service-finder/backend/app/schemas/asset.py

# /opt/docker/dev/service_finder/backend/app/schemas/asset.py
from pydantic import BaseModel, ConfigDict, Field, validator, root_validator, model_validator, field_validator
from typing import Optional, Dict, Any, List
from uuid import UUID
from datetime import datetime, date

class AssetCatalogResponse(BaseModel):
    """ A technikai katalógus (Master Data) teljes adattartalma. """
    id: int
    make: str
    model: str
    generation: Optional[str] = None
    engine_variant: Optional[str] = None
    year_from: Optional[int] = None
    year_to: Optional[int] = None
    vehicle_class: Optional[str] = None
    fuel_type: Optional[str] = None
    
    # Technikai paraméterek az automatizáláshoz
    power_kw: Optional[int] = None
    engine_capacity: Optional[int] = None
    max_weight_kg: Optional[int] = None
    axle_count: Optional[int] = None
    euro_class: Optional[str] = None
    body_type: Optional[str] = None
    engine_code: Optional[str] = None
    
    factory_data: Dict[str, Any] = Field(default_factory=dict)
    
    model_config = ConfigDict(from_attributes=True)

class AssetResponse(BaseModel):
    """ A konkrét járműpéldány (Asset) teljes válaszmodellje - Thick Digital Twin. """
    # === IDENTIFICATION ===
    id: UUID
    vin: Optional[str] = Field(None, min_length=1, max_length=50)
    license_plate: Optional[str] = None
    name: Optional[str] = None
    catalog_id: Optional[int] = None
    
    # === CLASSIFICATION ===
    vehicle_class: Optional[str] = None
    brand: Optional[str] = None
    model: Optional[str] = None
    trim_level: Optional[str] = None
    
    # === TECHNICAL SPECS ===
    fuel_type: Optional[str] = None
    engine_capacity: Optional[int] = None
    power_kw: Optional[int] = None
    torque_nm: Optional[int] = None
    cylinder_layout: Optional[str] = None
    transmission_type: Optional[str] = None
    drive_type: Optional[str] = None
    euro_classification: Optional[str] = None
    
    # === PHYSICAL DIMENSIONS ===
    curb_weight: Optional[int] = None
    max_weight: Optional[int] = None
    cargo_volume_x: Optional[float] = None
    cargo_volume_y: Optional[float] = None
    door_count: Optional[int] = None
    seat_count: Optional[int] = None
    
    # === EQUIPMENT ===
    roof_type: Optional[str] = None
    audio_system_type: Optional[str] = None
    individual_equipment: Dict[str, Any] = Field(default_factory=dict)
    
    # === STATUS ===
    current_mileage: int = Field(default=0)
    condition_score: int = Field(default=100)
    status: str
    data_status: Optional[str] = None
    is_verified: bool
    verification_method: Optional[str] = None
    catalog_match_score: Optional[float] = None
    
    # === TIMELINE ===
    year_of_manufacture: Optional[int] = None
    first_registration_date: Optional[datetime] = None
    created_at: datetime
    updated_at: Optional[datetime] = None
    
    # === WARRANTY ===
    is_under_warranty: bool = Field(default=False, description="Érvényes jótállás")
    warranty_expiry_date: Optional[datetime] = Field(None, description="Jótállás érvényességi dátuma")

    # === REGISTRATION DOCUMENTS ===
    registration_certificate_number: Optional[str] = Field(None, max_length=50, description="Forgalmi engedély száma")
    registration_certificate_validity: Optional[datetime] = Field(None, description="Forgalmi engedély érvényességi ideje")
    vehicle_registration_document_number: Optional[str] = Field(None, max_length=50, description="Törzskönyv száma")

    # === INTERNATIONALIZATION (ÚJ) ===
    registration_country: Optional[str] = Field(None, min_length=2, max_length=2, description="Regisztráció országa (ISO 3166-1 alpha-2, pl. 'HU', 'SK', 'DE')")
    first_domestic_registration_date: Optional[date] = Field(None, description="Első belföldi forgalomba helyezés dátuma")
    import_country: Optional[str] = Field(None, min_length=2, max_length=2, description="Importország (ISO 3166-1 alpha-2), ha importált jármű")
    title_document_number: Optional[str] = Field(None, max_length=50, description="Törzskönyv szám (title document)")
    engine_number: Optional[str] = Field(None, max_length=100, description="Motorszám")
    number_of_previous_owners: Optional[int] = Field(None, ge=0, description="Előző tulajdonosok száma")

