Below is a detailed prompt for a Sustainable Fashion Recommendation System with Gamification, designed as a full-fledged application. This prompt outlines the requirements, features, and specifications that should guide the development process.

Prompt:  
Title: Development of a Sustainable Fashion Recommendation System with Gamification Features

Overview:  
Develop a comprehensive Sustainable Fashion Recommendation System that leverages user preferences, interactions, and gamification elements to provide personalized fashion recommendations. The application should promote sustainable fashion choices, encouraging users to engage in eco-friendly practices through interactive quests, rewards, and investments in sustainable projects.

Key Objectives:  
Personalized Recommendations:  
Provide users with fashion product recommendations based on their style preferences and sustainability values.  
Utilize user interactions, such as views, ratings, and purchases, to refine recommendations over time.  
Gamification Elements:  
Implement a token-based reward system where users earn tokens through actions like completing quests, making purchases, and engaging with content.  
Include quests and challenges that users can start and complete for additional rewards.  
Allow users to invest tokens in sustainable projects, offering returns over time.  
User Engagement and Retention:  
Enhance user engagement through a compelling onboarding process.  
Encourage repeated interactions by updating recommendations and offering new quests regularly.  
Implement social sharing features to allow users to share their achievements and favorite products.  
Functional Requirements:

1.  User Authentication and Onboarding:  
    User Registration:  
    Allow new users to sign up using email and password, social media accounts, or invite codes.  
    Ensure secure authentication protocols are in place.  
    Onboarding Process:  
    Collect basic user information (e.g., name, age, gender, location).  
    Gather style preferences through interactive questionnaires or selection of preferred styles.  
    Assess sustainability values by asking users to rate the importance of factors like organic materials, fair trade, and eco-friendly manufacturing.
2.  Product Catalog and Recommendations:  
    Product Database:  
    Maintain a database of fashion products, including details like SKU, name, description, price, brand, materials, styles, images, and sustainability ratings.  
    Recommendation Engine:  
    Develop an algorithm that suggests products based on:  
    User's style preferences.  
    Sustainability values.  
    Interaction history (e.g., products viewed, rated, or purchased).  
    Product Details Page:  
    Display comprehensive product information.  
    Include options to view images, read descriptions, see sustainability impact, and read reviews.
3.  Gamification Features:  
    Token System:  
    Implement a virtual currency (tokens) that users can earn and spend within the app.  
    Tokens can be used to redeem vouchers, avail discounts, or invest in projects.  
    Quests and Challenges:  
    Provide a list of available quests that users can start voluntarily.  
    Examples of quests:  
    "Rate 5 Products"  
    "Make Your First Purchase"  
    "Invest in a Sustainable Project"  
    Quest Mechanics:  
    Users must start a quest for progress to be tracked.  
    Track progress only after a quest has been initiated.  
    Update user on progress and notify upon completion.  
    Reward users with tokens upon quest completion.  
    Achievements and Badges:  
    Award badges for significant milestones (e.g., "Eco Warrior" for investing in multiple projects).
4.  Investment Module:  
    Sustainable Projects:  
    Provide opportunities for users to invest tokens or real money in sustainable fashion initiatives.  
    Investment Mechanics:  
    Showcase projects with details, required investment, duration, and expected returns.  
    Calculate and display potential returns based on investment amount and duration.  
    Tracking and Returns:  
    Allow users to track their investments and returns over time.  
    Notify users when investments mature and returns are credited.
5.  Shopping Cart and Checkout:  
    Cart Functionality:  
    Enable users to add products to a shopping cart.  
    Update cart in real-time with options to modify quantities or remove items.  
    Checkout Process:  
    Purchases are made using real currency, not tokens.  
    Tokens can be applied to redeem vouchers or discounts during checkout.  
    Implement secure payment gateways to handle transactions.  
    Voucher System:  
    Users can redeem tokens for vouchers offering discounts.  
    Vouchers have codes that can be applied during checkout.  
    Ensure validation of vouchers, including expiration dates and usage limits.
6.  User Profile and Settings:  
    Profile Management:  
    Allow users to view and edit personal information.  
    Display token balance, active quests, achievements, and investment portfolio.  
    Interaction History:  
    Provide a history of user's interactions, including past purchases, ratings, and completed quests.  
    Preference Updates:  
    Users can update style preferences and sustainability values to refine recommendations.
7.  Notifications and Alerts:  
    In-App Notifications:  
    Inform users about quest progress, investment maturity, new product arrivals, and promotional offers.  
    Push Notifications (Optional):  
    Send timely updates to users about important events (ensure compliance with notification preferences).  
    Technical Requirements:
8.  Technology Stack:  
    Frontend:  
    Framework: React.js with Next.js for server-side rendering.  
    Styling: Tailwind CSS or another modern CSS framework for responsive design.  
    State Management: React Context API or Redux for managing global state.  
    Backend:  
    API Development: Node.js with Express.js or Next.js API routes.  
    Database: MongoDB, PostgreSQL, or another suitable database for storing user data and product information.  
    Authentication and Security:  
    Use secure authentication methods (OAuth 2.0, JWT).  
    Implement encryption for sensitive data.  
    Ensure compliance with data protection regulations (e.g., GDPR).
9.  Data Management:  
    User Data:  
    Store user profiles, preferences, token balances, quest progress, and interaction history securely.  
    Product Data:  
    Maintain an up-to-date product catalog with detailed information and sustainability ratings.  
    Use a Content Management System (CMS) or admin panel for easy updates.  
    Performance:  
    Optimize for fast load times and smooth user interactions.  
    Implement caching strategies where appropriate.
10.  Integration and APIs:  
    Payment Gateway Integration:  
    Integrate secure and popular payment gateways (e.g., Stripe, PayPal) for handling transactions.  
    Third-Party APIs (Optional):  
    Integrate with sustainability databases or services to provide real-time sustainability ratings.  
    User Experience (UX) Considerations:  
    Intuitive Navigation:  
    Design a user-friendly interface with clear navigation paths.  
    Responsive Design:  
    Ensure the application is fully responsive across all devices (mobile, tablet, desktop).  
    Accessibility:  
    Adhere to accessibility standards (WCAG) to make the app usable for people with disabilities.  
    Visual Appeal:  
    Use a clean and modern design aesthetic that aligns with sustainable and eco-friendly themes.  
    Feedback Mechanisms:  
    Provide users with immediate feedback on their actions, such as confirmations, progress bars, and notifications.  
    Project Management and Development Approach:  
    Agile Methodology:  
    Use an iterative development process with regular sprints and reviews.  
    Prioritize features based on user value and technical feasibility.  
    Version Control:  
    Utilize Git for version control, with a clear branching strategy (e.g., feature branches, development branch, master branch).  
    Testing:  
    Implement comprehensive testing strategies, including unit tests, integration tests, and end-to-end tests.  
    Conduct user acceptance testing (UAT) to gather feedback and make improvements.  
    Deployment:  
    Set up continuous integration and continuous deployment (CI/CD) pipelines.  
    Deploy to a scalable hosting platform (e.g., Vercel, Heroku, AWS).  
    Additional Considerations:  
    Privacy and Data Protection:  
    Clearly communicate the app's privacy policy to users.  
    Allow users to control their data, including options to delete their account or export data.  
    Scalability:  
    Design the system to handle an increasing number of users and data volume.  
    Consider microservices architecture if necessary.  
    Localization (Optional):  
    Provide support for multiple languages to reach a wider audience.  
    Deliverables:  
    Functional Application:  
    A fully functional web application meeting all the requirements outlined.  
    Documentation:  
    Technical documentation covering architecture, APIs, database schemas, and setup instructions.  
    User documentation including a user guide and FAQs.  
    Source Code:  
    Well-organized and commented source code hosted in a Git repository.  
    Testing Reports:  
    Results from testing phases, including any bug reports and resolutions.  
    Success Criteria:  
    User Engagement:  
    High user engagement metrics, such as time spent on the app, number of interactions, and quest completions.  
    Performance:  
    Fast load times and responsive interactions across all devices.  
    Security:  
    No critical security vulnerabilities.  
    Secure handling of user data and transactions.  
    Scalability:  
    Ability to support growth in the number of users without degradation in performance.  
    Timeline:  
    Provide a realistic timeline for the development phases, including:

Requirement analysis and design.  
Development sprints.  
Testing and QA.  
Deployment.  
Post-deployment support and maintenance.  
Conclusion:  
This project aims to create a platform that not only recommends sustainable fashion products but also motivates users to adopt eco-friendly practices through engaging gamification features. By combining personalization, interactivity, and a focus on sustainability, the application seeks to make a positive impact in the fashion industry and promote conscious consumerism.

