"""P2-06 ~ P2-12 管理端 admin API ViewSets

挂载在 /api/v1/admin/affinity/...，要求 RedisTokenAuthentication + is_staff。
所有接口走 StandardResponseMiddleware 自动包成 {success,code,message,data}。
"""

from __future__ import annotations

import logging
from datetime import datetime, timedelta

from django.db import transaction
from django.db.models import Avg, Count, Q
from django.shortcuts import get_object_or_404
from django.utils import timezone

from rest_framework import status, viewsets
from rest_framework.decorators import action
from rest_framework.response import Response
from rest_framework.views import APIView

from device_interaction.models import UserDevice
from userapp.authentication import RedisTokenAuthentication
from userapp.models import (
    AffinityLevel,
    AffinityLog,
    AffinityRule,
    AffinitySetting,
    ParadiseUser,
)

from .permissions import IsAdminUserStaff
from .serializers import (
    AffinityAdjustBatchSerializer,
    AffinityAdjustSerializer,
    AffinityLevelSerializer,
    AffinityLogSerializer,
    AffinityRuleSerializer,
    AffinitySettingSerializer,
    UserDeviceAffinitySerializer,
)
from .services import AffinityService, ApplyOutcome

logger = logging.getLogger(__name__)


# ---------- P2-06 AffinityRule admin CRUD ----------

class AffinityRuleAdminViewSet(viewsets.ModelViewSet):
    """好感度规则管理端 CRUD

    - GET 默认排除软删（is_deleted=False），加 ?include_deleted=true 全集
    - DELETE 走软删（is_deleted=True，is_enabled=False），保留 rule_key 但禁触发
    - POST/PATCH 走 serializer 跨字段校验 + DB CHECK 兜底
    """
    authentication_classes = [RedisTokenAuthentication]
    permission_classes = [IsAdminUserStaff]
    serializer_class = AffinityRuleSerializer
    queryset = AffinityRule.objects.all()

    def get_queryset(self):
        qs = AffinityRule.objects.all().order_by('-created_at')
        if self.request.query_params.get('include_deleted', '').lower() not in ('1', 'true', 'yes'):
            qs = qs.filter(is_deleted=False)
        return qs

    def perform_destroy(self, instance):
        """软删：is_deleted=True + is_enabled=False（service 层基于这两个标记拒绝触发）"""
        instance.is_deleted = True
        instance.is_enabled = False
        instance.save(update_fields=['is_deleted', 'is_enabled', 'updated_at'])

    @action(detail=True, methods=['post'], url_path='restore')
    def restore(self, request, pk=None):
        """恢复软删的规则。允许把 is_enabled 一起拉起来，默认 False（管理员手动启用）"""
        rule = get_object_or_404(AffinityRule, pk=pk)
        rule.is_deleted = False
        rule.save(update_fields=['is_deleted', 'updated_at'])
        return Response(AffinityRuleSerializer(rule).data)


# ---------- P2-07 AffinityLevel admin CRUD ----------

class AffinityLevelAdminViewSet(viewsets.ModelViewSet):
    authentication_classes = [RedisTokenAuthentication]
    permission_classes = [IsAdminUserStaff]
    serializer_class = AffinityLevelSerializer
    queryset = AffinityLevel.objects.all()

    def get_queryset(self):
        qs = AffinityLevel.objects.all().order_by('level')
        if self.request.query_params.get('include_deleted', '').lower() not in ('1', 'true', 'yes'):
            qs = qs.filter(is_deleted=False)
        return qs

    def perform_destroy(self, instance):
        instance.is_deleted = True
        instance.is_enabled = False
        instance.save(update_fields=['is_deleted', 'is_enabled', 'updated_at'])


# ---------- P2-08 AffinitySetting 单例 GET/PUT ----------

class AffinitySettingView(APIView):
    """好感度系统全局设置 — 单例 GET/PUT

    GET → 当前配置
    PUT → 全字段覆写（serializer 验证）
    PATCH → 部分字段更新
    """
    authentication_classes = [RedisTokenAuthentication]
    permission_classes = [IsAdminUserStaff]

    def get(self, request):
        instance = AffinitySetting.get_solo()
        return Response(AffinitySettingSerializer(instance).data)

    def put(self, request):
        instance = AffinitySetting.get_solo()
        ser = AffinitySettingSerializer(instance, data=request.data)
        ser.is_valid(raise_exception=True)
        ser.save()
        return Response(ser.data)

    def patch(self, request):
        instance = AffinitySetting.get_solo()
        ser = AffinitySettingSerializer(instance, data=request.data, partial=True)
        ser.is_valid(raise_exception=True)
        ser.save()
        return Response(ser.data)


