Service
Task Service
Integration Service
Notification Service
Preference Manager
Security Module

Technology Stack

Node.js with Express.js for service implementation
MongoDB for data storage
Redis for caching
Docker for containerization
Kubernetes for orchestration (optional for MVP, but good for scalability)

Implementation Guidelines

1. Authentication Service

The Authentication Service handles user registration, login, and token management.

// services/authService.js
const bcrypt = require('bcryptjs')
const jwt = require('jsonwebtoken')
const User = require('../models/User')
 
class AuthService {
  async register(userData) {
    const { email, password } = userData
    let user = await User.findOne({ email })
    if (user) {
      throw new Error('User already exists')
    }
    user = new User(userData)
    const salt = await bcrypt.genSalt(10)
    user.password = await bcrypt.hash(password, salt)
    await user.save()
    return this.generateToken(user)
  }
 
  async login(email, password) {
    const user = await User.findOne({ email })
    if (!user) {
      throw new Error('Invalid credentials')
    }
    const isMatch = await bcrypt.compare(password, user.password)
    if (!isMatch) {
      throw new Error('Invalid credentials')
    }
    return this.generateToken(user)
  }
 
  generateToken(user) {
    return jwt.sign({ userId: user.id }, process.env.JWT_SECRET, { expiresIn: '1d' })
  }
}
 
module.exports = new AuthService()

2. Task Service

The Task Service manages task creation, updating, deletion, and retrieval.

// services/taskService.js
const Task = require('../models/Task')
const tpe = require('./taskPrioritizationEngine')
 
class TaskService {
  async createTask(userId, taskData) {
    const task = new Task({ ...taskData, user: userId })
    await task.save()
    await tpe.prioritizeTasks(userId)
    return task
  }
 
  async updateTask(userId, taskId, updateData) {
    const task = await Task.findOneAndUpdate(
      { _id: taskId, user: userId },
      updateData,
      { new: true }
    )
    if (!task) {
      throw new Error('Task not found')
    }
    await tpe.prioritizeTasks(userId)
    return task
  }
 
  async deleteTask(userId, taskId) {
    const task = await Task.findOneAndDelete({ _id: taskId, user: userId })
    if (!task) {
      throw new Error('Task not found')
    }
    await tpe.prioritizeTasks(userId)
    return task
  }
 
  async getTasks(userId) {
    return Task.find({ user: userId }).sort({ priority: 'asc' })
  }
}
 
module.exports = new TaskService()

3. Integration Service

The Integration Service handles connections with external services like email, calendar, and task management tools.

// services/integrationService.js
const Integration = require('../models/Integration')
const dataIntegrationParser = require('./dataIntegrationParser')
 
class IntegrationService {
  async addIntegration(userId, integrationType, credentials) {
    const integration = new Integration({
      user: userId,
      type: integrationType,
      credentials
    })
    await integration.save()
    await this.syncData(userId, integrationType)
    return integration
  }
 
  async removeIntegration(userId, integrationId) {
    return Integration.findOneAndDelete({ _id: integrationId, user: userId })
  }
 
  async syncData(userId, integrationType) {
    const integration = await Integration.findOne({ user: userId, type: integrationType })
    if (!integration) {
      throw new Error('Integration not found')
    }
    const rawData = await this.fetchDataFromExternalService(integration)
    const parsedData = await dataIntegrationParser.parseData(integrationType, rawData)
    // Process and store the parsed data
    // Update tasks and knowledge graph as necessary
  }
 
  async fetchDataFromExternalService(integration) {
    // Implement logic to fetch data from the external service
    // This will vary depending on the integration type
  }
}
 
module.exports = new IntegrationService()

4. Notification Service

The Notification Service manages the creation and delivery of notifications to users.

// services/notificationService.js
const Notification = require('../models/Notification')
const webpush = require('web-push')
 
class NotificationService {
  async createNotification(userId, message, type) {
    const notification = new Notification({
      user: userId,
      message,
      type
    })
    await notification.save()
    await this.sendPushNotification(userId, message)
    return notification
  }
 
  async getNotifications(userId) {
    return Notification.find({ user: userId }).sort({ createdAt: 'desc' })
  }
 
  async sendPushNotification(userId, message) {
    const user = await User.findById(userId)
    if (user.pushSubscription) {
      webpush.sendNotification(user.pushSubscription, JSON.stringify({
        title: 'PDeck Notification',
        body: message
      }))
    }
  }
}
 
module.exports = new NotificationService()

5. Preference Manager

The Preference Manager handles user preferences and settings.

// services/preferenceManager.js
const UserPreference = require('../models/UserPreference')
 
class PreferenceManager {
  async getUserPreferences(userId) {
    let preferences = await UserPreference.findOne({ user: userId })
    if (!preferences) {
      preferences = new UserPreference({ user: userId })
      await preferences.save()
    }
    return preferences
  }
 
  async updateUserPreferences(userId, updates) {
    const preferences = await UserPreference.findOneAndUpdate(
      { user: userId },
      updates,
      { new: true, upsert: true }
    )
    return preferences
  }
}
 
module.exports = new PreferenceManager()

6. Security Module

The Security Module handles various security-related functionalities.

// services/securityModule.js
const crypto = require('crypto')
 
class SecurityModule {
  encryptSensitiveData(data) {
    const algorithm = 'aes-256-cbc'
    const key = Buffer.from(process.env.ENCRYPTION_KEY, 'hex')
    const iv = crypto.randomBytes(16)
    const cipher = crypto.createCipheriv(algorithm, key, iv)
    let encrypted = cipher.update(data, 'utf8', 'hex')
    encrypted += cipher.final('hex')
    return { iv: iv.toString('hex'), encryptedData: encrypted }
  }
 
  decryptSensitiveData(encryptedData, iv) {
    const algorithm = 'aes-256-cbc'
    const key = Buffer.from(process.env.ENCRYPTION_KEY, 'hex')
    const decipher = crypto.createDecipheriv(algorithm, key, Buffer.from(iv, 'hex'))
    let decrypted = decipher.update(encryptedData, 'hex', 'utf8')
    decrypted += decipher.final('utf8')
    return decrypted
  }
 
  // Add more security-related methods as needed
}
 
module.exports = new SecurityModule()

Best Practices

Use dependency injection for easier testing and modularity.
Implement proper error handling and logging in all services.
Use transactions for operations that involve multiple database updates.
Implement rate limiting and request validation to prevent abuse.
Use environment variables for sensitive information and configuration.
Write unit and integration tests for all services.
Use async/await for handling asynchronous operations.
Implement proper input sanitization to prevent injection attacks.

Next Steps

Implement the Task Prioritization Engine service.
Develop the Knowledge Graph Module service.
Create a service for handling asynchronous tasks and background jobs.
Implement caching strategies for frequently accessed data.
Set up monitoring and logging for all services.
Containerize services using Docker for easier deployment and scaling.

API Reference External Integrations