    # === SALES MODULE ===
    is_for_sale: bool = Field(default=False)
    price: Optional[float] = None
    currency: str = Field(default="EUR")
    
    # === ORGANIZATION & LOCATION ===
    current_organization_id: Optional[int] = None
    branch_id: Optional[UUID] = None
    relocation_performed: bool = Field(default=False)
    
    # === IDENTITY RELATIONSHIPS ===
    owner_organization_id: Optional[int] = None
    operator_person_id: Optional[int] = None
    owner_person_id: Optional[int] = None
    operator_org_id: Optional[int] = None
    
    # === CATALOG RELATIONSHIP ===
    catalog: Optional[AssetCatalogResponse] = None
    
    # === PROFILE COMPLETION ===
    profile_completion_percentage: int = Field(default=0, ge=0, le=100)
    
    # === PRIMARY VEHICLE FLAG ===
    is_primary: bool = Field(default=False, description="Elsődleges jármű (tárolva: individual_equipment JSONB)")
    
    model_config = ConfigDict(from_attributes=True)


class AssetCreate(BaseModel):
    """ Jármű létrehozásához szükséges adatok - Thick Digital Twin támogatással. """
    # === CORE IDENTIFICATION (Required for status determination) ===
    license_plate: Optional[str] = Field(None, min_length=2, max_length=20, description="Rendszám")
    vin: Optional[str] = Field(None, min_length=1, max_length=50, description="VIN szám (opcionális)")

    # ── Pre-validator: convert empty strings to None for optional string fields ──
    @validator('license_plate', 'vin', 'trim_level',
               'cylinder_layout', 'transmission_type', 'drive_type',
               'euro_classification', 'roof_type', 'audio_system_type',
               'data_status',
               pre=True, always=True)
    def empty_str_to_none(cls, v):
        """Convert empty strings to None so Pydantic doesn't reject them with min_length."""
        if v is not None and isinstance(v, str) and v.strip() == '':
            return None
        return v
    
    # ── Data normalization validators ──
    @field_validator('brand')
    @classmethod
    def normalize_brand(cls, v: Optional[str]) -> Optional[str]:
        """Brand: UPPERCASE, strip whitespace."""
        if v is None or not isinstance(v, str):
            return v
        return v.strip().upper()

    @field_validator('model')
    @classmethod
    def normalize_model(cls, v: Optional[str]) -> Optional[str]:
        """Model: UPPERCASE, remove ALL spaces."""
        if v is None or not isinstance(v, str):
            return v
        return v.upper().replace(' ', '')

    # ── Model validator: normalize type_designation inside individual_equipment ──
    @model_validator(mode='after')
    def normalize_individual_equipment(self):
        """Normalize type_designation inside individual_equipment.car_specs.
        
        SAFE None handling: checks every level before calling .upper().
        - individual_equipment may be None or empty dict
        - car_specs may be None or missing key
        - type_designation may be None, empty string, or a valid string
        """
        if not self.individual_equipment:
            return self
        if not isinstance(self.individual_equipment, dict):
            return self
            
        car_specs = self.individual_equipment.get('car_specs')
        if not car_specs or not isinstance(car_specs, dict):
            return self
            
        td = car_specs.get('type_designation')
        if td is not None and isinstance(td, str) and td.strip():
            car_specs['type_designation'] = td.strip().upper().replace(' ', '')
        return self
    
    # ── Root validator: ensure at least one of vin or license_plate is provided ──
    @root_validator(skip_on_failure=True)
    def validate_vin_or_plate(cls, values):
        """Legalább egy azonosítót meg kell adni: rendszám VAGY VIN szám."""
        license_plate = values.get('license_plate')
        vin = values.get('vin')
        if not license_plate and not vin:
            raise ValueError('Legalább egy azonosítót meg kell adni: rendszám VAGY VIN szám.')
        return values
    
    # === CLASSIFICATION (Optional, but affects status) ===
    brand: Optional[str] = Field(None, max_length=100, description="Márka (ha nincs catalog_id)")
    model: Optional[str] = Field(None, max_length=100, description="Modell (ha nincs catalog_id)")
    vehicle_class: Optional[str] = Field(None, max_length=50, description="Járműosztály")
    fuel_type: Optional[str] = Field(None, max_length=50, description="Üzemanyag típus")
    
