feat: add SVG QR CLI and TOML batch input

qr.py

@@ -1,41 +1,139 @@
-import qrcode
+"""Command-line SVG QR code generator."""
+
+from __future__ import annotations
+
 import argparse
-import os
+from pathlib import Path
+import re
+from typing import Sequence
 
-def main(input_text, output_filename):
-    # Add .png extension if not present
-    if not output_filename.endswith(".png"):
-        output_filename += ".png"
+import qrcode
 
-    # Create a QR code object
-    qr = qrcode.QRCode(
-        version=1,
+try:
+    import tomllib
+except ModuleNotFoundError:
+    import tomli as tomllib
+
+
+SVG_SUFFIX = ".svg"
+MAX_FILENAME_LENGTH = 32
+INVALID_FILENAME_CHARACTERS = re.compile(r'[<>:"/\\|?*\x00-\x1f]')
+
+
+def svg_path(text: str) -> str:
+    """Build an SVG containing the QR code as filled convex module paths."""
+    code = qrcode.QRCode(
+        version=None,
         error_correction=qrcode.constants.ERROR_CORRECT_L,
-        box_size=10,
-        border=0,
+        border=4,
+    )
+    code.add_data(text)
+    code.make(fit=True)
+
+    matrix = code.get_matrix()
+    size = len(matrix)
+    modules = []
+    for row_index, row in enumerate(matrix):
+        for column_index, is_dark in enumerate(row):
+            if is_dark:
+                modules.append(
+                    f"M{column_index} {row_index}H{column_index + 1}"
+                    f"V{row_index + 1}H{column_index}Z"
+                )
+
+    path_data = "".join(modules)
+    return (
+        '<?xml version="1.0" encoding="UTF-8"?>\n'
+        f'<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 {size} {size}" '
+        f'width="{size}" height="{size}" role="img">\n'
+        f'  <path fill="#000" d="{path_data}"/>\n'
+        "</svg>\n"
     )
 
-    # Add the input data to the QR code object
-    qr.add_data(input_text)
 
-    # Make the QR code
-    qr.make(fit=True)
+def write_svg(text: str, output_path: Path) -> None:
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+    output_path.write_text(svg_path(text), encoding="utf-8")
 
-    # Create an image object to store the generated QR code
-    img = qr.make_image(fill_color="black", back_color="white")
 
-    # Save the QR code image to a file
-    img.save(output_filename)
+def with_svg_suffix(path: Path) -> Path:
+    if path.suffix.lower() == SVG_SUFFIX:
+        return path
+    return path.with_name(f"{path.name}{SVG_SUFFIX}")
+
+
+def automatic_output_path(text: str, directory: Path = Path(".")) -> Path:
+    filename = INVALID_FILENAME_CHARACTERS.sub("_", text).rstrip(". ")
+    if filename in {"", ".", ".."}:
+        filename = "_"
+
+    stem_length = MAX_FILENAME_LENGTH - len(SVG_SUFFIX)
+    return directory / f"{filename[:stem_length]}{SVG_SUFFIX}"
+
+
+def read_toml_items(input_path: Path) -> dict[str, str]:
+    content = input_path.read_text(encoding="utf-8")
+    try:
+        items = tomllib.loads(content)
+    except tomllib.TOMLDecodeError:
+        items = {}
+        for line_number, line in enumerate(content.splitlines(), start=1):
+            if not line.strip() or line.lstrip().startswith("#"):
+                continue
+            key, separator, value = line.partition(":")
+            if not separator or not key.strip():
+                raise ValueError(
+                    f"{input_path}:{line_number}: expected a flat TOML item"
+                ) from None
+            items[key.strip()] = value.strip()
+
+    if not all(isinstance(key, str) and isinstance(value, str) for key, value in items.items()):
+        raise ValueError(f"{input_path}: TOML values must be top-level text strings")
+    return items
+
+
+def build_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(description="Generate SVG QR codes from text.")
+    parser.add_argument("text", nargs="?", help="Text to encode (the default input mode).")
+    parser.add_argument("-t", "--text", dest="option_text", help="Text to encode.")
+    parser.add_argument("-o", "--output", type=Path, help="Path for the generated SVG.")
+    parser.add_argument("-i", "--input", type=Path, help="File containing one QR value per line.")
+    parser.add_argument("--toml", type=Path, help="Flat TOML file containing output names and text.")
+    return parser
+
+
+def run(arguments: Sequence[str] | None = None) -> None:
+    parser = build_parser()
+    args = parser.parse_args(arguments)
+
+    if args.input is not None or args.toml is not None:
+        if args.input is not None and args.toml is not None:
+            parser.error("--input and --toml cannot be used together")
+        if args.text is not None or args.option_text is not None:
+            parser.error("text input cannot be used with batch input")
+
+        if args.input is not None:
+            for line in args.input.read_text(encoding="utf-8").splitlines():
+                write_svg(line, automatic_output_path(line, Path("output")))
+        else:
+            try:
+                items = read_toml_items(args.toml)
+            except ValueError as error:
+                parser.error(str(error))
+            for name, text in items.items():
+                write_svg(text, automatic_output_path(name, Path("output")))
+        return
+
+    if args.text is not None and args.option_text is not None:
+        parser.error("provide text either positionally or with --text, not both")
+
+    text = args.option_text if args.option_text is not None else args.text
+    if text is None:
+        parser.error("text is required unless --input is provided")
+
+    output_path = with_svg_suffix(args.output) if args.output else automatic_output_path(text)
+    write_svg(text, output_path)
 
 
 if __name__ == "__main__":
-    # Set up the argument parser
-    parser = argparse.ArgumentParser(description="Generate a QR code from input text.")
-    parser.add_argument("-i", "--input", required=True, help="Text to be embedded in the QR code.")
-    parser.add_argument("-o", "--output", required=True, help="Filename for the output image.")
-
-    # Parse the command-line arguments
-    args = parser.parse_args()
-
-    # Call the main function with the provided arguments
-    main(args.input, args.output)
+    run()