Added remote command: FROM_FILE

Remote commands can be read directly from a file (one per line).
Lines starting with `#` and empty lines are ignored.

picard/tagger.py

@@ -53,6 +53,7 @@ import logging
 import os
 import platform
 import re
+import shlex
 import shutil
 import signal
 import sys
@@ -229,6 +230,11 @@ REMOTE_COMMANDS = {
         "handle_command_fingerprint",
         help_text="Calculate acoustic fingerprints for all (matched) files in the album pane.",
     ),
+    "FROM_FILE": RemoteCommand(
+        "handle_command_from_file",
+        help_text="Load command pipeline from a file.",
+        help_args="[Absolute path to a file containing command pipeline]",
+    ),
     "LOAD": RemoteCommand(
         "handle_command_load",
         help_text="Load 1 or more files/MBIDs/URLs to Picard.",
@@ -491,6 +497,29 @@ class Tagger(QtWidgets.QApplication):
         for album_name in self.albums:
             self.analyze(self.albums[album_name].iterfiles())
 
+    @staticmethod
+    def _read_lines_from_file(filepath):
+        try:
+            yield from (line.strip() for line in open(filepath).readlines())
+        except Exception as e:
+            log.error("Error reading command file '%s': %s" % (filepath, e))
+
+    @staticmethod
+    def _parse_commands_from_lines(lines):
+        for line in lines:
+            if not line or line.startswith('#'):
+                continue
+            elements = shlex.split(line)
+            if not elements:
+                continue
+            command_args = elements[1:] or ['']
+            for element in command_args:
+                yield f"command://{elements[0]} {element}"
+
+    def handle_command_from_file(self, argstring):
+        for command in self._parse_commands_from_lines(self._read_lines_from_file(argstring)):
+            self.handle_command(command)
+
     def handle_command_load(self, argstring):
         if argstring.startswith("command://"):
             log.error("Cannot LOAD a command: %s", argstring)

test/test_parsing_files_with_commands.py

@@ -0,0 +1,47 @@
+from test.picardtestcase import PicardTestCase
+
+from picard.tagger import Tagger
+
+
+class TestParsingFilesWithCommands(PicardTestCase):
+
+    MOCK_FILE_CONTENTS = (
+        # should be split into 2 commands
+        "LOAD file1.mp3 file2.mp3",
+        # should be added as one
+        "FROM_FILE file0.mp3",
+        "CLUSTER",
+        "  FINGERPRINT  "
+        # should be ignored
+        "",
+        " ",
+        "\n",
+        "#commented command",
+    )
+
+    def setUp(self):
+        super().setUp()
+        self.result = tuple(x for x in Tagger._parse_commands_from_lines(self.MOCK_FILE_CONTENTS))
+
+    def test_no_argument_command(self):
+        self.assertIn("command://CLUSTER ", self.result)
+
+    def test_no_argument_command_stripped_correctly(self):
+        self.assertIn("command://FINGERPRINT ", self.result)
+
+    def test_single_argument_command(self):
+        self.assertIn("command://FROM_FILE file0.mp3", self.result)
+
+    def test_multiple_arguments_command(self):
+        self.assertIn("command://LOAD file1.mp3", self.result)
+        self.assertIn("command://LOAD file2.mp3", self.result)
+
+    def test_empty_lines(self):
+        self.assertNotIn("command:// ", self.result)
+        self.assertNotIn("command://", self.result)
+        # 1 FROM_FILE
+        # 2 LOADs
+        self.assertEqual(len(self.result), 5)
+
+    def test_commented_lines(self):
+        self.assertNotIn("command://#commented command", self.result)