    # === TECHNICAL SPECS (Optional) ===
    catalog_id: Optional[int] = Field(None, description="Opcionális katalógus ID (ha ismert a modell)")
    engine_capacity: Optional[int] = Field(None, ge=0, description="Hengerűrtartalom (cm³)")
    power_kw: Optional[int] = Field(None, ge=0, description="Teljesítmény (kW)")
    torque_nm: Optional[int] = Field(None, ge=0, description="Nyomaték (Nm)")
    cylinder_layout: Optional[str] = Field(None, max_length=50, description="Hengerelrendezés")
    transmission_type: Optional[str] = Field(None, max_length=50, description="Váltó típus")
    drive_type: Optional[str] = Field(None, max_length=50, description="Hajtás")
    euro_classification: Optional[str] = Field(None, max_length=10, description="EURO besorolás")
    
    # === PHYSICAL DIMENSIONS (Optional) ===
    curb_weight: Optional[int] = Field(None, ge=0, description="Saját tömeg (kg)")
    max_weight: Optional[int] = Field(None, ge=0, description="Össztömeg (kg)")
    cargo_volume_x: Optional[float] = Field(None, ge=0, description="Csomagtartó hossz (cm)")
    cargo_volume_y: Optional[float] = Field(None, ge=0, description="Csomagtartó szélesség (cm)")
    door_count: Optional[int] = Field(None, ge=0, description="Ajtók száma")
    seat_count: Optional[int] = Field(None, ge=0, description="Ülések száma")
    
    # === EQUIPMENT (Optional) ===
    trim_level: Optional[str] = Field(None, max_length=100, description="Felszereltségi szint")
    roof_type: Optional[str] = Field(None, max_length=50, description="Tető típus")
    audio_system_type: Optional[str] = Field(None, max_length=100, description="Hangrendszer")
    individual_equipment: Optional[Dict[str, Any]] = Field(default_factory=dict, description="Egyedi felszerelések")
    
    # === MILEAGE (Optional) ===
    current_mileage: Optional[int] = Field(None, ge=0, description="Aktuális km óra állás")

    # === TIMELINE (Optional) ===
    year_of_manufacture: Optional[int] = Field(None, ge=1900, le=2100, description="Gyártási év")
    first_registration_date: Optional[datetime] = Field(None, description="Első forgalomba helyezés dátuma")
    
    # === ORGANIZATION (Optional) ===
    organization_id: Optional[int] = Field(None, description="Szervezet ID (alapértelmezett a felhasználó szervezete)")
    branch_id: Optional[UUID] = Field(None, description="Garázs (Branch) ID, ahova a járművet rendeljük. Ha nincs megadva, a szervezet központi garázsába kerül.")
    
    # === WARRANTY ===
    is_under_warranty: bool = Field(default=False, description="Érvényes jótállás")
    warranty_expiry_date: Optional[datetime] = Field(None, description="Jótállás érvényességi dátuma")

    # === REGISTRATION DOCUMENTS ===
    registration_certificate_number: Optional[str] = Field(None, max_length=50, description="Forgalmi engedély száma")
    registration_certificate_validity: Optional[datetime] = Field(None, description="Forgalmi engedély érvényességi ideje")
    vehicle_registration_document_number: Optional[str] = Field(None, max_length=50, description="Törzskönyv száma")

    # === INTERNATIONALIZATION (ÚJ) ===
    registration_country: Optional[str] = Field(None, min_length=2, max_length=2, description="Regisztráció országa (ISO 3166-1 alpha-2, pl. 'HU', 'SK', 'DE')")
    first_domestic_registration_date: Optional[date] = Field(None, description="Első belföldi forgalomba helyezés dátuma")
    import_country: Optional[str] = Field(None, min_length=2, max_length=2, description="Importország (ISO 3166-1 alpha-2), ha importált jármű")
    title_document_number: Optional[str] = Field(None, max_length=50, description="Törzskönyv szám (title document)")
    engine_number: Optional[str] = Field(None, max_length=100, description="Motorszám")
    number_of_previous_owners: Optional[int] = Field(None, ge=0, description="Előző tulajdonosok száma")

    # === PRIMARY VEHICLE FLAG ===
    is_primary: bool = Field(default=False, description="Elsődleges jármű (tárolva: individual_equipment JSONB)")
    
    # === DATA STATUS (for transfer/duplicate scenarios) ===
    data_status: Optional[str] = Field(None, description="Adat státusz (pl. 'draft' tulajdonosváltáskor)")
    
