Add GitHub Actions CI/release workflow, rewrite changelog

1 files changed, 194 insertions, 0 deletions

diff --git a/.github/scripts/generate_release_notes.py b/.github/scripts/generate_release_notes.py
new file mode 100644
index 0000000..f3e4870
--- /dev/null
+++ b/.github/scripts/generate_release_notes.py
@@ -0,0 +1,194 @@
+#!/usr/bin/env python3
+# PSn00bSDK release notes generator
+# (C) 2021 spicyjpeg - MPL licensed
+
+import sys, re
+from time     import gmtime, strptime
+from argparse import ArgumentParser, FileType
+
+## Helpers
+
+VERSION_REGEX = re.compile(r"^(?:refs\/tags\/)?(?:v|ver|version|release)? *(.*)")
+
+def parse_date(date):
+	return strptime(date.strip(), "%Y-%m-%d")
+
+def normalize_version(version):
+	match = VERSION_REGEX.match(version.lower())
+	if not match:
+		raise ValueError(f"invalid version string: {version}")
+
+	return match.group(1)
+
+## Changelog parser
+
+BLOCK_REGEX   = re.compile(r"^#{2,}[ \t]*([0-9]{4}-[0-9]{2}-[0-9]{2})(?:[:\- \t]+(.+?))?$", re.MULTILINE)
+AUTHOR_REGEX  = re.compile(r"^([A-Za-z0-9_].*?)[ \t]*:.*?$", re.MULTILINE)
+FIRST_VERSION = "initial"
+
+def parse_authors(block):
+	# [ _crap, author, body, author, body, ... ]
+	items = AUTHOR_REGEX.split(block.strip())
+
+	if items[0].strip():
+		raise RuntimeError("a block has changes listed with no author specified")
+
+	authors = {}
+	for i in range(1, len(items), 2):
+		name, body = items[i:i + 2]
+
+		name = name.strip()
+		body = body.strip()
+		if name not in authors:
+			authors[name] = ""
+
+		authors[name] += body
+
+	return authors
+
+def parse_blocks(changelog):
+	# [ _crap, date, version, body, date, version, body, ... ]
+	items = BLOCK_REGEX.split(changelog.strip())
+
+	#if items[0].strip():
+		#raise RuntimeError("the changelog doesn't start with a valid block")
+
+	# Iterate over all blocks from bottom to top (i.e. oldest first).
+	last_version = FIRST_VERSION
+
+	for i in range(len(items), 1, -3):
+		date, version, body = items[i - 3:i]
+
+		# If no version is present in the header, assume it's the same as the
+		# previous block's version.
+		if version:
+			version      = normalize_version(version)
+			last_version = version
+		else:
+			version = last_version
+
+		yield parse_date(date), version, parse_authors(body)
+
+## Release notes generation
+
+VERSION_TEMPLATE = """New in version **{version}** (contributed by {authors}):
+
+{changes}
+
+"""
+NOTES_TEMPLATE = """{notes}
+
+-------------------------------------------------------
+_These notes have been generated automatically._
+_See the changelog or commit history for more details._
+"""
+
+NO_VERSIONS_TEMPLATE = "No information available about this release."
+AUTHOR_LINK_TEMPLATE = "**{0}**"
+#AUTHOR_LINK_TEMPLATE = "[{0}](https://github.com/{0})"
+
+def generate_notes(versions):
+	notes = ""
+
+	for version, ( authors, changes ) in versions.items():
+		_authors = list(set(authors))
+		_authors.sort()
+		_authors = map(AUTHOR_LINK_TEMPLATE.format, _authors)
+
+		notes += VERSION_TEMPLATE.format(
+			version = version,
+			authors = ", ".join(_authors),
+			changes = "\n\n".join(changes)
+		)
+
+	if not notes:
+		notes = NO_VERSIONS_TEMPLATE
+
+	return NOTES_TEMPLATE.format(notes = notes.strip())
+
+## Main
+
+def get_args():
+	parser = ArgumentParser(
+		description = "Generates and outputs release notes from a Markdown changelog file.",
+		add_help    = False
+	)
+
+	tools_group = parser.add_argument_group("Tools")
+	tools_group.add_argument(
+		"-h", "--help",
+		action = "help",
+		help   = "Show this help message and exits"
+	)
+
+	files_group = parser.add_argument_group("Files")
+	files_group.add_argument(
+		"changelog",
+		type    = FileType("rt"),
+		help    = "Markdown changelog file to parse"
+	)
+	files_group.add_argument(
+		"-o", "--output",
+		type    = FileType("wt"),
+		default = sys.stdout,
+		help    = "Where to output release notes (stdout by default)",
+		metavar = "file"
+	)
+
+	filter_group = parser.add_argument_group("Filters")
+	filter_group.add_argument(
+		"-v", "--version",
+		action  = "append",
+		type    = str,
+		help    = "Ignore all changes not belonging to a version (can be specified multiple times)",
+		metavar = "name"
+	)
+	filter_group.add_argument(
+		"-f", "--from-date",
+		type    = parse_date,
+		default = parse_date("2000-01-01"),
+		help    = "Ignore all changes before date",
+		metavar = "yyyy-mm-dd"
+	)
+	filter_group.add_argument(
+		"-t", "--to-date",
+		type    = parse_date,
+		default = gmtime(),
+		help    = "Ignore all changes after date",
+		metavar = "yyyy-mm-dd"
+	)
+
+	return parser.parse_args()
+
+def main():
+	args         = get_args()
+	version_list = list(map(normalize_version, args.version or []))
+
+	with args.changelog as _file:
+		changelog = _file.read()
+
+	# Iterate over all blocks in the changelog and sort them by version,
+	# merging all changes and authors for each version.
+	versions = {}
+
+	for date, version, authors in parse_blocks(changelog):
+		# Apply version and date filters.
+		if version_list and (version not in version_list):
+			continue
+		if date < args.from_date or date > args.to_date:
+			continue
+
+		if version not in versions:
+			versions[version] = [], []
+
+		_authors, _changes = versions[version]
+		_authors.extend(authors.keys())
+		_changes.extend(authors.values())
+
+	notes = generate_notes(versions)
+
+	with args.output as _file:
+		_file.write(notes)
+
+if __name__ == "__main__":
+	main()