# Advanced Analytics Implementation - Change Summary

## Overview

Successfully implemented the Advanced Analytics feature with permission-based access control in the Django backend. All analytics endpoints are gated behind the `advanced_analytics` permission from the subscription plan.

## Files Created

### Analytics App (`/smoothschedule/analytics/`)

1. **`__init__.py`** - Package initialization
2. **`apps.py`** - Django app configuration
3. **`admin.py`** - Admin interface (read-only app, no models)
4. **`views.py`** - AnalyticsViewSet with 3 endpoints:
   - `dashboard()` - Summary statistics
   - `appointments()` - Detailed appointment analytics
   - `revenue()` - Revenue analytics (dual-permission gated)
5. **`serializers.py`** - Response serializers for data validation
6. **`urls.py`** - URL routing
7. **`tests.py`** - Comprehensive pytest test suite
8. **`migrations/`** - Empty migrations directory
9. **`README.md`** - Full API documentation
10. **`IMPLEMENTATION_GUIDE.md`** - Developer implementation guide

## Files Modified

### 1. `/smoothschedule/core/permissions.py`

**Changes:**
- Added `advanced_analytics` and `advanced_reporting` to the `FEATURE_NAMES` dictionary in `HasFeaturePermission`

**Before:**
```python
FEATURE_NAMES = {
    'can_use_sms_reminders': 'SMS Reminders',
    ...
    'can_use_calendar_sync': 'Calendar Sync',
}
```

**After:**
```python
FEATURE_NAMES = {
    'can_use_sms_reminders': 'SMS Reminders',
    ...
    'can_use_calendar_sync': 'Calendar Sync',
    'advanced_analytics': 'Advanced Analytics',
    'advanced_reporting': 'Advanced Reporting',
}
```

### 2. `/smoothschedule/config/urls.py`

**Changes:**
- Added analytics URL include in the API URL patterns

**Before:**
```python
# Schedule API (internal)
path("", include("schedule.urls")),
# Payments API
path("payments/", include("payments.urls")),
```

**After:**
```python
# Schedule API (internal)
path("", include("schedule.urls")),
# Analytics API
path("", include("analytics.urls")),
# Payments API
path("payments/", include("payments.urls")),
```

### 3. `/smoothschedule/config/settings/base.py`

**Changes:**
- Added `analytics` app to `LOCAL_APPS`

**Before:**
```python
LOCAL_APPS = [
    "smoothschedule.users",
    "core",
    "schedule",
    "payments",
    ...
]
```

**After:**
```python
LOCAL_APPS = [
    "smoothschedule.users",
    "core",
    "schedule",
    "analytics",
    "payments",
    ...
]
```

## API Endpoints

All endpoints are located at `/api/analytics/` and require:
- Authentication via token or session
- `advanced_analytics` permission in tenant's subscription plan

### 1. Dashboard Summary
```
GET /api/analytics/analytics/dashboard/
```

Returns:
- Total appointments (this month and all-time)
- Active resources and services count
- Upcoming appointments
- Average appointment duration
- Peak booking day and hour

### 2. Appointment Analytics
```
GET /api/analytics/analytics/appointments/
```

Query Parameters:
- `days` (default: 30)
- `status` (optional: confirmed, cancelled, no_show)
- `service_id` (optional)
- `resource_id` (optional)

Returns:
- Total appointments
- Breakdown by status
- Breakdown by service and resource
- Daily breakdown
- Booking trends and rates

### 3. Revenue Analytics
```
GET /api/analytics/analytics/revenue/
```

Query Parameters:
- `days` (default: 30)
- `service_id` (optional)

Returns:
- Total revenue in cents
- Transaction count
- Average transaction value
- Revenue by service
- Daily breakdown

**Note:** Requires both `advanced_analytics` AND `can_accept_payments` permissions

## Permission Gating Implementation

### How It Works

1. **Request arrives at endpoint**
2. **IsAuthenticated check** - Verifies user is logged in
3. **HasFeaturePermission('advanced_analytics') check**:
   - Gets tenant from request
   - Calls `tenant.has_feature('advanced_analytics')`
   - Checks both direct field and subscription plan JSON
4. **If permission exists** - View logic executes
5. **If permission missing** - 403 Forbidden returned with message

### Permission Check Logic

```python
# In core/models.py - Tenant.has_feature()
def has_feature(self, permission_key):
    # Check direct field on Tenant model
    if hasattr(self, permission_key):
        return bool(getattr(self, permission_key))

    # Check subscription plan permissions JSON
    if self.subscription_plan:
        plan_perms = self.subscription_plan.permissions or {}
        return bool(plan_perms.get(permission_key, False))

    return False
```

## Enabling Analytics for a Plan

### Via Django Admin
1. Go to `/admin/platform_admin/subscriptionplan/`
2. Edit a plan
3. Add to "Permissions" JSON field:
```json
{
    "advanced_analytics": true
}
```