Use NextJS app router for web application.

**Introduction**

Thank you for providing a comprehensive and detailed project brief for the development of a Sustainable Fashion Recommendation System with Gamification Features. This is an exciting project that combines technology, sustainability, and user engagement through gamification. I'll outline how to approach this development using Next.js App Router, covering key aspects such as project setup, architecture, and implementation strategies for each of the functional requirements specified.

----------

### **Project Overview**

We'll utilize the following technologies:

-   **Frontend and Backend Framework:**  Next.js with the App Router for both server-side rendering and API routes.
-   **Styling:**  Tailwind CSS for responsive and modern UI components.
-   **State Management:**  React Context API for simplicity or Redux for more complex state needs.
-   **Database:**  PostgreSQL with Prisma ORM for structured and scalable data management.
-   **Authentication:**  NextAuth.js for secure authentication flows.
-   **Payment Processing:**  Stripe for handling secure payments.
-   **Deployment:**  Vercel for seamless deployment and scalability.

----------

### **Development Plan**

#### **1. Project Setup**

**Initialize Next.js Project with App Router**

```bash
npx create-next-app@latest sustainable-fashion-app --experimental-app
cd sustainable-fashion-app

```

**Install Dependencies**

```bash
npm install tailwindcss postcss autoprefixer prisma @prisma/client next-auth react-redux @reduxjs/toolkit axios stripe

```

**Initialize Tailwind CSS**

```bash
npx tailwindcss init -p

```

Configure  `tailwind.config.js`:

```javascript
/** @type {import('tailwindcss').Config} */
module.exports = {
  content: [
    './app/**/*.{js,ts,jsx,tsx}', // Note the 'app' directory for Next.js App Router
    './components/**/*.{js,ts,jsx,tsx}',
  ],
  theme: {
    extend: {},
  },
  plugins: [],
};

```

Include Tailwind CSS in  `app/globals.css`:

```css
@tailwind base;
@tailwind components;
@tailwind utilities;

```

----------

#### **2. Database Setup with Prisma and PostgreSQL**

**Initialize Prisma**

```bash
npx prisma init

```

Set up your  `DATABASE_URL`  in the  `.env`  file, pointing to your PostgreSQL instance.

**Define the Database Schema in  `prisma/schema.prisma`:**

```prisma
datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

generator client {
  provider = "prisma-client-js"
}

model User {
  id                 Int       @id @default(autoincrement())
  name               String?
  email              String    @unique
  password           String?
  tokens             Int       @default(0)
  quests             QuestProgress[]
  achievements       Achievement[]
  investments        Investment[]
  preferences        Preferences?
  interactions       InteractionHistory[]
  createdAt          DateTime  @default(now())
  updatedAt          DateTime  @updatedAt
}

model Product {
  id                  Int       @id @default(autoincrement())
  sku                 String    @unique
  name                String
  description         String
  price               Float
  brand               String
  materials           String
  styles              String
  images              String[]
  sustainabilityRating Int
  createdAt           DateTime  @default(now())
  updatedAt           DateTime  @updatedAt
}

model Quest {
  id          Int       @id @default(autoincrement())
  name        String
  description String
  reward      Int
  action      String
  goal        Int
}

model QuestProgress {
  id         Int     @id @default(autoincrement())
  user       User    @relation(fields: [userId], references: [id])
  userId     Int
  quest      Quest   @relation(fields: [questId], references: [id])
  questId    Int
  progress   Int     @default(0)
  isCompleted Boolean @default(false)
}

model Achievement {
  id          Int    @id @default(autoincrement())
  name        String
  description String
  user        User   @relation(fields: [userId], references: [id])
  userId      Int
}

model Investment {
  id              Int       @id @default(autoincrement())
  user            User      @relation(fields: [userId], references: [id])
  userId          Int
  projectName     String
  amount          Int
  expectedReturn  Int
  investedAt      DateTime  @default(now())
  maturityDate    DateTime
  isMatured       Boolean   @default(false)
}

model Preferences {
  id                 Int     @id @default(autoincrement())
  user               User    @relation(fields: [userId], references: [id])
  userId             Int
  preferredStyles    String[]
  sustainabilityValues String[]
}

model InteractionHistory {
  id         Int       @id @default(autoincrement())
  user       User      @relation(fields: [userId], references: [id])
  userId     Int
  product    Product   @relation(fields: [productId], references: [id])
  productId  Int
  action     String
  createdAt  DateTime  @default(now())
}

model CartItem {
  id        Int      @id @default(autoincrement())
  user      User     @relation(fields: [userId], references: [id])
  userId    Int
  product   Product  @relation(fields: [productId], references: [id])
  productId Int
  quantity  Int      @default(1)
}

model Voucher {
  id          Int      @id @default(autoincrement())
  code        String   @unique
  discount    Float
  expiresAt   DateTime
  isRedeemed  Boolean  @default(false)
  user        User?    @relation(fields: [userId], references: [id])
  userId      Int?
}

```

**Generate Prisma Client**

```bash
npx prisma generate

```

----------

#### **3. Implementing Authentication with NextAuth.js**

**Setup NextAuth.js**

Create a new API route in  `app/api/auth/[...nextauth]/route.js`:

```javascript
import NextAuth from "next-auth";
import Providers from "next-auth/providers";
import { PrismaAdapter } from "@next-auth/prisma-adapter";
import { prisma } from "@/lib/prisma";

const handler = NextAuth({
  adapter: PrismaAdapter(prisma),
  providers: [
    Providers.Credentials({
      name: "Credentials",
      authorize: async (credentials) => {
        // Implement user lookup and verification
      },
    }),
    // Add other providers like Google, Facebook, etc.
  ],
  pages: {
    signIn: '/auth/signin',
  },
  session: {
    strategy: "jwt",
  },
  callbacks: {
    async session({ session, user, token }) {
      session.user.id = token.sub;
      return session;
    },
  },
  secret: process.env.NEXTAUTH_SECRET,
});

export { handler as GET, handler as POST };

```

----------

#### **4. Building the Onboarding Process**

**Create Onboarding Pages**

-   **Personal Information:**  `app/onboarding/personal-info/page.js`
-   **Style Preferences:**  `app/onboarding/style-preferences/page.js`
-   **Sustainability Values:**  `app/onboarding/sustainability-values/page.js`

**Collect User Inputs and Update the Database**

Use forms to collect data and submit via API routes to update the user's profile and preferences.

----------

#### **5. Developing the Product Catalog and Recommendation Engine**

**Product Listing Page:**  `app/products/page.js`

Fetch and display products:

```javascript
import { prisma } from "@/lib/prisma";

export default async function ProductsPage() {
  const products = await prisma.product.findMany();

  return (
    <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
      {products.map((product) => (
        <ProductCard key={product.id} product={product} />
      ))}
    </div>
  );
}

```

**Product Details Page:**  `app/products/[id]/page.js`

Fetch product details based on  `id`.

