from pydantic import BaseModel, Field, model_validator
from typing import Optional, List, Dict, Any
from decimal import Decimal
from datetime import datetime, date

# --- Brand ---
class BrandCreate(BaseModel):
    name: str = Field(..., min_length=1, max_length=100)
    logo_url: Optional[str] = Field(None, max_length=500)
    device_types: Optional[List[str]] = None

class BrandUpdate(BaseModel):
    name: Optional[str] = Field(None, min_length=1, max_length=100)
    logo_url: Optional[str] = Field(None, max_length=500)
    is_active: Optional[bool] = None
    device_types: Optional[List[str]] = None

class BrandResponse(BaseModel):
    brand_id: str
    name: str
    slug: str
    logo_url: Optional[str]
    is_active: bool
    device_types: List[str] = []
    created_at: Optional[datetime] = None

    class Config:
        from_attributes = True

# --- Category ---
class CategoryCreate(BaseModel):
    name: str = Field(..., min_length=1, max_length=100)
    parent_category_id: Optional[str] = Field(None, min_length=26, max_length=26)
    description: Optional[str] = Field(None, max_length=500)
    image_url: Optional[str] = Field(None, max_length=500)
    sort_order: Optional[str] = "0"
    is_parent_feature: bool = False

class CategoryUpdate(BaseModel):
    name: Optional[str] = Field(None, min_length=1, max_length=100)
    parent_category_id: Optional[str] = Field(None, min_length=26, max_length=26)
    description: Optional[str] = Field(None, max_length=500)
    image_url: Optional[str] = Field(None, max_length=500)
    sort_order: Optional[str] = None
    is_active: Optional[bool] = None
    is_parent_feature: Optional[bool] = None

class CategoryResponse(BaseModel):
    category_id: str
    parent_category_id: Optional[str]
    name: str
    slug: str
    description: Optional[str]
    image_url: Optional[str]
    sort_order: str
    is_parent_feature: bool = False
    is_active: bool
    created_at: Optional[datetime] = None

    class Config:
        from_attributes = True

# --- Category Parent Hierarchy (nested response) ---
class HierarchyModelItem(BaseModel):
    model_id: str
    name: str
    slug: str
    image_url: Optional[str] = None

class HierarchySeriesItem(BaseModel):
    series_id: str
    name: str
    slug: str
    models: List[HierarchyModelItem] = []

class HierarchyBrandItem(BaseModel):
    brand_id: str
    name: str
    slug: str
    logo_url: Optional[str] = None
    series: List[HierarchySeriesItem] = []

class CategoryParentHierarchyResponse(BaseModel):
    category_id: str
    brands: List[HierarchyBrandItem] = []

# --- Tag ---
class TagCreate(BaseModel):
    name: str = Field(..., min_length=1, max_length=100)

class TagResponse(BaseModel):
    tag_id: str
    name: str
    slug: str
    is_active: bool

    class Config:
        from_attributes = True

# --- Collection ---
class CollectionCreate(BaseModel):
    name: str = Field(..., min_length=1, max_length=100)
    description: Optional[str] = Field(None, max_length=500)

class CollectionResponse(BaseModel):
    collection_id: str
    name: str
    slug: str
    description: Optional[str]
    is_active: bool

    class Config:
        from_attributes = True

# --- SEO Metadata ---
class SeoMetadataCreate(BaseModel):
    entity_type: str = Field(..., description="product, category, brand, device_model, repair_service")
    entity_id: str
    meta_title: str = Field(..., max_length=255)
    meta_description: str
    canonical_url: Optional[str] = Field(None, max_length=500)
    og_image: Optional[str] = Field(None, max_length=500)
    schema_markup: Optional[Dict[str, Any]] = Field(None, alias="schema_json")

    class Config:
        populate_by_name = True
        from_attributes = True

class SeoMetadataResponse(BaseModel):
    seo_id: str
    entity_type: str
    entity_id: str
    meta_title: str
    meta_description: str
    canonical_url: Optional[str]
    og_image: Optional[str]
    schema_markup: Optional[Dict[str, Any]] = Field(None, alias="schema_json")

