feat(fish_api): add FishAction folder watch via Pydantic settings

Add ACTION_WATCH_* settings, background watch loop in FastAPI lifespan,
and shared action_watch service that updates app_state. Add fish-action-watch
CLI and optional FishAction watch_folder_predict.py for standalone use.

Made-with: Cursor

FishAction/watch_folder_predict.py

@@ -0,0 +1,310 @@
+#!/usr/bin/env python3
+"""
+持续监控某个目录，对新出现的 MP4 做与 fish_api 相同流程的 X3D 推理。
+
+- 仅标准库：轮询目录 + 连续多次文件大小不变视为写入完成。
+- 已处理路径写入 state 文件，避免重复推理（可指定路径或关闭）。
+
+若使用 **fish_api** 与 Pydantic 管理配置，请在 `fish_api/.env` 中设置 `ACTION_WATCH_DIR`
+（及可选的 `ACTION_WATCH_POLL_INTERVAL` 等），由网关进程或 `python -m app.action_watch_cli`
+统一监控；无需再跑本脚本。
+
+示例（独立离线使用）：
+
+  python watch_folder_predict.py \\
+    --watch-dir /data/incoming_mp4 \\
+    --checkpoint checkpoints/ptv_x3d_m/checkpoint_best.pt
+"""
+
+from __future__ import annotations
+
+import argparse
+import json
+import os
+import subprocess
+import sys
+import tempfile
+import time
+import traceback
+from pathlib import Path
+from typing import Any, Dict, Set
+
+
+def _load_state(path: Path) -> Set[str]:
+    if not path.is_file():
+        return set()
+    try:
+        with open(path, encoding="utf-8") as f:
+            data = json.load(f)
+        if isinstance(data, list):
+            return set(str(x) for x in data)
+        if isinstance(data, dict) and "processed" in data:
+            return set(str(x) for x in data["processed"])
+    except (json.JSONDecodeError, OSError):
+        pass
+    return set()
+
+
+def _save_state(path: Path, processed: Set[str]) -> None:
+    path.parent.mkdir(parents=True, exist_ok=True)
+    tmp = path.with_suffix(path.suffix + ".tmp")
+    with open(tmp, "w", encoding="utf-8") as f:
+        json.dump(sorted(processed), f, indent=0, ensure_ascii=False)
+    tmp.replace(path)
+
+
+def _run_predict(
+    repo_root: Path,
+    script: Path,
+    checkpoint: str,
+    mp4_path: Path,
+    clips_per_video: int,
+    batch_size: int,
+    num_workers: int,
+    device: str,
+    output_json: str,
+) -> None:
+    mp4_path = mp4_path.resolve()
+    path_prefix = str(mp4_path.parent)
+    rel_name = mp4_path.name
+    with tempfile.NamedTemporaryFile(
+        mode="w", suffix=".csv", delete=False, encoding="utf-8"
+    ) as tmp:
+        tmp.write(f"{rel_name} 0\n")
+        csv_path = tmp.name
+    try:
+        cmd = [
+            sys.executable,
+            str(script),
+            "--checkpoint",
+            checkpoint,
+            "--csv",
+            csv_path,
+            "--path_prefix",
+            path_prefix,
+            "--clips_per_video",
+            str(clips_per_video),
+            "--batch_size",
+            str(batch_size),
+            "--num_workers",
+            str(num_workers),
+            "--output_json",
+            output_json,
+            "--log_interval",
+            "0",
+        ]
+        if device.strip():
+            cmd.extend(["--device", device.strip()])
+        proc = subprocess.run(
+            cmd,
+            cwd=str(repo_root),
+            env=os.environ.copy(),
+            capture_output=True,
+            text=True,
+        )
+        if proc.returncode != 0:
+            err = (proc.stderr or "") + (proc.stdout or "")
+            raise RuntimeError(
+                f"predict_video_x3d_3class.py failed ({proc.returncode}): {err[-4000:]}"
+            )
+    finally:
+        Path(csv_path).unlink(missing_ok=True)
+
+
+def _iter_mp4(watch_dir: Path, recursive: bool) -> list[Path]:
+    if recursive:
+        return sorted(
+            p
+            for p in watch_dir.rglob("*")
+            if p.is_file() and p.suffix.lower() == ".mp4"
+        )
+    return sorted(
+        p
+        for p in watch_dir.iterdir()
+        if p.is_file() and p.suffix.lower() == ".mp4"
+    )
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Monitor a folder and run FishAction X3D on each new MP4."
+    )
+    parser.add_argument(
+        "--watch-dir",
+        type=str,
+        required=True,
+        help="Directory to watch (non-recursive unless --recursive).",
+    )
+    parser.add_argument(
+        "--recursive",
+        action="store_true",
+        help="Also scan subdirectories for .mp4.",
+    )
+    parser.add_argument("--checkpoint", type=str, required=True)
+    parser.add_argument(
+        "--poll-interval",
+        type=float,
+        default=2.0,
+        help="Seconds between directory scans (default: 2).",
+    )
+    parser.add_argument(
+        "--stable-polls",
+        type=int,
+        default=3,
+        help="Require this many consecutive polls with unchanged size (default: 3).",
+    )
+    parser.add_argument(
+        "--state-file",
+        type=str,
+        default="",
+        help="JSON file listing processed absolute paths. Default: <watch-dir>/.fishaction_watch_processed.json",
+    )
+    parser.add_argument(
