xref: /linux/tools/docs/lib/enrich_formatter.py (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
1#!/usr/bin/env python3
2# SPDX-License-Identifier: GPL-2.0
3# Copyright (c) 2025 by Mauro Carvalho Chehab <mchehab@kernel.org>.
4
5"""
6Ancillary argparse HelpFormatter class that works on a similar way as
7argparse.RawDescriptionHelpFormatter, e.g. description maintains line
8breaks, but it also implement transformations to the help text. The
9actual transformations ar given by enrich_text(), if the output is tty.
10
11Currently, the follow transformations are done:
12
13    - Positional arguments are shown in upper cases;
14    - if output is TTY, ``var`` and positional arguments are shown prepended
15      by an ANSI SGR code. This is usually translated to bold. On some
16      terminals, like, konsole, this is translated into a colored bold text.
17"""
18
19import argparse
20import re
21import sys
22
23class EnrichFormatter(argparse.HelpFormatter):
24    """
25    Better format the output, making easier to identify the positional args
26    and how they're used at the __doc__ description.
27    """
28    def __init__(self, *args, **kwargs):
29        """Initialize class and check if is TTY"""
30        super().__init__(*args, **kwargs)
31        self._tty = sys.stdout.isatty()
32
33    def enrich_text(self, text):
34        """Handle ReST markups (currently, only ``foo``)"""
35        if self._tty and text:
36            # Replace ``text`` with ANSI SGR (bold)
37            return re.sub(r'\`\`(.+?)\`\`',
38                          lambda m: f'\033[1m{m.group(1)}\033[0m', text)
39        return text
40
41    def _fill_text(self, text, width, indent):
42        """Enrich descriptions with markups on it"""
43        enriched = self.enrich_text(text)
44        return "\n".join(indent + line for line in enriched.splitlines())
45
46    def _format_usage(self, usage, actions, groups, prefix):
47        """Enrich positional arguments at usage: line"""
48
49        prog = self._prog
50        parts = []
51
52        for action in actions:
53            if action.option_strings:
54                opt = action.option_strings[0]
55                if action.nargs != 0:
56                    opt += f" {action.dest.upper()}"
57                parts.append(f"[{opt}]")
58            else:
59                # Positional argument
60                parts.append(self.enrich_text(f"``{action.dest.upper()}``"))
61
62        usage_text = f"{prefix or 'usage: '} {prog} {' '.join(parts)}\n"
63        return usage_text
64
65    def _format_action_invocation(self, action):
66        """Enrich argument names"""
67        if not action.option_strings:
68            return self.enrich_text(f"``{action.dest.upper()}``")
69
70        return ", ".join(action.option_strings)
71