# ---------- P2-09 AffinityLog 查询 ----------

class AffinityLogListView(APIView):
    """好感度变化日志查询

    支持过滤参数：
        user_id  — 用户 ID
        device_id — UserDevice 绑定 ID
        rule_key — 规则代码
        source   — 来源（device_event / mobile_event / system_decay / admin_adjust_*）
        date_from / date_to — created_at 范围（ISO 日期）
        page / page_size — 分页（默认 page_size=20，最大 200）
    """
    authentication_classes = [RedisTokenAuthentication]
    permission_classes = [IsAdminUserStaff]

    def get(self, request):
        qs = AffinityLog.objects.select_related('user', 'rule', 'device__device').order_by('-created_at')

        user_id = request.query_params.get('user_id')
        device_id = request.query_params.get('device_id')
        rule_key = request.query_params.get('rule_key')
        source = request.query_params.get('source')
        date_from = request.query_params.get('date_from')
        date_to = request.query_params.get('date_to')

        if user_id:
            qs = qs.filter(user_id=user_id)
        if device_id:
            qs = qs.filter(device_id=device_id)
        if rule_key:
            qs = qs.filter(rule_key=rule_key)
        if source:
            qs = qs.filter(source=source)
        if date_from:
            qs = qs.filter(created_at__gte=date_from)
        if date_to:
            qs = qs.filter(created_at__lte=date_to)

        # 简易分页
        try:
            page = max(int(request.query_params.get('page', 1)), 1)
            page_size = min(max(int(request.query_params.get('page_size', 20)), 1), 200)
        except (TypeError, ValueError):
            page, page_size = 1, 20

        total = qs.count()
        items = qs[(page - 1) * page_size: page * page_size]
        data = AffinityLogSerializer(items, many=True).data
        return Response({
            'total': total, 'page': page, 'page_size': page_size,
            'items': data,
        })


# ---------- P2-10 数据统计 ----------

class AffinityStatsView(APIView):
    """好感度系统数据统计（admin 概览）

    返回结构（与设计文档 §7 对齐）：
        avg_favorability — 全设备平均好感度
        max_favorability — 当前最高好感度值
        top_count — 达到 max_affinity 上限的设备数
        active_devices_7d — 近 7 日有互动（last_active_at）的设备数
        total_devices — 已绑定（is_bound=True）设备总数
        today_interactions — 今日（local timezone）触发数
        today_change_sum — 今日好感度变化总和（含正负）
        rule_freq_top — 互动规则触发频次 Top 10
        level_distribution — 各等级设备数占比
    """
    authentication_classes = [RedisTokenAuthentication]
    permission_classes = [IsAdminUserStaff]

    def get(self, request):
        setting = AffinitySetting.get_solo()
        max_aff = setting.max_affinity

        # 仅统计有效绑定（is_bound=True）的设备
        active_qs = UserDevice.active.all()
        total_devices = active_qs.count()
        avg_fav = active_qs.aggregate(v=Avg('favorability'))['v'] or 0.0
        max_fav = active_qs.order_by('-favorability').values_list('favorability', flat=True).first() or 0
        top_count = active_qs.filter(favorability__gte=max_aff).count()

        seven_days_ago = timezone.now() - timedelta(days=7)
        active_7d = active_qs.filter(last_active_at__gte=seven_days_ago).count()

        # 今日（local timezone）日志聚合
        from .counters import local_today_date
        today = local_today_date(setting.timezone)
        # date → datetime 边界（避免时区错位，用 UTC 范围更稳）
        today_logs = AffinityLog.objects.filter(created_at__date=today)
        today_interactions = today_logs.count()
        today_change_sum = today_logs.aggregate(s=Count('id'))['s']  # 触发数
        # 用 Sum 更合理
        from django.db.models import Sum
        today_change_sum_val = today_logs.aggregate(s=Sum('change_value'))['s'] or 0

        rule_freq_top = list(
            AffinityLog.objects
            .filter(created_at__gte=seven_days_ago, rule_key__isnull=False)
            .exclude(rule_key='')
            .values('rule_key')
            .annotate(c=Count('id'))
            .order_by('-c')[:10]
        )

        level_distribution = list(
            active_qs
            .values('affinity_level')
            .annotate(c=Count('id'))
            .order_by('affinity_level')
        )

        return Response({
            'avg_favorability': round(float(avg_fav), 2),
            'max_favorability': max_fav,
            'top_count': top_count,
            'active_devices_7d': active_7d,
            'total_devices': total_devices,
            'today_interactions': today_interactions,
            'today_change_sum': today_change_sum_val,
            'rule_freq_top': rule_freq_top,
            'level_distribution': level_distribution,
            'computed_at': timezone.now().isoformat(),
        })


