# Customer Authentication Implementation

**Date**: 2025-11-24
**Status**: Completed

## Overview

This document describes the implementation of customer authentication for the shop frontend, including login, registration, and account management pages. This work creates a complete separation between customer authentication and admin/vendor authentication systems.

## Problem Statement

The shop frontend needed proper authentication pages (login, registration, forgot password) and a working customer authentication system. The initial implementation had several issues:

1. No styled authentication pages for customers
2. Customer authentication was incorrectly trying to use the User model (admins/vendors)
3. Cookie paths were hardcoded and didn't work with multi-access routing (domain, subdomain, path-based)
4. Vendor detection method was inconsistent between direct path access and API calls via referer

## Solution Architecture

### 1. Customer vs User Separation

**Key Insight**: Customers are NOT users. They are a separate entity in the system.

- **Users** (`models/database/user.py`): Admin and vendor accounts
  - Have `role` field (admin/vendor)
  - Have `username` field
  - Managed via `app/services/auth_service.py`

- **Customers** (`models/database/customer.py`): Shop customers
  - Vendor-scoped (each vendor has independent customers)
  - No `role` or `username` fields
  - Have `customer_number`, `total_orders`, vendor relationship
  - Managed via `app/services/customer_service.py`

### 2. JWT Token Structure

Customer tokens have a distinct structure:

```python
{
    "sub": str(customer.id),           # Customer ID
    "email": customer.email,
    "vendor_id": vendor_id,            # Important: Vendor isolation
    "type": "customer",                # CRITICAL: Distinguishes from User tokens
    "exp": expire_timestamp,
    "iat": issued_at_timestamp,
}
```

User tokens have `type` implicitly set to user role (admin/vendor) and different payload structure.

### 3. Cookie Path Management

Cookies must be set with paths that match how the vendor is accessed:

| Access Method | Example URL | Cookie Path |
|--------------|-------------|-------------|
| Domain | `wizamart.com/shop/account/login` | `/shop` |
| Subdomain | `wizamart.localhost/shop/account/login` | `/shop` |
| Path-based | `localhost/vendors/wizamart/shop/account/login` | `/vendors/wizamart/shop` |

This ensures cookies are only sent to the correct vendor's routes.

## Implementation Details

### Files Created

1. **`app/templates/shop/account/login.html`**
   - Customer login page
   - Extends `shop/base.html` (follows design pattern)
   - Uses Tailwind CSS and Alpine.js
   - Theme-aware styling with CSS variables
   - Two-column layout (branding + form)
   - Form validation and error handling

2. **`app/templates/shop/account/register.html`**
   - Customer registration page
   - Fields: first_name, last_name, email, phone (optional), password
   - Client-side validation
   - Marketing consent checkbox
   - Theme integration

3. **`app/templates/shop/account/forgot-password.html`**
   - Password reset request page
   - Two-state UI (form → success)
   - Email validation

4. **`app/templates/shop/account/dashboard.html`**
   - Customer account dashboard
   - Displays account summary, order statistics
   - Quick links to orders, profile, addresses
   - Logout functionality
   - Follows shop design pattern (extends base.html)

### Important Schema Change

#### `models/schema/auth.py` - Unified Login Schema

Changed the `UserLogin` schema to use `email_or_username` instead of `username` to support both username and email login across all contexts (admin, vendor, and customer).

**Before**:
```python
class UserLogin(BaseModel):
    username: str
    password: str
```

**After**:
```python
class UserLogin(BaseModel):
    email_or_username: str = Field(..., description="Username or email address")
    password: str
    vendor_code: Optional[str] = Field(None, description="Optional vendor code for context")
```

**Impact**: This change affects all login endpoints:
- Admin login: `/api/v1/admin/auth/login`
- Vendor login: `/api/v1/vendor/auth/login`
- Customer login: `/api/v1/shop/auth/login`

