# Email Settings Implementation

This document describes the technical implementation of the email settings system for both vendor and platform (admin) configurations.

## Architecture Overview

```
┌─────────────────────────────────────────────────────────────────────────┐
│                          Email System Architecture                       │
├─────────────────────────────────────────────────────────────────────────┤
│                                                                          │
│  ┌──────────────────┐        ┌──────────────────┐                       │
│  │  Platform Email  │        │   Vendor Email    │                       │
│  │   (Admin/Billing)│        │ (Customer-facing) │                       │
│  └────────┬─────────┘        └────────┬─────────┘                       │
│           │                           │                                  │
│           ▼                           ▼                                  │
│  ┌──────────────────┐        ┌──────────────────┐                       │
│  │ get_platform_    │        │ get_vendor_      │                       │
│  │ email_config(db) │        │ provider()       │                       │
│  └────────┬─────────┘        └────────┬─────────┘                       │
│           │                           │                                  │
│           ▼                           ▼                                  │
│  ┌──────────────────┐        ┌──────────────────┐                       │
│  │ AdminSettings DB │        │VendorEmailSettings│                       │
│  │    (.env fallback)│        │     (per vendor) │                       │
│  └────────┬─────────┘        └────────┬─────────┘                       │
│           │                           │                                  │
│           └───────────┬───────────────┘                                  │
│                       ▼                                                  │
│              ┌──────────────────┐                                        │
│              │   EmailService   │                                        │
│              │    send_raw()    │                                        │
│              └────────┬─────────┘                                        │
│                       │                                                  │
│                       ▼                                                  │
│              ┌──────────────────┐                                        │
│              │  Email Providers │                                        │
│              │ SMTP/SG/MG/SES  │                                        │
│              └──────────────────┘                                        │
└─────────────────────────────────────────────────────────────────────────┘
```

## Database Models

### VendorEmailSettings

```python
# models/database/vendor_email_settings.py

class VendorEmailSettings(Base):
    __tablename__ = "vendor_email_settings"

    id: int
    vendor_id: int  # FK to vendors.id (one-to-one)

    # Sender Identity
    from_email: str
    from_name: str
    reply_to_email: str | None

    # Signature
    signature_text: str | None
    signature_html: str | None

    # Provider
    provider: str = "smtp"  # smtp, sendgrid, mailgun, ses

    # SMTP Settings
    smtp_host: str | None
    smtp_port: int = 587
    smtp_username: str | None
    smtp_password: str | None
    smtp_use_tls: bool = True
    smtp_use_ssl: bool = False

    # SendGrid
    sendgrid_api_key: str | None

    # Mailgun
    mailgun_api_key: str | None
    mailgun_domain: str | None

    # SES
    ses_access_key_id: str | None
    ses_secret_access_key: str | None
    ses_region: str = "eu-west-1"

    # Status
    is_configured: bool = False
    is_verified: bool = False
    last_verified_at: datetime | None
    verification_error: str | None
```

### Admin Settings (Platform Email)

Platform email settings are stored in the generic `admin_settings` table with category="email":

```python
# Keys stored in admin_settings table
EMAIL_SETTING_KEYS = {
    "email_provider",
    "email_from_address",
    "email_from_name",
    "email_reply_to",
    "smtp_host",
    "smtp_port",
    "smtp_user",
    "smtp_password",
    "smtp_use_tls",
    "smtp_use_ssl",
    "sendgrid_api_key",
    "mailgun_api_key",
    "mailgun_domain",
    "aws_access_key_id",
    "aws_secret_access_key",
    "aws_region",
    "email_enabled",
    "email_debug",
}
```

## API Endpoints

### Vendor Email Settings

| Endpoint | Method | Description |
|----------|--------|-------------|
| `/api/v1/vendor/email-settings` | GET | Get current email settings |
| `/api/v1/vendor/email-settings` | PUT | Create/update email settings |
| `/api/v1/vendor/email-settings` | DELETE | Delete email settings |
| `/api/v1/vendor/email-settings/status` | GET | Get configuration status |
| `/api/v1/vendor/email-settings/providers` | GET | Get available providers for tier |
| `/api/v1/vendor/email-settings/verify` | POST | Send test email |

### Admin Email Settings

| Endpoint | Method | Description |
|----------|--------|-------------|
| `/api/v1/admin/settings/email/status` | GET | Get effective email config |
| `/api/v1/admin/settings/email/settings` | PUT | Update email settings in DB |
| `/api/v1/admin/settings/email/settings` | DELETE | Reset to .env defaults |
| `/api/v1/admin/settings/email/test` | POST | Send test email |

## Services

### VendorEmailSettingsService

Location: `app/services/vendor_email_settings_service.py`

Key methods:
- `get_settings(vendor_id)` - Get settings for a vendor
- `create_or_update(vendor_id, data, current_tier)` - Create/update settings
- `delete(vendor_id)` - Delete settings
- `verify_settings(vendor_id, test_email)` - Send test email
- `get_available_providers(tier)` - Get providers for subscription tier

### EmailService Integration

The EmailService (`app/services/email_service.py`) uses:

