downloader: supports Content-Disposition

feed

@@ -511,18 +511,35 @@ def get_parser():
     return p
 
 
-def downloader(url, dest):
+def normalize_filename(original: str) -> str:
+    fname = original.split('/')[-1]
+    return "".join(
+        c for c in fname if c.isalnum() or c in list("._-")
+    ).rstrip()
+
+
+def downloader(url: str, destdir: str, prefix: str) -> str:
+    r = requests.head(url)
+    fname = posixpath.basename(urlparse(url).path)
+    if r.status_code == 200 and 'Content-Disposition' in r.headers:
+        matches = re.findall(r'''filename="(.+)"''', r.headers['Content-Disposition'])
+        if matches:
+            fname = matches[0]
+    fname = normalize_filename(fname)
+    dest = os.path.join(destdir, prefix + fname)
     headers = {}
     mode = "wb"
     if os.path.exists(dest):
-        headers["Range"] = "bytes=%d-" % os.stat(dest).st_size
-        mode = "ab"
+        if 'Content-Length' in r.headers and os.stat(dest).st_size < int(r.headers['Content-Length']):
+            headers["Range"] = "bytes=%d-" % os.stat(dest).st_size
+            mode = "ab"
     r = requests.get(url, stream=True, headers=headers)
     if r.status_code == 416:  # range not satisfiable
-        return
+        return dest
     with open(dest, mode) as f:
         for chunk in r.iter_content(chunk_size=1 << 16):
             f.write(chunk)
+    return dest
 
 
 def put(audio, copy=False):
@@ -534,13 +551,7 @@ def put(audio, copy=False):
         os.makedirs(destdir, exist_ok=True)
         for url in audio.urls:
             if url.split(":")[0] in ("http", "https"):
-                fname = posixpath.basename(urlparse(url).path)
-                # sanitize
-                fname = "".join(
-                    c for c in fname if c.isalnum() or c in list("._-")
-                ).rstrip()
-                dest = os.path.join(destdir, "feed-" + fname)
-                downloader(url, dest)
+                dest = downloader(url, destdir=destdir, prefix="feed-")
                 print("file://%s" % os.path.realpath(dest))
             elif url.startswith("file:///"):
                 src = url[len('file://'):]