from datetime import datetime, timezone
import os
import subprocess
import re

LINE_REGEX = re.compile(
    r"""(?x)
^(?P<commit>[A-Fa-f0-9]+)\s+
\(
    <(?P<email>[^>]+)>\s+
    (?P<date>[^\s]+\s[^\s]+\s[^\s]+)\s+
    (?P<line>\d+)
\)\s
(?P<content>.*)$
"""
)
VERSION_REGEX = re.compile(r"^#+\s*v?\d")

# contains lines in the form of
# {commit-sha} (<{email}>\s+{date}\s+{line-no}) {line}
p = subprocess.run(
    ["git", "blame", "-e", "--date=iso", "../CHANGELOG.md"],
    cwd=os.path.dirname(os.path.realpath(__file__)),
    text=True,
    check=True,
    capture_output=True,
)

unreleased_lines: list[tuple[datetime, str]] = []
for line in p.stdout.splitlines():
    if not line:
        continue
    m = LINE_REGEX.match(line)
    assert m, f"Failed to match '{line}'"
    content = m.group("content")

    if not content:
        continue
    if content.startswith("#"):
        if VERSION_REGEX.match(content):
            break
        continue  # ignore lines with '#'

    d = datetime.fromisoformat(m.group("date"))
    d = d.astimezone(tz=timezone.utc)
    content = content.replace("- ", f"- [{d.strftime('%Y-%m-%d')}] ", 1)
    unreleased_lines.append((d, content))

unreleased_lines.sort(key=lambda it: it[0], reverse=True)

if len(unreleased_lines) == 0:
    print("No changes since last release.")

for _, line in unreleased_lines[:5]:
    print(line)

if len(unreleased_lines) > 5:
    print("<details><summary>More Changes</summary>\n")
    for _, line in unreleased_lines[5:]:
        print(line)
    print("</details>")