# Stripe Configuration - Lazy Initialization Approach

## Problem
The "Retour" link on the collect_names page sometimes displayed a Stripe API key error:
```
Erreur de traitement du paiement : No API key provided. Set your API key using "Stripe.api_key = <API-KEY>".
```

## Root Cause
The error occurred because Stripe was being initialized at application startup, and if there were any configuration issues, it would affect the entire application.

## Solution Implemented - Lazy Initialization

1. **Deferred Stripe Initialization** (`config/initializers/stripe.rb`):
   - Stripe configuration is loaded at startup but API key is NOT set
   - Stripe.api_key is only set during the checkout process when needed

2. **Enhanced Stripe Helper** (`app/helpers/stripe_helper.rb`):
   - Added `initialize_stripe` method to initialize Stripe only when needed
   - Updated `safe_stripe_call` to automatically initialize Stripe if not already done

3. **Checkout Process Updates**:
   - Added explicit Stripe initialization in `process_payment` method
   - Added explicit Stripe initialization in `payment_success` method
   - Added proper error handling for initialization failures

4. **Benefits of This Approach**:
   - Stripe is only initialized when actually needed (during checkout)
   - Application startup is not dependent on Stripe service availability
   - Payment-related issues are isolated and don't affect other application features
   - More efficient resource usage (Stripe library only fully loaded during checkout)

5. **Verification**:
   - Created `bin/test_stripe_config.rb` to verify the lazy initialization approach
   - Confirmed that Stripe is not initialized at startup but can be initialized during checkout

## Code Changes

### config/initializers/stripe.rb
- Removed automatic Stripe.api_key initialization
- Added informational log message

### app/helpers/stripe_helper.rb
- Added `initialize_stripe` method
- Enhanced `safe_stripe_call` method

### app/controllers/events_controller.rb
- Added Stripe initialization in `process_payment` method
- Added Stripe initialization in `payment_success` method
- Updated error handling to use helper methods

## Testing
The new approach has been verified to work correctly:
- Stripe is not initialized at application startup
- Stripe is properly initialized during the checkout process
- All Stripe functionality works as expected
- Error handling is improved

This approach provides better isolation of payment functionality and ensures that issues with Stripe configuration don't affect the rest of the application.