**Recommendation Engine Logic**

Create a helper function in  `lib/recommendation.js`:

```javascript
import { prisma } from "@/lib/prisma";

export async function getRecommendedProducts(userId) {
  const user = await prisma.user.findUnique({
    where: { id: userId },
    include: { preferences: true, interactions: true },
  });

  const products = await prisma.product.findMany();

  // Simple filtering based on user preferences
  const recommendedProducts = products.filter((product) => {
    const matchesStyle = user.preferences.preferredStyles.some((style) =>
      product.styles.includes(style)
    );
    const matchesSustainability = user.preferences.sustainabilityValues.every(
      (value) => product.sustainabilityRating >= parseInt(value)
    );
    return matchesStyle && matchesSustainability;
  });

  // Sort or further process recommendations as needed
  return recommendedProducts;
}

```

----------

#### **6. Implementing Gamification Features**

**Token System**

-   Update user token balances upon completing actions.
-   Create utility functions to add or subtract tokens.

**Quest Mechanics**

Create a Quest Manager in  `lib/questManager.js`:

```javascript
export async function startQuest(userId, questId) {
  await prisma.questProgress.create({
    data: {
      userId,
      questId,
    },
  });
}

export async function updateQuestProgress(userId, actionType) {
  const activeQuests = await prisma.questProgress.findMany({
    where: { userId, isCompleted: false },
    include: { quest: true },
  });

  for (const questProgress of activeQuests) {
    if (questProgress.quest.action === actionType) {
      await prisma.questProgress.update({
        where: { id: questProgress.id },
        data: { progress: { increment: 1 } },
      });
      // Check for completion
      if (questProgress.progress + 1 >= questProgress.quest.goal) {
        await completeQuest(questProgress.id);
      }
    }
  }
}

export async function completeQuest(questProgressId) {
  const questProgress = await prisma.questProgress.update({
    where: { id: questProgressId },
    data: { isCompleted: true },
    include: { quest: true },
  });

  // Reward tokens to the user
  await rewardTokens(questProgress.userId, questProgress.quest.reward);
}

```

**Rewarding Tokens**

In  `lib/tokenManager.js`:

```javascript
export async function rewardTokens(userId, amount) {
  await prisma.user.update({
    where: { id: userId },
    data: { tokens: { increment: amount } },
  });
}

```

----------

#### **7. Building the Investment Module**

**Investment Opportunities Page:**  `app/investments/page.js`

Display a list of sustainable projects:

```javascript
export default function InvestmentsPage() {
  const projects = [
    // Fetch or define investment projects
    {
      id: 1,
      name: "Organic Cotton Farming",
      requiredInvestment: 1000,
      duration: 180, // days
      expectedReturnRate: 10, // percent
    },
    // Add more projects
  ];

  return (
    <div>
      {projects.map((project) => (
        <InvestmentCard key={project.id} project={project} />
      ))}
    </div>
  );
}

```

**Investing Tokens**

In the InvestmentCard component, allow users to invest tokens:

```javascript
import { investTokens } from "@/lib/investmentManager";

function InvestmentCard({ project }) {
  const [amount, setAmount] = useState(0);

  const handleInvest = async () => {
    await investTokens(user.id, project.id, amount);
  };

  return (
    <div>
      {/* Display project details */}
      <input
        type="number"
        value={amount}
        onChange={(e) => setAmount(parseInt(e.target.value))}
      />
      <button onClick={handleInvest}>Invest Tokens</button>
    </div>
  );
}

```

In  `lib/investmentManager.js`:

```javascript
export async function investTokens(userId, projectId, amount) {
  // Deduct tokens from user
  await prisma.user.update({
    where: { id: userId },
    data: { tokens: { decrement: amount } },
  });

  // Create investment record
  await prisma.investment.create({
    data: {
      userId,
      projectName: "Project Name", // Fetch based on projectId
      amount,
      expectedReturn: calculateExpectedReturn(amount, 10), // Example return rate
      maturityDate: new Date(Date.now() + 180 * 24 * 60 * 60 * 1000), // 180 days from now
    },
  });
}

```

----------

#### **8. Shopping Cart and Checkout Implementation**

**Cart Page:**  `app/cart/page.js`

Display cart items and allow users to modify the cart.

**Integrate Stripe for Payment Processing**

Create an API route for creating Stripe checkout sessions:

`app/api/checkout/route.js`

```javascript
import { NextResponse } from 'next/server';
import Stripe from 'stripe';

const stripe = new Stripe(process.env.STRIPE_SECRET_KEY);

export async function POST(request) {
  const { cartItems } = await request.json();

  const lineItems = cartItems.map((item) => ({
    price_data: {
      currency: 'usd',
      product_data: {
        name: item.product.name,
        images: [item.product.images[0]],
      },
      unit_amount: item.product.price * 100,
    },
    quantity: item.quantity,
  }));

  const session = await stripe.checkout.sessions.create({
    payment_method_types: ['card'],
    line_items: lineItems,
    mode: 'payment',
    success_url: `${process.env.NEXT_PUBLIC_BASE_URL}/success`,
    cancel_url: `${process.env.NEXT_PUBLIC_BASE_URL}/cart`,
  });

  return NextResponse.json({ id: session.id });
}

```

**Apply Vouchers**

During checkout, allow users to enter voucher codes and apply discounts.

----------

#### **9. User Profile and Settings**

**Profile Page:**  `app/profile/page.js`

Display user information:

-   Personal details
-   Token balance
-   Active quests
-   Achievements
-   Investment portfolio
-   Interaction history

**Allow Users to Update Preferences**

Include forms to update style preferences and sustainability values.

----------

#### **10. Notifications and Alerts**

Implement a notification system using a combination of:

-   **In-App Notifications:**  Stored in the database and fetched/displayed in a notifications panel.
-   **Real-Time Updates:**  Using WebSockets or libraries like  `socket.io`  for real-time notifications.
-   **Push Notifications (Optional):**  If needed, integrate service workers for push notifications.

----------

### **Additional Considerations**

#### **Accessibility and Responsive Design**

Ensure all components are accessible and responsive:

-   Use semantic HTML elements.
-   Add ARIA labels where necessary.
-   Test across devices and screen readers.

#### **Performance Optimization**

-   Optimize images using Next.js Image component.
-   Utilize dynamic imports for code splitting.
-   Implement caching strategies for data fetching.

#### **Security Measures**

-   Protect API routes with authentication checks.
-   Sanitize user inputs to prevent SQL injection and XSS attacks.
-   Use HTTPS in production environments.

#### **Testing Strategy**

Implement testing at various levels:

-   **Unit Tests:**  Using Jest and React Testing Library.
-   **Integration Tests:**  Test interactions between components and APIs.
-   **End-to-End Tests:**  Using Cypress for simulating user flows.

----------

### **Deployment**

**Using Vercel**

Vercel offers seamless deployment for Next.js applications.

1.  **Connect Repository:**  Link your GitHub repository to Vercel.
2.  **Environment Variables:**  Set up environment variables in Vercel settings.
3.  **Automatic Deployments:**  Pushes to the main branch trigger deployments.

----------

### **Project Management and Agile Approach**

-   **Sprint Planning:**  Divide the project into manageable sprints (e.g., 2 weeks).
-   **Backlog Prioritization:**  Use tools like Jira or Trello to manage tasks.
-   **Daily Stand-ups:**  Keep the team aligned with daily updates.
-   **Sprint Reviews and Retrospectives:**  Reflect on progress and areas for improvement.

----------

### **Timeline Estimate**

1.  **Week 1-2:**  Requirement Analysis and Design
    
    -   Finalizing tech stack
    -   Designing database schema
    -   Wireframes and UI mockups
2.  **Week 3-6:**  Development Sprints
    
    -   Sprint 1: User Authentication and Onboarding
    -   Sprint 2: Product Catalog and Recommendation Engine
    -   Sprint 3: Gamification Features
3.  **Week 7-8:**  Testing and QA
    
    -   Implementing automated tests
    -   User Acceptance Testing (UAT)
4.  **Week 9:**  Deployment
    
    -   Setting up CI/CD
    -   Deploying to production environment
5.  **Week 10+:**  Post-Deployment Support and Maintenance
    
    -   Monitoring performance
    -   Gathering user feedback
    -   Iterative improvements

----------

### **Conclusion**

By following this structured approach, you can develop a robust and engaging Sustainable Fashion Recommendation System with Gamification Features using Next.js App Router. The integration of personalized recommendations, gamification elements, and a focus on sustainability will provide users with a compelling experience that promotes eco-friendly fashion choices.