1. **Platform Config**: `get_platform_email_config(db)` checks database first, then .env
2. **Vendor Config**: `get_vendor_provider(settings)` creates provider from VendorEmailSettings
3. **Provider Selection**: `send_raw()` uses vendor provider when `vendor_id` provided and `is_platform_email=False`

```python
# EmailService.send_raw() flow
def send_raw(self, to_email, subject, body_html, vendor_id=None, is_platform_email=False):
    if vendor_id and not is_platform_email:
        # Use vendor's email provider
        vendor_settings = self._get_vendor_email_settings(vendor_id)
        if vendor_settings and vendor_settings.is_configured:
            provider = get_vendor_provider(vendor_settings)
    else:
        # Use platform provider (DB config > .env)
        provider = self.provider  # Set in __init__ via get_platform_provider(db)
```

## Tier-Based Features

### Premium Provider Gating

Premium providers (SendGrid, Mailgun, SES) are gated to Business+ tiers:

```python
PREMIUM_EMAIL_PROVIDERS = {EmailProvider.SENDGRID, EmailProvider.MAILGUN, EmailProvider.SES}
PREMIUM_TIERS = {TierCode.BUSINESS, TierCode.ENTERPRISE}

def create_or_update(self, vendor_id, data, current_tier):
    provider = data.get("provider", "smtp")
    if provider in [p.value for p in PREMIUM_EMAIL_PROVIDERS]:
        if current_tier not in PREMIUM_TIERS:
            raise AuthorizationException(...)
```

### White-Label Branding

Emails include "Powered by Wizamart" footer for non-whitelabel tiers:

```python
WHITELABEL_TIERS = {"business", "enterprise"}

POWERED_BY_FOOTER_HTML = """
<div style="margin-top: 30px; ...">
    <p>Powered by <a href="https://wizamart.com">Wizamart</a></p>
</div>
"""

def _inject_powered_by_footer(self, body_html, vendor_id):
    tier = self._get_vendor_tier(vendor_id)
    if tier and tier.lower() in WHITELABEL_TIERS:
        return body_html  # No footer for business/enterprise
    return body_html.replace("</body>", f"{POWERED_BY_FOOTER_HTML}</body>")
```

## Configuration Priority

### Platform Email

1. **Database** (admin_settings table) - Highest priority
2. **Environment Variables** (.env) - Fallback

```python
def get_platform_email_config(db: Session) -> dict:
    def get_db_setting(key: str) -> str | None:
        setting = db.query(AdminSetting).filter(AdminSetting.key == key).first()
        return setting.value if setting else None

    # Check DB first, fallback to .env
    db_provider = get_db_setting("email_provider")
    config["provider"] = db_provider if db_provider else settings.email_provider
    ...
```

### Vendor Email

Vendors have their own dedicated settings table with no fallback - they must configure their own email.

## Frontend Components

### Vendor Settings Page

- **Location**: `app/templates/vendor/settings.html`, `static/vendor/js/settings.js`
- **Alpine.js State**: `emailSettings`, `emailForm`, `hasEmailChanges`
- **Methods**: `loadEmailSettings()`, `saveEmailSettings()`, `sendTestEmail()`

### Admin Settings Page

- **Location**: `app/templates/admin/settings.html`, `static/admin/js/settings.js`
- **Alpine.js State**: `emailSettings`, `emailForm`, `emailEditMode`
- **Methods**: `loadEmailSettings()`, `saveEmailSettings()`, `resetEmailSettings()`, `sendTestEmail()`

### Warning Banner

Shows until email is configured:

```html
<!-- app/templates/shared/macros/feature_gate.html -->
{% macro email_settings_warning() %}
<div x-data="emailSettingsWarning()" x-show="showWarning">
    Configure email settings to send emails to customers.
</div>
{% endmacro %}
```

## Testing

### Unit Tests

Location: `tests/unit/services/test_vendor_email_settings_service.py`

Tests:
- Read operations (get_settings, get_status, is_configured)
- Write operations (create_or_update, delete)
- Tier validation (premium providers)
- Verification (mock SMTP)
- Provider availability

### Integration Tests

Locations:
- `tests/integration/api/v1/vendor/test_email_settings.py`
- `tests/integration/api/v1/admin/test_email_settings.py`

Tests:
- CRUD operations via API
- Authentication/authorization
- Validation errors
- Status endpoints

## Files Modified/Created

### New Files
- `models/database/vendor_email_settings.py` - Model
- `alembic/versions/v0a1b2c3d4e5_add_vendor_email_settings.py` - Migration
- `app/services/vendor_email_settings_service.py` - Service
- `app/api/v1/vendor/email_settings.py` - API endpoints
- `scripts/install.py` - Installation wizard

### Modified Files
- `app/services/email_service.py` - Added platform config, vendor providers
- `app/api/v1/admin/settings.py` - Added email endpoints
- `app/templates/admin/settings.html` - Email tab
- `app/templates/vendor/settings.html` - Email tab
- `static/admin/js/settings.js` - Email JS
- `static/vendor/js/settings.js` - Email JS
- `static/vendor/js/init-alpine.js` - Warning banner component