Metadati: campo 'Origine (macOS · kMDItemWhereFroms)'

kMDItemWhereFroms non e un tag ID3/MP4/Vorbis: e' un extended
attribute filesystem di macOS che Safari/Mail/AirDrop e altri tool
impostano per ricordare l'origine di un file scaricato.

- core/metadata.py: _read_where_from / _write_where_from via subprocess
  xattr + plistlib (lettura/scrittura del plist binario embedded
  nell'attributo)
- read_metadata espone 'where_from' (lista URL) e 'is_macos'
- write_metadata applica l'xattr se data['where_from'] e fornito;
  lista vuota -> rimuove l'attributo
- webui: textarea 'Origine' visibile solo su macOS (is_macos=true),
  una URL per riga

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

core/metadata.py

@@ -3,7 +3,10 @@
 from __future__ import annotations
 
 import base64
+import plistlib
+import subprocess
 import struct
+import sys
 from pathlib import Path
 from typing import Optional
 
@@ -19,6 +22,53 @@ from mutagen.wave import WAVE
 
 SUPPORTED_EXTS = (".mp3", ".m4a", ".mp4", ".aac", ".flac", ".wav")
 
+_WHERE_FROM_ATTR = "com.apple.metadata:kMDItemWhereFroms"
+
+
+def _read_where_from(path: str) -> list:
+    """Legge l'xattr macOS 'kMDItemWhereFroms' (lista di URL/origini).
+    Ritorna [] se non e macOS o se l'attributo non esiste."""
+    if sys.platform != "darwin":
+        return []
+    try:
+        res = subprocess.run(
+            ["xattr", "-px", _WHERE_FROM_ATTR, path],
+            capture_output=True, text=True, timeout=5,
+        )
+        if res.returncode != 0:
+            return []
+        hex_str = "".join(res.stdout.split())
+        if not hex_str:
+            return []
+        raw = bytes.fromhex(hex_str)
+        items = plistlib.loads(raw)
+        if isinstance(items, list):
+            return [str(x) for x in items]
+        return [str(items)]
+    except Exception:
+        return []
+
+
+def _write_where_from(path: str, urls: list) -> None:
+    """Scrive l'xattr macOS 'kMDItemWhereFroms'. Lista vuota -> rimuove."""
+    if sys.platform != "darwin":
+        return
+    try:
+        clean = [u.strip() for u in (urls or []) if u and u.strip()]
+        if not clean:
+            subprocess.run(
+                ["xattr", "-d", _WHERE_FROM_ATTR, path],
+                capture_output=True, timeout=5,
+            )
+            return
+        data = plistlib.dumps(clean, fmt=plistlib.FMT_BINARY)
+        subprocess.run(
+            ["xattr", "-wx", _WHERE_FROM_ATTR, data.hex(), path],
+            capture_output=True, timeout=5, check=True,
+        )
+    except Exception:
+        pass
+
 
 def _text(value) -> str:
     """Estrai testo da un frame mutagen."""
@@ -242,6 +292,8 @@ def read_metadata(path: str) -> dict:
         "bpm": "", "key": "",
         "duration": 0, "bitrate": 0,
         "cover_base64": "", "cover_mime": "",
+        "where_from": _read_where_from(str(p)),
+        "is_macos": sys.platform == "darwin",
     }
 
     audio = MutagenFile(str(p))
@@ -448,7 +500,9 @@ def _write_wav(path: str, data: dict, cover_path: Optional[str], remove_cover: b
 def write_metadata(path: str, data: dict, cover_path: Optional[str] = None,
                     remove_cover: bool = False) -> None:
     """Salva i metadati. Se remove_cover=True rimuove la copertina esistente
-    senza sostituirla. Se cover_path e fornito, la sostituisce."""
+    senza sostituirla. Se cover_path e fornito, la sostituisce.
+    Su macOS aggiorna anche l'xattr kMDItemWhereFroms se data['where_from']
+    e fornito (lista di stringhe)."""
     ext = Path(path).suffix.lower()
     if ext == ".mp3":
         _write_mp3(path, data, cover_path, remove_cover)
@@ -460,3 +514,7 @@ def write_metadata(path: str, data: dict, cover_path: Optional[str] = None,
         _write_wav(path, data, cover_path, remove_cover)
     else:
         raise ValueError(f"Formato non supportato: {ext}")
+
+    # macOS extended attribute: kMDItemWhereFroms (lista URL/origini)
+    if "where_from" in data:
+        _write_where_from(path, data.get("where_from") or [])

webui/index.html

@@ -305,6 +305,13 @@
                 <label class="field-label">Commento</label>
                 <textarea id="metaComment" class="input textarea" rows="3"></textarea>
               </div>
+              <div class="field full" id="metaWhereFromField" hidden>
+                <label class="field-label">
+                  Origine (macOS · kMDItemWhereFroms)
+                </label>
+                <textarea id="metaWhereFrom" class="input textarea" rows="2" placeholder="https://... (uno per riga)"></textarea>
+                <div class="cover-hint">Extended attribute macOS — una URL per riga. Vuoto = rimuove l'attributo.</div>
+              </div>
             </div>
           </div>
 

webui/js/app.js

@@ -414,6 +414,15 @@ function populateMetaForm(d) {
   $("#metaKey").value = d.key || "";
   $("#metaComment").value = d.comment || "";
 
+  // WhereFroms (macOS only)
+  if (d.is_macos) {
+    $("#metaWhereFromField").hidden = false;
+    $("#metaWhereFrom").value = (d.where_from || []).join("\n");
+  } else {
+    $("#metaWhereFromField").hidden = true;
+    $("#metaWhereFrom").value = "";
+  }
+
   // Info riga sotto il path
   const info = $("#metaInfo");
   info.hidden = false;
@@ -511,6 +520,10 @@ $("#metaSaveBtn").addEventListener("click", async () => {
       bpm: $("#metaBpm").value,
       key: $("#metaKey").value,
       comment: $("#metaComment").value,
+      where_from: $("#metaWhereFrom").value
+        .split("\n")
+        .map(s => s.trim())
+        .filter(Boolean),
     },
     cover_path: state.meta.newCoverPath,
     remove_cover: state.meta.removeCover,