invest-copilot/tasks/alert-service-create/SPEC.md

Task: Create AlertService class

Goal

Create src/backend/services/alert_service.py with the AlertService class. This is Phase 1 of the alert refactor — only create the service, don't touch the router yet.

Requirements

Create src/backend/services/alert_service.py

Implement an AlertService class with these methods:

1. get_user_alerts(watchlist_id, status, page, page_size, user_id) — returns list of alert dicts + total count
2. create_alert(watchlist_id, type, trigger_type, message, severity, ticker, metadata, user_id) — inserts alert, returns alert dict
3. get_alert(alert_id, user_id) — returns alert dict or None
4. update_alert(alert_id, updates_dict, user_id) — updates fields, returns alert dict
5. resolve_alert(alert_id, user_id) — sets status='resolved', returns alert dict
6. dismiss_alert(alert_id, user_id) — deletes alert, returns None
7. _require_watchlist_owner(watchlist_id, user_id) — raises HTTPException if not owner

Implementation Details

• Import execute_query, execute_command, execute_one from database
• Import HTTPException from fastapi
• All methods should be async
• Use parameterized queries (no f-strings for SQL)
• Handle the watchlist_id IN (...) pattern for listing alerts across multiple watchlists

Service Pattern

Follow the existing SentimentService or RotationService pattern for class structure.

Acceptance Criteria

1. File src/backend/services/alert_service.py exists
2. AlertService class has all 7 methods listed above
3. File is under 200 lines (per RULES.md)
4. Can be imported without errors: from services.alert_service import AlertService

Files to Create

• src/backend/services/alert_service.py

Files to Read First

• src/backend/routers/alerts.py — extract logic from each endpoint
• src/backend/services/sentiment_service.py — follow as pattern reference
• src/backend/services/rotation_service.py — follow as pattern reference