"""Excel 导入服务"""
import pandas as pd
from typing import List, Dict
from sqlalchemy.orm import Session
from app.models.device import ONUDevice
import math

# 定义字段映射：Excel列名 -> 数据库字段名
FIELD_MAPPING = {
    'mac_address': 'mac_address',
    'region': 'region',
    'school_name': 'school_name',
    'building': 'building',
    'place_type': 'place_type',
    'room_number': 'room_number',
    'notes': 'notes',
}


def clean_value(value) -> str:
    """清理单元格值，处理NaN和None"""
    if value is None:
        return ''
    if isinstance(value, float) and math.isnan(value):
        return ''
    return str(value).strip()


class ImportService:
    def __init__(self, db: Session):
        self.db = db

    def parse_excel(self, file_path: str) -> List[Dict]:
        """解析 Excel 文件"""
        df = pd.read_excel(file_path)
        # 标准化列名（去除空格，转小写）
        df.columns = [col.strip().lower() for col in df.columns]
        # 转换为记录列表
        records = []
        for _, row in df.iterrows():
            record = {}
            for col_name, db_field in FIELD_MAPPING.items():
                if col_name in row:
                    record[db_field] = clean_value(row[col_name])
            records.append(record)
        return records

    def validate_data(self, records: List[Dict]) -> Dict:
        """验证数据"""
        valid = []
        invalid = []

        for idx, record in enumerate(records):
            mac = record.get('mac_address', '').strip()
            if not mac:
                invalid.append({'row': idx + 2, 'mac': mac, 'reason': 'MAC地址缺失'})
                continue

            # 标准化MAC地址：统一使用横杠分隔小写格式
            # 支持格式：AA:BB:CC:DD:EE:FF, AA-BB-CC-DD-EE-FF, AABBCCDDEEFF, aa:bb:cc:dd:ee:ff
            mac_clean = mac.upper().replace(':', '-')

            # 验证基本格式：12个十六进制字符（可能有分隔符）
            hex_chars = mac_clean.replace('-', '')
            if len(hex_chars) != 12 or not all(c in '0123456789ABCDEF' for c in hex_chars):
                invalid.append({'row': idx + 2, 'mac': mac, 'reason': f'MAC地址格式错误 "{mac}"'})
                continue

            # 转换为标准格式 34dc-99c8-56e0（小写4位分组）
            mac_formatted = '-'.join([hex_chars[i:i+4].lower() for i in range(0, 12, 4)])
            record['mac_address'] = mac_formatted
            valid.append(record)

        return {'valid': valid, 'invalid': invalid}

    def import_devices(self, records: List[Dict], olt_id: int = None) -> Dict:
        """批量导入设备，存在则更新，不存在则新增"""
        created_count = 0
        updated_count = 0

        for record in records:
            mac = record.get('mac_address', '')
            if not mac:
                continue

            # 查询是否已存在该 MAC 地址
            existing = self.db.query(ONUDevice).filter(ONUDevice.mac_address == mac).first()

            if existing:
                # 更新现有记录（MAC 地址不变）
                existing.region = record.get('region', '')
                existing.school_name = record.get('school_name', '')
                existing.building = record.get('building') or None
                existing.place_type = record.get('place_type') or None
                existing.room_number = record.get('room_number') or None
                existing.notes = record.get('notes') or None
                updated_count += 1
            else:
                # 新增记录
                device = ONUDevice(
                    mac_address=mac,
                    olt_id=olt_id,
                    region=record.get('region', ''),
                    school_name=record.get('school_name', ''),
                    building=record.get('building') or None,
                    place_type=record.get('place_type') or None,
                    room_number=record.get('room_number') or None,
                    notes=record.get('notes') or None
                )
                self.db.add(device)
                created_count += 1

        self.db.commit()
        return {'success': created_count + updated_count, 'created': created_count, 'updated': updated_count}