"""
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