Initial video AI analysis project

video_ai_analysis_poc/paths.py

@@ -0,0 +1,71 @@
+from __future__ import annotations
+
+import hashlib
+from pathlib import Path
+
+
+FORBIDDEN_REFERENCE_ROOT = Path("/Users/yoilun/AI-train/zhengxin-vlm-0413")
+
+
+def resolve_path(path: str | Path, *, base_dir: Path | None = None) -> Path:
+    candidate = Path(path).expanduser()
+    if not candidate.is_absolute() and base_dir is not None:
+        candidate = base_dir / candidate
+    return candidate.resolve(strict=False)
+
+
+def _is_relative_to(path: Path, parent: Path) -> bool:
+    try:
+        path.relative_to(parent)
+        return True
+    except ValueError:
+        return False
+
+
+def validate_output_dir(
+    input_dir: str | Path,
+    output_dir: str | Path,
+    *,
+    forbidden_root: Path = FORBIDDEN_REFERENCE_ROOT,
+) -> Path:
+    resolved_input = resolve_path(input_dir)
+    resolved_output = resolve_path(output_dir)
+    resolved_forbidden = resolve_path(forbidden_root)
+
+    if resolved_output == resolved_input:
+        raise ValueError("output dir must not equal input dir")
+    if _is_relative_to(resolved_output, resolved_forbidden):
+        raise ValueError(
+            f"output dir must not be inside forbidden reference dir: {resolved_forbidden}"
+        )
+    return resolved_output
+
+
+def stable_video_id(path: str | Path) -> str:
+    resolved = str(resolve_path(path))
+    digest = hashlib.sha1(resolved.encode("utf-8")).hexdigest()[:16]
+    return f"video-{digest}"
+
+
+def hik_cloud_download_path(
+    output_dir: str | Path,
+    device_serial: str,
+    channel_no: int | str,
+    time_begin: int,
+    time_end: int,
+) -> Path:
+    safe_device = _safe_path_component(device_serial)
+    safe_channel = _safe_path_component(str(channel_no))
+    filename = f"{safe_device}_ch{safe_channel}_{int(time_begin)}_{int(time_end)}.mp4"
+    return (
+        resolve_path(output_dir)
+        / "downloads"
+        / "hik_cloud"
+        / safe_device
+        / f"ch{safe_channel}"
+        / filename
+    )
+
+
+def _safe_path_component(value: str) -> str:
+    return "".join(char if char.isalnum() or char in "._-" else "_" for char in value)