from enum import Enum
from typing import List

from sqlalchemy import ForeignKey, Integer, String, BigInteger, Text
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.models.base import BaseModel


class FileType(str, Enum):
    """文件类型"""
    SALARY = "工资表"
    SOCIAL_SECURITY = "社保表"
    TAX = "个税表"


class ParseStatus(str, Enum):
    """解析状态"""
    PENDING = "待解析"
    PARSING = "解析中"
    SUCCESS = "解析成功"
    FAILED = "解析失败"


class UploadedFile(BaseModel):
    """
    上传文件模型
    
    Attributes:
        company_id: 企业ID
        task_id: 对账任务ID（可选）
        file_type: 文件类型
        original_filename: 原始文件名
        stored_filename: 存储文件名
        file_size: 文件大小（字节）
        mime_type: MIME类型
        parse_status: 解析状态
        parse_error: 解析错误信息
    """
    
    __tablename__ = "uploaded_files"

    company_id: Mapped[int] = mapped_column(Integer, ForeignKey("companies.id"), nullable=False, index=True)
    task_id: Mapped[int | None] = mapped_column(Integer, nullable=True, index=True)
    file_type: Mapped[str] = mapped_column(String(50), nullable=False, index=True)
    original_filename: Mapped[str] = mapped_column(String(255), nullable=False)
    stored_filename: Mapped[str] = mapped_column(String(255), nullable=False, unique=True)
    file_size: Mapped[int] = mapped_column(BigInteger, nullable=False)
    mime_type: Mapped[str] = mapped_column(String(100), nullable=False)
    parse_status: Mapped[str] = mapped_column(String(20), nullable=False, default=ParseStatus.PENDING.value, index=True)
    parse_error: Mapped[str | None] = mapped_column(Text, nullable=True)

    # 关系
    field_mappings: Mapped[List["FieldMapping"]] = relationship(
        "FieldMapping", back_populates="file", lazy="selectin"
    )

    def __repr__(self) -> str:
        return f"<UploadedFile(id={self.id}, filename='{self.original_filename}', type='{self.file_type}')>"