from typing import Optional

from pydantic import BaseModel, Field, field_validator


class TrailerBaseDTO(BaseModel):
    trailer_number: str = Field(..., description="Trailer number (primary identifier)")
    trailer_id: Optional[int] = Field(None, description="Internal trailer integer ID")
    ace_trailer_number: Optional[str] = None
    trailer_type_key: Optional[str] = None
    seal: Optional[str] = None
    entity_code: Optional[str] = None
    plate_number: Optional[str] = None
    state: Optional[str] = None
    country: Optional[str] = None
    container_key: Optional[str] = None

    @field_validator("trailer_number", mode="before")
    @classmethod
    def strip_trailer_number(cls, v: object) -> object:
        if isinstance(v, str):
            return v.strip()
        return v

    @field_validator("trailer_type_key", mode="before")
    @classmethod
    def trailer_type_key_optional_fk(cls, v: object) -> Optional[str]:
        """Empty string from JSON must become NULL for FK; normalize case for catalog match."""
        if v is None:
            return None
        if not isinstance(v, str):
            return None
        s = v.strip().upper()
        return None if s == "" else s

    @field_validator(
        "ace_trailer_number",
        "seal",
        "entity_code",
        "plate_number",
        "state",
        "country",
        "container_key",
        mode="before",
    )
    @classmethod
    def empty_optional_str_to_none(cls, v: object) -> Optional[str]:
        """JSON often sends ''; nullable columns should get NULL, not ''."""
        if v is None:
            return None
        if not isinstance(v, str):
            return None
        s = v.strip()
        return None if s == "" else s


class TrailerCreateDTO(TrailerBaseDTO):
    """Schema for creating a trailer"""
    pass


class TrailerUpdateDTO(TrailerBaseDTO):
    """Schema for updating a trailer"""
    trailer_number: Optional[str] = Field(None, description="Trailer number (cannot be modified)")


class TrailerResponseDTO(TrailerBaseDTO):
    """Schema for trailer response"""
    company_id: int
    tenant_id: int

    class Config:
        from_attributes = True