#!/usr/bin/env python3
"""回填 signals.matched_project_id 对应的 project_signal_links。"""

from __future__ import annotations

import argparse
import asyncio

from sqlalchemy import and_, select

from app.core.database import AsyncSessionLocal
from app.models import ProjectSignalLink, Signal


async def _query_orphans(*, tenant_id: int, signal_id: int | None) -> list[tuple[int, int, int, str]]:
    async with AsyncSessionLocal() as db:
        stmt = (
            select(
                Signal.id,
                Signal.tenant_id,
                Signal.matched_project_id,
                Signal.title,
            )
            .outerjoin(
                ProjectSignalLink,
                and_(
                    ProjectSignalLink.tenant_id == Signal.tenant_id,
                    ProjectSignalLink.signal_id == Signal.id,
                ),
            )
            .where(
                and_(
                    Signal.tenant_id == int(tenant_id),
                    Signal.matched_project_id.is_not(None),
                    ProjectSignalLink.id.is_(None),
                )
            )
            .order_by(Signal.id.asc())
        )
        if signal_id is not None:
            stmt = stmt.where(Signal.id == int(signal_id))
        rows = (await db.execute(stmt)).all()
        return [
            (
                int(row[0]),
                int(row[1]),
                int(row[2]),
                str(row[3] or ""),
            )
            for row in rows
            if row[0] is not None and row[1] is not None and row[2] is not None
        ]


async def _apply_backfill(*, tenant_id: int, signal_id: int | None) -> int:
    rows = await _query_orphans(tenant_id=tenant_id, signal_id=signal_id)
    if not rows:
        return 0

    async with AsyncSessionLocal() as db:
        for sid, tid, pid, _ in rows:
            db.add(
                ProjectSignalLink(
                    tenant_id=tid,
                    signal_id=sid,
                    project_id=pid,
                    link_type="matched_project",
                    relevance_score=1.0,
                )
            )
        await db.commit()
    return len(rows)


async def _main() -> None:
    parser = argparse.ArgumentParser(description="Backfill orphan project_signal_links from signals.matched_project_id")
    parser.add_argument("--tenant-id", type=int, default=1, help="目标租户 ID，默认 1")
    parser.add_argument("--signal-id", type=int, default=None, help="仅修复指定 signal_id")
    parser.add_argument("--apply", action="store_true", help="执行写入；不传时仅预览")
    args = parser.parse_args()

    rows = await _query_orphans(tenant_id=args.tenant_id, signal_id=args.signal_id)
    print(f"[preview] tenant_id={args.tenant_id} orphan_count={len(rows)}")
    for sid, _, pid, title in rows[:20]:
        print(f"- signal_id={sid} -> project_id={pid} title={title[:80]}")
    if len(rows) > 20:
        print(f"... ({len(rows) - 20} more)")

    if not args.apply:
        print("[dry-run] 未执行写入。加 --apply 以回填。")
        return

    inserted = await _apply_backfill(tenant_id=args.tenant_id, signal_id=args.signal_id)
    remaining = await _query_orphans(tenant_id=args.tenant_id, signal_id=args.signal_id)
    print(f"[apply] inserted={inserted} remaining_orphans={len(remaining)}")


if __name__ == "__main__":
    asyncio.run(_main())