core-api/src/domains/scribe/models.py

"""
Scribe Domain Models

The Scribe is the household's message bus (workspace D-66, D-68, D-73): a
retained pub/sub log where an address is a topic. This round ships the
primitives migration 006 creates — addresses, messages, mailbox entries —
for direct messaging only; groups, subscriptions, the notification matrix
and delivery are later work (workspace T-176).

SQLAlchemy 2.0 Mapped/mapped_column style, timestamptz, following
src/domains/book/models.py. Every table carries `owner_tenant` and every
query in the service layer filters on it (D-73's hard tenant boundary) —
there is no database-level RLS here, so that filter is load-bearing in
Python, not just in SQL.
"""
from datetime import datetime
from typing import List, Optional

from sqlalchemy import (
    Computed,
    DateTime,
    ForeignKey,
    Identity,
    Integer,
    String,
    Text,
    UniqueConstraint,
    func,
)
from sqlalchemy.dialects.postgresql import ARRAY, TSVECTOR
from sqlalchemy.orm import Mapped, mapped_column

from src.shared.database import Base

# Address name shape, identical to src/domains/auth/callers.py's identity
# rule (an address is named for an identity, D-66) — not imported from there
# because that module's constants are private to it; kept here so a drift
# between the two never happens silently, the regex is asserted equal in
# tests/test_scribe.py instead.
ADDRESS_NAME_PATTERN = r"^[a-z0-9][a-z0-9-]{0,62}$"
RESERVED_ADDRESS_NAMES = {"book", "office", "scheduler", "tatlock"}


class ScribeAddress(Base):
    """
    An address: a topic named for an identity. `register` creates it once
    (D-66) — the pair (owner_tenant, name) is the natural key, so no
    surrogate id: no route ever references an address except by name.
    """

    __tablename__ = "scribe_addresses"
    __table_args__ = (
        UniqueConstraint("owner_tenant", "name", name="uq_scribe_addresses_tenant_name"),
    )

    # FK to tenants.id added by migration 007 (core-api T-8).
    owner_tenant: Mapped[str] = mapped_column(
        String(63), ForeignKey("tenants.id", ondelete="RESTRICT"), primary_key=True
    )
    name: Mapped[str] = mapped_column(String(63), primary_key=True)
    # Nullable: a "user"-kind caller (direct OIDC, not through the Office)
    # carries no consumer (src/domains/auth/callers.py), so an address it
    # registers has none either.
    owner_consumer: Mapped[Optional[str]] = mapped_column(String(63), nullable=True)
    created_by: Mapped[str] = mapped_column(String(63), nullable=False)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        server_default=func.now(),
        nullable=False,
    )

    def __repr__(self) -> str:
        return f"<ScribeAddress {self.owner_tenant}/{self.name}>"


class ScribeMessage(Base):
    """
    A retained message. `topics` is the set of addresses (and, later,
    groups) it was published to — an integer array is denormalized from
    the mailbox entries so `history` can read the retained log directly
    without joining through them (D-66: "topics are retained and
    re-readable"). Nothing deletes a message.
    """

    __tablename__ = "scribe_messages"

    id: Mapped[int] = mapped_column(Integer, Identity(always=False), primary_key=True)
    # FK to tenants.id added by migration 007 (core-api T-8).
    owner_tenant: Mapped[str] = mapped_column(
        String(63), ForeignKey("tenants.id", ondelete="RESTRICT"), nullable=False, index=True
    )
    topics: Mapped[List[str]] = mapped_column(ARRAY(Text), nullable=False, default=list)
    from_identity: Mapped[str] = mapped_column(String(63), nullable=False)
    from_consumer: Mapped[Optional[str]] = mapped_column(String(63), nullable=True)
    subject: Mapped[Optional[str]] = mapped_column(String(500), nullable=True)
    body: Mapped[str] = mapped_column(Text, nullable=False)
    tags: Mapped[List[str]] = mapped_column(ARRAY(Text), nullable=False, default=list)
    reply_to: Mapped[Optional[int]] = mapped_column(
        Integer, ForeignKey("scribe_messages.id"), nullable=True
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        server_default=func.now(),
        nullable=False,
    )
    # Generated by migration 006 (`to_tsvector('simple', ...)`, GIN-indexed),
    # 'simple' for the same reason as book_records.search: mixed Dutch/
    # English content. `Computed` mirrors the migration's SQL.
    search: Mapped[Optional[str]] = mapped_column(
        TSVECTOR,
        Computed("to_tsvector('simple', coalesce(subject, '') || ' ' || body)", persisted=True),
        nullable=True,
    )

    def __repr__(self) -> str:
        return f"<ScribeMessage {self.id} from={self.from_identity}>"


class ScribeMailboxEntry(Base):
    """One row per recipient address per message — what lands in a mailbox."""

    __tablename__ = "scribe_mailbox_entries"
    __table_args__ = (
        UniqueConstraint("address", "message_id", name="uq_scribe_mailbox_entries_address_message"),
    )

    id: Mapped[int] = mapped_column(Integer, Identity(always=False), primary_key=True)
    address: Mapped[str] = mapped_column(String(63), nullable=False)
    # FK to tenants.id added by migration 007 (core-api T-8).
    owner_tenant: Mapped[str] = mapped_column(
        String(63), ForeignKey("tenants.id", ondelete="RESTRICT"), nullable=False
    )
    message_id: Mapped[int] = mapped_column(
        Integer, ForeignKey("scribe_messages.id"), nullable=False
    )
    read_at: Mapped[Optional[datetime]] = mapped_column(DateTime(timezone=True), nullable=True)
    tags: Mapped[List[str]] = mapped_column(ARRAY(Text), nullable=False, default=list)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        server_default=func.now(),
        nullable=False,
    )

    def __repr__(self) -> str:
        return f"<ScribeMailboxEntry {self.id} address={self.address} message={self.message_id}>"