"""
回填质检标签 (backfill)
========================
把 output 根目录 a1/a2/a3 原始文件里的条目, 按对应 *_strict.json 打上质检标签:
  - 出现在 strict 文件里的 -> human_valid_label_strict = True
  - 未出现的 (当初被淘汰)   -> human_valid_label_strict = False

目的: 让增量续跑时 step_a6 的 _already_checked (规则2: 已有标签就跳过) 命中,
从而旧批用户跳过三教师质检、且严格保留原有 strict 结果 (通过的保通过, 淘汰的仍淘汰),
新用户 (无标签) 正常质检。

匹配键: A1 按 user_id, A2 按 session_id, A3 按 QA id。
幂等: 已有标签的条目不覆盖 (二次运行安全)。原子写 (.tmp 再 rename)。

用法:
    python backfill_labels.py            # 回填 a1/a2/a3
    python backfill_labels.py --dry-run  # 只统计, 不写文件
"""
import argparse
import json
import re
import sys
from pathlib import Path

sys.path.append(str(Path(__file__).resolve().parent))
from config import (
    OUTPUT_A1, OUTPUT_A1_STRICT,
    OUTPUT_A2, OUTPUT_A2_STRICT,
    OUTPUT_A3, OUTPUT_A3_STRICT,
)


def _user_num(item: dict):
    """解析 user 编号: profile/QA 用 user_id, session 用 session_id 前缀 (u0036_s001 -> 36)."""
    uid = item.get("user_id")
    if not uid:
        sid = item.get("session_id", "")
        uid = sid.split("_", 1)[0] if sid else ""
    m = re.match(r"[uU]?(\d+)", str(uid))
    return int(m.group(1)) if m else None


def _load(path: Path):
    if not path.exists():
        return None
    with open(path, "r", encoding="utf-8") as f:
        return json.load(f)


def _atomic_dump(obj, path: Path):
    tmp = path.with_suffix(path.suffix + ".tmp")
    with open(tmp, "w", encoding="utf-8") as f:
        json.dump(obj, f, ensure_ascii=False, indent=2)
    tmp.replace(path)


def _set_label(item: dict, passed: bool):
    """给条目打上质检标签 (仅当尚无稳定标签时)。返回是否新打了标签。"""
    if "human_valid_label_strict" in item and isinstance(item.get("quality_check"), dict) \
            and "error" not in item["quality_check"]:
        return False  # 已有稳定标签, 不覆盖 (幂等)
    item["quality_check"] = {
        "final_valid_loose": passed,
        "final_valid_strict": passed,
        "final_valid": passed,
        "backfilled": True,
    }
    item["human_valid_label_loose"] = passed
    item["human_valid_label_strict"] = passed
    item["human_valid_label"] = passed
    return True


def backfill_a1(dry: bool, max_id: int):
    raw = _load(OUTPUT_A1)
    strict = _load(OUTPUT_A1_STRICT)
    if raw is None or strict is None:
        print(f"[A1] 跳过: 缺 {OUTPUT_A1.name} 或 {OUTPUT_A1_STRICT.name}")
        return
    strict_ids = {p["user_id"] for p in strict}
    n_pass = n_fail = n_skip = n_new = 0
    for p in raw:
        num = _user_num(p)
        if num is None or num > max_id:
            n_new += 1  # 新用户/超范围: 不回填, 保持无标签待质检
            continue
        passed = p["user_id"] in strict_ids
        if _set_label(p, passed):
            n_pass += passed
            n_fail += (not passed)
        else:
            n_skip += 1
    print(f"[A1] {len(raw)} profiles | 新打通过={n_pass} 新打淘汰={n_fail} 已有标签跳过={n_skip} 新用户不回填={n_new}")
    if not dry:
        _atomic_dump(raw, OUTPUT_A1)
        print(f"[A1] 写回 {OUTPUT_A1.name}")


def backfill_a2(dry: bool, max_id: int):
    raw = _load(OUTPUT_A2)
    strict = _load(OUTPUT_A2_STRICT)
    if raw is None or strict is None:
        print(f"[A2] 跳过: 缺 {OUTPUT_A2.name} 或 {OUTPUT_A2_STRICT.name}")
        return
    strict_sids = set()
    for u in strict:
        for s in u.get("evidence_sessions", []):
            strict_sids.add(s["session_id"])
    n_pass = n_fail = n_skip = n_new = 0
    for u in raw:
        for s in u.get("evidence_sessions", []):
            num = _user_num(s)
            if num is None or num > max_id:
                n_new += 1
                continue
            passed = s["session_id"] in strict_sids
            if _set_label(s, passed):
                n_pass += passed
                n_fail += (not passed)
            else:
                n_skip += 1
    print(f"[A2] evidence sessions | 新打通过={n_pass} 新打淘汰={n_fail} 已有标签跳过={n_skip} 新用户不回填={n_new}")
    if not dry:
        _atomic_dump(raw, OUTPUT_A2)
        print(f"[A2] 写回 {OUTPUT_A2.name}")


def backfill_a3(dry: bool, max_id: int):
    raw = _load(OUTPUT_A3)
    strict = _load(OUTPUT_A3_STRICT)
    if raw is None or strict is None:
        print(f"[A3] 跳过: 缺 {OUTPUT_A3.name} 或 {OUTPUT_A3_STRICT.name}")
        return
    strict_ids = {q["id"] for q in strict}
    n_pass = n_fail = n_skip = n_new = 0
    for q in raw:
        num = _user_num(q)
        if num is None or num > max_id:
            n_new += 1
            continue
        passed = q["id"] in strict_ids
        if _set_label(q, passed):
            n_pass += passed
            n_fail += (not passed)
        else:
            n_skip += 1
    print(f"[A3] {len(raw)} QA | 新打通过={n_pass} 新打淘汰={n_fail} 已有标签跳过={n_skip} 新用户不回填={n_new}")
    if not dry:
        _atomic_dump(raw, OUTPUT_A3)
        print(f"[A3] 写回 {OUTPUT_A3.name}")


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--dry-run", action="store_true", help="只统计不写文件")
    ap.add_argument("--max-id", type=int, default=200,
                    help="只回填 user 编号 <= 此值的旧批条目; 更大编号的新用户保持无标签待质检 (默认 200)")
    args = ap.parse_args()
    print(f"{'[DRY-RUN] ' if args.dry_run else ''}回填质检标签 (旧批 user_id<={args.max_id}; 通过=strict里有, 淘汰=strict里没有)")
    backfill_a1(args.dry_run, args.max_id)
    backfill_a2(args.dry_run, args.max_id)
    backfill_a3(args.dry_run, args.max_id)
    print("完成。" + ("" if args.dry_run else " 现在增量跑时旧批跳过质检并保留原 strict 结果, 新用户正常质检。"))


if __name__ == "__main__":
    main()