"""Schémas Pydantic pour les objets d'inventaire.

Définit les schémas de validation pour les requêtes et réponses API.
"""

from datetime import date, datetime
from decimal import Decimal
from typing import Any

from pydantic import BaseModel, ConfigDict, Field, model_validator

from app.models.item import ItemStatus
from app.schemas.category import CategoryResponse
from app.schemas.location import LocationResponse


class ItemBase(BaseModel):
    """Schéma de base pour les objets."""

    name: str = Field(..., min_length=1, max_length=200, description="Nom de l'objet")
    description: str | None = Field(None, description="Description détaillée")
    quantity: int = Field(default=1, ge=0, description="Quantité en stock")
    status: ItemStatus = Field(default=ItemStatus.IN_STOCK, description="Statut de l'objet")
    brand: str | None = Field(None, max_length=100, description="Marque")
    model: str | None = Field(None, max_length=100, description="Modèle")
    serial_number: str | None = Field(None, max_length=100, description="Numéro de série")
    url: str | None = Field(None, max_length=500, description="Lien vers page produit")
    price: Decimal | None = Field(None, ge=0, decimal_places=2, description="Prix d'achat")
    purchase_date: date | None = Field(None, description="Date d'achat")
    characteristics: dict[str, str] | None = Field(None, description="Caractéristiques techniques (clé-valeur)")
    notes: str | None = Field(None, description="Notes libres")


class ItemCreate(ItemBase):
    """Schéma pour la création d'un objet."""

    category_id: int = Field(..., description="ID de la catégorie")
    location_id: int = Field(..., description="ID de l'emplacement")
    parent_item_id: int | None = Field(None, description="ID de l'objet parent (si intégré)")
    shop_id: int | None = Field(None, description="ID de la boutique d'achat")


class ItemUpdate(BaseModel):
    """Schéma pour la mise à jour d'un objet (tous les champs optionnels)."""

    name: str | None = Field(None, min_length=1, max_length=200)
    description: str | None = None
    quantity: int | None = Field(None, ge=0)
    status: ItemStatus | None = None
    brand: str | None = Field(None, max_length=100)
    model: str | None = Field(None, max_length=100)
    serial_number: str | None = Field(None, max_length=100)
    url: str | None = Field(None, max_length=500)
    price: Decimal | None = Field(None, ge=0)
    purchase_date: date | None = None
    characteristics: dict[str, str] | None = None
    notes: str | None = None
    category_id: int | None = None
    location_id: int | None = None
    parent_item_id: int | None = None
    shop_id: int | None = None


class ItemResponse(ItemBase):
    """Schéma de réponse pour un objet."""

    model_config = ConfigDict(from_attributes=True)

    id: int
    category_id: int
    location_id: int
    parent_item_id: int | None = None
    shop_id: int | None = None
    created_at: datetime
    updated_at: datetime


class ItemWithRelations(ItemResponse):
    """Schéma de réponse avec les relations (catégorie et emplacement)."""

    category: CategoryResponse
    location: LocationResponse
    thumbnail_id: int | None = None
    parent_item_name: str | None = None

    @model_validator(mode="before")
    @classmethod
    def extract_computed_fields(cls, data: Any) -> Any:
        """Extrait les champs calculés : thumbnail et nom du parent."""
        from sqlalchemy.orm import InstanceState

        thumbnail_id = None
        parent_item_name = None

        # Vérifier que les relations sont chargées (éviter lazy load en async)
        loaded_relations: set[str] = set()
        if hasattr(data, "_sa_instance_state"):
            state: InstanceState = data._sa_instance_state
            loaded_relations = set(state.dict.keys())

        if "documents" in loaded_relations:
            for doc in data.documents:
                if doc.type.value == "photo":
                    thumbnail_id = doc.id
                    break

        if "parent_item" in loaded_relations and data.parent_item is not None:
            parent_item_name = data.parent_item.name

        if isinstance(data, dict):
            if thumbnail_id:
                data["thumbnail_id"] = thumbnail_id
            if parent_item_name:
                data["parent_item_name"] = parent_item_name
        elif thumbnail_id or parent_item_name:
            result = {}
            for k in dir(data):
                if k.startswith("_"):
                    continue
                # Ne pas accéder aux relations non chargées
                if k in ("documents", "parent_item", "children", "shop"):
                    continue
                try:
                    result[k] = getattr(data, k)
                except Exception:
                    pass
            if thumbnail_id:
                result["thumbnail_id"] = thumbnail_id
            if parent_item_name:
                result["parent_item_name"] = parent_item_name
            return result

        return data


class ItemSummary(BaseModel):
    """Schéma résumé pour les listes d'objets."""

    model_config = ConfigDict(from_attributes=True)

    id: int
    name: str
    quantity: int
    status: ItemStatus
    brand: str | None
    category_id: int
    location_id: int


class ItemFilter(BaseModel):
    """Schéma pour filtrer les objets."""

    category_id: int | None = None
    location_id: int | None = None
    status: ItemStatus | None = None
    search: str | None = Field(None, min_length=2, description="Recherche textuelle")
    min_price: Decimal | None = None
    max_price: Decimal | None = None