from datetime import datetime, timezone
from typing import Optional

from sqlalchemy import DateTime, ForeignKey, Integer, String, Text, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column

from app.db import Base


class GeneratedContractVersion(Base):
    __tablename__ = "generated_contract_versions"
    __table_args__ = (
        UniqueConstraint("tenant_id", "contract_id", "version_number", name="uq_generated_contract_versions_tenant_contract_number"),
    )

    id: Mapped[str] = mapped_column(String(64), primary_key=True)
    tenant_id: Mapped[str] = mapped_column(String(64), nullable=False, index=True)
    contract_id: Mapped[str] = mapped_column(String(64), ForeignKey("generated_contracts.id"), nullable=False, index=True)
    review_id: Mapped[Optional[str]] = mapped_column(String(64), ForeignKey("review_tasks.id"), nullable=True, index=True)
    review_risk_action_id: Mapped[Optional[str]] = mapped_column(
        String(64),
        ForeignKey("review_risk_actions.id"),
        nullable=True,
        index=True,
    )
    version_number: Mapped[int] = mapped_column(Integer, nullable=False, default=1, index=True)
    version_label: Mapped[str] = mapped_column(String(32), nullable=False)
    source_version_id: Mapped[Optional[str]] = mapped_column(String(64), nullable=True, index=True)
    change_type: Mapped[str] = mapped_column(String(64), nullable=False, default="review_suggestion")
    change_summary: Mapped[Optional[str]] = mapped_column(String(500), nullable=True)
    original_text: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    replacement_text: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    content: Mapped[str] = mapped_column(Text, nullable=False)
    locate_status: Mapped[str] = mapped_column(String(32), nullable=False, default="applied", index=True)
    created_by: Mapped[Optional[str]] = mapped_column(String(64), nullable=True, index=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc))