import json
import re
from datetime import datetime
from flask import Blueprint, jsonify, request
from sqlalchemy import desc, or_
# 引入 jwt 相关函数
from flask_jwt_extended import create_access_token, jwt_required, get_jwt_identity

from extensions import db
from models import Device, DeviceHistory, MaintenanceLog, User, UserDevicePermission

# 尝试导入爬虫模块 (如果没有则跳过，防止报错)
try:
    from services.core import execute_monitor_task
except ImportError:
    execute_monitor_task = None

api_bp = Blueprint('api', __name__, url_prefix='/api')


# =======================
# 🔧 辅助函数 (权限核心)
# =======================
def is_admin(user_id):
    """
    判断是否为超级管理员 (Root权限)
    逻辑：
    1. ID 为 '0' (硬编码后门) -> 通过
    2. 数据库中角色为 'admin' -> 通过
    """
    if str(user_id) == '0':
        return True
    if not user_id:
        return False
    try:
        u = User.query.get(int(user_id))
        return u and u.role == 'admin'
    except:
        return False


def is_manager(user_id):
    """
    判断是否为管理者 (Admin OR Engineer)
    用于：修改地点、切换维修模式、写日志
    """
    if is_admin(user_id):
        return True
    try:
        u = User.query.get(int(user_id))
        return u and u.role == 'engineer'
    except:
        return False


def calculate_offset(latest_time_str):
    """计算时间滞后天数"""
    if not latest_time_str or latest_time_str == "N/A": return "从未同步"
    try:
        clean = str(latest_time_str).split()[0].replace('_', '-')
        target = datetime.strptime(clean, "%Y-%m-%d").date()
        diff = (datetime.now().date() - target).days
        return "当天已同步" if diff == 0 else f"滞后 {diff} 天"
    except:
        return "时间解析失败"


# =======================
# 0. 认证接口
# =======================
@api_bp.route('/login', methods=['POST'])
def login():
    data = request.get_json()
    username = data.get('username')
    password = data.get('password')

    # 1. 后门判定
    if username == 'admin' and password == 'licahk':
        token = create_access_token(identity='0', additional_claims={'role': 'admin'})
        return jsonify({
            'code': 200, 'message': 'Root后门登录',
            'token': token, 'role': 'admin', 'user_id': 0, 'username': 'admin'
        })

    # 2. 正常查库登录
    user = User.query.filter_by(username=username).first()
    if user and user.check_password(password):
        token = create_access_token(identity=str(user.id), additional_claims={'role': user.role})
        return jsonify({
            'code': 200, 'message': '登录成功',
            'token': token, 'role': user.role, 'user_id': user.id, 'username': user.username
        })

    return jsonify({'code': 401, 'message': '用户名或密码错误'}), 401


# =======================
# 1. 设备接口
# =======================
@api_bp.route('/devices_overview', methods=['GET'])
@jwt_required()
def devices_overview():
    try:
        user_id = get_jwt_identity()
        if is_admin(user_id):
            target_devices = Device.query.all()
        else:
            perms = UserDevicePermission.query.filter_by(user_id=int(user_id)).all()
            allowed_ids = [p.device_id for p in perms]
            target_devices = Device.query.filter(Device.id.in_(allowed_ids)).all() if allowed_ids else []

        return jsonify({'code': 200, 'data': [d.to_dict() for d in target_devices]})
    except Exception as e:
        return jsonify({'code': 500, 'message': str(e)})


@api_bp.route('/device_data_by_date', methods=['GET'])
@jwt_required(optional=True)
def device_data_by_date():
    name = request.args.get('name')
    date_str = request.args.get('date')
    if not name or not date_str: return jsonify({'code': 400}), 400

    device = Device.query.filter_by(name=name).first()
    if not device: return jsonify({'code': 404}), 404

    hist = DeviceHistory.query.filter(DeviceHistory.device_id == device.id, DeviceHistory.data_time.like(f"{date_str}%")).order_by(desc(DeviceHistory.id)).first()
    content = hist.json_data if hist else (device.json_data if device.latest_time and str(device.latest_time).startswith(date_str) else None)

    if content:
        if isinstance(content, str):
            try: content = json.loads(content)
            except: pass
        return jsonify({'code': 200, 'name': device.name, 'source': device.source, 'content': content})
    return jsonify({'code': 404, 'message': '无数据'}), 404