----------

**If you need further assistance with specific sections of the code, implementation details, or have questions about best practices, feel free to ask!**

don't use redux use simpler zustand. Use simpler alternatives if possible.

Certainly! Thank you for clarifying your preferences. I'll update the development plan to use  **Zustand**  instead of Redux for state management and suggest simpler alternatives where possible to streamline the development process.

----------

**Revised Development Plan**

### **1. Project Setup (Updated)**

**Initialize Next.js Project with App Router**

```bash
npx create-next-app@latest sustainable-fashion-app --use-npm --experimental-app
cd sustainable-fashion-app

```

**Install Dependencies (Updated)**

```bash
npm install tailwindcss postcss autoprefixer prisma @prisma/client next-auth axios stripe zustand

```

-   **Removed Redux dependencies**
-   **Added Zustand**  for state management

**Initialize Tailwind CSS**

```bash
npx tailwindcss init -p

```

Configure  `tailwind.config.js`:

```javascript
/** @type {import('tailwindcss').Config} */
module.exports = {
  content: [
    './app/**/*.{js,ts,jsx,tsx}', // Include the 'app' directory for Next.js App Router
    './components/**/*.{js,ts,jsx,tsx}',
  ],
  theme: {
    extend: {},
  },
  plugins: [],
};

```

Include Tailwind CSS in  `app/globals.css`:

```css
@tailwind base;
@tailwind components;
@tailwind utilities;

```

----------

### **2. State Management with Zustand**

Zustand is a lightweight and intuitive state management library that simplifies the handling of global and component-level state without the boilerplate associated with Redux.

**Setting Up Zustand**

Create a  `store`  directory and initialize your global store.

```javascript
// store/useStore.js

import create from 'zustand';

export const useStore = create((set) => ({
  // User state
  user: null,
  setUser: (userData) => set({ user: userData }),

  // Token balance
  tokens: 0,
  increaseTokens: (amount) => set((state) => ({ tokens: state.tokens + amount })),
  decreaseTokens: (amount) => set((state) => ({ tokens: state.tokens - amount })),

  // Cart state
  cart: [],
  addToCart: (product) =>
    set((state) => ({ cart: [...state.cart, product] })),
  removeFromCart: (productId) =>
    set((state) => ({
      cart: state.cart.filter((item) => item.id !== productId),
    })),
  clearCart: () => set({ cart: [] }),

  // Other states and actions can be added here
}));

```

----------

### **3. Implementing Authentication with NextAuth.js**

NextAuth.js remains a simple yet powerful solution for authentication that integrates seamlessly with Next.js.

**Setup NextAuth.js**

Create a new API route in  `app/api/auth/[...nextauth]/route.js`:

```javascript
// app/api/auth/[...nextauth]/route.js

import NextAuth from 'next-auth';
import CredentialsProvider from 'next-auth/providers/credentials';
import { PrismaAdapter } from '@next-auth/prisma-adapter';
import { prisma } from '@/lib/prisma';

const handler = NextAuth({
  adapter: PrismaAdapter(prisma),
  providers: [
    CredentialsProvider({
      name: 'Credentials',
      authorize: async (credentials) => {
        // Implement user lookup and verification
        const user = await prisma.user.findUnique({
          where: { email: credentials.email },
        });

        if (user && user.password === credentials.password) {
          return user;
        } else {
          return null;
        }
      },
    }),
    // Add other providers like Google, Facebook if needed
  ],
  pages: {
    signIn: '/auth/signin',
  },
  callbacks: {
    async session({ session, token }) {
      session.user.id = token.sub;
      return session;
    },
  },
  secret: process.env.NEXTAUTH_SECRET,
});

export { handler as GET, handler as POST };

```

----------

### **4. Building the Onboarding Process**

**Create Onboarding Pages**

-   **Personal Information:**  `app/onboarding/personal-info/page.js`
-   **Style Preferences:**  `app/onboarding/style-preferences/page.js`
-   **Sustainability Values:**  `app/onboarding/sustainability-values/page.js`

**Collect User Inputs and Update the Database**

Use forms to collect data and submit via API routes to update the user's profile and preferences in the database using Prisma.

Example of updating preferences:

```javascript
// app/onboarding/style-preferences/page.js

'use client';

import { useState } from 'react';
import { useRouter } from 'next/navigation';
import { useSession } from 'next-auth/react';
import axios from 'axios';

export default function StylePreferences() {
  const [styles, setStyles] = useState([]);
  const router = useRouter();
  const { data: session } = useSession();

  const handleSubmit = async () => {
    await axios.post('/api/user/preferences', {
      userId: session.user.id,
      preferredStyles: styles,
    });
    router.push('/onboarding/sustainability-values');
  };

  return (
    <div>
      {/* Form elements to select styles */}
      <button onClick={handleSubmit}>Next</button>
    </div>
  );
}

```

Create the corresponding API route:

```javascript
// app/api/user/preferences/route.js

import { NextResponse } from 'next/server';
import { prisma } from '@/lib/prisma';

export async function POST(request) {
  const { userId, preferredStyles } = await request.json();

  await prisma.preferences.upsert({
    where: { userId },
    update: { preferredStyles },
    create: { userId, preferredStyles },
  });

  return NextResponse.json({ success: true });
}

```

----------

### **5. Developing the Product Catalog and Recommendation Engine**

**Product Listing Page:**  `app/products/page.js`

Display products, applying basic filters based on user preferences.

**Recommendation Engine (Simplified)**

Implement a simple server-side function to filter products based on user preferences without complex algorithms initially.

```javascript
// app/products/page.js

import { prisma } from '@/lib/prisma';
import { getServerSession } from 'next-auth';
import { authOptions } from '../api/auth/[...nextauth]/route';

export default async function ProductsPage() {
  const session = await getServerSession(authOptions);
  const user = await prisma.user.findUnique({
    where: { id: session.user.id },
    include: { preferences: true },
  });

  const products = await prisma.product.findMany({
    where: {
      styles: {
        hasSome: user.preferences.preferredStyles,
      },
      sustainabilityRating: {
        gte: user.preferences.minSustainabilityRating || 0,
      },
    },
  });

  return (
    <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
      {products.map((product) => (
        <ProductCard key={product.id} product={product} />
      ))}
    </div>
  );
}

```

----------

### **6. Implementing Gamification Features**

**Token System Using Zustand**

Manage tokens using the global store.

```javascript
// Example of increasing tokens after an action

import { useStore } from '@/store/useStore';

function SomeComponent() {
  const increaseTokens = useStore((state) => state.increaseTokens);

  const handleAction = () => {
    // ... action logic
    increaseTokens(10); // Reward 10 tokens
  };

  return <button onClick={handleAction}>Do Action</button>;
}

```

**Quest System Using Zustand**

Extend your store to include quest state.

```javascript
// store/useQuestStore.js

import create from 'zustand';

export const useQuestStore = create((set) => ({
  quests: [],
  activeQuests: [],
  startQuest: (questId) =>
    set((state) => {
      const quest = state.quests.find((q) => q.id === questId);
      return {
        activeQuests: [...state.activeQuests, { ...quest, progress: 0 }],
      };
    }),
  updateQuestProgress: (questId, increment = 1) =>
    set((state) => ({
      activeQuests: state.activeQuests.map((quest) =>
        quest.id === questId
          ? { ...quest, progress: quest.progress + increment }
          : quest
      ),
    })),
  completeQuest: (questId) =>
    set((state) => ({
      activeQuests: state.activeQuests.filter((q) => q.id !== questId),
    })),
  setQuests: (quests) => set({ quests }),
}));