**Updated Files**:
- `app/services/auth_service.py` - Changed `user_credentials.username` to `user_credentials.email_or_username`
- `app/api/v1/admin/auth.py` - Updated logging to use `email_or_username`
- `static/admin/js/login.js` - Send `email_or_username` in payload
- `static/vendor/js/login.js` - Send `email_or_username` in payload

### Files Modified

#### 1. `app/api/v1/shop/auth.py`

**Changes**:
- Added `CustomerLoginResponse` model (uses `CustomerResponse` instead of `UserResponse`)
- Updated `customer_login` endpoint to:
  - Calculate cookie path dynamically based on vendor access method
  - Set cookie with correct path for multi-access support
  - Return `CustomerLoginResponse` with proper customer data
- Updated `customer_logout` endpoint to calculate cookie path dynamically

**Key Code**:
```python
# Calculate cookie path based on vendor access method
vendor_context = getattr(request.state, 'vendor_context', None)
access_method = vendor_context.get('detection_method', 'unknown') if vendor_context else 'unknown'

cookie_path = "/shop"  # Default for domain/subdomain access
if access_method == "path":
    # For path-based access like /vendors/wizamart/shop
    full_prefix = vendor_context.get('full_prefix', '/vendor/') if vendor_context else '/vendor/'
    cookie_path = f"{full_prefix}{vendor.subdomain}/shop"

response.set_cookie(
    key="customer_token",
    value=token,
    httponly=True,
    secure=should_use_secure_cookies(),
    samesite="lax",
    max_age=expires_in,
    path=cookie_path,  # Dynamic path
)
```

#### 2. `app/services/customer_service.py`

**Changes**:
- Updated `login_customer` to create JWT tokens directly using `auth_manager`
- No longer tries to use `auth_service.create_access_token()` (that's for Users only)
- Directly uses `jose.jwt.encode()` with custom customer payload

**Key Code**:
```python
from jose import jwt
from datetime import datetime, timedelta, timezone

auth_manager = self.auth_service.auth_manager
expires_delta = timedelta(minutes=auth_manager.token_expire_minutes)
expire = datetime.now(timezone.utc) + expires_delta

payload = {
    "sub": str(customer.id),
    "email": customer.email,
    "vendor_id": vendor_id,
    "type": "customer",  # Critical distinction
    "exp": expire,
    "iat": datetime.now(timezone.utc),
}

token = jwt.encode(payload, auth_manager.secret_key, algorithm=auth_manager.algorithm)
```

#### 3. `app/api/deps.py`

**Major Rewrite**: `get_current_customer_from_cookie_or_header`

**Before**: Tried to validate customer tokens as User tokens, expected `role` field

**After**:
- Decodes JWT manually
- Validates `type == "customer"` in payload
- Loads Customer from database (not User)
- Returns Customer object

**Key Code**:
```python
def get_current_customer_from_cookie_or_header(
        request: Request,
        credentials: Optional[HTTPAuthorizationCredentials] = Depends(security),
        customer_token: Optional[str] = Cookie(None),
        db: Session = Depends(get_db),
):
    from models.database.customer import Customer
    from jose import jwt, JWTError

    token, source = _get_token_from_request(...)

    if not token:
        raise InvalidTokenException("Customer authentication required")

    # Decode and validate customer JWT token
    payload = jwt.decode(token, auth_manager.secret_key, algorithms=[auth_manager.algorithm])

    # Verify this is a customer token
    if payload.get("type") != "customer":
        raise InvalidTokenException("Customer authentication required")

    customer_id = payload.get("sub")
    customer = db.query(Customer).filter(Customer.id == int(customer_id)).first()

    if not customer or not customer.is_active:
        raise InvalidTokenException("Customer not found or inactive")

    return customer  # Returns Customer, not User
```

#### 4. `app/routes/shop_pages.py`

**Changes**:
- Changed import from `User` to `Customer`
- Updated all protected route handlers:
  - Changed parameter type from `current_user: User` to `current_customer: Customer`
  - Updated function calls from `user=current_user` to `user=current_customer`

**Affected Routes**:
- `/account/dashboard`
- `/account/orders`
- `/account/orders/{order_id}`
- `/account/profile`
- `/account/addresses`
- `/account/wishlist`
- `/account/reviews`

#### 5. `middleware/vendor_context.py`

**Critical Fix**: Harmonized vendor detection methods

**Problem**:
- Direct page access: `detection_method = "path"`
- API call via referer: `detection_method = "referer_path"`
- This inconsistency broke cookie path calculation

**Solution**:
When detecting vendor from referer path, use the same `detection_method = "path"` and include the same fields (`full_prefix`, `path_prefix`) as direct path detection.