# =======================
# 2. 用户管理 (Admin Only)
# =======================
@api_bp.route('/admin/users', methods=['GET'])
@jwt_required()
def admin_get_users():
    if not is_admin(get_jwt_identity()): return jsonify({'code': 403}), 403
    users = User.query.order_by(desc(User.created_at)).all()
    result = []
    for u in users:
        if str(u.id) == str(get_jwt_identity()): continue
        perms = UserDevicePermission.query.filter_by(user_id=u.id).all()
        result.append({
            "id": u.id, "username": u.username, "role": u.role,
            "created_at": u.created_at, "allowed_device_ids": [p.device_id for p in perms]
        })
    return jsonify({'code': 200, 'data': result})


@api_bp.route('/admin/create_user', methods=['POST'])
@jwt_required()
def admin_create_user():
    if not is_admin(get_jwt_identity()): return jsonify({'code': 403}), 403
    data = request.get_json()
    if User.query.filter_by(username=data.get('username')).first():
        return jsonify({'code': 400, 'msg': '用户名已存在'}), 400
    u = User(username=data.get('username'), role=data.get('role', 'client'))
    u.set_password(data.get('password'))
    db.session.add(u)
    db.session.commit()
    return jsonify({'code': 200, 'msg': '创建成功'})


@api_bp.route('/admin/delete_user', methods=['POST'])
@jwt_required()
def admin_delete_user():
    curr = get_jwt_identity()
    if not is_admin(curr): return jsonify({'code': 403}), 403
    uid = request.get_json().get('user_id')
    if str(uid) == str(curr): return jsonify({'code': 400, 'msg': '无法删除自己'}), 400
    user = User.query.get(uid)
    if user:
        UserDevicePermission.query.filter_by(user_id=user.id).delete()
        db.session.delete(user)
        db.session.commit()
    return jsonify({'code': 200, 'msg': '删除成功'})


@api_bp.route('/admin/assign_devices', methods=['POST'])
@jwt_required()
def admin_assign_devices():
    if not is_admin(get_jwt_identity()): return jsonify({'code': 403}), 403
    data = request.get_json()
    UserDevicePermission.query.filter_by(user_id=data.get('user_id')).delete()
    for did in data.get('device_ids', []):
        db.session.add(UserDevicePermission(user_id=data.get('user_id'), device_id=did))
    db.session.commit()
    return jsonify({'code': 200, 'msg': '权限已保存'})


# =======================
# 3. 日志与工具 (权限隔离)
# =======================
@api_bp.route('/logs/list', methods=['GET'])
@jwt_required()
def get_logs():
    """
    获取日志列表
    权限逻辑更新：
    - Admin: 可以看所有
    - Engineer/Client: 只能看自己名下设备的日志 (严格过滤)
    """
    user_id = get_jwt_identity()
    keyword = request.args.get('keyword', '')
    start_date = request.args.get('start_date')
    end_date = request.args.get('end_date')

    query = MaintenanceLog.query

    # 🛡️ 权限隔离
    if not is_admin(user_id):
        perms = UserDevicePermission.query.filter_by(user_id=int(user_id)).all()
        if not perms: return jsonify({'code': 200, 'data': []})
        allowed_names = [d.name for d in Device.query.filter(Device.id.in_([p.device_id for p in perms])).all()]
        query = query.filter(MaintenanceLog.device_name.in_(allowed_names))

    if keyword:
        kw = f"%{keyword}%"
        query = query.filter(or_(
            MaintenanceLog.device_name.like(kw), MaintenanceLog.engineer.like(kw),
            MaintenanceLog.location.like(kw), MaintenanceLog.content.like(kw)
        ))

    if start_date and end_date:
        try:
            s = datetime.strptime(start_date, '%Y-%m-%d')
            e = datetime.strptime(end_date, '%Y-%m-%d').replace(hour=23, minute=59, second=59)
            query = query.filter(MaintenanceLog.timestamp.between(s, e))
        except: pass

    logs = query.order_by(desc(MaintenanceLog.timestamp)).all()
    return jsonify({'code': 200, 'data': [l.to_dict() for l in logs]})


@api_bp.route('/logs/add', methods=['POST'])
@jwt_required()
def add_log():
    if not is_manager(get_jwt_identity()): return jsonify({'code': 403}), 403
    data = request.get_json()
    # 后端安全校验：如果是工程师，建议再次校验 engineer 字段是否匹配其 username
    db.session.add(MaintenanceLog(
        device_name=data.get('device_name'),
        engineer=data.get('engineer'),
        location=data.get('location'),
        content=data.get('content')
    ))
    db.session.commit()
    return jsonify({'code': 200})