```

**Using the Quest Store in Components**

```javascript
// components/Quests.js

import { useQuestStore } from '@/store/useQuestStore';
import { useStore } from '@/store/useStore';

export default function Quests() {
  const { quests, activeQuests, startQuest, completeQuest, updateQuestProgress } =
    useQuestStore();
  const increaseTokens = useStore((state) => state.increaseTokens);

  const handleCompleteQuest = (questId) => {
    // Reward tokens upon completion
    const quest = quests.find((q) => q.id === questId);
    increaseTokens(quest.reward);
    completeQuest(questId);
  };

  return (
    <div>
      {/* Display available quests and active quests */}
      {/* Handle quest progression and completion */}
    </div>
  );
}

```

----------

### **7. Building the Investment Module**

**Investment Management with Zustand**

Create a separate store for investments.

```javascript
// store/useInvestmentStore.js

import create from 'zustand';

export const useInvestmentStore = create((set) => ({
  investments: [],
  invest: (project, amount) =>
    set((state) => ({
      investments: [
        ...state.investments,
        {
          project,
          amount,
          investedAt: new Date(),
          maturityDate: new Date(Date.now() + project.duration * 86400000),
        },
      ],
    })),
}));

```

**Using Investment Store in Components**

```javascript
// components/Investments.js

import { useState } from 'react';
import { useInvestmentStore } from '@/store/useInvestmentStore';
import { useStore } from '@/store/useStore';

export default function Investments() {
  const invest = useInvestmentStore((state) => state.invest);
  const decreaseTokens = useStore((state) => state.decreaseTokens);
  const [amount, setAmount] = useState(0);

  const handleInvest = (project) => {
    invest(project, amount);
    decreaseTokens(amount);
  };

  return (
    <div>
      {/* Display investment projects */}
      <button onClick={() => handleInvest(project)}>Invest</button>
    </div>
  );
}

```

----------

### **8. Shopping Cart and Checkout Implementation**

**Cart Management with Zustand**

Cart actions are already defined in the  `useStore`.

**Cart Page**

```javascript
// app/cart/page.js

'use client';

import { useStore } from '@/store/useStore';

export default function CartPage() {
  const cart = useStore((state) => state.cart);
  const removeFromCart = useStore((state) => state.removeFromCart);
  const clearCart = useStore((state) => state.clearCart);

  const handleCheckout = async () => {
    // Implement checkout logic
    // Redirect to Stripe Checkout or handle payment
  };

  return (
    <div>
      {cart.map((item) => (
        <div key={item.id}>
          {/* Display cart item details */}
          <button onClick={() => removeFromCart(item.id)}>Remove</button>
        </div>
      ))}
      <button onClick={handleCheckout}>Checkout</button>
    </div>
  );
}

```

**Integrate Stripe Checkout**

Use Stripe's pre-built checkout to simplify payment processing.

```javascript
// app/api/checkout/route.js

import { NextResponse } from 'next/server';
import Stripe from 'stripe';

const stripe = new Stripe(process.env.STRIPE_SECRET_KEY);

export async function POST(request) {
  const { cartItems } = await request.json();

  // Create Stripe Checkout Session
  const session = await stripe.checkout.sessions.create({
    payment_method_types: ['card'],
    line_items: cartItems.map((item) => ({
      price_data: {
        currency: 'usd',
        product_data: { name: item.name },
        unit_amount: item.price * 100, // Convert to cents
      },
      quantity: 1,
    })),
    mode: 'payment',
    success_url: `${process.env.NEXT_PUBLIC_BASE_URL}/success`,
    cancel_url: `${process.env.NEXT_PUBLIC_BASE_URL}/cart`,
  });

  return NextResponse.json({ id: session.id });
}

```

**Client-side Checkout Handling**

```javascript
// app/cart/page.js

import { loadStripe } from '@stripe/stripe-js';

const stripePromise = loadStripe(process.env.NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY);

const handleCheckout = async () => {
  const stripe = await stripePromise;
  const response = await fetch('/api/checkout', {
    method: 'POST',
    body: JSON.stringify({ cartItems }),
  });
  const { id } = await response.json();
  await stripe.redirectToCheckout({ sessionId: id });
};

```

----------

### **9. User Profile and Settings**

**Profile Page**

```javascript
// app/profile/page.js

'use client';

import { useSession } from 'next-auth/react';
import { useStore } from '@/store/useStore';

export default function ProfilePage() {
  const { data: session } = useSession();
  const tokens = useStore((state) => state.tokens);

  return (
    <div>
      <h1>Welcome, {session.user.name}</h1>
      <p>Token Balance: {tokens}</p>
      {/* Display other user information */}
    </div>
  );
}

```

**Allow Users to Update Preferences**

Provide forms to update preferences and submit changes via API routes.

----------

### **10. Notifications and Alerts (Simplified)**

**Implementing a Simple Notification System**

Instead of setting up real-time notifications, use Zustand to manage notifications in the UI.

```javascript
// store/useNotificationStore.js

import create from 'zustand';

export const useNotificationStore = create((set) => ({
  notifications: [],
  addNotification: (notification) =>
    set((state) => ({
      notifications: [...state.notifications, notification],
    })),
  removeNotification: (id) =>
    set((state) => ({
      notifications: state.notifications.filter((n) => n.id !== id),
    })),
}));

```

**Using Notifications in Components**

```javascript
// app/layout.js

'use client';

import { useNotificationStore } from '@/store/useNotificationStore';

export default function Layout({ children }) {
  const notifications = useNotificationStore((state) => state.notifications);

  return (
    <div>
      {/* Header and navigation */}
      {children}
      {/* Notification bar */}
      <div>
        {notifications.map((notification) => (
          <div key={notification.id}>
            <p>{notification.message}</p>
          </div>
        ))}
      </div>
    </div>
  );
}

```

Add notifications upon certain actions:

```javascript
// components/SomeComponent.js

import { useNotificationStore } from '@/store/useNotificationStore';

export default function SomeComponent() {
  const addNotification = useNotificationStore((state) => state.addNotification);

  const handleAction = () => {
    // ... action logic
    addNotification({ id: Date.now(), message: 'Action completed successfully!' });
  };

  return <button onClick={handleAction}>Do Action</button>;
}

```

----------

### **Additional Considerations**

#### **Simplifying Data Fetching**

-   Use React Query or SWR for data fetching to simplify server state management.
-   These libraries handle caching, refetching, and updating data efficiently.

**Example with SWR**

```javascript
// components/ProductList.js

import useSWR from 'swr';

const fetcher = (url) => fetch(url).then((res) => res.json());

export default function ProductList() {
  const { data, error } = useSWR('/api/products', fetcher);

  if (error) return <div>Error loading products.</div>;
  if (!data) return <div>Loading...</div>;

  return (
    <div>
      {data.products.map((product) => (
        <ProductCard key={product.id} product={product} />
      ))}
    </div>
  );
}

```

----------

### **Updated Timeline**

By opting for simpler tools and technologies, the development timeline becomes more efficient.

1.  **Week 1:**  Project Setup, Authentication, and Onboarding
2.  **Week 2:**  Product Catalog, Basic Recommendation Engine, and State Management with Zustand
3.  **Week 3:**  Gamification Features (Token System, Quests, Achievements)
4.  **Week 4:**  Investment Module and User Profile
5.  **Week 5:**  Shopping Cart, Checkout Integration with Stripe, and Notifications
6.  **Week 6:**  Testing, QA, and Deployment

----------

### **Conclusion**

By using  **Zustand**  for state management, you achieve a simpler and more maintainable codebase without the overhead of Redux. This approach aligns with your preference for simpler alternatives and accelerates the development process.

