# models/database/vendor_platform.py
"""
VendorPlatform junction table for many-to-many relationship between Vendor and Platform.

A vendor CAN belong to multiple platforms (e.g., both OMS and Loyalty Program).
Each membership can have:
- Platform-specific subscription tier
- Custom subdomain for that platform
- Platform-specific settings
- Active/inactive status
"""

from datetime import UTC, datetime

from sqlalchemy import (
    JSON,
    Boolean,
    Column,
    DateTime,
    ForeignKey,
    Index,
    Integer,
    String,
    UniqueConstraint,
)
from sqlalchemy.orm import relationship

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


class VendorPlatform(Base, TimestampMixin):
    """
    Junction table linking vendors to platforms.

    Allows a vendor to:
    - Subscribe to multiple platforms (OMS + Loyalty)
    - Have different tiers per platform
    - Have platform-specific subdomains
    - Store platform-specific settings

    Example:
    - Vendor "WizaMart" is on OMS platform (Professional tier)
    - Vendor "WizaMart" is also on Loyalty platform (Basic tier)
    """

    __tablename__ = "vendor_platforms"

    id = Column(Integer, primary_key=True, index=True)

    # ========================================================================
    # Foreign Keys
    # ========================================================================

    vendor_id = Column(
        Integer,
        ForeignKey("vendors.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
        comment="Reference to the vendor",
    )

    platform_id = Column(
        Integer,
        ForeignKey("platforms.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
        comment="Reference to the platform",
    )

    tier_id = Column(
        Integer,
        ForeignKey("subscription_tiers.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
        comment="Platform-specific subscription tier",
    )

    # ========================================================================
    # Membership Status
    # ========================================================================

    is_active = Column(
        Boolean,
        default=True,
        nullable=False,
        comment="Whether the vendor is active on this platform",
    )

    is_primary = Column(
        Boolean,
        default=False,
        nullable=False,
        comment="Whether this is the vendor's primary platform",
    )

    # ========================================================================
    # Platform-Specific Configuration
    # ========================================================================

    custom_subdomain = Column(
        String(100),
        nullable=True,
        comment="Platform-specific subdomain (if different from main subdomain)",
    )

    settings = Column(
        JSON,
        nullable=True,
        default=dict,
        comment="Platform-specific vendor settings",
    )

    # ========================================================================
    # Timestamps
    # ========================================================================

    joined_at = Column(
        DateTime(timezone=True),
        default=lambda: datetime.now(UTC),
        nullable=False,
        comment="When the vendor joined this platform",
    )

    # ========================================================================
    # Relationships
    # ========================================================================

    vendor = relationship(
        "Vendor",
        back_populates="vendor_platforms",
    )

    platform = relationship(
        "Platform",
        back_populates="vendor_platforms",
    )

    tier = relationship(
        "SubscriptionTier",
        foreign_keys=[tier_id],
    )

    # ========================================================================
    # Constraints & Indexes
    # ========================================================================

    __table_args__ = (
        # Each vendor can only be on a platform once
        UniqueConstraint(
            "vendor_id",
            "platform_id",
            name="uq_vendor_platform",
        ),
        # Performance indexes
        Index(
            "idx_vendor_platform_active",
            "vendor_id",
            "platform_id",
            "is_active",
        ),
        Index(
            "idx_vendor_platform_primary",
            "vendor_id",
            "is_primary",
        ),
    )

    # ========================================================================
    # Properties
    # ========================================================================

    @property
    def tier_code(self) -> str | None:
        """Get the tier code for this platform membership."""
        return self.tier.code if self.tier else None

    @property
    def tier_name(self) -> str | None:
        """Get the tier name for this platform membership."""
        return self.tier.name if self.tier else None

    def __repr__(self) -> str:
        return (
            f"<VendorPlatform("
            f"vendor_id={self.vendor_id}, "
            f"platform_id={self.platform_id}, "
            f"is_active={self.is_active})>"
        )