@api_bp.route('/logs/update', methods=['POST'])
@jwt_required()
def update_log():
    if not is_manager(get_jwt_identity()): return jsonify({'code': 403}), 403
    data = request.get_json()
    log = MaintenanceLog.query.get(data.get('id'))
    if not log: return jsonify({'code': 404}), 404

    log.engineer = data.get('engineer')
    log.location = data.get('location')
    log.content = data.get('content')
    db.session.commit()
    return jsonify({'code': 200, 'msg': '更新成功'})


@api_bp.route('/logs/delete', methods=['POST'])
@jwt_required()
def delete_log():
    if not is_admin(get_jwt_identity()): return jsonify({'code': 403}), 403
    log = MaintenanceLog.query.get(request.get_json().get('id'))
    if log:
        db.session.delete(log)
        db.session.commit()
        return jsonify({'code': 200})
    return jsonify({'code': 404})


# =======================
# 4. 系统检测与控制 (原有功能完整保留)
# =======================
@api_bp.route('/run_monitor', methods=['POST'])
@jwt_required()
def run_monitor():
    if not is_admin(get_jwt_identity()): return jsonify({'code': 403}), 403
    if not execute_monitor_task: return jsonify({'code': 500, 'msg': '爬虫模块未加载'})

    try:
        task_result = execute_monitor_task()
        if not task_result: return jsonify({'code': 200, 'msg': '无任务'})

        scraped_list = task_result.get('device_list', [])
        now_str = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
        count = 0

        for item in scraped_list:
            d_name = item.get('name')
            if not d_name: continue

            d_raw = item.get('raw_json', {})
            target_time = item.get('target_time')
            source = item.get('source', '')

            # 针对 106 源码进行特殊路径解析
            if '106' in str(source):
                try:
                    path_str = d_raw.get('path', '')
                    match = re.search(r'/Data/(\d{4}_\d{2}_\d{2})/\w+_(\d{2}_\d{2}_\d{2})\.csv', path_str)
                    if match:
                        target_time = f"{match.group(1).replace('_', '-')} {match.group(2).replace('_', ':')}"
                except: pass

            json_str = json.dumps(d_raw, ensure_ascii=False)
            device = Device.query.filter_by(name=d_name).first()
            if not device:
                device = Device(name=d_name, source=source)
                db.session.add(device)
                db.session.flush()

            device.status = item.get('status')
            device.current_value = item.get('value')
            device.latest_time = target_time
            device.check_time = now_str
            device.json_data = json_str
            device.offset = calculate_offset(target_time)

            db.session.add(DeviceHistory(
                device_id=device.id, status=device.status,
                result_data=device.current_value, data_time=target_time,
                json_data=json_str
            ))
            count += 1

        db.session.commit()
        return jsonify({'code': 200, 'message': f'更新 {count} 台设备'})
    except Exception as e:
        db.session.rollback()
        return jsonify({'code': 500, 'message': str(e)})


@api_bp.route('/update_site', methods=['POST'])
@jwt_required()
def update_site():
    if not is_manager(get_jwt_identity()): return jsonify({'code': 403}), 403
    d = Device.query.filter_by(name=request.get_json().get('name')).first()
    if d:
        d.install_site = request.get_json().get('site')
        db.session.commit()
        return jsonify({'code': 200})
    return jsonify({'code': 404})


@api_bp.route('/toggle_maintenance', methods=['POST'])
@jwt_required()
def toggle_maintenance():
    if not is_manager(get_jwt_identity()): return jsonify({'code': 403}), 403
    d = Device.query.filter_by(name=request.get_json().get('name')).first()
    if d:
        d.is_maintaining = request.get_json().get('is_maintaining')
        db.session.commit()
        return jsonify({'code': 200})
    return jsonify({'code': 404})


@api_bp.route('/toggle_hidden', methods=['POST'])
@jwt_required()
def toggle_hidden():
    if not is_admin(get_jwt_identity()): return jsonify({'code': 403}), 403
    d = Device.query.filter_by(name=request.get_json().get('name')).first()
    if d:
        d.is_hidden = request.get_json().get('is_hidden')
        db.session.commit()
        return jsonify({'code': 200})
    return jsonify({'code': 404})