**Key Code**:
```python
# Method 1: Path-based detection from referer path
if referer_path.startswith("/vendors/") or referer_path.startswith("/vendor/"):
    prefix = "/vendors/" if referer_path.startswith("/vendors/") else "/vendor/"
    path_parts = referer_path[len(prefix):].split("/")
    if len(path_parts) >= 1 and path_parts[0]:
        vendor_code = path_parts[0]
        prefix_len = len(prefix)

        # Use "path" as detection_method to be consistent with direct path detection
        return {
            "subdomain": vendor_code,
            "detection_method": "path",  # Consistent!
            "path_prefix": referer_path[:prefix_len + len(vendor_code)],
            "full_prefix": prefix,
            "host": referer_host,
            "referer": referer,
        }
```

#### 6. `app/exceptions/handler.py`

**Changes**:
- Password sanitization in validation error logging
- Already had proper redirect logic for customer login (no changes needed)

#### 7. `models/schema/auth.py`

**Changes**:
- Updated `UserLogin` schema to accept `email_or_username` instead of `username`
- This allows customers to login with email (they don't have usernames)

### Multi-Access Routing Support

The implementation properly supports all three vendor access methods:

#### Domain-based Access
```
URL: https://wizamart.com/shop/account/login
Cookie Path: /shop
Cookie Sent To: https://wizamart.com/shop/*
```

#### Subdomain-based Access
```
URL: https://wizamart.myplatform.com/shop/account/login
Cookie Path: /shop
Cookie Sent To: https://wizamart.myplatform.com/shop/*
```

#### Path-based Access
```
URL: https://myplatform.com/vendors/wizamart/shop/account/login
Cookie Path: /vendors/wizamart/shop
Cookie Sent To: https://myplatform.com/vendors/wizamart/shop/*
```

## Authentication Flow

### Login Flow

1. **User loads login page** → `GET /vendors/wizamart/shop/account/login`
   - Middleware detects vendor from path
   - Sets `detection_method = "path"` in vendor_context
   - Renders login template

2. **User submits credentials** → `POST /api/v1/shop/auth/login`
   - Middleware detects vendor from Referer header
   - Sets `detection_method = "path"` (harmonized!)
   - Validates credentials via `customer_service.login_customer()`
   - Creates JWT token with `type: "customer"`
   - Calculates cookie path based on access method
   - Sets `customer_token` cookie with correct path
   - Returns token + customer data

3. **Browser redirects to dashboard** → `GET /vendors/wizamart/shop/account/dashboard`
   - Browser sends `customer_token` cookie (path matches!)
   - Dependency `get_current_customer_from_cookie_or_header` extracts token
   - Decodes JWT, validates `type == "customer"`
   - Loads Customer from database
   - Renders dashboard with customer data

### Logout Flow

1. **User clicks logout button** → Shows Tailwind modal confirmation
   - Custom modal (not browser confirm dialog)
   - Alpine.js state management
   - Smooth animations with transitions
   - Dark mode support

2. **User confirms logout** → `POST /api/v1/shop/auth/logout`
   - Calculates cookie path (same logic as login)
   - Deletes cookie with matching path
   - Returns success message

3. **Frontend redirects to login page**
   - Shows success toast notification
   - Clears localStorage token
   - Redirects after 500ms delay

