#!/usr/bin/env python3
"""Prepare an explicit release by updating application version metadata."""

import argparse
from datetime import datetime
from pathlib import Path
import re
from zoneinfo import ZoneInfo

VERSION_FILE = Path(__file__).resolve().parents[1] / "core" / "version.py"


def bump_version(part="patch", *, version_file=VERSION_FILE, release_date=None):
    """Increment a semantic version and update its date; return the new version."""
    if part not in {"major", "minor", "patch"}:
        raise ValueError("Choose major, minor, or patch.")
    content = version_file.read_text(encoding="utf-8")
    match = re.search(r'^__version__ = "(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)"$',
                      content, re.MULTILINE)
    if not match or not re.search(r'^__release_date__ = "\d{4}-\d{2}-\d{2}"$', content, re.MULTILINE):
        raise ValueError("Expected semantic version and release date in the version file.")
    major, minor, patch = map(int, match.groups())
    if part == "major":
        major, minor, patch = major + 1, 0, 0
    elif part == "minor":
        minor, patch = minor + 1, 0
    else:
        patch += 1
    version = f"{major}.{minor}.{patch}"
    date = release_date or datetime.now(ZoneInfo("Europe/Zurich")).date()
    content = content[:match.start()] + f'__version__ = "{version}"' + content[match.end():]
    content = re.sub(r'^__release_date__ = ".*"$',
                     f'__release_date__ = "{date.isoformat()}"', content, flags=re.MULTILINE)
    version_file.write_text(content, encoding="utf-8")
    return version


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("part", choices=("major", "minor", "patch"), nargs="?", default="patch")
    args = parser.parse_args()
    print(f"Prepared version {bump_version(args.part)}")


if __name__ == "__main__":
    main()