Convert wav files via the web interface.

Still very ugly, and there are permission issues that
needs to be solved.

mp3wavweb.py

@@ -3,6 +3,7 @@ import stat
 import io
 import urllib.parse
 import sys
+import multiprocessing.connection
 
 sys.path.insert(0, os.path.dirname(__file__))
 
@@ -11,6 +12,23 @@ import mp3wavcfg
 def quote(s):
     return urllib.parse.quote(s)
 
+# Taken from
+# http://stackoverflow.com/questions/4579908/cross-platform-splitting-of-path-in-python
+# but with debug removed since Python 3 does not support that print
+# syntax (and debug was pointless anyhow).
+def os_path_split_asunder(path):
+    parts = []
+    while True:
+        newpath, tail = os.path.split(path)
+        if newpath == path:
+            assert not tail
+            if path: parts.append(path)
+            break
+        parts.append(tail)
+        path = newpath
+    parts.reverse()
+    return parts
+
 def application(environ, start_response):
     if environ["REQUEST_METHOD"] != "GET":
        start_response("405 Method Not Allowed",
@@ -25,31 +43,69 @@ def application(environ, start_response):
                        [("Location", environ["SCRIPT_NAME"] + "/")])
         return []
 
-    subdir = os.path.dirname(path)
-    if len(subdir) > 0 and subdir[0] == "/":
-        subdir = subdir[1:]
-
-    filename = os.path.basename(path)
+    parts = os_path_split_asunder(path)
+    if len(parts) > 0 and parts[0] == "/":
+        parts = parts[1:]
 
-    realfile = os.path.join(mp3wavcfg.BASE, subdir, filename)
+    realfile = os.path.join(mp3wavcfg.BASE, *parts)
 
     try:
         status = os.stat(realfile)
-    except os.error:
+    except (os.error, FileNotFoundError):
+        dirparts, basename, ops = locate_mp3(parts)
+
+        if ops is not None and len(ops) > 0 and ops[0] in MP3_OPS:
+            rel_base = os.path.join(*(dirparts + [basename]))
+            basefile = os.path.join(mp3wavcfg.BASE, rel_base)
+            try:
+                wavstat = os.stat(basefile + ".wav")
+            except os.error:
+                pass
+            else:
+                return MP3_OPS[ops[0]](start_response, rel_base, ops[1:])
+
         start_response("404 Not found", [])
 
         return []
 
     if stat.S_ISDIR(status.st_mode):
         return handle_directory(environ, start_response,
-                                os.path.join(subdir, filename))
+                                os.path.join(*parts))
     elif stat.S_ISREG(status.st_mode):
         return handle_file(environ, start_response,
-                           os.path.join(subdir, filename))
+                           os.path.join(*parts))
 
     start_response("404 Not found", [])
     return []
 
+def convert(start_response, rel_base, ops):
+    if len(ops) > 0:
+        start_response("404 Not found", [])
+        return []
+    c = multiprocessing.connection.Client(mp3wavcfg.socketpath, 'AF_UNIX')
+    c.send(("encode", rel_base))
+    while True:
+        msg = c.recv()
+        if msg[0] != "progress":
+            break
+
+    start_response("301 Moved Permanently",
+                   [("Content-Type", "text/plain"),
+                    ("Location", "..")])
+    return ["File converted to mp3"]
+
+MP3_OPS = {
+    'convert': convert,
+}
+
+def locate_mp3(parts):
+    pos = len(parts) - 1
+    while pos >= 0:
+        fn, ext = os.path.splitext(parts[pos])
+        if ext == ".mp3":
+            return parts[:pos], fn, parts[pos+1:]
+        pos -= 1
+    return None, None, None
 
 def sizeof_fmt(num):
     for x in ['bytes','KB','MB','GB']:
@@ -106,7 +162,10 @@ def handle_directory(environ, start_response, rel_path):
             res.write(" <a href=\"%s.mp3\">.mp3</a>" % quote(w))
             res.write(" (" + sizeof_fmt(mp3s[w].st_size) + ")")
         else:
-            res.write(" (FIXME: add button to convert to mp3)")
+            res.write("<form method=\"GET\" action=\"%s.mp3/convert\">\n" % (
+                quote(w)))
+            res.write("<button>Convert to mp3</button>")
+            res.write("</form>")
         res.write("</li>\n")
     res.write("</ul>")
     res.write("</body>")