Improve the cmdline script to accept more options

Author: rimas-kudelis

Lib/extractor/__init__.py

@@ -84,28 +84,57 @@ def cmdline():
 
     Usage: extractufo font [font ...]
     """
-    from sys import argv, exit
-    try:
-        from ufoLib2 import Font
-        library = "ufoLib2"
-    except ImportError:
+    import os
+    from sys import exit
+    from argparse import ArgumentParser
+
+    parser = ArgumentParser(
+        description="Extract data from font binaries and build UFO objects from them.",
+        epilog="Each resulting UFO will be saved as FONT_FILE.ufo(z) in the same directory as the original FONT_FILE. "
+               "If destination file or directory already exists, conversion for that source file will be skipped and the application exit code will indicate an error.",
+    )
+    parser.add_argument('FONT_FILE', help='Input font path', nargs="+")
+    parser.add_argument('-m', '--ufo-module', choices=['ufoLib2', 'defcon'],
+                        help='Select the default library for writing UFOs (default: autodetect, prefer ufoLib2)')
+    parser.add_argument('-z', '--zip', action="store_true", help="Output UFO ZIP")
+
+    args = parser.parse_args()
+    if args.ufo_module is None:
+        try:
+            from ufoLib2 import Font
+            print("Will use ufoLib2 for UFO output.")
+        except ImportError:
+            try:
+                from defcon import Font
+                print("Will use defcon for UFO output.")
+            except ImportError:
+                print("Either ufoLib2 or, alternatively, defcon library is required to run this command.\nPlease install one of them.")
+                exit(1)
+    elif args.ufo_module == 'ufoLib2':
+        try:
+            from ufoLib2 import Font
+        except ImportError:
+            print("Can't find ufoLib2 installed. Please install it or specify a different UFO library.")
+            exit(1)
+    else:
         try:
             from defcon import Font
-            library = "defcon"
         except ImportError:
-            print("Either ufoLib2 or defcon library is required for this command to work.\nPlease install one of them.")
+            print("Can't find defcon installed. Please install it or specify a different UFO library.")
             exit(1)
 
-    if len(argv) <= 1:
-        print("No font path supplied.\nUsage: extractufo font [font ...]")
-        exit(1)
-
-    print(f"Will use {library} library for UFO output.")
-
-    for font_path in argv[1:]:
-        ufo_path = f"{font_path}.ufo"
+    structure = "zip" if args.zip else "package"
+    had_write_errors = False
+    for font_path in args.FONT_FILE:
+        ufo_path = f"{font_path}.ufo" if not args.zip else f"{font_path}.ufoz"
         print(f"Extracting {ufo_path}... ", end="")
+        if os.path.exists(ufo_path):
+            print("path already exists, skipping.")
+            had_write_errors = True
+            continue
         ufo = Font()
         extractUFO(font_path, ufo)
-        ufo.save(ufo_path, overwrite=True)
+        ufo.save(ufo_path, structure=structure)
         print("done.")
+
+    exit(had_write_errors)