Similarly, we can simplify other aspects by:

-   Utilizing  **Next.js API routes**  to keep backend code minimal and within the same framework.
-   Leveraging  **SWR**  for data fetching to simplify server state management.
-   Using Stripe's hosted checkout to handle payments securely with less custom code.

This adjusted plan maintains the core functionalities you outlined while focusing on simplicity and efficiency. If you have any questions or need further adjustments, please let me know!

----------

**I'm here to help with any other preferences or questions you might have.**

implement full logic-you can rest aside complex unimportant like notifications and payment - you can add custom test payment. Implement Considerations to simplify data.

**Introduction**

Thank you for the clarification. I'll focus on implementing the full logic of the Sustainable Fashion Recommendation System, simplifying data considerations where possible. We'll set aside complex and less critical features like notifications and payment integration for now. Instead, we'll use a custom test payment to simulate the checkout process.

This revised plan will provide a comprehensive guide to building the application's core functionalities, emphasizing the implementation of essential logic.

----------

### **Revised Development Plan**

#### **Overview**

We'll develop the core features of the application:

-   **User Authentication and Onboarding**
-   **Product Catalog and Recommendation Engine**
-   **Gamification Elements (Token System, Quests, Investments)**
-   **User Profile and Settings**
-   **Simplified Shopping Cart and Custom Test Payment**

We'll simplify data handling by using straightforward data models and focus on implementing the logic that drives user interactions and experiences.

----------

### **1. Project Setup**

**Initialize the Next.js Project**

```bash
npx create-next-app@latest sustainable-fashion-app --use-npm --experimental-app
cd sustainable-fashion-app

```

**Install Dependencies**

```bash
npm install tailwindcss postcss autoprefixer prisma @prisma/client next-auth axios zustand

```

-   **Tailwind CSS**: For styling
-   **Prisma**: ORM for database interactions
-   **NextAuth.js**: For authentication
-   **Axios**: For HTTP requests
-   **Zustand**: For state management

**Initialize Tailwind CSS**

```bash
npx tailwindcss init -p

```

Configure  `tailwind.config.js`  and include Tailwind CSS in  `app/globals.css`  as before.

----------

### **2. Database Setup with Prisma and Simplified Data Models**

**Initialize Prisma**

```bash
npx prisma init

```

Set up the  `DATABASE_URL`  in the  `.env`  file, pointing to a local SQLite database for simplicity:

```env
DATABASE_URL="file:./dev.db"

```

**Define Simplified Database Schema in  `prisma/schema.prisma`:**

We'll simplify data models to focus on the core logic.

```prisma
datasource db {
  provider = "sqlite"
  url      = env("DATABASE_URL")
}

generator client {
  provider = "prisma-client-js"
}

model User {
  id                   Int              @id @default(autoincrement())
  name                 String?
  email                String           @unique
  password             String?
  tokens               Int              @default(0)
  preferences          Preferences?
  quests               QuestProgress[]
  achievements         Achievement[]
  investments          Investment[]
  interactions         Interaction[]
}

model Product {
  id                   Int              @id @default(autoincrement())
  name                 String
  description          String
  price                Float
  styles               String[]
  sustainabilityRating Int
}

model Preferences {
  id                   Int      @id @default(autoincrement())
  userId               Int      @unique
  preferredStyles      String[]
  sustainabilityValues String[]
  user                 User     @relation(fields: [userId], references: [id])
}

model Quest {
  id          Int      @id @default(autoincrement())
  name        String
  description String
  reward      Int
  action      String
  goal        Int
}

model QuestProgress {
  id         Int      @id @default(autoincrement())
  userId     Int
  questId    Int
  progress   Int      @default(0)
  isCompleted Boolean @default(false)
  user       User     @relation(fields: [userId], references: [id])
  quest      Quest    @relation(fields: [questId], references: [id])
}

model Achievement {
  id          Int      @id @default(autoincrement())
  name        String
  description String
  userId      Int
  user        User     @relation(fields: [userId], references: [id])
}

model Investment {
  id              Int       @id @default(autoincrement())
  userId          Int
  projectName     String
  amount          Int
  expectedReturn  Int
  investedAt      DateTime  @default(now())
  maturityDate    DateTime
  isMatured       Boolean   @default(false)
  user            User      @relation(fields: [userId], references: [id])
}

model Interaction {
  id         Int      @id @default(autoincrement())
  userId     Int
  productId  Int
  action     String
  createdAt  DateTime @default(now())
  user       User     @relation(fields: [userId], references: [id])
  product    Product  @relation(fields: [productId], references: [id])
}

```

**Generate Prisma Client**

```bash
npx prisma generate

```

----------

### **3. Implementing User Authentication and Onboarding**

**Setup NextAuth.js**

Create an API route for authentication at  `app/api/auth/[...nextauth]/route.js`:

```javascript
import NextAuth from 'next-auth';
import CredentialsProvider from 'next-auth/providers/credentials';
import { PrismaAdapter } from '@next-auth/prisma-adapter';
import { prisma } from '@/lib/prisma';

const handler = NextAuth({
  adapter: PrismaAdapter(prisma),
  providers: [
    CredentialsProvider({
      name: 'Credentials',
      authorize: async (credentials) => {
        const user = await prisma.user.findUnique({
          where: { email: credentials.email },
        });

        if (user && user.password === credentials.password) {
          return user;
        } else {
          throw new Error('Invalid credentials');
        }
      },
    }),
  ],
  secret: process.env.NEXTAUTH_SECRET,
});

export { handler as GET, handler as POST };

```

**Onboarding Process**

Create pages under  `app/onboarding`:

1.  **Personal Information**:  `app/onboarding/personal-info/page.js`
2.  **Style Preferences**:  `app/onboarding/style-preferences/page.js`
3.  **Sustainability Values**:  `app/onboarding/sustainability-values/page.js`

**Example: Collecting Style Preferences**

```javascript
'use client';

import { useState } from 'react';
import { useRouter } from 'next/navigation';
import { useSession } from 'next-auth/react';
import axios from 'axios';

export default function StylePreferences() {
  const [styles, setStyles] = useState([]);
  const router = useRouter();
  const { data: session } = useSession();

  const handleSubmit = async () => {
    await axios.post('/api/user/preferences', {
      userId: session.user.id,
      preferredStyles: styles,
    });
    router.push('/onboarding/sustainability-values');
  };

  return (
    <div>
      {/* Implement UI for selecting styles */}
      <button onClick={handleSubmit}>Next</button>
    </div>
  );
}

```

**API Route to Save Preferences**

```javascript
// app/api/user/preferences/route.js

import { NextResponse } from 'next/server';
import { prisma } from '@/lib/prisma';

export async function POST(request) {
  const { userId, preferredStyles } = await request.json();

  await prisma.preferences.upsert({
    where: { userId },
    update: { preferredStyles },
    create: { userId, preferredStyles },
  });

  return NextResponse.json({ success: true });
}

```

----------

### **4. Building the Product Catalog and Recommendation Engine**

**Product Catalog**

Create a page to display products:  `app/products/page.js`

```javascript
import { prisma } from '@/lib/prisma';
import ProductCard from '@/components/ProductCard';

export default async function ProductsPage() {
  const products = await prisma.product.findMany();

  return (
    <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
      {products.map((product) => (
        <ProductCard key={product.id} product={product} />
      ))}
    </div>
  );
}

```

**Product Details Page**

Create dynamic routes for product details:  `app/products/[id]/page.js`

```javascript
import { prisma } from '@/lib/prisma';

export default async function ProductPage({ params }) {
  const product = await prisma.product.findUnique({
    where: { id: parseInt(params.id) },
  });

  return (
    <div>
      <h1>{product.name}</h1>
      {/* Display product details */}
    </div>
  );
}

```

**Recommendation Engine**

Implement a simple recommendation algorithm based on user's preferences.

```javascript
// app/products/page.js

import { prisma } from '@/lib/prisma';
import { getServerSession } from 'next-auth';
import { authOptions } from '../../api/auth/[...nextauth]/route';
import ProductCard from '@/components/ProductCard';

export default async function ProductsPage() {
  const session = await getServerSession(authOptions);

  let products;

  if (session) {
    const userPreferences = await prisma.preferences.findUnique({
      where: { userId: session.user.id },
    });

    products = await prisma.product.findMany({
      where: {
        styles: {
          hasSome: userPreferences.preferredStyles,
        },
        sustainabilityRating: {
          gte: 3, // For example, only show products with rating 3 or higher
        },
      },
    });
  } else {
    products = await prisma.product.findMany();
  }

  return (
    <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
      {products.map((product) => (
        <ProductCard key={product.id} product={product} />
      ))}
    </div>
  );
}

```

----------

### **5. Implementing Gamification Features**

#### **Token System**

Manage the user's token balance using the database and Zustand for state management.

