Phase 3 Step 5: Enhanced Dashboard with Charts & Analytics

Implemented dashboard visualizations and statistics API endpoints:

New Features:
- Stats API endpoints (/api/stats/scan-trend, /api/stats/summary)
- Chart.js trending chart showing 30-day scan activity
- Schedules widget displaying next 3 upcoming scheduled scans
- Enhanced Quick Actions with Manage Schedules button

Stats API (web/api/stats.py):
- scan-trend endpoint with configurable days (1-365)
- Summary endpoint for dashboard statistics
- Automatic date range filling with zeros for missing days
- Proper authentication and validation

Dashboard Enhancements (web/templates/dashboard.html):
- Chart.js line chart with dark theme styling
- Real-time schedules widget with human-readable time display
- Auto-refresh for schedules every 30 seconds
- Responsive 8-4 column layout for chart and schedules

Tests (tests/test_stats_api.py):
- 18 comprehensive test cases for stats API
- Coverage for date validation, authentication, edge cases
- Tests for empty data handling and date formatting

Progress: 64% complete (9/14 days)
Next: Step 6 - Scheduler Integration

web/api/stats.py

@@ -0,0 +1,151 @@
+"""
+Stats API blueprint.
+
+Handles endpoints for dashboard statistics, trending data, and analytics.
+"""
+
+import logging
+from datetime import datetime, timedelta
+from flask import Blueprint, current_app, jsonify, request
+from sqlalchemy import func, Date
+from sqlalchemy.exc import SQLAlchemyError
+
+from web.auth.decorators import api_auth_required
+from web.models import Scan
+
+bp = Blueprint('stats', __name__)
+logger = logging.getLogger(__name__)
+
+
+@bp.route('/scan-trend', methods=['GET'])
+@api_auth_required
+def scan_trend():
+    """
+    Get scan activity trend data for charts.
+
+    Query params:
+        days: Number of days to include (default: 30, max: 365)
+
+    Returns:
+        JSON response with labels and values arrays for Chart.js
+        {
+            "labels": ["2025-01-01", "2025-01-02", ...],
+            "values": [5, 3, 7, 2, ...]
+        }
+    """
+    try:
+        # Get and validate query parameters
+        days = request.args.get('days', 30, type=int)
+
+        # Validate days parameter
+        if days < 1:
+            return jsonify({'error': 'days parameter must be at least 1'}), 400
+        if days > 365:
+            return jsonify({'error': 'days parameter cannot exceed 365'}), 400
+
+        # Calculate date range
+        end_date = datetime.utcnow().date()
+        start_date = end_date - timedelta(days=days - 1)
+
+        # Query scan counts per day
+        db_session = current_app.db_session
+        scan_counts = (
+            db_session.query(
+                func.date(Scan.timestamp).label('scan_date'),
+                func.count(Scan.id).label('scan_count')
+            )
+            .filter(func.date(Scan.timestamp) >= start_date)
+            .filter(func.date(Scan.timestamp) <= end_date)
+            .group_by(func.date(Scan.timestamp))
+            .order_by('scan_date')
+            .all()
+        )
+
+        # Create a dictionary of date -> count
+        scan_dict = {str(row.scan_date): row.scan_count for row in scan_counts}
+
+        # Generate all dates in range (fill missing dates with 0)
+        labels = []
+        values = []
+        current_date = start_date
+        while current_date <= end_date:
+            date_str = str(current_date)
+            labels.append(date_str)
+            values.append(scan_dict.get(date_str, 0))
+            current_date += timedelta(days=1)
+
+        return jsonify({
+            'labels': labels,
+            'values': values,
+            'start_date': str(start_date),
+            'end_date': str(end_date),
+            'total_scans': sum(values)
+        }), 200
+
+    except SQLAlchemyError as e:
+        logger.error(f"Database error in scan_trend: {str(e)}")
+        return jsonify({'error': 'Database error occurred'}), 500
+    except Exception as e:
+        logger.error(f"Error in scan_trend: {str(e)}")
+        return jsonify({'error': 'An error occurred'}), 500
+
+
+@bp.route('/summary', methods=['GET'])
+@api_auth_required
+def summary():
+    """
+    Get dashboard summary statistics.
+
+    Returns:
+        JSON response with summary stats
+        {
+            "total_scans": 150,
+            "completed_scans": 140,
+            "failed_scans": 5,
+            "running_scans": 5,
+            "scans_today": 3,
+            "scans_this_week": 15
+        }
+    """
+    try:
+        db_session = current_app.db_session
+
+        # Get total counts by status
+        total_scans = db_session.query(func.count(Scan.id)).scalar() or 0
+        completed_scans = db_session.query(func.count(Scan.id)).filter(
+            Scan.status == 'completed'
+        ).scalar() or 0
+        failed_scans = db_session.query(func.count(Scan.id)).filter(
+            Scan.status == 'failed'
+        ).scalar() or 0
+        running_scans = db_session.query(func.count(Scan.id)).filter(
+            Scan.status == 'running'
+        ).scalar() or 0
+
+        # Get scans today
+        today = datetime.utcnow().date()
+        scans_today = db_session.query(func.count(Scan.id)).filter(
+            func.date(Scan.timestamp) == today
+        ).scalar() or 0
+
+        # Get scans this week (last 7 days)
+        week_ago = today - timedelta(days=6)
+        scans_this_week = db_session.query(func.count(Scan.id)).filter(
+            func.date(Scan.timestamp) >= week_ago
+        ).scalar() or 0
+
+        return jsonify({
+            'total_scans': total_scans,
+            'completed_scans': completed_scans,
+            'failed_scans': failed_scans,
+            'running_scans': running_scans,
+            'scans_today': scans_today,
+            'scans_this_week': scans_this_week
+        }), 200
+
+    except SQLAlchemyError as e:
+        logger.error(f"Database error in summary: {str(e)}")
+        return jsonify({'error': 'Database error occurred'}), 500
+    except Exception as e:
+        logger.error(f"Error in summary: {str(e)}")
+        return jsonify({'error': 'An error occurred'}), 500