    # ── Internationalization validators ──
    @field_validator('registration_country', 'import_country')
    @classmethod
    def validate_iso_country(cls, v: Optional[str]) -> Optional[str]:
        """registration_country és import_country: pontosan 2 karakteres nagybetűs string (ISO 3166-1 alpha-2)."""
        if v is None or not isinstance(v, str):
            return v
        cleaned = v.strip().upper()
        if len(cleaned) != 2:
            raise ValueError(f'Az országkódnak pontosan 2 karakter hosszúnak kell lennie (ISO 3166-1 alpha-2), kapott: "{v}"')
        return cleaned

    @field_validator('number_of_previous_owners')
    @classmethod
    def validate_previous_owners(cls, v: Optional[int]) -> Optional[int]:
        """number_of_previous_owners >= 0."""
        if v is not None and v < 0:
            raise ValueError('Az előző tulajdonosok száma nem lehet negatív')
        return v

    @field_validator('first_domestic_registration_date')
    @classmethod
    def validate_not_future_date(cls, v: Optional[date]) -> Optional[date]:
        """first_domestic_registration_date nem lehet jövőbeli dátum."""
        if v is not None and v > date.today():
            raise ValueError('Az első belföldi forgalomba helyezés dátuma nem lehet jövőbeli')
        return v

    # === STATUS VALIDATION ===
    @validator('status', pre=True, always=True)
    def determine_status(cls, v, values):
        """Automatikus státusz meghatározás az adatkomplettség alapján."""
        if v is not None:
            return v
            
        # Ellenőrizzük az 5 alapvető mezőt
        required_fields = ['license_plate', 'brand', 'model', 'vehicle_class', 'fuel_type']
        has_all_required = all(
            values.get(field) is not None and str(values.get(field)).strip() != ''
            for field in required_fields
        )
        
        return "active" if has_all_required else "draft"
    
    # === COMPUTED FIELD: status ===
    status: Optional[str] = Field(None, description="Automatikusan számított státusz (draft/active)")
    
    model_config = ConfigDict(from_attributes=True)


class AssetUpdate(BaseModel):
    """ Jármű adatainak frissítése - minden mező opcionális. """
    # === CORE IDENTIFICATION ===
    license_plate: Optional[str] = Field(None, min_length=2, max_length=20, description="Rendszám")
    vin: Optional[str] = Field(None, min_length=1, max_length=50, description="VIN szám")

    # ── Pre-validator: convert empty strings to None for optional string fields ──
    @validator('license_plate', 'vin', 'trim_level',
               'cylinder_layout', 'transmission_type', 'drive_type',
               'euro_classification', 'roof_type', 'audio_system_type',
               pre=True, always=True)
    def empty_str_to_none(cls, v):
        """Convert empty strings to None so Pydantic doesn't reject them with min_length."""
        if v is not None and isinstance(v, str) and v.strip() == '':
            return None
        return v
    
    # ── Data normalization validators ──
    @field_validator('brand')
    @classmethod
    def normalize_brand(cls, v: Optional[str]) -> Optional[str]:
        """Brand: UPPERCASE, strip whitespace."""
        if v is None or not isinstance(v, str):
            return v
        return v.strip().upper()

    @field_validator('model')
    @classmethod
    def normalize_model(cls, v: Optional[str]) -> Optional[str]:
        """Model: UPPERCASE, remove ALL spaces."""
        if v is None or not isinstance(v, str):
            return v
        return v.upper().replace(' ', '')

    # ── Model validator: normalize type_designation inside individual_equipment ──
    @model_validator(mode='after')
    def normalize_individual_equipment(self):
        """Normalize type_designation inside individual_equipment.car_specs.
        
        SAFE None handling: checks every level before calling .upper().
        - individual_equipment may be None or empty dict
        - car_specs may be None or missing key
        - type_designation may be None, empty string, or a valid string
        """
        if not self.individual_equipment:
            return self
        if not isinstance(self.individual_equipment, dict):
            return self
            
        car_specs = self.individual_equipment.get('car_specs')
        if not car_specs or not isinstance(car_specs, dict):
            return self
            
        td = car_specs.get('type_designation')
        if td is not None and isinstance(td, str) and td.strip():
            car_specs['type_designation'] = td.strip().upper().replace(' ', '')
        return self
    
    # ── Model validator: ensure at least one of vin or license_plate is provided ──
    @model_validator(mode='after')
    def validate_vin_or_plate(self):
        """Update esetén: ha mindkét mezőt None-ra állítják explicit, az nem engedélyezett.
        
