"""Version comparison for I2P router updates.

Handles semver-like version strings (e.g. "0.9.62", "2.4.0").

Ported from net.i2p.CoreVersion.
"""

from __future__ import annotations

from dataclasses import dataclass


@dataclass
class Version:
    """Parsed version number."""
    major: int
    minor: int
    patch: int

    def __init__(self, version_str: str) -> None:
        parts = version_str.strip().split(".")
        self.major = int(parts[0]) if len(parts) > 0 else 0
        self.minor = int(parts[1]) if len(parts) > 1 else 0
        self.patch = int(parts[2]) if len(parts) > 2 else 0

    def __str__(self) -> str:
        return f"{self.major}.{self.minor}.{self.patch}"

    def as_tuple(self) -> tuple[int, int, int]:
        return (self.major, self.minor, self.patch)


def compare_versions(a: str, b: str) -> int:
    """Compare two version strings.

    Returns:
        > 0 if a is newer than b
        0 if equal
        < 0 if a is older than b
    """
    va = Version(a).as_tuple()
    vb = Version(b).as_tuple()
    if va > vb:
        return 1
    elif va < vb:
        return -1
    return 0