blog.pyaqa.ru/app/infrastructure/database/models.py

"""SQLAlchemy ORM models.

This module defines the database ORM models that map to database tables.
Models are used by repositories for data persistence.
"""

from __future__ import annotations

from datetime import UTC, datetime
from uuid import uuid4

from sqlalchemy import JSON, Boolean, DateTime, ForeignKey, Integer, String, Text
from sqlalchemy.orm import Mapped, declarative_base, mapped_column, relationship

Base = declarative_base()


class PostORM(Base):  # type: ignore[valid-type,misc]
    """SQLAlchemy model for Blog Post.

    Database table representation of blog posts.
    Maps to the 'posts' table with all post attributes.

    Attributes:
        id: Primary key as UUID string.
        title: Post title (max 200 chars).
        content: Post content (text).
        slug: URL-friendly unique identifier.
        author_id: Author reference.
        published: Publication status flag.
        tags: JSON array of tags.
        created_at: Creation timestamp.
        updated_at: Last update timestamp.

    Example:
        >>> post = PostORM(title="Post", content="...", slug="post", author_id="user-1")
    """

    __tablename__ = "posts"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid4()))
    title: Mapped[str] = mapped_column(String(200), nullable=False)
    content: Mapped[str] = mapped_column(Text, nullable=False)
    slug: Mapped[str] = mapped_column(String(200), nullable=False, unique=True, index=True)
    author_id: Mapped[str] = mapped_column(String(100), nullable=False, index=True)
    published: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False, index=True)
    like_count: Mapped[int] = mapped_column(default=0, nullable=False)
    likes: Mapped[list[PostLikeORM]] = relationship(
        back_populates="post", cascade="all, delete-orphan"
    )
    comments: Mapped[list[CommentORM]] = relationship(
        back_populates="post", cascade="all, delete-orphan"
    )
    tags: Mapped[list[str]] = mapped_column(JSON, default=list)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(UTC),
        nullable=False,
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(UTC),
        onupdate=lambda: datetime.now(UTC),
        nullable=False,
    )


class PostLikeORM(Base):  # type: ignore[valid-type,misc]
    """SQLAlchemy model for PostLike.

    Database table representation of post likes.
    Maps to the 'post_likes' table tracking which users/devices liked which posts.

    Attributes:
        id: Primary key as UUID string.
        post_id: Foreign key to the liked post.
        liked_by: User ID or device identifier.
        created_at: Creation timestamp.
    """

    __tablename__ = "post_likes"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid4()))
    post_id: Mapped[str] = mapped_column(
        String(36), ForeignKey("posts.id", ondelete="CASCADE"), nullable=False, index=True
    )
    liked_by: Mapped[str] = mapped_column(String(200), nullable=False, index=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(UTC),
        nullable=False,
    )

    post: Mapped[PostORM] = relationship(back_populates="likes")


class CommentORM(Base):  # type: ignore[valid-type,misc]
    """SQLAlchemy model for Comment.

    Database table representation of comments on blog posts.
    Maps to the 'comments' table with support for nested replies.

    Attributes:
        id: Primary key as UUID string.
        post_id: Foreign key to the parent post.
        author_id: Comment author reference.
        content: Comment text content (Markdown supported).
        parent_id: Optional foreign key to parent comment (replies).
        like_count: Number of likes on this comment.
        created_at: Creation timestamp.
        updated_at: Last update timestamp.
    """

    __tablename__ = "comments"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid4()))
    post_id: Mapped[str] = mapped_column(
        String(36), ForeignKey("posts.id", ondelete="CASCADE"), nullable=False, index=True
    )
    author_id: Mapped[str] = mapped_column(String(100), nullable=False, index=True)
    content: Mapped[str] = mapped_column(Text, nullable=False)
    parent_id: Mapped[str | None] = mapped_column(
        String(36),
        ForeignKey("comments.id", ondelete="SET NULL"),
        nullable=True,
        index=True,
    )
    like_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(UTC),
        nullable=False,
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(UTC),
        onupdate=lambda: datetime.now(UTC),
        nullable=False,
    )

    post: Mapped[PostORM] = relationship(back_populates="comments")
    replies: Mapped[list[CommentORM]] = relationship(
        back_populates="parent",
    )
    parent: Mapped[CommentORM | None] = relationship(
        back_populates="replies",
        remote_side="CommentORM.id",
    )


class CommentLikeORM(Base):  # type: ignore[valid-type,misc]
    """SQLAlchemy model for CommentLike.

    Database table representation of comment likes.
    Maps to the 'comment_likes' table tracking which users liked which comments.

    Attributes:
        id: Primary key as UUID string.
        comment_id: Foreign key to the liked comment.
        liked_by: User identifier.
        created_at: Creation timestamp.
    """

    __tablename__ = "comment_likes"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid4()))
    comment_id: Mapped[str] = mapped_column(
        String(36),
        ForeignKey("comments.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    liked_by: Mapped[str] = mapped_column(String(200), nullable=False, index=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(UTC),
        nullable=False,
    )