import enum
import uuid
from datetime import datetime

from sqlalchemy import DateTime, Enum, ForeignKey, String, func
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.db.base_class import Base


class DistributionTargetType(str, enum.Enum):
    SITE = "SITE"
    ROLE = "ROLE"
    USER = "USER"


class DistributionStatus(str, enum.Enum):
    ACTIVE = "ACTIVE"
    CLOSED = "CLOSED"


class Distribution(Base):
    __tablename__ = "distributions"

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    document_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("documents.id"), nullable=False)
    version_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("document_versions.id"), nullable=False)
    target_type: Mapped[DistributionTargetType] = mapped_column(
        Enum(DistributionTargetType, name="distribution_target_type"),
        nullable=False,
    )
    target_id: Mapped[str] = mapped_column(String(50), nullable=False)
    status: Mapped[DistributionStatus] = mapped_column(
        Enum(DistributionStatus, name="distribution_status"),
        nullable=False,
        server_default=DistributionStatus.ACTIVE.value,
    )
    due_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    closed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    created_by: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())

    document = relationship("Document")
    version = relationship("DocumentVersion", back_populates="distributions")
    acknowledgements = relationship(
        "Acknowledgement",
        back_populates="distribution",
        cascade="all, delete-orphan",
    )