        Működés:
        - Ha egyik mező sincs a payload-ban (üres update) → engedélyezve (nincs változás)
        - Ha mindkettő None explicit → hiba (nem lehet mindkettőt elvenni)
        - Ha legalább az egyik meg van adva → OK
        """
        # model_fields_set tartalmazza az explicit megadott mezőket
        if 'license_plate' not in self.model_fields_set and 'vin' not in self.model_fields_set:
            return self
        
        if not self.license_plate and not self.vin:
            raise ValueError('Legalább egy azonosítót meg kell adni: rendszám VAGY VIN szám.')
        return self
    
    # === CLASSIFICATION ===
    brand: Optional[str] = Field(None, max_length=100, description="Márka")
    model: Optional[str] = Field(None, max_length=100, description="Modell")
    vehicle_class: Optional[str] = Field(None, max_length=50, description="Járműosztály")
    fuel_type: Optional[str] = Field(None, max_length=50, description="Üzemanyag típus")
    
    # === TECHNICAL SPECS ===
    catalog_id: Optional[int] = Field(None, description="Katalógus ID")
    engine_capacity: Optional[int] = Field(None, ge=0, description="Hengerűrtartalom (cm³)")
    power_kw: Optional[int] = Field(None, ge=0, description="Teljesítmény (kW)")
    torque_nm: Optional[int] = Field(None, ge=0, description="Nyomaték (Nm)")
    cylinder_layout: Optional[str] = Field(None, max_length=50, description="Hengerelrendezés")
    transmission_type: Optional[str] = Field(None, max_length=50, description="Váltó típus")
    drive_type: Optional[str] = Field(None, max_length=50, description="Hajtás")
    euro_classification: Optional[str] = Field(None, max_length=10, description="EURO besorolás")
    
    # === PHYSICAL DIMENSIONS ===
    curb_weight: Optional[int] = Field(None, ge=0, description="Saját tömeg (kg)")
    max_weight: Optional[int] = Field(None, ge=0, description="Össztömeg (kg)")
    cargo_volume_x: Optional[float] = Field(None, ge=0, description="Csomagtartó hossz (cm)")
    cargo_volume_y: Optional[float] = Field(None, ge=0, description="Csomagtartó szélesség (cm)")
    door_count: Optional[int] = Field(None, ge=0, description="Ajtók száma")
    seat_count: Optional[int] = Field(None, ge=0, description="Ülések száma")
    
    # === EQUIPMENT ===
    trim_level: Optional[str] = Field(None, max_length=100, description="Felszereltségi szint")
    roof_type: Optional[str] = Field(None, max_length=50, description="Tető típus")
    audio_system_type: Optional[str] = Field(None, max_length=100, description="Hangrendszer")
    individual_equipment: Optional[Dict[str, Any]] = Field(None, description="Egyedi felszerelések")
    
    # === TIMELINE ===
    year_of_manufacture: Optional[int] = Field(None, ge=1900, le=2100, description="Gyártási év")
    first_registration_date: Optional[datetime] = Field(None, description="Első forgalomba helyezés dátuma")
    
    # === WARRANTY ===
    is_under_warranty: Optional[bool] = Field(None, description="Érvényes jótállás")
    warranty_expiry_date: Optional[datetime] = Field(None, description="Jótállás érvényességi dátuma")

    # === REGISTRATION DOCUMENTS ===
    registration_certificate_number: Optional[str] = Field(None, max_length=50, description="Forgalmi engedély száma")
    registration_certificate_validity: Optional[datetime] = Field(None, description="Forgalmi engedély érvényességi ideje")
    vehicle_registration_document_number: Optional[str] = Field(None, max_length=50, description="Törzskönyv száma")

    # === INTERNATIONALIZATION (ÚJ) ===
    registration_country: Optional[str] = Field(None, min_length=2, max_length=2, description="Regisztráció országa (ISO 3166-1 alpha-2, pl. 'HU', 'SK', 'DE')")
    first_domestic_registration_date: Optional[date] = Field(None, description="Első belföldi forgalomba helyezés dátuma")
    import_country: Optional[str] = Field(None, min_length=2, max_length=2, description="Importország (ISO 3166-1 alpha-2), ha importált jármű")
    title_document_number: Optional[str] = Field(None, max_length=50, description="Törzskönyv szám (title document)")
    engine_number: Optional[str] = Field(None, max_length=100, description="Motorszám")
    number_of_previous_owners: Optional[int] = Field(None, ge=0, description="Előző tulajdonosok száma")

