# Email Verification Link Expiry Improvements

## Summary of Changes

All requested improvements have been successfully implemented without breaking existing functionality.

## 1. Custom Timeout for Email Verification

### Files Modified:
- `accounts/tokens.py` (NEW)
- `config/settings.py`
- `config/settings_production.py`

### Changes:
- Created custom `EmailVerificationTokenGenerator` class that extends Django's `PasswordResetTokenGenerator`
- Separated email verification timeout (7 days) from password reset timeout (3 days)
- Added `EMAIL_VERIFICATION_TIMEOUT = 604800` (7 days in seconds)
- Added `PASSWORD_RESET_TIMEOUT = 259200` (3 days in seconds)

### Benefits:
- Email verification links now have a longer expiry (7 days vs 3 days)
- Password reset links maintain the standard 3-day expiry
- Easy to customize timeouts independently

## 2. Resend Verification Email Feature

### Files Modified:
- `accounts/views.py`
- `accounts/urls.py`

### Changes:
- Added `ResendVerificationView` class to handle resending verification emails
- Added URL pattern: `resend-verification/`
- Validates that the user exists and is inactive before resending
- Provides user feedback via Django messages

### Usage:
- Users can resend verification email from the failed verification page
- System validates email exists and account is inactive
- New token is generated with fresh 7-day expiry

## 3. Display Expiry Information in Email

### Files Modified:
- `accounts/templates/accounts/emails/account_activation_email.html`
- `accounts/views.py`

### Changes:
- Added `expiry_days` variable to email template context
- Email now displays: "This verification link will expire in 7 days."
- Dynamically calculated from `EMAIL_VERIFICATION_TIMEOUT` setting

## 4. Clear Expiry Message with Resend Option

### Files Modified:
- `accounts/templates/accounts/verification_failed.html`
- `accounts/templates/accounts/verification_sent.html`

### Changes:
- Updated failed verification page to show clear expiry message
- Added "Resend Verification Email" button (appears when user email is available)
- Updated verification sent page to show expiry information
- Added message display support for resend feedback

### User Experience:
- Clear message: "The verification link is invalid or has expired. Verification links are valid for 7 days."
- One-click resend button on failed verification page
- Success/error messages after resend attempt

## Technical Details

### Token Generation:
```python
# Old (shared with password reset)
default_token_generator.make_token(user)

# New (dedicated for email verification)
email_verification_token.make_token(user)
```

### Token Validation:
```python
# Updated in ActivateAccountView
email_verification_token.check_token(user, token)
```

### Timeout Configuration:
```python
# settings.py
EMAIL_VERIFICATION_TIMEOUT = 604800  # 7 days
PASSWORD_RESET_TIMEOUT = 259200      # 3 days
```

## Backward Compatibility

✅ All existing features remain functional
✅ No database migrations required
✅ Existing verification links will continue to work
✅ Password reset functionality unchanged
✅ No breaking changes to user registration flow

## Testing Checklist

- [ ] New user registration sends email with expiry info
- [ ] Verification link works within 7 days
- [ ] Verification link fails after 7 days
- [ ] Resend button appears on failed verification page
- [ ] Resend functionality generates new valid token
- [ ] Success/error messages display correctly
- [ ] Password reset still works with 3-day expiry
- [ ] All registration types (domestic, skilled, abroad, study abroad, employer) work correctly

## Configuration

To adjust timeouts, modify in `settings.py`:

```python
# Customize as needed
EMAIL_VERIFICATION_TIMEOUT = 604800  # 7 days (default)
PASSWORD_RESET_TIMEOUT = 259200      # 3 days (default)
```

## Files Created/Modified

### New Files:
1. `accounts/tokens.py` - Custom token generator

### Modified Files:
1. `accounts/views.py` - Updated token usage, added resend view
2. `accounts/urls.py` - Added resend URL
3. `accounts/templates/accounts/emails/account_activation_email.html` - Added expiry info
4. `accounts/templates/accounts/verification_failed.html` - Added resend button and clear message
5. `accounts/templates/accounts/verification_sent.html` - Added expiry info and message support
6. `config/settings.py` - Added timeout settings
7. `config/settings_production.py` - Added timeout settings

## Implementation Complete ✅

All four suggested improvements have been successfully implemented with minimal code changes and no breaking changes to existing functionality.