**Update Token Balance**

Create utility functions to update tokens:

```javascript
// lib/tokenManager.js

import { prisma } from '@/lib/prisma';

export async function adjustTokens(userId, amount) {
  await prisma.user.update({
    where: { id: userId },
    data: { tokens: { increment: amount } },
  });
}

```

**Display Token Balance**

In the user interface, display the current token balance:

```javascript
'use client';

import { useSession } from 'next-auth/react';
import { useEffect, useState } from 'react';
import axios from 'axios';

export default function TokenBalance() {
  const { data: session } = useSession();
  const [tokens, setTokens] = useState(0);

  useEffect(() => {
    if (session) {
      axios.get(`/api/user/${session.user.id}/tokens`).then((response) => {
        setTokens(response.data.tokens);
      });
    }
  }, [session]);

  return <div>Your Tokens: {tokens}</div>;
}

```

**API Route to Get Token Balance**

```javascript
// app/api/user/[id]/tokens/route.js

import { NextResponse } from 'next/server';
import { prisma } from '@/lib/prisma';

export async function GET(request, { params }) {
  const user = await prisma.user.findUnique({
    where: { id: parseInt(params.id) },
    select: { tokens: true },
  });

  return NextResponse.json({ tokens: user.tokens });
}

```

#### **Quests and Challenges**

Implement a system where users can start quests and track their progress.

**Quest Data**

Define quests in the database or as static data.

```javascript
// data/quests.js

export const quests = [
  {
    id: 1,
    name: 'Rate 5 Products',
    description: 'Rate any 5 products to earn tokens.',
    reward: 50,
    action: 'rate_product',
    goal: 5,
  },
  // Add more quests
];

```

**Starting a Quest**

Create API route to start a quest:

```javascript
// app/api/quests/start/route.js

import { NextResponse } from 'next/server';
import { prisma } from '@/lib/prisma';

export async function POST(request) {
  const { userId, questId } = await request.json();

  await prisma.questProgress.create({
    data: {
      userId,
      questId,
    },
  });

  return NextResponse.json({ success: true });
}

```

**Updating Quest Progress**

When a user performs an action (e.g., rates a product), update their quest progress.

```javascript
// lib/questManager.js

import { prisma } from '@/lib/prisma';

export async function updateQuestProgress(userId, actionType) {
  const activeQuests = await prisma.questProgress.findMany({
    where: {
      userId,
      isCompleted: false,
      quest: { action: actionType },
    },
    include: { quest: true },
  });

  for (const questProgress of activeQuests) {
    await prisma.questProgress.update({
      where: { id: questProgress.id },
      data: { progress: { increment: 1 } },
    });

    // Check if quest is completed
    if (questProgress.progress + 1 >= questProgress.quest.goal) {
      await completeQuest(questProgress.id);
    }
  }
}

async function completeQuest(questProgressId) {
  const questProgress = await prisma.questProgress.update({
    where: { id: questProgressId },
    data: { isCompleted: true },
    include: { quest: true },
  });

  // Reward tokens
  await adjustTokens(questProgress.userId, questProgress.quest.reward);
}

```

**Example: Rating a Product**

When a user rates a product, invoke  `updateQuestProgress`:

```javascript
// app/products/[id]/page.js

'use client';

import { useSession } from 'next-auth/react';
import axios from 'axios';

export default function ProductPage({ params }) {
  const { data: session } = useSession();

  const handleRateProduct = async (rating) => {
    await axios.post('/api/products/rate', {
      userId: session.user.id,
      productId: parseInt(params.id),
      rating,
    });

    // Update quest progress
    await updateQuestProgress(session.user.id, 'rate_product');
  };

  return (
    <div>
      {/* Display product details */}
      <button onClick={() => handleRateProduct(5)}>Rate 5 Stars</button>
    </div>
  );
}

```

**API Route to Handle Product Rating**

```javascript
// app/api/products/rate/route.js

import { NextResponse } from 'next/server';
import { prisma } from '@/lib/prisma';

export async function POST(request) {
  const { userId, productId, rating } = await request.json();

  await prisma.interaction.create({
    data: {
      userId,
      productId,
      action: 'rate',
      createdAt: new Date(),
    },
  });

  // Additional logic for storing the rating can be added here

  return NextResponse.json({ success: true });
}

```

#### **Achievements**

Implement a simple achievements system.

**Awarding Achievements**

```javascript
// lib/achievementManager.js

import { prisma } from '@/lib/prisma';

export async function checkAndAwardAchievements(userId) {
  const totalInvestments = await prisma.investment.count({
    where: { userId },
  });

  if (totalInvestments >= 5) {
    // Award 'Eco Warrior' achievement
    await prisma.achievement.upsert({
      where: { userId_name: { userId, name: 'Eco Warrior' } },
      update: {},
      create: {
        userId,
        name: 'Eco Warrior',
        description: 'Invested in multiple sustainable projects.',
      },
    });
  }
}

```

Invoke  `checkAndAwardAchievements`  after relevant actions, like completing an investment.

----------

### **6. Building the Investment Module**

We'll create a simplified investment module allowing users to invest tokens into projects.

**Displaying Investment Opportunities**

```javascript
// app/investments/page.js

const projects = [
  {
    id: 1,
    name: 'Organic Cotton Initiative',
    requiredInvestment: 100,
    expectedReturnRate: 0.1, // 10%
    duration: 30, // days
  },
  // Additional projects
];

export default function InvestmentsPage() {
  return (
    <div>
      {projects.map((project) => (
        <InvestmentCard key={project.id} project={project} />
      ))}
    </div>
  );
}

```

**InvestmentCard Component**

```javascript
'use client';

import { useState } from 'react';
import { useSession } from 'next-auth/react';
import axios from 'axios';

export default function InvestmentCard({ project }) {
  const [amount, setAmount] = useState(0);
  const { data: session } = useSession();

  const handleInvest = async () => {
    await axios.post('/api/investments', {
      userId: session.user.id,
      project,
      amount: parseInt(amount),
    });

    // Optionally, update local state or give feedback to the user
  };

  return (
    <div>
      <h2>{project.name}</h2>
      {/* Display project details */}
      <input
        type="number"
        value={amount}
        onChange={(e) => setAmount(e.target.value)}
        min="1"
      />
      <button onClick={handleInvest}>Invest Tokens</button>
    </div>
  );
}

```

**API Route to Handle Investments**

```javascript
// app/api/investments/route.js

import { NextResponse } from 'next/server';
import { prisma } from '@/lib/prisma';
import { adjustTokens } from '@/lib/tokenManager';

export async function POST(request) {
  const { userId, project, amount } = await request.json();

  // Deduct tokens from the user
  await adjustTokens(userId, -amount);

  // Calculate expected return
  const expectedReturn = Math.floor(amount * project.expectedReturnRate);

  // Create investment record
  await prisma.investment.create({
    data: {
      userId,
      projectName: project.name,
      amount,
      expectedReturn,
      maturityDate: new Date(Date.now() + project.duration * 24 * 60 * 60 * 1000),
    },
  });

  return NextResponse.json({ success: true });
}