    # ── Internationalization validators ──
    @field_validator('registration_country', 'import_country')
    @classmethod
    def validate_iso_country(cls, v: Optional[str]) -> Optional[str]:
        """registration_country és import_country: pontosan 2 karakteres nagybetűs string (ISO 3166-1 alpha-2)."""
        if v is None or not isinstance(v, str):
            return v
        cleaned = v.strip().upper()
        if len(cleaned) != 2:
            raise ValueError(f'Az országkódnak pontosan 2 karakter hosszúnak kell lennie (ISO 3166-1 alpha-2), kapott: "{v}"')
        return cleaned

    @field_validator('number_of_previous_owners')
    @classmethod
    def validate_previous_owners(cls, v: Optional[int]) -> Optional[int]:
        """number_of_previous_owners >= 0."""
        if v is not None and v < 0:
            raise ValueError('Az előző tulajdonosok száma nem lehet negatív')
        return v

    @field_validator('first_domestic_registration_date')
    @classmethod
    def validate_not_future_date(cls, v: Optional[date]) -> Optional[date]:
        """first_domestic_registration_date nem lehet jövőbeli dátum."""
        if v is not None and v > date.today():
            raise ValueError('Az első belföldi forgalomba helyezés dátuma nem lehet jövőbeli')
        return v

    # === STATUS ===
    current_mileage: Optional[int] = Field(None, ge=0, description="Aktuális km óra állás")
    is_primary: Optional[bool] = Field(None, description="Elsődleges jármű")
    
    model_config = ConfigDict(from_attributes=True)


class AssetEventCreate(BaseModel):
    """Schema for creating a new AssetEvent (Service Book entry)."""
    event_type: str = Field(..., description="Event type: SERVICE, REPAIR, ACCIDENT, INSPECTION, TIRE_CHANGE, MAINTENANCE, UPGRADE, RECALL")
    event_date: Optional[datetime] = Field(None, description="Event date (default: now)")
    odometer_reading: Optional[int] = Field(None, ge=0, description="Odometer reading at event time")
    description: Optional[str] = Field(None, max_length=2000, description="Event description")
    cost_id: Optional[UUID] = Field(None, description="Associated cost record ID")
    cost_amount: Optional[float] = Field(None, gt=0, description="Cost amount in the given currency. If > 0, an AssetCost record is auto-created.")
    currency: Optional[str] = Field(None, min_length=3, max_length=3, description="Currency code (e.g. HUF, EUR). Defaults to HUF on backend.")
    status: Optional[str] = Field(None, description="Event status (DRAFT, MISSING_TECH_DATA, COMPLETED) - auto-set by backend")
    linked_expense_id: Optional[UUID] = Field(None, description="Associated AssetCost ID (bidirectional link)")

    model_config = ConfigDict(from_attributes=True)


class AssetEventResponse(BaseModel):
    """Schema for returning an AssetEvent."""
    id: UUID
    asset_id: UUID
    user_id: Optional[int] = None
    organization_id: Optional[int] = None
    event_type: str
    odometer_reading: Optional[int] = None
    description: Optional[str] = None
    cost_id: Optional[UUID] = None
    cost_amount: Optional[float] = Field(None, description="Auto-created cost amount")
    currency: Optional[str] = Field(None, description="Currency code (e.g. HUF)")
    status: str = "DRAFT"
    linked_expense_id: Optional[UUID] = None
    event_date: datetime
    created_at: datetime
    updated_at: Optional[datetime] = None

    model_config = ConfigDict(from_attributes=True)

    @classmethod
    def model_validate(cls, obj, **kwargs):
        """Override to resolve cost_amount and currency from the related AssetCost.
        
        GROSS-FIRST: cost_amount resolves from amount_gross (Bruttó) as primary source.
        """
        data = {}
        if hasattr(obj, '__dict__'):
            # Copy ORM attributes
            for field in cls.model_fields:
                if hasattr(obj, field):
                    data[field] = getattr(obj, field)
            
            # Resolve cost_amount and currency from the cost relationship
            cost = getattr(obj, 'cost', None)
            if cost is not None:
                if data.get('cost_amount') is None:
                    # GROSS-FIRST: prefer amount_gross as the source of truth
                    data['cost_amount'] = float(cost.amount_gross) if cost.amount_gross is not None else (
                        float(cost.amount_net) if cost.amount_net is not None else None
                    )
                if data.get('currency') is None:
                    data['currency'] = cost.currency
        return cls(**data)