    class Config:
        populate_by_name = True
        from_attributes = True

# --- Part ---
class PartCreate(BaseModel):
    sku: str = Field(..., min_length=1, max_length=100)
    name: str = Field(..., min_length=1, max_length=255)
    cost_price: Decimal
    low_stock_alert: Optional[int] = 3
    supplier: Optional[str] = Field(None, max_length=255)
    barcode: Optional[str] = Field(None, max_length=100)

class PartUpdate(BaseModel):
    sku: Optional[str] = Field(None, min_length=1, max_length=100)
    name: Optional[str] = Field(None, min_length=1, max_length=255)
    cost_price: Optional[Decimal] = None
    low_stock_alert: Optional[int] = None
    supplier: Optional[str] = None
    barcode: Optional[str] = None
    is_active: Optional[bool] = None

class PartResponse(BaseModel):
    part_id: str
    sku: str
    name: str
    cost_price: Decimal
    low_stock_alert: int
    supplier: Optional[str]
    barcode: Optional[str]
    is_active: bool
    stock: int = 0  # computed from stock ledger

    class Config:
        from_attributes = True

# --- Part Compatibility ---
class PartDeviceCompatibilityCreate(BaseModel):
    part_id: str
    model_id: str

class PartDeviceCompatibilityResponse(BaseModel):
    id: str
    part_id: str
    model_id: str

    class Config:
        from_attributes = True

# --- Stock Movement ---
class StockMovementCreate(BaseModel):
    entity_type: str = Field(..., description="variant or part")
    entity_id: str
    movement_type: str = Field(..., description="Purchase, Sale, Repair, Adjustment, Return, Transfer, Damage")
    quantity: int
    reference_type: str = Field(..., description="Order, PurchaseOrder, RepairBooking, ManualAdjustment")
    reference_id: str

class StockMovementResponse(BaseModel):
    movement_id: str
    entity_type: str
    entity_id: str
    movement_type: str
    quantity: int
    reference_type: str
    reference_id: str
    created_at: datetime

    class Config:
        from_attributes = True

# --- Purchase Order ---
class PurchaseOrderItemCreate(BaseModel):
    part_id: str
    quantity_ordered: int
    unit_price: Decimal

class PurchaseOrderCreate(BaseModel):
    supplier_name: str = Field(..., min_length=1, max_length=255)
    items: List[PurchaseOrderItemCreate]

class PurchaseOrderUpdate(BaseModel):
    status: Optional[str] = None # Draft, Ordered, Received, Cancelled
    items_received: Optional[List[Dict[str, Any]]] = None # list of {"id": item_id, "quantity_received": int}

class PurchaseOrderItemResponse(BaseModel):
    id: str
    part_id: str
    quantity_ordered: int
    quantity_received: int
    unit_price: Decimal

    class Config:
        from_attributes = True

class PurchaseOrderResponse(BaseModel):
    purchase_order_id: str
    po_number: str
    supplier_name: str
    status: str
    total_amount: Decimal
    created_at: datetime
    items: List[PurchaseOrderItemResponse]

    class Config:
        from_attributes = True

# --- Device Series ---
class DeviceSeriesCreate(BaseModel):
    brand_id: str
    name: str = Field(..., min_length=1, max_length=100)
    device_type: Optional[str] = None # laptop, tablet, mobile
    sort_order: Optional[int] = 0

class DeviceSeriesUpdate(BaseModel):
    brand_id: Optional[str] = None
    name: Optional[str] = None
    device_type: Optional[str] = None
    sort_order: Optional[int] = None
    is_active: Optional[bool] = None

class DeviceSeriesResponse(BaseModel):
    series_id: str
    brand_id: Optional[str] = None
    name: str
    slug: str
    device_type: Optional[str] = None
    sort_order: int
    is_active: bool

    class Config:
        from_attributes = True

# --- Device Model ---
class DeviceModelCreate(BaseModel):
    series_id: Optional[str] = None
    brand_id: Optional[str] = None
    name: str = Field(..., min_length=1, max_length=100)
    device_type: Optional[str] = None # laptop, tablet, mobile
    release_year: Optional[int] = None
    image_url: Optional[str] = Field(None, max_length=500)

