"""仪表盘路由"""
from datetime import date, datetime

from flask import render_template
from sqlalchemy import func
from sqlalchemy.orm import joinedload

from models import (
    db, Student, Course, Teacher, Class_, StudentAccount,
    MonthlySnapshot, ConsumptionRecord,
)
from utils import login_required
from keshi_display import get_latest_period, snapshot_lessons_display
from keshi_stats import period_overview, monthly_trend_from_snapshots
import business_rules as rules


def register_routes(app):

    @app.route('/', endpoint='dashboard')
    @app.route('/dashboard', endpoint='dashboard')
    @login_required
    def dashboard():
        today = date.today()
        py, pm = get_latest_period()
        period_label = f'{py}-{pm:02d}' if py and pm else ''

        total_students = Student.query.filter_by(status=1).count()
        total_courses = Course.query.filter_by(status=1).count()
        total_teachers = Teacher.query.filter_by(status=1).count()
        total_classes = Class_.query.filter_by(status=1).count()

        month_recharge = 0.0
        month_consumption = 0.0
        if py and pm:
            ov = period_overview(py, pm)
            month_recharge = ov['recharge']
            month_consumption = ov['consumed_hours']

        today_consumption = ConsumptionRecord.query.filter(
            ConsumptionRecord.consume_date == today,
        ).count()

        recent_recharges = []

        threshold = rules.LOW_HOURS_WARNING_THRESHOLD
        low_hours_accounts = []
        if py and pm:
            snaps = (
                MonthlySnapshot.query.options(
                    joinedload(MonthlySnapshot.account).joinedload(StudentAccount.student),
                    joinedload(MonthlySnapshot.account).joinedload(StudentAccount.course),
                )
                .filter(MonthlySnapshot.year == py, MonthlySnapshot.month == pm)
                .all()
            )
            candidates = []
            for s in snaps:
                acc = s.account
                if not acc or not acc.student:
                    continue
                disp = snapshot_lessons_display(s, acc)
                total_h = disp.get('end_total_lessons')
                if total_h is None:
                    continue
                th = float(total_h)
                if 0 < th <= threshold:
                    candidates.append((acc, th, disp))
            candidates.sort(key=lambda x: x[1])
            low_hours_accounts = candidates[:8]

        recent_consumptions = ConsumptionRecord.query.order_by(
            ConsumptionRecord.consume_date.desc(),
        ).limit(8).all()

        trend = monthly_trend_from_snapshots()
        monthly_chart = []
        max_amount = 1.0
        for item in trend[-6:]:
            amt = float(item['recharge'])
            max_amount = max(max_amount, amt)
            monthly_chart.append({
                'label': item['label'],
                'amount': amt,
                'is_current': item['month'] == period_label,
            })
        if not monthly_chart:
            max_amount = 1.0

        hour = datetime.now().hour
        if hour < 12:
            greeting = '早上好'
        elif hour < 18:
            greeting = '下午好'
        else:
            greeting = '晚上好'

        return render_template(
            'dashboard.html',
            greeting=greeting,
            monthly_chart=monthly_chart,
            chart_max=max_amount,
            recent_consumptions=recent_consumptions,
            total_students=total_students,
            total_courses=total_courses,
            total_teachers=total_teachers,
            total_classes=total_classes,
            month_recharge=float(month_recharge),
            month_consumption=float(month_consumption),
            today_consumption=today_consumption,
            recent_recharges=recent_recharges,
            low_hours_accounts=low_hours_accounts,
            period_label=period_label,
        )