"""Price Alert model for TLD price notifications."""
from datetime import datetime
from typing import Optional
from sqlalchemy import String, Float, Boolean, DateTime, Integer, ForeignKey, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base


class PriceAlert(Base):
    """
    Price Alert model for tracking user's TLD price subscriptions.
    
    Users can subscribe to price alerts for specific TLDs and get notified
    when prices change by a certain threshold.
    """
    
    __tablename__ = "price_alerts"
    __table_args__ = (
        UniqueConstraint('user_id', 'tld', name='unique_user_tld_alert'),
    )
    
    id: Mapped[int] = mapped_column(primary_key=True, index=True)
    
    # User who created the alert
    user_id: Mapped[int] = mapped_column(Integer, ForeignKey("users.id"), nullable=False)
    
    # TLD to monitor (without dot, e.g., "com", "io")
    tld: Mapped[str] = mapped_column(String(50), index=True, nullable=False)
    
    # Alert settings
    is_active: Mapped[bool] = mapped_column(Boolean, default=True)
    
    # Optional: only alert if price drops below this threshold
    target_price: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
    
    # Optional: only alert if price changes by this percentage
    threshold_percent: Mapped[float] = mapped_column(Float, default=5.0)  # 5% default
    
    # Track last notification to avoid spam
    last_notified_at: Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)
    last_notified_price: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
    
    # Timestamps
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime, default=datetime.utcnow, onupdate=datetime.utcnow
    )
    
    # Relationship to user
    user: Mapped["User"] = relationship("User", back_populates="price_alerts")
    
    def __repr__(self) -> str:
        status = "active" if self.is_active else "paused"
        return f"<PriceAlert user={self.user_id} tld=.{self.tld} ({status})>"