### Via Django Shell
```bash
docker compose -f docker-compose.local.yml exec django python manage.py shell

from platform_admin.models import SubscriptionPlan
plan = SubscriptionPlan.objects.get(name='Professional')
perms = plan.permissions or {}
perms['advanced_analytics'] = True
plan.permissions = perms
plan.save()
```

## Testing

### Permission Tests Included

The `analytics/tests.py` file includes comprehensive tests:

1. **TestAnalyticsPermissions**
   - `test_analytics_requires_authentication` - 401 without auth
   - `test_analytics_denied_without_permission` - 403 without permission
   - `test_analytics_allowed_with_permission` - 200 with permission
   - `test_dashboard_endpoint_structure` - Verify response structure
   - `test_appointments_endpoint_with_filters` - Query parameters work
   - `test_revenue_requires_payments_permission` - Dual permission check
   - `test_multiple_permission_check` - Both checks enforced

2. **TestAnalyticsData**
   - `test_dashboard_counts_appointments_correctly` - Correct counts
   - `test_appointments_counts_by_status` - Status breakdown
   - `test_cancellation_rate_calculation` - Rate calculation

### Running Tests

```bash
# Run all analytics tests
docker compose -f docker-compose.local.yml exec django pytest analytics/tests.py -v

# Run specific test
docker compose -f docker-compose.local.yml exec django pytest analytics/tests.py::TestAnalyticsPermissions::test_analytics_denied_without_permission -v

# Run with coverage
docker compose -f docker-compose.local.yml exec django pytest analytics/tests.py --cov=analytics
```

## Error Responses

### 401 Unauthorized (No Authentication)
```json
{
    "detail": "Authentication credentials were not provided."
}
```

### 403 Forbidden (No Permission)
```json
{
    "detail": "Your current plan does not include Advanced Analytics. Please upgrade your subscription to access this feature."
}
```

### 403 Forbidden (Revenue Endpoint - Missing Payments Permission)
```json
{
    "error": "Payment analytics not available",
    "detail": "Your plan does not include payment processing."
}
```

## Example Usage

### Get Dashboard Stats (with cURL)
```bash
TOKEN="your_auth_token_here"

curl -H "Authorization: Token $TOKEN" \
    http://lvh.me:8000/api/analytics/analytics/dashboard/ | jq
```

### Get Appointment Analytics (with filters)
```bash
curl -H "Authorization: Token $TOKEN" \
    "http://lvh.me:8000/api/analytics/analytics/appointments/?days=7&status=confirmed" | jq
```

### Get Revenue Analytics
```bash
curl -H "Authorization: Token $TOKEN" \
    http://lvh.me:8000/api/analytics/analytics/revenue/ | jq
```

## Key Design Decisions

1. **ViewSet without models** - Analytics is calculated on-the-fly, no database models
2. **Read-only endpoints** - No POST/PUT/DELETE, only GET for querying
3. **Comprehensive permission naming** - Both `advanced_analytics` and `advanced_reporting` supported for flexibility
4. **Dual permission check** - Revenue endpoint requires both analytics and payments permissions
5. **Query parameter filtering** - Flexible filtering for reports
6. **Detailed error messages** - User-friendly upgrade prompts

## Documentation Provided

1. **README.md** - Complete API documentation with examples
2. **IMPLEMENTATION_GUIDE.md** - Developer guide for enabling and debugging
3. **Code comments** - Detailed docstrings in views and serializers
4. **Test file** - Comprehensive test suite with examples

## Next Steps

1. **Migrate** - No migrations needed (no database models)
2. **Configure Plans** - Add `advanced_analytics` permission to desired subscription plans
3. **Test** - Run the test suite to verify functionality
4. **Deploy** - Push to production
5. **Monitor** - Check logs for any issues

## Implementation Checklist

- [x] Create analytics app with ViewSet
- [x] Implement dashboard endpoint with summary statistics
- [x] Implement appointments endpoint with filtering
- [x] Implement revenue endpoint with dual permission check
- [x] Add permission to FEATURE_NAMES in core/permissions.py
- [x] Register app in INSTALLED_APPS
- [x] Add URL routing
- [x] Create serializers for response validation
- [x] Write comprehensive test suite
- [x] Document API endpoints
- [x] Document implementation details
- [x] Provide developer guide

## Files Summary

**Total Files Created:** 11
- 10 Python files (app code + tests)
- 2 Documentation files

**Total Files Modified:** 3
- core/permissions.py
- config/urls.py
- config/settings/base.py

**Lines of Code:**
- views.py: ~350 lines
- tests.py: ~260 lines
- serializers.py: ~80 lines
- Documentation: ~1000 lines

## Questions or Issues?

Refer to:
1. `analytics/README.md` - API usage and endpoints
2. `analytics/IMPLEMENTATION_GUIDE.md` - Setup and debugging
3. `analytics/tests.py` - Examples of correct usage
4. `core/permissions.py` - Permission checking logic