```

----------

### **7. User Profile and Settings**

**Profile Page**

Create a user profile page to display user information:

```javascript
// app/profile/page.js

import { prisma } from '@/lib/prisma';
import { getServerSession } from 'next-auth';
import { authOptions } from '../api/auth/[...nextauth]/route';

export default async function ProfilePage() {
  const session = await getServerSession(authOptions);

  const user = await prisma.user.findUnique({
    where: { id: session.user.id },
    include: {
      preferences: true,
      quests: { include: { quest: true } },
      achievements: true,
      investments: true,
    },
  });

  return (
    <div>
      <h1>{user.name}'s Profile</h1>
      <p>Tokens: {user.tokens}</p>
      <h2>Achievements</h2>
      <ul>
        {user.achievements.map((achievement) => (
          <li key={achievement.id}>{achievement.name}</li>
        ))}
      </ul>
      {/* Display other user data */}
    </div>
  );
}

```

**Updating Preferences**

Allow users to update their style preferences and sustainability values.

```javascript
// app/profile/preferences/page.js

'use client';

import { useState, useEffect } from 'react';
import { useSession } from 'next-auth/react';
import axios from 'axios';

export default function PreferencesPage() {
  const { data: session } = useSession();
  const [preferredStyles, setPreferredStyles] = useState([]);
  const [sustainabilityValues, setSustainabilityValues] = useState([]);

  useEffect(() => {
    if (session) {
      axios.get(`/api/user/${session.user.id}/preferences`).then((response) => {
        setPreferredStyles(response.data.preferredStyles || []);
        setSustainabilityValues(response.data.sustainabilityValues || []);
      });
    }
  }, [session]);

  const handleSubmit = async () => {
    await axios.post(`/api/user/preferences`, {
      userId: session.user.id,
      preferredStyles,
      sustainabilityValues,
    });
  };

  return (
    <div>
      {/* Implement UI for updating preferences */}
      <button onClick={handleSubmit}>Save Preferences</button>
    </div>
  );
}

```

----------

### **8. Simplified Shopping Cart and Custom Test Payment**

Since we're setting aside complex payment integrations, we'll create a custom test payment process.

**Cart Management**

Use Zustand to manage the cart state:

```javascript
// store/useCartStore.js

import create from 'zustand';

export const useCartStore = create((set) => ({
  cartItems: [],
  addToCart: (product) =>
    set((state) => ({ cartItems: [...state.cartItems, product] })),
  removeFromCart: (productId) =>
    set((state) => ({
      cartItems: state.cartItems.filter((item) => item.id !== productId),
    })),
  clearCart: () => set({ cartItems: [] }),
}));

```

**Adding Products to Cart**

```javascript
// app/products/[id]/page.js

'use client';

import { useCartStore } from '@/store/useCartStore';

export default function ProductPage({ params }) {
  const addToCart = useCartStore((state) => state.addToCart);

  const handleAddToCart = (product) => {
    addToCart(product);
  };

  return (
    <div>
      {/* Display product details */}
      <button onClick={() => handleAddToCart(product)}>Add to Cart</button>
    </div>
  );
}

```

**Cart Page**

```javascript
// app/cart/page.js

'use client';

import { useCartStore } from '@/store/useCartStore';
import { useRouter } from 'next/navigation';

export default function CartPage() {
  const cartItems = useCartStore((state) => state.cartItems);
  const clearCart = useCartStore((state) => state.clearCart);
  const router = useRouter();

  const handleCheckout = () => {
    // Simulate payment process
    alert('Payment Successful! Thank you for your purchase.');
    clearCart();
    router.push('/products');
  };

  return (
    <div>
      <h1>Your Cart</h1>
      {cartItems.length === 0 ? (
        <p>Your cart is empty.</p>
      ) : (
        <>
          <ul>
            {cartItems.map((item) => (
              <li key={item.id}>{item.name} - ${item.price.toFixed(2)}</li>
            ))}
          </ul>
          <button onClick={handleCheckout}>Proceed to Payment</button>
        </>
      )}
    </div>
  );
}

```

**Custom Test Payment**

Since we're not integrating a real payment gateway, we simulate the payment process in the  `handleCheckout`  function.

----------

### **9. Simplifying Data Handling**

To simplify data considerations:

-   **Use In-Memory Data for Static Content**: For quests and investment projects, store data in local files or constants instead of databases.
    
    -   Example: Define quests in  `data/quests.js`.
-   **Limit Data Models**: Only include fields necessary for core logic in your data models.
    
-   **Use SQLite for Development**: Use SQLite with Prisma for a lightweight and simple database solution during development.
    
-   **Minimize Server-Side Data Fetching**: Fetch data on the client side when possible to simplify server logic.
    

**Example: Fetching Products with SWR**

```javascript
// components/ProductList.js

'use client';

import useSWR from 'swr';
import ProductCard from './ProductCard';

const fetcher = (url) => fetch(url).then((res) => res.json());

export default function ProductList() {
  const { data, error } = useSWR('/api/products', fetcher);

  if (error) return <div>Error loading products.</div>;
  if (!data) return <div>Loading...</div>;

  return (
    <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
      {data.products.map((product) => (
        <ProductCard key={product.id} product={product} />
      ))}
    </div>
  );
}

```

**API Route to Provide Product Data**

```javascript
// app/api/products/route.js

import { NextResponse } from 'next/server';
import { prisma } from '@/lib/prisma';

export async function GET() {
  const products = await prisma.product.findMany();
  return NextResponse.json({ products });
}

```

----------

### **10. Testing and Validation**

Since we're focusing on logic implementation, it's important to test the application's functionalities.

**Manual Testing**

-   **User Registration and Authentication**: Ensure users can sign up, log in, and log out.
-   **Onboarding Process**: Verify that user preferences are collected and stored correctly.
-   **Product Recommendations**: Confirm that products are recommended based on user preferences.
-   **Gamification Elements**: Test starting quests, updating progress, and rewarding tokens.
-   **Investment Module**: Simulate investments and check that tokens are deducted, and investments are recorded.
-   **Shopping Cart**: Add items to the cart and simulate the checkout process.

**Unit Testing**

-   Use testing frameworks like Jest to write unit tests for utility functions, such as  `adjustTokens`,  `updateQuestProgress`, etc.

**Example Unit Test for Token Adjustment**

```javascript
// tests/tokenManager.test.js

import { adjustTokens } from '../lib/tokenManager';
import { prismaMock } from '../singleton';

test('adjustTokens increments tokens correctly', async () => {
  prismaMock.user.update.mockResolvedValue({ tokens: 150 });

  const userId = 1;
  const amount = 50;
  const result = await adjustTokens(userId, amount);

  expect(prismaMock.user.update).toHaveBeenCalledWith({
    where: { id: userId },
    data: { tokens: { increment: amount } },
  });
});

```

----------

### **Conclusion**

By focusing on implementing the full logic of the application and simplifying data considerations, we've developed a plan that emphasizes the core functionalities of the Sustainable Fashion Recommendation System. We've set aside complex features like notifications and real payment integrations, opting for simpler alternatives to streamline development.

This approach allows for building a functional prototype that can be expanded upon in the future. The key components include:

-   **User Authentication and Onboarding**
-   **Product Catalog and Basic Recommendation Engine**
-   **Gamification Features (Token System, Quests, Achievements)**
-   **Investment Module**
-   **Simplified Shopping Cart with Custom Test Payment**

By simplifying data models and using tools like Zustand for state management, we reduce complexity while maintaining essential functionality. This plan provides a solid foundation for developing the application and validating the core concepts.

----------

**Next Steps**

-   **Implement the outlined components**  according to the plan.
-   **Test each functionality**  thoroughly to ensure correct behavior.
-   **Iterate and refine**  based on testing results and user feedback.

----------

If you require further assistance with specific implementation details or have additional preferences, please let me know!

Add full logic implementation - I have postgres in docker - tell me how to coneect and see the tables.