"""Seller reviews — left by buyers after a listing is marked sold."""
from datetime import datetime
from app.utils.time import utcnow
from app.extensions import db


class Review(db.Model):
    __tablename__ = "reviews"

    id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
                   primary_key=True, autoincrement=True)
    listing_id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
                           db.ForeignKey("listings.id"), nullable=False, index=True)
    author_id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
                          db.ForeignKey("users.id"), nullable=False, index=True)
    seller_id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
                          db.ForeignKey("users.id"), nullable=False, index=True)
    rating = db.Column(db.SmallInteger, nullable=False)   # 1–5
    body = db.Column(db.Text, nullable=True)
    created_at = db.Column(db.DateTime, default=utcnow, nullable=False)

    listing = db.relationship("Listing",
                              backref=db.backref("reviews", lazy="dynamic"))
    author = db.relationship("User", foreign_keys=[author_id],
                             backref=db.backref("reviews_written", lazy="dynamic"))
    seller = db.relationship("User", foreign_keys=[seller_id],
                             backref=db.backref("reviews_received", lazy="dynamic"))

    __table_args__ = (
        db.UniqueConstraint("listing_id", "author_id", name="uq_review_listing_author"),
        db.CheckConstraint("rating BETWEEN 1 AND 5", name="ck_review_rating"),
    )

    def __repr__(self):
        return f"<Review L{self.listing_id} by u{self.author_id} {self.rating}*>"