## Security Features

### Cookie Security

```python
response.set_cookie(
    key="customer_token",
    value=token,
    httponly=True,        # JavaScript cannot access (XSS protection)
    secure=True,          # HTTPS only (production/staging)
    samesite="lax",       # CSRF protection
    max_age=1800,         # 30 minutes (matches JWT expiry)
    path=cookie_path,     # Restricted to vendor's shop routes
)
```

### Token Validation

- JWT expiration checked
- Customer active status verified
- Token type validated (`type == "customer"`)
- Vendor isolation enforced (customer must belong to vendor)

### Password Security

- Bcrypt hashing via `auth_manager.hash_password()`
- Validation errors sanitized (passwords never logged)
- Minimum password length enforced

## Design Patterns Followed

### Frontend Templates

All authentication pages follow the shop template pattern:

```jinja2
{% extends "shop/base.html" %}

{% block title %}Page Title{% endblock %}

{% block alpine_data %}componentName(){% endblock %}

{% block content %}
<!-- Page content -->
{% endblock %}

{% block extra_scripts %}
<script>
function componentName() {
    return {
        ...shopLayoutData(),
        // Component-specific data/methods
    }
}
</script>
{% endblock %}
```

**Benefits**:
- Consistent header/footer/navigation
- Theme CSS variables automatically injected
- Dark mode support
- Mobile responsive
- Alpine.js component pattern

### Service Layer

- Customer operations in `customer_service.py`
- Auth operations in `auth_service.py`
- Clear separation of concerns
- Database operations via SQLAlchemy ORM

### Exception Handling

- Custom exceptions for customer-specific errors
- Consistent error responses (JSON for API, HTML for pages)
- Automatic redirect to login on 401 for HTML page requests

### UI Components

#### Logout Confirmation Modal

Custom Tailwind CSS modal for logout confirmation instead of browser's native `confirm()` dialog.

**Features**:
- Beautiful animated modal with backdrop overlay
- Warning icon (red triangle with exclamation mark)
- Clear confirmation message
- Two action buttons: "Logout" (red) and "Cancel" (gray)
- Dark mode support
- Mobile responsive
- Keyboard accessible (ARIA attributes)
- Click backdrop to dismiss

**Implementation**:
```html
<!-- Modal trigger -->
<button @click="showLogoutModal = true">Logout</button>

<!-- Modal component -->
<div x-show="showLogoutModal" x-cloak class="fixed inset-0 z-50">
    <!-- Backdrop with fade animation -->
    <div x-show="showLogoutModal"
         x-transition:enter="ease-out duration-300"
         x-transition:enter-start="opacity-0"
         x-transition:enter-end="opacity-100"
         @click="showLogoutModal = false"
         class="fixed inset-0 bg-gray-500 bg-opacity-75">
    </div>

    <!-- Modal panel with slide+scale animation -->
    <div x-show="showLogoutModal"
         x-transition:enter="ease-out duration-300"
         x-transition:enter-start="opacity-0 scale-95"
         x-transition:enter-end="opacity-100 scale-100"
         class="bg-white dark:bg-gray-800 rounded-lg">
        <!-- Modal content -->
    </div>
</div>
```

**Alpine.js Component**:
```javascript
function accountDashboard() {
    return {
        ...shopLayoutData(),
        showLogoutModal: false,  // Modal state

        confirmLogout() {
            this.showLogoutModal = false;
            // Perform logout API call
            // Show toast notification
            // Redirect to login
        }
    }
}
```

**Why Custom Modal vs Browser Confirm**:
- ✅ Consistent with design system
- ✅ Customizable styling and animations
- ✅ Dark mode support
- ✅ Better mobile experience
- ✅ More professional appearance
- ✅ Accessible (ARIA labels, keyboard navigation)
- ❌ Browser confirm: Cannot be styled, looks dated, poor mobile UX

