from __future__ import annotations

from datetime import datetime
from typing import Optional
from uuid import UUID, uuid4

from sqlalchemy import Boolean, ForeignKey, Integer, String, Text
from sqlalchemy.dialects.postgresql import JSONB, UUID as PGUUID
from sqlalchemy.orm import Mapped, mapped_column
from sqlalchemy.sql import func
from sqlalchemy.types import DateTime

from src.core.database import Base


class L3Candidate(Base):
    """A project-scoped extension proposed by Codegen, never canonical by default."""

    __tablename__ = "l3_candidates"

    id: Mapped[UUID] = mapped_column(PGUUID(as_uuid=True), primary_key=True, default=uuid4)
    candidate_id: Mapped[str] = mapped_column(String(160), unique=True, nullable=False)
    semantic: Mapped[str] = mapped_column(String(160), nullable=False, index=True)
    scope: Mapped[str] = mapped_column(String(20), nullable=False, server_default="project")
    status: Mapped[str] = mapped_column(String(40), nullable=False, server_default="discovered", index=True)
    project_id: Mapped[UUID] = mapped_column(PGUUID(as_uuid=True), ForeignKey("projects.id", ondelete="CASCADE"), nullable=False, index=True)
    generation_run_id: Mapped[Optional[UUID]] = mapped_column(PGUUID(as_uuid=True), ForeignKey("codegen_runs.id", ondelete="SET NULL"), nullable=True, index=True)
    requirement_summary: Mapped[str] = mapped_column(Text, nullable=False)
    gap_reason: Mapped[str] = mapped_column(Text, nullable=False)
    architecture_manifest_sha: Mapped[Optional[str]] = mapped_column(String(64), nullable=True)
    proposed_contract: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
    dependencies: Mapped[list] = mapped_column(JSONB, nullable=False, default=list)
    evidence: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
    source_locations: Mapped[list] = mapped_column(JSONB, nullable=False, default=list)
    related_candidate_ids: Mapped[list] = mapped_column(JSONB, nullable=False, default=list)
    commit_sha: Mapped[Optional[str]] = mapped_column(String(64), nullable=True)
    version: Mapped[str] = mapped_column(String(32), nullable=False, server_default="0.1.0")
    promotion_candidate: Mapped[bool] = mapped_column(Boolean, nullable=False, server_default="true")
    review_notes: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    reviewed_by: Mapped[Optional[UUID]] = mapped_column(PGUUID(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL"), nullable=True)
    reviewed_at: Mapped[Optional[datetime]] = mapped_column(DateTime(timezone=True), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now())