from __future__ import annotations

from datetime import date, datetime

from pydantic import BaseModel, ConfigDict, Field

from .models import BaseUnit, Role


# ---- Auth / Users ----
class Token(BaseModel):
    access_token: str
    token_type: str = "bearer"
    role: Role
    username: str


class UserOut(BaseModel):
    model_config = ConfigDict(from_attributes=True)
    id: int
    username: str
    role: Role
    created_at: datetime


class UserCreate(BaseModel):
    username: str = Field(min_length=1, max_length=64)
    password: str = Field(min_length=4, max_length=255)
    role: Role = Role.user


class UserUpdate(BaseModel):
    password: str | None = Field(default=None, min_length=4, max_length=255)
    role: Role | None = None


# ---- Groups ----
class GroupOut(BaseModel):
    model_config = ConfigDict(from_attributes=True)
    id: int
    name: str
    min_stock: float | None = None
    # angereichert:
    product_count: int = 0
    stock: float = 0.0


class GroupCreate(BaseModel):
    name: str = Field(min_length=1, max_length=120)
    min_stock: float | None = Field(default=None, ge=0)


class GroupUpdate(BaseModel):
    name: str | None = Field(default=None, min_length=1, max_length=120)
    min_stock: float | None = Field(default=None, ge=0)


# ---- Locations ----
class LocationOut(BaseModel):
    model_config = ConfigDict(from_attributes=True)
    id: int
    name: str
    parent_id: int | None = None


class LocationCreate(BaseModel):
    name: str = Field(min_length=1, max_length=120)
    parent_id: int | None = None


# ---- Products ----
class ProductBase(BaseModel):
    barcode: str | None = None
    name: str = Field(min_length=1, max_length=255)
    brand: str | None = None
    image_url: str | None = None
    base_unit: BaseUnit = BaseUnit.piece
    package_size: float | None = Field(default=None, gt=0)
    group_id: int | None = None
    min_stock: float | None = Field(default=None, ge=0)


class ProductCreate(ProductBase):
    pass


class ProductUpdate(BaseModel):
    barcode: str | None = None
    name: str | None = Field(default=None, min_length=1, max_length=255)
    brand: str | None = None
    image_url: str | None = None
    base_unit: BaseUnit | None = None
    package_size: float | None = Field(default=None, gt=0)
    group_id: int | None = None
    min_stock: float | None = Field(default=None, ge=0)


class ProductOut(BaseModel):
    model_config = ConfigDict(from_attributes=True)
    id: int
    barcode: str | None
    name: str
    brand: str | None
    image_url: str | None
    base_unit: BaseUnit
    package_size: float | None
    group_id: int | None
    min_stock: float | None
    source: str
    created_at: datetime
    # angereichert:
    stock: float = 0.0


class LookupResult(BaseModel):
    found: bool
    existing_product: ProductOut | None = None
    suggestion: dict | None = None


# ---- Stock movements ----
class CheckInRequest(BaseModel):
    product_id: int | None = None
    barcode: str | None = None
    quantity: float = Field(gt=0)
    unit: str
    best_before: date | None = None
    location_id: int | None = None
    note: str | None = None


class CheckOutRequest(BaseModel):
    product_id: int | None = None
    barcode: str | None = None
    quantity: float = Field(gt=0)
    unit: str
    note: str | None = None


class LotOut(BaseModel):
    model_config = ConfigDict(from_attributes=True)
    id: int
    product_id: int
    quantity: float
    best_before: date | None
    location_id: int | None
    created_at: datetime


class CheckInResponse(BaseModel):
    lot: LotOut
    product_stock: float


class CheckInLine(BaseModel):
    """Eine Charge innerhalb eines Sammel-Einlagerns (Menge + eigenes MHD)."""
    quantity: float = Field(gt=0)
    best_before: date | None = None
    location_id: int | None = None


class BatchCheckInRequest(BaseModel):
    product_id: int | None = None
    barcode: str | None = None
    unit: str
    lines: list[CheckInLine] = Field(min_length=1)
    note: str | None = None


class BatchCheckInResponse(BaseModel):
    lots: list[LotOut]
    product_stock: float


class CheckOutResponse(BaseModel):
    affected_lots: list[dict]
    product_stock: float


# ---- Views ----
class ShoppingItem(BaseModel):
    product_id: int
    name: str
    base_unit: BaseUnit
    package_size: float | None = None
    stock: float
    min_stock: float
    deficit: float


class ExpiringItem(BaseModel):
    lot_id: int
    product_id: int
    product_name: str
    quantity: float
    base_unit: BaseUnit
    best_before: date
    days_left: int


class GroupShoppingItem(BaseModel):
    group_id: int
    name: str
    stock: float
    min_stock: float
    deficit: float
    product_count: int


class MovementOut(BaseModel):
    id: int
    product_id: int
    product_name: str
    type: str
    quantity: float
    base_unit: BaseUnit
    unit_used: str
    username: str | None
    note: str | None
    created_at: datetime


class SettingOut(BaseModel):
    key: str
    value: str