"""
访问统计插件：后台统计主页 + 3 个 JSON 接口 + 全站 before_request 埋点。

URL 前缀：/system/stats （与框架原路径一致）；埋点用 before_request 挂在框架 app 上。
"""
import datetime
import os
import time
from collections import defaultdict

from flask import Blueprint, render_template, request, jsonify

from applications.common.utils.rights import authorize
from applications.extensions import db
from applications.models import VisitLog, PageStat, NavClick

dir_path = os.path.dirname(os.path.abspath(__file__))
bp = Blueprint(
    'site_stats', __name__,
    url_prefix='/system/stats',
    template_folder=os.path.join(dir_path, '..', 'templates'),
)

# 公开埋点 blueprint：无 url_prefix，路径就是 /site/nav/<id>/click
site_bp = Blueprint(
    'site_stats_public', __name__,
    template_folder=os.path.join(dir_path, '..', 'templates'),
)


@bp.get('/')
@authorize("site:stats:main")
def main():
    return render_template('system/stat/main.html')


@bp.get('/summary')
@authorize("site:stats:main")
def summary():
    today = datetime.date.today().strftime('%Y-%m-%d')
    pv_total = db.session.query(db.func.coalesce(db.func.sum(PageStat.pv), 0)).scalar() or 0
    today_pv = (db.session.query(db.func.coalesce(db.func.sum(PageStat.pv), 0))
                .filter(PageStat.day == today).scalar()) or 0

    today_uv_set = set()
    for r in PageStat.query.filter(PageStat.day == today, PageStat.uv_ip_set != '').all():
        for ip in (r.uv_ip_set or '').split(','):
            ip = ip.strip()
            if ip:
                today_uv_set.add(ip)
    today_uv = len(today_uv_set)

    all_uv_set = set()
    for r in PageStat.query.filter(PageStat.uv_ip_set != '').all():
        for ip in (r.uv_ip_set or '').split(','):
            ip = ip.strip()
            if ip:
                all_uv_set.add(ip)
    uv_all = len(all_uv_set)

    latest = VisitLog.query.order_by(VisitLog.visit_at.desc()).limit(5).all()
    latest_rows = [{
        'path': r.path,
        'ip': r.ip or '-',
        'visit_at': r.visit_at.strftime('%Y-%m-%d %H:%M:%S') if r.visit_at else '',
    } for r in latest]

    return jsonify({
        'code': 0,
        'msg': '请求成功',
        'data': {
            'pv_total': int(pv_total),
            'uv_total': uv_all,
            'today_pv': int(today_pv),
            'today_uv': today_uv,
            'latest': latest_rows,
        }
    })


@bp.get('/days')
@authorize("site:stats:main")
def days():
    try:
        days = max(1, min(30, int(request.args.get('days', 7))))
    except (TypeError, ValueError):
        days = 7
    cutoff = datetime.date.today() - datetime.timedelta(days=days - 1)
    cutoff_str = cutoff.strftime('%Y-%m-%d')

    rows = PageStat.query.filter(PageStat.day >= cutoff_str).all()
    pv_by_day = defaultdict(int)
    uv_by_day = defaultdict(set)
    for r in rows:
        pv_by_day[r.day] += r.pv
        for ip in (r.uv_ip_set or '').split(','):
            ip = ip.strip()
            if ip:
                uv_by_day[r.day].add(ip)

    out = []
    for i in range(days):
        d = (cutoff + datetime.timedelta(days=i)).strftime('%Y-%m-%d')
        out.append({
            'day': d,
            'pv': pv_by_day.get(d, 0),
            'uv': len(uv_by_day.get(d, set())),
        })
    return jsonify({'code': 0, 'msg': '请求成功', 'data': out})


@bp.get('/paths')
@authorize("site:stats:main")
def paths():
    rows = PageStat.query.filter(PageStat.path != '').order_by(PageStat.pv.desc()).limit(10).all()
    out = []
    for r in rows:
        out.append({
            'path': r.path,
            'pv': r.pv or 0,
            'last_hit': r.last_hit.strftime('%Y-%m-%d %H:%M:%S') if r.last_hit else '',
        })
    return jsonify({'code': 0, 'msg': '请求成功', 'data': out})


def record_visit():
    """before_request 钩子调用：埋点 /site/* GET。"""
    if not request.path.startswith('/site'):
        return
    if request.method != 'GET':
        return
    path = request.path
    day = datetime.date.today().strftime('%Y-%m-%d')
    ip = (request.headers.get('X-Forwarded-For', '').split(',')[0].strip()
          or request.remote_addr or '')
    ua_short = (request.user_agent.string or '')[:255]
    referer = request.headers.get('Referer', '')[:255]

    try:
        log = VisitLog(path=path, referer=referer, ua=ua_short, ip=ip, day=day)
        db.session.add(log)
        stat = PageStat.query.filter_by(path=path, day=day).first()
        if stat is None:
            stat = PageStat(path=path, day=day, pv=1, uv=1 if ip else 0,
                            uv_ip_set=(ip + ',') if ip else '',
                            last_hit=datetime.datetime.now())
            db.session.add(stat)
        else:
            stat.pv = (stat.pv or 0) + 1
            stat.last_hit = datetime.datetime.now()
            existing = (stat.uv_ip_set or '').split(',')
            existing = [x.strip() for x in existing if x.strip()]
            if ip and ip not in existing:
                existing.append(ip)
                stat.uv_ip_set = ','.join(existing) + ','
            stat.uv = len(existing)
        db.session.commit()
    except Exception:
        db.session.rollback()


# ---------- 导航卡片点击埋点 ----------

# 进程级内存缓存，避免每个聚合页请求都 GROUP BY 一次
# 结构：{nav_id: count}
_visit_count_cache = {}
_visit_count_cache_at = 0.0
_VISIT_COUNT_TTL = 60.0  # 秒


def get_nav_visit_counts():
    """返回 {nav_id: total_clicks}，60 秒内走缓存。"""
    global _visit_count_cache, _visit_count_cache_at
    now = time.time()
    if _visit_count_cache and (now - _visit_count_cache_at) < _VISIT_COUNT_TTL:
        return _visit_count_cache
    rows = db.session.query(
        NavClick.nav_id,
        db.func.count(NavClick.id),
    ).group_by(NavClick.nav_id).all()
    counts = {int(nid): int(c) for nid, c in rows}
    _visit_count_cache = counts
    _visit_count_cache_at = now
    return counts


@site_bp.post('/site/nav/<int:nav_id>/click')
def nav_click(nav_id):
    """导航卡片点击埋点：JS sendBeacon 调用，返回 204 无副作用。"""
    try:
        ip = (request.headers.get('X-Forwarded-For', '').split(',')[0].strip()
              or request.remote_addr or '')
        day = datetime.date.today().strftime('%Y-%m-%d')
        db.session.add(NavClick(nav_id=nav_id, day=day, ip=ip[:64]))
        db.session.commit()
        # 让缓存尽快失效（最多延迟 60s 也无所谓，统计本来就不需要实时）
        global _visit_count_cache_at
        _visit_count_cache_at = 0.0
    except Exception:
        db.session.rollback()
    # 204 No Content：无响应体，beacon 友好
    return ('', 204)