from __future__ import annotations

import uuid
from datetime import datetime

from sqlalchemy import DateTime, ForeignKey, Text, UniqueConstraint, func
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import Mapped, mapped_column

from . import Base


class Group(Base):
    """A named set of users. Sharing a resource with a group grants it to every
    member (see thoughtsync.acl.visible_to_user)."""

    __tablename__ = "groups"

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    name: Mapped[str] = mapped_column(Text(), nullable=False)
    owner_id: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL"), nullable=True
    )
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())


class GroupMember(Base):
    __tablename__ = "group_members"
    __table_args__ = (UniqueConstraint("group_id", "user_id", name="uq_group_members_group_user"),)

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    group_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), ForeignKey("groups.id", ondelete="CASCADE"), nullable=False
    )
    user_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), nullable=False
    )
    role: Mapped[str] = mapped_column(Text(), nullable=False, server_default="member")
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())