"""
异常项模型

存储对账过程中检测到的异常
"""

from datetime import datetime
from enum import Enum
from typing import Optional

from sqlalchemy import ForeignKey, Integer, String, Text, DateTime, JSON, Float
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.models.base import BaseModel


class ExceptionType(str, Enum):
    """异常类型"""
    # 第一阶段：工资表内部异常
    MISSING_EMPLOYEE = "MISSING_EMPLOYEE"  # 员工缺失（三个表之一缺失该员工）
    AMOUNT_MISMATCH = "AMOUNT_MISMATCH"  # 金额不匹配
    ZERO_AMOUNT = "ZERO_AMOUNT"  # 金额为零
    NEGATIVE_AMOUNT = "NEGATIVE_AMOUNT"  # 负数金额
    UNUSUAL_AMOUNT = "UNUSUAL_AMOUNT"  # 金额异常（过大或过小）
    DUPLICATE_EMPLOYEE = "DUPLICATE_EMPLOYEE"  # 重复员工
    
    # 第二阶段：银行实发对账（预留）
    BANK_MISMATCH = "BANK_MISMATCH"  # 银行实发与工资表不匹配
    BANK_MISSING = "BANK_MISSING"  # 银行记录缺失
    BANK_EXTRA = "BANK_EXTRA"  # 银行多余记录


class ExceptionStatus(str, Enum):
    """异常状态"""
    PENDING = "PENDING"  # 待处理
    CONFIRMED = "CONFIRMED"  # 已确认
    IGNORED = "IGNORED"  # 已忽略
    RESOLVED = "RESOLVED"  # 已解决


class ExceptionSeverity(str, Enum):
    """异常严重程度"""
    LOW = "LOW"  # 低
    MEDIUM = "MEDIUM"  # 中
    HIGH = "HIGH"  # 高
    CRITICAL = "CRITICAL"  # 严重


class ExceptionItem(BaseModel):
    """
    异常项模型

    记录对账过程中检测到的各类异常
    """

    __tablename__ = "exception_items"

    company_id: Mapped[int] = mapped_column(Integer, ForeignKey("companies.id"), nullable=False, index=True)
    task_id: Mapped[int] = mapped_column(Integer, ForeignKey("reconciliation_tasks.id"), nullable=False, index=True)
    
    # 异常基本信息
    exception_type: Mapped[str] = mapped_column(String(50), nullable=False, index=True, comment="异常类型")
    severity: Mapped[str] = mapped_column(String(20), nullable=False, default=ExceptionSeverity.MEDIUM.value, comment="严重程度")
    status: Mapped[str] = mapped_column(String(20), nullable=False, default=ExceptionStatus.PENDING.value, index=True, comment="状态")
    
    # 关联的员工信息
    employee_id: Mapped[Optional[str]] = mapped_column(String(100), nullable=True, index=True, comment="员工ID")
    employee_name: Mapped[Optional[str]] = mapped_column(String(100), nullable=True, comment="员工姓名")
    
    # 异常详情
    description: Mapped[str] = mapped_column(Text, nullable=False, comment="异常描述")
    detail: Mapped[Optional[dict]] = mapped_column(JSON, nullable=True, comment="详细信息")
    
    # 涉及的金额
    salary_amount: Mapped[Optional[float]] = mapped_column(Float, nullable=True, comment="工资表金额")
    social_security_amount: Mapped[Optional[float]] = mapped_column(Float, nullable=True, comment="社保表金额")
    tax_amount: Mapped[Optional[float]] = mapped_column(Float, nullable=True, comment="个税表金额")
    bank_amount: Mapped[Optional[float]] = mapped_column(Float, nullable=True, comment="银行实发金额")
    
    # 差异金额
    difference_amount: Mapped[Optional[float]] = mapped_column(Float, nullable=True, comment="差异金额")
    
    # 建议处理方式
    suggested_action: Mapped[Optional[str]] = mapped_column(String(200), nullable=True, comment="建议处理方式")
    ai_suggestion: Mapped[Optional[str]] = mapped_column(Text, nullable=True, comment="AI 分析建议")
    
    # 处理信息
    handled_by: Mapped[Optional[int]] = mapped_column(Integer, ForeignKey("users.id"), nullable=True)
    handled_at: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)
    handling_note: Mapped[Optional[str]] = mapped_column(Text, nullable=True, comment="处理备注")
    
    # 关系
    company = relationship("Company", backref="exceptions")
    task = relationship("ReconciliationTask", backref="exceptions")
    handler = relationship("User", foreign_keys=[handled_by])

    def __repr__(self) -> str:
        return f"<ExceptionItem(id={self.id}, type='{self.exception_type}', status='{self.status}')>"