Refactor Canvas with new revert(), text(), fill() methods

dymo_bluetooth/__main__.py

@@ -22,28 +22,46 @@
 
 from argparse import ArgumentParser, BooleanOptionalAction
 from pathlib import Path
-from typing import cast
+from typing import Literal, Union, cast
 from dymo_bluetooth.bluetooth import discover_printers, create_image
 import sys
 import asyncio
 import os
 
 async def print_image(
-    input_file : Path, 
-    max_timeout : int, 
-    stretch_factor : int, 
-    use_dither : bool
+    input_file: Path, 
+    max_timeout: int, 
+    stretch_factor: int, 
+    use_dither: bool,
+    ensure_mac: bool,
+    padding: int,
+    reverse: bool,
+    is_preview: Union[None, Literal["large", "small"]]
 ):
     canvas = create_image(input_file, dither = use_dither)
-    canvas = canvas.stretch_image(factor = stretch_factor)
-    printers = await discover_printers(max_timeout)
+    if stretch_factor != 1:
+        canvas = canvas.stretch(factor = stretch_factor)
+    if padding != 0:
+        canvas = canvas.fill(padding, padding)
+    if reverse:
+        canvas = canvas.revert()
+
+    if is_preview:
+        print(canvas.text(False if is_preview == "large" else True))
+        exit(0)
+
+    print(f"Image size: {canvas.size}", file = sys.stderr)
+    print(f"Searching for nearby printers to print (timeout: {max_timeout})...", file = sys.stderr)
+    printers = await discover_printers(max_timeout, ensure_mac)
     if not printers:
-        print("Couldn't find any printers in given timeout!")
+        print("Couldn't find any printers, is the printer online?", file = sys.stderr)
         exit(1)
     printer = printers[0]
-    print(f"Starting to print on {printer._impl.address}...")
+    print(f"Found: {printer._impl.address}", file = sys.stderr)
     await printer.connect()
-    await printer.print(canvas)
+    print("Printing...", file = sys.stderr)
+    result = await printer.print(canvas)
+    print(f"Result: {result.name} ({result.value})", file = sys.stderr)
 
 
 def main():
@@ -51,28 +69,107 @@ def main():
     args = ArgumentParser(
         prog = f"python -m {module_name}",
         description = (
-            "Print monochrome labels with DYMO LetraTag LT-200B label printer over "
-            "Bluetooth."
+            "Print monochrome labels with DYMO LetraTag LT-200B label printer over Bluetooth. "
+            "If executed without --preview, it will search for a printer nearby and automatically "
+            "start printing the image."
         )
     )
-    args.add_argument("image", help = "Image file to print. Must be 32 pixels in height.", type = Path, metavar = "IMAGE") # noqa: E501
-    args.add_argument("--timeout", default = 5, type = int, help = "Maximum timeout to search for printers.") # noqa: E501
-    args.add_argument("--dither", default = True, action = BooleanOptionalAction,
-        help = "Use or don't use dithering when converting it to monochrome image."
+    args.add_argument(
+        "image", 
+        help = (
+            "Image file to print. Can be any type of image that is supported by Pillow. "
+            "Must be 32 pixels in height, otherwise it will be cropped out."
+        ), 
+        type = Path, 
+        metavar = "IMAGE"
     )
-    args.add_argument("--factor", default = 2, type = int,
-        help = "Stretch the image N times. Default is 2, otherwise printer" + \
-        "will print images too thin."
+    args.add_argument(
+        "--ensure-mac", 
+        default = 5, 
+        action = "store_true",
+        help = (
+            "Also ensures the MAC address does match with the pre-defined MAC prefixes when "
+            "searching for a printer. Otherwise it will only search for printers by "
+            "looking for service UUID and its Bluetooth name."
+        )
+    )
+    args.add_argument(
+        "--timeout", 
+        default = 5, 
+        type = int, 
+        help = "Maximum timeout in seconds to search for printers."
+    )
+    args.add_argument(
+        "--dither", 
+        default = True, 
+        action = BooleanOptionalAction,
+        help = (
+            "Use or don't use Floyd-Steinberg dithering provided by Pillow when converting "
+            "the image to a monochrome image."
+        )
+    )
+    args.add_argument(
+        "--stretch", 
+        default = 2, 
+        type = int,
+        help = (
+            "Stretch the image N times. Default is 2 (as-is in the mobile app), otherwise "
+            "the printed label will become too thin to actually read."
+        )
+    )
+    args.add_argument(
+        "--padding", 
+        default = 0, 
+        type = int,
+        help = (
+            "Adds N blank width in both sides of the image, leaving the content in the center. "
+            "So the output width will be ((N * 2) + image width)."
+        )
+    )
+    args.add_argument(
+        "--reverse",
+        action = "store_true",
+        help = (
+            "Flip the image in color (black becomes white, white becomes black)."
+        )
+    )
+    args.add_argument(
+        "--preview",
+        const = "small",
+        nargs = "?",
+        choices = ("large", "small"),
+        help = (
+            "Don't actually print anything, just print the image in the console with all settings "
+            "applied to it. The default is 'small', which is the recommended option."
+        )
     )
     parsed = args.parse_args()
     input_file = cast(Path, parsed.image).absolute()
     max_timeout = cast(int, parsed.timeout)
-    stretch_factor = cast(int, parsed.factor)
+    stretch_factor = cast(int, parsed.stretch)
     use_dither = cast(bool, parsed.dither)
+    ensure_mac = cast(bool, parsed.ensure_mac)
+    padding = cast(int, parsed.padding)
+    reverse = cast(bool, parsed.reverse)
+    is_preview = cast(Union[None, Literal["large", "small"]], parsed.preview)
+
     if not input_file.exists():
-        print(f"Given image file doesn't exists: {input_file.as_posix()}")
+        print(f"Input file doesn't exists: {input_file.as_posix()}", file = sys.stderr)
         exit(1)
-    asyncio.run(print_image(input_file, max_timeout, stretch_factor, use_dither))
+    if input_file.is_dir():
+        print(f"Input file can't be a directory: {input_file.as_posix()}", file = sys.stderr)
+        exit(1)
+
+    asyncio.run(print_image(
+        input_file, 
+        max_timeout, 
+        stretch_factor, 
+        use_dither,
+        ensure_mac,
+        padding,
+        reverse,
+        is_preview
+    ))
 
 
 if __name__ == "__main__":