from sqlalchemy import Column, String, Boolean, DateTime, Integer, Numeric, ForeignKey, Index, JSON
from sqlalchemy.sql import func
from sqlalchemy.orm import relationship
from app.core.database.db_session import Base
from app.models.TagModel import product_tags
from app.models.CollectionModel import product_collections
from app.models.DeviceCatalogModel import DeviceSeries, DeviceModel

class AttributeType(Base):
    __tablename__ = "attribute_types"

    attribute_id = Column(String(26), primary_key=True)
    name = Column(String(100), nullable=False)
    code = Column(String(100), unique=True, nullable=False)  # e.g., "color", "screen_type", "storage"
    status = Column(String(20), default="active")  # active, inactive
    preset_values = Column(JSON, nullable=True)

class Product(Base):
    __tablename__ = "products"

    product_id = Column(String(26), primary_key=True)
    category_id = Column(String(26), ForeignKey("categories.category_id", ondelete="SET NULL"), nullable=True, index=True)
    brand_id = Column(String(26), ForeignKey("brands.brand_id", ondelete="SET NULL"), nullable=True, index=True)
    device_series_id = Column(String(26), ForeignKey("device_series.series_id", ondelete="SET NULL"), nullable=True)
    device_model_id = Column(String(26), ForeignKey("device_models.model_id", ondelete="SET NULL"), nullable=True)
    device_type = Column(String(50), nullable=True) # laptop, tablet, mobile
    name = Column(String(255), nullable=False)
    slug = Column(String(255), unique=True, nullable=False)
    full_path = Column(String(500), nullable=False)
    description = Column(String(1000), nullable=True)
    status = Column(String(20), default="draft", index=True)  # draft, active, archived
    created_at = Column(DateTime, server_default=func.now(), index=True)
    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now())

    __table_args__ = (
        Index('idx_products_parent_hierarchy', 'category_id', 'brand_id', 'device_series_id', 'device_model_id'),
    )

    # Relations
    category = relationship("Category")
    brand = relationship("Brand")
    device_series = relationship("DeviceSeries")
    device_model = relationship("DeviceModel")
    images = relationship("ProductImage", back_populates="product", cascade="all, delete-orphan")
    variants = relationship("ProductVariant", back_populates="product", cascade="all, delete-orphan")
    tags = relationship("Tag", secondary=product_tags, backref="products")
    collections = relationship("Collection", secondary=product_collections, backref="products")

class ProductImage(Base):
    __tablename__ = "product_images"

    image_id = Column(String(26), primary_key=True)
    product_id = Column(String(26), ForeignKey("products.product_id", ondelete="CASCADE"), nullable=False)
    image_url = Column(String(500), nullable=False)
    alt_text = Column(String(255), nullable=True)
    sort_order = Column(Integer, default=0)
    is_banner = Column(Boolean, default=False)

    product = relationship("Product", back_populates="images")

class ProductVariant(Base):
    __tablename__ = "product_variants"

    variant_id = Column(String(26), primary_key=True)
    product_id = Column(String(26), ForeignKey("products.product_id", ondelete="CASCADE"), nullable=False)
    sku = Column(String(100), unique=True, nullable=False)
    barcode = Column(String(100), unique=True, nullable=True)
    price = Column(Numeric(10, 2), nullable=False, index=True)
    compare_price = Column(Numeric(10, 2), nullable=True)
    cost_price = Column(Numeric(10, 2), nullable=False)
    low_stock_threshold = Column(Integer, default=5)
    status = Column(String(20), default="active", index=True)  # active, inactive
    created_at = Column(DateTime, server_default=func.now())


    product = relationship("Product", back_populates="variants")
    attributes = relationship("VariantAttribute", back_populates="variant", cascade="all, delete-orphan")
    images = relationship("VariantImage", back_populates="variant", cascade="all, delete-orphan")

class VariantAttribute(Base):
    __tablename__ = "variant_attributes"

    id = Column(String(26), primary_key=True)
    variant_id = Column(String(26), ForeignKey("product_variants.variant_id", ondelete="CASCADE"), nullable=False)
    attribute_id = Column(String(26), ForeignKey("attribute_types.attribute_id", ondelete="RESTRICT"), nullable=False)
    attribute_value = Column(String(255), nullable=False)

    variant = relationship("ProductVariant", back_populates="attributes")
    attribute_type = relationship("AttributeType")

class VariantImage(Base):
    __tablename__ = "variant_images"

    image_id = Column(String(26), primary_key=True)
    variant_id = Column(String(26), ForeignKey("product_variants.variant_id", ondelete="CASCADE"), nullable=False)
    image_url = Column(String(500), nullable=False)
    sort_order = Column(Integer, default=0)
    is_primary = Column(Boolean, default=False)

    variant = relationship("ProductVariant", back_populates="images")