# ---------- P2-11 按用户列出设备好感度 ----------

class UserAffinityDevicesView(APIView):
    """admin 按 user_id 列出该用户名下所有设备的好感度状态

    GET /api/v1/admin/affinity/devices/?user_id=123
        &include_unbound=true  — 是否含已解绑历史（默认 false）
    """
    authentication_classes = [RedisTokenAuthentication]
    permission_classes = [IsAdminUserStaff]

    def get(self, request):
        user_id = request.query_params.get('user_id')
        if not user_id:
            return Response({'detail': 'user_id 必传'}, status=status.HTTP_400_BAD_REQUEST)

        if not ParadiseUser.objects.filter(id=user_id).exists():
            return Response({'detail': f'用户 {user_id} 不存在'}, status=status.HTTP_404_NOT_FOUND)

        include_unbound = request.query_params.get('include_unbound', '').lower() in ('1', 'true', 'yes')
        # CR-001 修复：默认仅返回 is_bound=True，include_unbound=true 时给历史
        qs = (UserDevice.objects if include_unbound else UserDevice.active).filter(user_id=user_id)
        qs = qs.select_related('user', 'device').order_by('-is_primary', '-bound_at')

        data = UserDeviceAffinitySerializer(qs, many=True).data
        return Response({
            'user_id': int(user_id),
            'count': len(data),
            'items': data,
        })


# ---------- P2-12 admin 手动调整 ----------

class AffinityAdjustView(APIView):
    """单台设备调整

    POST /api/v1/admin/affinity/adjust/
    Body: { user_id, device_id, delta, reason }
    """
    authentication_classes = [RedisTokenAuthentication]
    permission_classes = [IsAdminUserStaff]

    def post(self, request):
        ser = AffinityAdjustSerializer(data=request.data)
        ser.is_valid(raise_exception=True)
        params = ser.validated_data

        result = AffinityService.admin_adjust(
            user_id=params['user_id'],
            device_id=params['device_id'],
            delta=params['delta'],
            operator_admin_id=request.user.id,
            reason=params.get('reason', ''),
            batch=False,
        )

        return Response(_apply_result_to_dict(result),
                        status=_status_from_outcome(result.outcome))


class AffinityAdjustBatchView(APIView):
    """批量调整：给某 user 名下所有绑定设备各加 delta

    POST /api/v1/admin/affinity/adjust-batch/
    Body: { user_id, delta, reason }
    返回每台设备的处理结果。
    """
    authentication_classes = [RedisTokenAuthentication]
    permission_classes = [IsAdminUserStaff]

    def post(self, request):
        ser = AffinityAdjustBatchSerializer(data=request.data)
        ser.is_valid(raise_exception=True)
        params = ser.validated_data
        user_id = params['user_id']
        delta = params['delta']
        reason = params.get('reason', '')

        if not ParadiseUser.objects.filter(id=user_id).exists():
            return Response({'detail': f'用户 {user_id} 不存在'},
                            status=status.HTTP_404_NOT_FOUND)

        device_ids = list(UserDevice.active.filter(user_id=user_id).values_list('id', flat=True))
        if not device_ids:
            return Response({'detail': '该用户名下无有效绑定设备'},
                            status=status.HTTP_404_NOT_FOUND)

        results = []
        applied_count = 0
        for did in device_ids:
            res = AffinityService.admin_adjust(
                user_id=user_id, device_id=did, delta=delta,
                operator_admin_id=request.user.id, reason=reason, batch=True,
            )
            results.append(_apply_result_to_dict(res, device_id=did))
            if res.is_applied:
                applied_count += 1

        return Response({
            'user_id': user_id,
            'device_count': len(device_ids),
            'applied_count': applied_count,
            'results': results,
        })


# ---------- 辅助 ----------

def _apply_result_to_dict(result, *, device_id=None) -> dict:
    d = {
        'outcome': result.outcome,
        'applied': result.is_applied,
        'change_value': result.change_value,
        'before_value': result.before_value,
        'after_value': result.after_value,
        'rule_key': result.rule_key,
        'old_level': result.old_level,
        'new_level': result.new_level,
        'log_id': result.log_id,
        'rewards_granted': result.rewards_granted,
        'rewards_failed': result.rewards_failed,
        'error': result.error,
    }
    if device_id is not None:
        d['device_id'] = device_id
    return d


def _status_from_outcome(outcome: str) -> int:
    if outcome == ApplyOutcome.APPLIED:
        return status.HTTP_200_OK
    if outcome == ApplyOutcome.ERROR:
        return status.HTTP_400_BAD_REQUEST
    # 其他 NOOP_* 视为业务正常拒绝
    return status.HTTP_200_OK