class DeviceModelUpdate(BaseModel):
    series_id: Optional[str] = None
    brand_id: Optional[str] = None
    name: Optional[str] = None
    device_type: Optional[str] = None
    release_year: Optional[int] = None
    image_url: Optional[str] = None
    is_active: Optional[bool] = None

class DeviceModelResponse(BaseModel):
    model_id: str
    series_id: Optional[str] = None
    brand_id: Optional[str] = None
    name: str
    slug: str
    device_type: Optional[str] = None
    full_path: str
    release_year: Optional[int]
    image_url: Optional[str]
    is_active: bool

    class Config:
        from_attributes = True

# --- Service Type ---
class ServiceTypeCreate(BaseModel):
    name: str = Field(..., min_length=1, max_length=100)
    icon_url: Optional[str] = Field(None, max_length=500)
    description: Optional[str] = Field(None, max_length=500)

class ServiceTypeUpdate(BaseModel):
    name: Optional[str] = None
    icon_url: Optional[str] = None
    description: Optional[str] = None
    is_active: Optional[bool] = None

class ServiceTypeResponse(BaseModel):
    service_type_id: str
    name: str
    slug: str
    icon_url: Optional[str]
    description: Optional[str]
    is_active: bool

    class Config:
        from_attributes = True

# --- Repair Service ---
class RepairServiceCreate(BaseModel):
    model_id: str
    service_type_id: str
    description: Optional[str] = Field(None, max_length=1000)

class RepairServiceUpdate(BaseModel):
    model_id: Optional[str] = None
    service_type_id: Optional[str] = None
    description: Optional[str] = None

class RepairServiceResponse(BaseModel):
    repair_service_id: str
    model_id: str
    service_type_id: str
    slug: str
    full_path: str
    description: Optional[str]

    class Config:
        from_attributes = True

# --- Repair Variant & BOM Part ---
class RepairVariantPartCreate(BaseModel):
    part_id: str
    quantity: Optional[int] = 1

class RepairVariantCreate(BaseModel):
    repair_service_id: str
    name: str = Field(..., min_length=1, max_length=100)
    price: Decimal
    cost: Optional[Decimal] = Decimal(0.0)
    duration_minutes: Optional[int] = 45
    warranty_days: Optional[int] = 90
    parts: Optional[List[RepairVariantPartCreate]] = []

class RepairVariantUpdate(BaseModel):
    repair_service_id: Optional[str] = None
    name: Optional[str] = None
    price: Optional[Decimal] = None
    cost: Optional[Decimal] = None
    duration_minutes: Optional[int] = None
    warranty_days: Optional[int] = None
    parts: Optional[List[RepairVariantPartCreate]] = None
    status: Optional[str] = None

class RepairVariantPartResponse(BaseModel):
    id: str
    variant_id: str
    part_id: str
    quantity: int

    class Config:
        from_attributes = True

class RepairVariantResponse(BaseModel):
    variant_id: str
    repair_service_id: str
    name: str
    price: Decimal
    cost: Decimal
    duration_minutes: int
    warranty_days: int
    status: str
    created_at: datetime
    bom_parts: List[RepairVariantPartResponse] = []

    class Config:
        from_attributes = True

# --- Attribute Type ---
class AttributeTypeCreate(BaseModel):
    name: str = Field(..., min_length=1, max_length=100)
    code: str = Field(..., min_length=1, max_length=100)
    preset_values: Optional[List[str]] = []

class AttributeTypeUpdate(BaseModel):
    name: Optional[str] = None
    code: Optional[str] = None
    preset_values: Optional[List[str]] = None

class AttributeTypeResponse(BaseModel):
    attribute_id: str
    name: str
    code: str
    status: str
    preset_values: Optional[List[str]] = []

    class Config:
        from_attributes = True

# --- Variant Attribute ---
class VariantAttributeCreate(BaseModel):
    attribute_id: str
    attribute_value: str = Field(..., min_length=1, max_length=255)

class VariantAttributeResponse(BaseModel):
    id: str
    variant_id: str
    attribute_id: str
    attribute_value: str
    attribute_name: Optional[str] = None
    attribute_code: Optional[str] = None