## Testing Checklist

- [x] Customer can register new account
- [x] Customer can login with email/password
- [x] Admin can login with username (using unified schema)
- [x] Vendor can login with username (using unified schema)
- [x] Cookie is set with correct path for path-based access
- [x] Cookie is sent on subsequent requests to dashboard
- [x] Customer authentication dependency validates token correctly
- [x] Dashboard loads with customer data
- [x] Customer can logout
- [x] Logout confirmation modal displays correctly
- [x] Modal has smooth animations and transitions
- [x] Modal supports dark mode
- [x] Toast notification shows on logout
- [x] Cookie is properly deleted on logout
- [x] Unauthorized access redirects to login
- [x] Theme styling is applied correctly
- [x] Dark mode works
- [x] Mobile responsive layout
- [x] Admin/vendor login button spinner aligns correctly

## Known Limitations

1. **Password Reset Not Implemented**: `forgot-password` and `reset-password` endpoints are placeholders (TODO comments in code)

2. **Email Verification Not Implemented**: Customers are immediately active after registration

3. **Session Management**: No refresh tokens, single JWT with 30-minute expiry

4. **Account Pages Are Placeholders**:
   - `/account/orders` - needs order history implementation
   - `/account/profile` - needs profile editing implementation
   - `/account/addresses` - needs address management implementation

## Future Enhancements

1. **Password Reset Flow**:
   - Generate secure reset tokens
   - Send password reset emails
   - Token expiry and validation
   - Password reset form

2. **Email Verification**:
   - Send verification email on registration
   - Verification token validation
   - Resend verification email

3. **Account Management**:
   - Edit profile (name, email, phone)
   - Change password
   - Manage addresses (CRUD)
   - View order history with filtering/search
   - Order tracking

4. **Security Enhancements**:
   - Refresh tokens for longer sessions
   - Rate limiting on login/registration
   - Account lockout after failed attempts
   - 2FA/MFA support

5. **User Experience**:
   - Remember me functionality
   - Social login (OAuth)
   - Progressive disclosure of forms
   - Better error messages

## References

- **Customer Model**: `models/database/customer.py`
- **Customer Service**: `app/services/customer_service.py`
- **Auth Endpoints**: `app/api/v1/shop/auth.py`
- **Auth Dependencies**: `app/api/deps.py`
- **Shop Routes**: `app/routes/shop_pages.py`
- **Vendor Context**: `middleware/vendor_context.py`
- **Templates**: `app/templates/shop/account/`

## Deployment Notes

### Environment Variables

No new environment variables required. Uses existing:
- `JWT_SECRET_KEY` - for token signing
- `JWT_EXPIRE_MINUTES` - token expiry (default: 30)
- `ENVIRONMENT` - for secure cookie setting

### Database

No migrations required. Uses existing `customer` table.

### Static Files

Ensure these files exist:
- `static/shared/js/log-config.js`
- `static/shared/js/icons.js`
- `static/shop/js/shop-layout.js`
- `static/shared/js/utils.js`
- `static/shared/js/api-client.js`
- `static/shop/css/shop.css`

## Troubleshooting

### Issue: "No token for path"

**Cause**: Cookie path doesn't match request path

**Solution**:
- Check vendor context middleware is running
- Verify `detection_method` is set correctly
- Confirm cookie path calculation includes vendor subdomain for path-based access

### Issue: "Invalid token type"

**Cause**: Trying to use User token for customer route or vice versa

**Solution**:
- Ensure customer login creates token with `type: "customer"`
- Verify dependency checks `type == "customer"`

### Issue: Cookie not sent by browser

**Cause**: Cookie path doesn't match or cookie expired

**Solution**:
- Check browser DevTools → Application → Cookies
- Verify cookie path matches request URL
- Check cookie expiry timestamp

## Summary

This implementation establishes a complete customer authentication system that is:

✅ **Secure**: HTTP-only cookies, CSRF protection, password hashing
✅ **Scalable**: Multi-tenant with vendor isolation
✅ **Flexible**: Supports domain, subdomain, and path-based access
✅ **Maintainable**: Clear separation of concerns, follows established patterns
✅ **User-Friendly**: Responsive design, theme integration, proper UX flows

The key architectural decision was recognizing that customers and users are fundamentally different entities requiring separate authentication flows, token structures, and database models.
