from datetime import datetime, timezone
from sqlalchemy import String, Boolean, Integer, Float, DateTime, ForeignKey, Index
from sqlalchemy.orm import Mapped, mapped_column, relationship

from backend.models.base import Base


class Post(Base):
    __tablename__ = "posts"
    __table_args__ = (
        Index("ix_posts_subreddit_created", "subreddit_id", "created_utc"),
    )

    id: Mapped[int] = mapped_column(primary_key=True)
    reddit_id: Mapped[str] = mapped_column(String(20), unique=True, nullable=False)
    subreddit_id: Mapped[int] = mapped_column(ForeignKey("monitored_subreddits.id"), index=True)
    author_id: Mapped[int | None] = mapped_column(ForeignKey("authors.id"), index=True)
    title: Mapped[str] = mapped_column(nullable=False)
    selftext: Mapped[str | None] = mapped_column()
    url: Mapped[str | None] = mapped_column()
    permalink: Mapped[str | None] = mapped_column()
    flair: Mapped[str | None] = mapped_column(String(255))
    score: Mapped[int] = mapped_column(Integer, default=0, index=True)
    upvote_ratio: Mapped[float | None] = mapped_column(Float)
    num_comments: Mapped[int] = mapped_column(Integer, default=0)
    is_self: Mapped[bool | None] = mapped_column(Boolean)
    over_18: Mapped[bool] = mapped_column(Boolean, default=False)
    hot_rank: Mapped[int | None] = mapped_column(Integer)
    created_utc: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    collected_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )

    subreddit: Mapped["MonitoredSubreddit"] = relationship(back_populates="posts")  # noqa: F821
    author: Mapped["Author | None"] = relationship(back_populates="posts")  # noqa: F821
    comments: Mapped[list["Comment"]] = relationship(back_populates="post")  # noqa: F821
    metric_snapshots: Mapped[list["MetricSnapshot"]] = relationship(back_populates="post")  # noqa: F821