"""一次性回填脚本:为 Qdrant 存量 point 的 payload 补充 sources 多源字段。

背景:
    M5/M6 旧链路未把 M3 多源记录写入 EmbeddingResult / Qdrant payload,
    导致知识库检索只能看到单源。新链路修复后,此脚本为存量数据补齐。

数据来源(按优先级):
    1. 指纹库 data/dedup/fingerprints.sqlite3 的 source_ids 列(权威多源记录);
    2. source_ids 为 NULL 的旧行回退 [source_id];
    3. 指纹库查不到的 point 回退 payload.source_id。

实现:
    本地文件模式 Qdrant 的 set_payload 逐点极慢(≈0.65s/点,33k 条约 6 小时),
    故采用与正常 ingest 相同的快速路径:
        scroll 分页取全部 point(含向量)→ 合并 sources → 批量 upsert 回写。

注意:
    Qdrant 为本地文件模式,同一时刻仅允许一个进程打开;
    执行前请确认无 pipeline 子进程正在运行(避开调度窗口)。

用法:
    uv run python -m scripts.backfill_qdrant_sources          # 实际执行
    uv run python -m scripts.backfill_qdrant_sources --dry-run  # 只统计不写入
"""

from __future__ import annotations

import argparse
import json
import sqlite3
import sys
from pathlib import Path

from loguru import logger
from qdrant_client.http.models import PointStruct

from vectorstore import DEFAULT_COLLECTION, make_qdrant_client

_SCROLL_LIMIT = 1000
_UPSERT_BATCH = 100


def _setup_logger(level: str) -> None:
    logger.remove()
    logger.add(
        sys.stderr,
        level=level,
        format="{time:YYYY-MM-DD HH:mm:ss} | {level} | {name} | {message}",
    )


def _load_fingerprint_sources(db_path: Path) -> dict[str, list[str]]:
    """从指纹库读 url_hash -> sources(source_ids 为 NULL 时回退 [source_id])。"""
    conn = sqlite3.connect(db_path)
    conn.row_factory = sqlite3.Row
    rows = conn.execute(
        "SELECT url_hash, source_id, source_ids FROM fingerprints"
    ).fetchall()
    conn.close()

    result: dict[str, list[str]] = {}
    for r in rows:
        sources: list[str] = []
        if r["source_ids"]:
            try:
                val = json.loads(r["source_ids"])
                if isinstance(val, list):
                    sources = [s for s in val if s]
            except (TypeError, ValueError):
                sources = []
        if not sources:
            sources = [r["source_id"]] if r["source_id"] else []
        # 保证主源居首
        if r["source_id"] and r["source_id"] in sources:
            sources = [r["source_id"], *[s for s in sources if s != r["source_id"]]]
        if sources:
            result[r["url_hash"]] = sources
    return result


def _build_points(
    records: list,
    fp_sources: dict[str, list[str]],
) -> list[PointStruct]:
    """把 scroll 记录转回 PointStruct,payload 补入 sources 字段。"""
    points: list[PointStruct] = []
    for rec in records:
        payload = dict(rec.payload or {})
        url_hash = payload.get("url_hash") or ""
        source_id = payload.get("source_id") or ""
        sources = fp_sources.get(url_hash) or ([source_id] if source_id else [])
        if sources:
            payload["sources"] = sources
        points.append(PointStruct(
            id=rec.id,
            vector=rec.vector,
            payload=payload,
        ))
    return points


def main() -> int:
    parser = argparse.ArgumentParser(description="Qdrant 存量 payload 回填 sources 多源字段")
    parser.add_argument("--db", default="data/dedup/fingerprints.sqlite3",
                        help="指纹库路径")
    parser.add_argument("--collection", default=DEFAULT_COLLECTION)
    parser.add_argument("--dry-run", action="store_true", help="只统计不写入")
    parser.add_argument("--log-level", default="INFO")
    args = parser.parse_args()

    _setup_logger(args.log_level)

    fp_sources = _load_fingerprint_sources(Path(args.db))
    logger.info("指纹库加载完成: {} 条,其中多源 {} 条",
                len(fp_sources), sum(1 for v in fp_sources.values() if len(v) > 1))

    client = make_qdrant_client()

    # scroll 分页 + (非 dry-run) 批量 upsert 回写
    total = 0
    multi_cnt = 0
    updated = 0
    offset = None
    while True:
        records, offset = client.scroll(
            collection_name=args.collection,
            limit=_SCROLL_LIMIT,
            offset=offset,
            with_payload=True,
            with_vectors=True,
        )
        if not records:
            if offset is None:
                break
            continue
        total += len(records)
        multi_cnt += sum(
            1 for r in records
            if len((r.payload or {}).get("sources") or []) > 1
        )
        if not args.dry_run:
            points = _build_points(records, fp_sources)
            for i in range(0, len(points), _UPSERT_BATCH):
                client.upsert(
                    collection_name=args.collection,
                    points=points[i : i + _UPSERT_BATCH],
                )
            updated += len(points)
        if offset is None:
            break

    logger.info("Qdrant 现存 point: {} 条(其中 payload 已含多源 {} 条)", total, multi_cnt)
    if args.dry_run:
        logger.info("--dry-run: 不执行写入")
        client.close()
        return 0

    logger.info("回填完成: 重新 upsert {} 条 point(payload 已补 sources)", updated)
    client.close()
    return 0


if __name__ == "__main__":
    raise SystemExit(main())