add /api/play with filename passed in request body

app.py

@@ -208,7 +208,35 @@ def api_nowplaying():
 
 
 @app.route("/api/play/<path:filename_or_url>", methods=["POST"])
-def api_play_file(filename_or_url: str, error_str: str = "Could not play file '{filename}'"):
+def api_play_file(
+    filename_or_url: str, error_str: str = "Could not play file '{filename}'"
+):
+    if re.match("^https?://.*", filename_or_url):
+        playback_uri = filename_or_url
+    else:
+        file_path = music_path.joinpath(filename_or_url)
+        if not file_path.exists():
+            return jsonify(error_str.format(filename=filename_or_url)), 404
+        playback_uri = str(file_path)
+
+    if not is_playing():
+        playback_start()
+
+    sock = mpv_socket_open()
+    if sock is not None:
+        mpv_socket_command(sock, {"command": ["loadfile", playback_uri]})
+        sock.close()
+
+        time.sleep(0.1)
+        if is_playing():
+            return jsonify("ok")
+
+    return jsonify(error_str.format(filename=filename_or_url)), 500
+
+
+@app.route("/api/play", methods=["POST"])
+def api_play_file2(error_str: str = "Could not play file '{filename}'"):
+    filename_or_url = request.get_data().decode()
     if re.match("^https?://.*", filename_or_url):
         playback_uri = filename_or_url
     else: