"""Product Translation model for vendor-specific localized content.

This model stores vendor-specific translations. Translations are independent
entities with all fields populated at creation time from the source
marketplace product translation.

The marketplace product translation can be accessed via the product's
marketplace_product relationship for "view original source" comparison.
"""

from sqlalchemy import (
    Column,
    ForeignKey,
    Index,
    Integer,
    String,
    Text,
    UniqueConstraint,
)
from sqlalchemy.orm import relationship

from app.core.database import Base
from models.database.base import TimestampMixin


class ProductTranslation(Base, TimestampMixin):
    """Vendor-specific localized content - independent copy.

    Each vendor has their own translations with all fields populated
    at creation time. The source marketplace translation can be accessed
    for comparison via the product's marketplace_product relationship.
    """

    __tablename__ = "product_translations"

    id = Column(Integer, primary_key=True, index=True)
    product_id = Column(
        Integer,
        ForeignKey("products.id", ondelete="CASCADE"),
        nullable=False,
    )
    language = Column(String(5), nullable=False)  # 'en', 'fr', 'de', 'lb'

    # === LOCALIZED FIELDS (copied from marketplace at creation) ===
    title = Column(String)
    description = Column(Text)
    short_description = Column(String(500))

    # SEO Fields
    meta_title = Column(String(70))
    meta_description = Column(String(160))
    url_slug = Column(String(255))

    # === RELATIONSHIPS ===
    product = relationship("Product", back_populates="translations")

    __table_args__ = (
        UniqueConstraint("product_id", "language", name="uq_product_translation"),
        Index("idx_pt_product_id", "product_id"),
        Index("idx_pt_product_language", "product_id", "language"),
    )

    def __repr__(self):
        return (
            f"<ProductTranslation(id={self.id}, "
            f"product_id={self.product_id}, "
            f"language='{self.language}', "
            f"title='{self.title[:30] if self.title else None}...')>"
        )

    # === SOURCE COMPARISON METHOD ===

    def _find_marketplace_translation(self):
        """Get the corresponding marketplace translation for comparison."""
        product = self.product
        if product and product.marketplace_product:
            mp = product.marketplace_product
            for t in mp.translations:
                if t.language == self.language:
                    return t
        return None

    def get_source_comparison_info(self) -> dict:
        """Get current values with source values for comparison.

        Returns a dict with current field values and original source values
        from the marketplace product translation. Used for "view original source" feature.
        """
        mp_translation = self._find_marketplace_translation()

        return {
            # Title
            "title": self.title,
            "title_source": mp_translation.title if mp_translation else None,
            # Description
            "description": self.description,
            "description_source": mp_translation.description if mp_translation else None,
            # Short Description
            "short_description": self.short_description,
            "short_description_source": (
                mp_translation.short_description if mp_translation else None
            ),
            # Meta Title
            "meta_title": self.meta_title,
            "meta_title_source": mp_translation.meta_title if mp_translation else None,
            # Meta Description
            "meta_description": self.meta_description,
            "meta_description_source": (
                mp_translation.meta_description if mp_translation else None
            ),
            # URL Slug
            "url_slug": self.url_slug,
            "url_slug_source": mp_translation.url_slug if mp_translation else None,
        }