+        "--no-state",
+        action="store_true",
+        help="Do not read/write state file (may re-process files on restart).",
+    )
+    parser.add_argument(
+        "--output-json-dir",
+        type=str,
+        default="",
+        help="If set, write each prediction to <dir>/<video_stem>_pred.json.",
+    )
+    parser.add_argument(
+        "--clips_per_video",
+        type=int,
+        default=10,
+    )
+    parser.add_argument("--batch_size", type=int, default=8)
+    parser.add_argument("--num_workers", type=int, default=4)
+    parser.add_argument(
+        "--device",
+        type=str,
+        default="",
+        help="cuda|cpu (empty = predict script default).",
+    )
+    parser.add_argument(
+        "--once",
+        action="store_true",
+        help="Process all currently pending stable files once then exit.",
+    )
+    args = parser.parse_args()
+
+    watch_dir = Path(args.watch_dir).expanduser().resolve()
+    if not watch_dir.is_dir():
+        raise SystemExit(f"Not a directory: {watch_dir}")
+
+    repo_root = Path(__file__).resolve().parent
+    script = repo_root / "predict_video_x3d_3class.py"
+    if not script.is_file():
+        raise SystemExit(f"Missing script: {script}")
+
+    state_path = (
+        Path(args.state_file).expanduser().resolve()
+        if args.state_file.strip()
+        else watch_dir / ".fishaction_watch_processed.json"
+    )
+    processed: Set[str] = set() if args.no_state else _load_state(state_path)
+
+    out_json_dir = (
+        Path(args.output_json_dir).expanduser().resolve()
+        if args.output_json_dir.strip()
+        else None
+    )
+    if out_json_dir is not None:
+        out_json_dir.mkdir(parents=True, exist_ok=True)
+
+    # path -> (last_size, consecutive_stable_count)
+    stability: Dict[str, tuple[int, int]] = {}
+
+    def process_one(mp4: Path) -> None:
+        key = str(mp4.resolve())
+        if key in processed:
+            return
+        if out_json_dir is not None:
+            out_json = str(out_json_dir / f"{mp4.stem}_pred.json")
+        else:
+            out_fd, out_json = tempfile.mkstemp(suffix="_pred.json")
+            os.close(out_fd)
+        try:
+            print(f"[watch] inference: {mp4}", flush=True)
+            _run_predict(
+                repo_root,
+                script,
+                os.path.abspath(os.path.expanduser(args.checkpoint)),
+                mp4,
+                args.clips_per_video,
+                args.batch_size,
+                args.num_workers,
+                args.device,
+                out_json,
+            )
+            with open(out_json, encoding="utf-8") as f:
+                rows: Any = json.load(f)
+            if rows:
+                pred = rows[0].get("pred_3class", "")
+                print(f"[watch] done: {mp4.name} -> {pred}", flush=True)
+            processed.add(key)
+            if not args.no_state:
+                _save_state(state_path, processed)
+        finally:
+            if out_json_dir is None:
+                Path(out_json).unlink(missing_ok=True)
+
+    def tick() -> bool:
+        """Returns True if any file was processed this tick."""
+        did = False
+        seen_keys: Set[str] = set()
+        for mp4 in _iter_mp4(watch_dir, args.recursive):
+            key = str(mp4.resolve())
+            seen_keys.add(key)
+            if key in processed:
+                continue
+            try:
+                st = mp4.stat()
+            except OSError:
+                continue
+            size = int(st.st_size)
+            if size <= 0:
+                stability.pop(key, None)
+                continue
+            last = stability.get(key)
+            if last is None or last[0] != size:
+                stability[key] = (size, 1)
+            else:
+                _, cnt = last
+                stability[key] = (size, cnt + 1)
+            _, cnt = stability[key]
+            if cnt >= args.stable_polls:
+                try:
+                    process_one(mp4)
+                    stability.pop(key, None)
+                    did = True
+                except Exception as e:
+                    print(f"[watch] error on {mp4}: {e}", flush=True)
+                    traceback.print_exc()
+                    # 重置稳定计数，避免每个 poll 都重试打满日志
+                    stability[key] = (size, 1)
+        for k in list(stability.keys()):
+            if k not in seen_keys:
+                del stability[k]
+        return did
+
+    print(
+        f"[watch] watching {watch_dir} (poll={args.poll_interval}s, "
+        f"stable_polls={args.stable_polls}, state={state_path if not args.no_state else 'off'})",
+        flush=True,
+    )
+
+    if args.once:
+        while tick():
+            pass
+        return
+
+    while True:
+        tick()
+        time.sleep(max(args.poll_interval, 0.1))
+
+
+if __name__ == "__main__":
+    main()