nassh/bin/generate-changelog

#!/usr/bin/env python3
# Copyright 2020 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Utility code for generating ChangeLog.html."""

import html
import logging
import os
import sys
from typing import List

import nassh  # pylint: disable=wrong-import-order
import libdot


CHANGELOG_FILE = os.path.join(nassh.DIR, "html", "changelog.html")
CHANGELOG_TEMPLATE = os.path.join(nassh.DIR, "html", "changelog.html.in")

CHANGELOG_ENTRY_TEMPLATE = """\
<div><a href="https://crrev.com/%(commit)s">%(summary)s</a></div>
"""


def generate_html(tag: str, entries: List[List[str]]):
    """Generate the changelog file from |entries|."""
    with open(CHANGELOG_TEMPLATE, "r", encoding="utf-8") as fp:
        template = fp.read()
    output = ""
    for (commit, summary) in entries:
        output += CHANGELOG_ENTRY_TEMPLATE % {
            "commit": commit,
            "summary": html.escape(summary),
        }
    output = template.replace("%%COMMITS%%", output).replace("%%TAG%%", tag)
    with open(CHANGELOG_FILE, "w", encoding="utf-8") as fp:
        fp.write(output)


def get_entries(tag: str) -> List[List[str]]:
    """Find all the commits since |tag|."""
    output = libdot.run(
        ["git", "log", "--format=%H %s", f"{tag}..HEAD"],
        capture_output=True,
        encoding="utf-8",
        cwd=nassh.DIR,
    ).stdout
    return [x.split(" ", 1) for x in output.splitlines()]


def get_previous_tag() -> str:
    """Find the most recent nassh tag."""
    return libdot.run(
        [
            "git",
            "describe",
            "--tags",
            "--abbrev=0",
            "--match",
            "nassh-*",
            "HEAD",
        ],
        capture_output=True,
        encoding="utf-8",
        cwd=nassh.DIR,
    ).stdout.strip()


def generate_changelog(prev_tag: str = None):
    """Generate the changelog.html file from recent git history."""
    # Ebuilds don't currently checkout the entire tree, so stub it.
    if "EAPI" in os.environ:
        logging.warning("Generating a stub changelog for ebuild.")
        generate_html("", [])
        return

    if prev_tag is None:
        prev_tag = get_previous_tag()
    logging.info('Generating history since tag "%s"', prev_tag)
    entries = get_entries(prev_tag)
    logging.info("Found %i commits", len(entries))
    generate_html(prev_tag, entries)


def get_parser():
    """Get a command line parser."""
    parser = libdot.ArgumentParser(description=__doc__)
    parser.add_argument("--commit", help="Commit to generate history back to")
    return parser


def main(argv: List[str]):
    """The main func!"""
    parser = get_parser()
    opts = parser.parse_args(argv)

    generate_changelog(prev_tag=opts.commit)


if __name__ == "__main__":
    sys.exit(main(sys.argv[1:]))