"""Dashboard Stats Blueprint — In-app real-time analytics.

Endpoints for sales, productivity, and top products charts.
"""
from flask import Blueprint, request, jsonify, g
from functools import wraps
from datetime import datetime, timedelta
from decimal import Decimal
import json

dashboard_stats_bp = Blueprint('dashboard_stats', __name__, url_prefix='/pos/api/dashboard')


from middleware import require_auth


class DecimalEncoder(json.JSONEncoder):
    def default(self, o):
        if isinstance(o, Decimal):
            return float(o)
        return super().default(o)


@dashboard_stats_bp.route('/stats', methods=['GET'])
@require_auth()
def get_stats():
    """Summary stats for today and this month."""
    from tenant_db import get_tenant_db
    db = get_tenant_db()
    today = datetime.utcnow().date()
    month_start = today.replace(day=1)

    # Sales today
    today_sales = db.execute(
        """SELECT COUNT(*) as count, COALESCE(SUM(total), 0) as total
           FROM sales WHERE DATE(created_at) = %s""", (today,)
    ).fetchone()

    # Sales this month
    month_sales = db.execute(
        """SELECT COUNT(*) as count, COALESCE(SUM(total), 0) as total
           FROM sales WHERE DATE(created_at) >= %s""", (month_start,)
    ).fetchone()

    # Top 5 products today
    top_products = db.execute(
        """SELECT p.name, SUM(si.quantity) as qty, SUM(si.total) as revenue
           FROM sale_items si
           JOIN sales s ON si.sale_id = s.id_sale
           JOIN parts p ON si.part_id = p.id_part
           WHERE DATE(s.created_at) = %s
           GROUP BY p.name
           ORDER BY revenue DESC
           LIMIT 5""", (today,)
    ).fetchall()

    # Hourly sales today (0-23)
    hourly = db.execute(
        """SELECT EXTRACT(HOUR FROM created_at)::int as hour,
                  COUNT(*) as count, COALESCE(SUM(total), 0) as total
           FROM sales WHERE DATE(created_at) = %s
           GROUP BY hour ORDER BY hour""", (today,)
    ).fetchall()
    hourly_map = {row['hour']: {'count': row['count'], 'total': row['total']} for row in hourly}

    return jsonify({
        'today': {
            'sales_count': today_sales['count'],
            'sales_total': today_sales['total'],
        },
        'month': {
            'sales_count': month_sales['count'],
            'sales_total': month_sales['total'],
        },
        'top_products': [
            {'name': row['name'], 'quantity': row['qty'], 'revenue': row['revenue']}
            for row in top_products
        ],
        'hourly_sales': [
            {'hour': h, 'count': hourly_map.get(h, {}).get('count', 0),
             'total': hourly_map.get(h, {}).get('total', 0)}
            for h in range(24)
        ],
    }, cls=DecimalEncoder)


@dashboard_stats_bp.route('/stats/employees', methods=['GET'])
@require_auth()
def get_employee_stats():
    """Sales per employee today."""
    from tenant_db import get_tenant_db
    db = get_tenant_db()
    today = datetime.utcnow().date()
    rows = db.execute(
        """SELECT e.name, COUNT(s.id_sale) as sales, COALESCE(SUM(s.total), 0) as total
           FROM sales s
           JOIN employees e ON s.employee_id = e.id_employee
           WHERE DATE(s.created_at) = %s
           GROUP BY e.name
           ORDER BY total DESC""", (today,)
    ).fetchall()
    return jsonify({
        'employees': [
            {'name': row['name'], 'sales': row['sales'], 'total': row['total']}
            for row in rows
        ]
    }, cls=DecimalEncoder)