    @model_validator(mode="before")
    @classmethod
    def resolve_attribute_type(cls, data: Any) -> Any:
        if not isinstance(data, dict) and hasattr(data, "attribute_type") and data.attribute_type:
            return {
                "id": data.id,
                "variant_id": data.variant_id,
                "attribute_id": data.attribute_id,
                "attribute_value": data.attribute_value,
                "attribute_name": data.attribute_type.name,
                "attribute_code": data.attribute_type.code
            }
        return data

    class Config:
        from_attributes = True

# --- Product Image ---
class ProductImageCreate(BaseModel):
    image_url: str = Field(..., max_length=500)
    alt_text: Optional[str] = Field(None, max_length=255)
    sort_order: Optional[int] = 0
    is_banner: Optional[bool] = False

class ProductImageResponse(BaseModel):
    image_id: str
    product_id: str
    image_url: str
    alt_text: Optional[str]
    sort_order: int
    is_banner: bool

    class Config:
        from_attributes = True

# --- Variant Image ---
class VariantImageCreate(BaseModel):
    image_url: str = Field(..., max_length=500)
    sort_order: Optional[int] = 0
    is_primary: Optional[bool] = False

class VariantImageResponse(BaseModel):
    image_id: str
    variant_id: str
    image_url: str
    sort_order: int
    is_primary: bool

    class Config:
        from_attributes = True

# --- Product Variant ---
class ProductVariantCreate(BaseModel):
    sku: str = Field(..., min_length=1, max_length=100)
    barcode: Optional[str] = Field(None, max_length=100)
    price: Decimal
    compare_price: Optional[Decimal] = None
    cost_price: Decimal
    low_stock_threshold: Optional[int] = 5
    initial_stock: Optional[int] = Field(None, ge=0, description="Sellable units; create defaults to 0, update omitted means leave ledger unchanged")
    attributes: List[VariantAttributeCreate]
    images: Optional[List[VariantImageCreate]] = []

class ProductVariantResponse(BaseModel):
    variant_id: str
    product_id: str
    sku: str
    barcode: Optional[str]
    price: Decimal
    compare_price: Optional[Decimal]
    cost_price: Decimal
    low_stock_threshold: int
    status: str
    available_stock: int = 0
    attributes: List[VariantAttributeResponse] = []
    images: List[VariantImageResponse] = []

    class Config:
        from_attributes = True

# --- Product ---
class ProductCreate(BaseModel):
    category_id: str
    brand_id: Optional[str] = None
    device_series_id: Optional[str] = None
    device_model_id: Optional[str] = None
    device_type: Optional[str] = None # laptop, tablet, mobile
    name: str = Field(..., min_length=1, max_length=255)
    description: Optional[str] = Field(None, max_length=1000)
    images: Optional[List[ProductImageCreate]] = []
    variants: List[ProductVariantCreate]

class ProductResponse(BaseModel):
    product_id: str
    category_id: str
    brand_id: Optional[str]
    device_series_id: Optional[str]
    device_model_id: Optional[str]
    device_type: Optional[str] = None
    name: str
    slug: str
    full_path: str
    description: Optional[str]
    status: str
    created_at: Optional[datetime] = None
    images: List[ProductImageResponse] = []
    variants: List[ProductVariantResponse] = []

    @model_validator(mode="after")
    def populate_images(self) -> 'ProductResponse':
        if not self.images and self.variants:
            first_var = self.variants[0]
            if first_var.images:
                self.images = [
                    ProductImageResponse(
                        image_id=vi.image_id,
                        product_id=self.product_id,
                        image_url=vi.image_url,
                        alt_text=self.name,
                        sort_order=vi.sort_order,
                        is_banner=vi.is_primary
                    ) for vi in first_var.images
                ]
        return self

    class Config:
        from_attributes = True

class ProductCardResponse(BaseModel):
    product_id: str
    category_id: Optional[str] = None
    slug: str
    name: str
    thumbnail_url: Optional[str] = None
    price: Decimal
    compare_price: Optional[Decimal] = None
    discount_percent: int = 0
    rating: float = 5.0
    stock_count: int = 10
    first_variant_id: Optional[str] = None
    badge: Optional[str] = None
    brand_name: Optional[str] = None

    class Config:
        from_attributes = True

class ProductPaginatedResponse(BaseModel):
    total: int
    page: int
    limit: int
    cursor: Optional[str] = None
    products: List[ProductCardResponse]