"""Store schema.

Tenant keying, from the first migration onward, per
`business-app-service-contract_v0.1` § 1.3. Every table holding owned data
carries `tenant`, and no query may assume it is the only tenant (§ 1.4). The
service is deployed single-tenant today; the key is here so a later
consolidation is a data copy rather than a rewrite.

The format's three distinct things stay distinct:

- a **package version** is immutable content addressed by `<id>@<version>`
  (§ 17), scoped to a registry because identity is registry-scoped (§ 3.2);
- an **index entry** records how a version arrived in this store (§ 20.3);
- **files** are content, stored as blobs rather than parsed into rows.
"""

from __future__ import annotations

import datetime as dt

from sqlalchemy import (
    BigInteger,
    DateTime,
    ForeignKey,
    Index,
    LargeBinary,
    String,
    Text,
    UniqueConstraint,
)
from sqlalchemy.orm import Mapped, mapped_column, relationship

from .db import Base


def utcnow() -> dt.datetime:
    return dt.datetime.now(dt.timezone.utc)


class PackageVersion(Base):
    """One immutable `<registry>:<id>@<version>` within one tenant."""

    __tablename__ = "package_versions"
    __table_args__ = (
        UniqueConstraint(
            "tenant", "registry", "package_id", "version", name="uq_package_version"
        ),
        Index("ix_package_versions_tenant_id", "tenant", "package_id"),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    tenant: Mapped[str] = mapped_column(String(64), nullable=False)
    registry: Mapped[str] = mapped_column(String(128), nullable=False)
    package_id: Mapped[str] = mapped_column(String(512), nullable=False)
    version: Mapped[str] = mapped_column(String(64), nullable=False)

    # Indexed manifest fields, for discovery without opening every package.
    name: Mapped[str] = mapped_column(String(256), nullable=False)
    summary: Mapped[str] = mapped_column(Text, nullable=False, default="")
    package_type: Mapped[str] = mapped_column(String(32), nullable=False, default="template")
    license: Mapped[str | None] = mapped_column(String(128))
    tags: Mapped[str] = mapped_column(Text, nullable=False, default="")

    # The manifest as published, so a consumer sees exactly what was stored.
    manifest: Mapped[str] = mapped_column(Text, nullable=False)
    content_digest: Mapped[str] = mapped_column(String(71), nullable=False)
    published_at: Mapped[dt.datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, default=utcnow
    )

    files: Mapped[list["PackageFile"]] = relationship(
        back_populates="package_version", cascade="all, delete-orphan"
    )


class PackageFile(Base):
    """A file belonging to a package version. Content, not parsed rows."""

    __tablename__ = "package_files"
    __table_args__ = (
        UniqueConstraint("package_version_id", "path", name="uq_package_file_path"),
        Index("ix_package_files_tenant", "tenant"),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    tenant: Mapped[str] = mapped_column(String(64), nullable=False)
    package_version_id: Mapped[int] = mapped_column(
        ForeignKey("package_versions.id", ondelete="CASCADE"), nullable=False
    )
    path: Mapped[str] = mapped_column(String(1024), nullable=False)
    content: Mapped[bytes] = mapped_column(LargeBinary, nullable=False)

    package_version: Mapped[PackageVersion] = relationship(back_populates="files")


class IndexEntry(Base):
    """How a package version arrived in this store (§ 20.3).

    Store metadata, deliberately separate from the package: `included_at` is
    first arrival and is never overwritten; a re-record updates `last_seen_at`.
    """

    __tablename__ = "index_entries"
    __table_args__ = (
        UniqueConstraint(
            "tenant", "registry", "package_id", "version", name="uq_index_entry"
        ),
    )

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True, autoincrement=True)
    tenant: Mapped[str] = mapped_column(String(64), nullable=False)
    registry: Mapped[str] = mapped_column(String(128), nullable=False)
    package_id: Mapped[str] = mapped_column(String(512), nullable=False)
    version: Mapped[str] = mapped_column(String(64), nullable=False)

    source: Mapped[str] = mapped_column(Text, nullable=False)
    method: Mapped[str] = mapped_column(String(32), nullable=False)
    declared_author: Mapped[str | None] = mapped_column(String(256))
    declared_source: Mapped[str | None] = mapped_column(Text)
    license: Mapped[str | None] = mapped_column(String(128))

    included_at: Mapped[dt.datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, default=utcnow
    )
    last_seen_at: Mapped[dt.datetime | None] = mapped_column(DateTime(timezone=True))