Implement own "Version" class to get rid of distutils/packaging dependency. (#561)

Fixes #550.

Author: horstle

lib/inputstreamhelper/utils.py

@@ -8,6 +8,8 @@
 from socket import timeout
 from ssl import SSLError
 import struct
+from typing import NamedTuple
+from functools import total_ordering
 
 
 try:  # Python 3
@@ -22,6 +24,31 @@
 from .unicodes import compat_path, from_unicode, to_unicode
 
 
+@total_ordering
+class Version(NamedTuple):
+    """Minimal version class used for parse_version. Should be enough for our purpose."""
+    major: int = 0
+    minor: int = 0
+    micro: int = 0
+    nano: int = 0
+
+    def __str__(self):
+        return f"{self.major}.{self.minor}.{self.micro}.{self.nano}"
+
+    def __lt__(self, other):
+        if self.major != other.major:
+            return self.major < other.major
+        if self.minor != other.minor:
+            return self.minor < other.minor
+        if self.micro != other.micro:
+            return self.micro < other.micro
+
+        return self.nano < other.nano
+
+    def __eq__(self, other):
+        return all((self.major == other.major, self.minor == other.minor, self.micro == other.micro, self.nano == other.nano))
+
+
 def temp_path():
     """Return temporary path, usually ~/.kodi/userdata/addon_data/script.module.inputstreamhelper/temp/"""
     tmp_path = translate_path(os.path.join(get_setting('temp_path', 'special://masterprofile/addon_data/script.module.inputstreamhelper'), 'temp', ''))
@@ -350,11 +377,18 @@ def remove_tree(path):
     rmtree(compat_path(path))
 
 
-def parse_version(version):
+def parse_version(vstring):
     """Parse a version string and return a comparable version object"""
+    vstring = vstring.strip('v')
+    vstrings = vstring.split('.')
     try:
-        from packaging.version import parse
-        return parse(version)
-    except ImportError:
-        from distutils.version import LooseVersion  # pylint: disable=deprecated-module
-        return LooseVersion(version)
+        vnums = tuple(int(v) for v in vstrings)
+    except ValueError:
+        log(3, f"Version string {vstring} can't be interpreted! Contains non-numerics.")
+        return Version(0, 0, 0, 0)
+
+    if len(vnums) > 4:
+        log(3, f"Version string {vstring} can't be interpreted! Too long.")
+        return Version(0, 0, 0, 0)
+
+    return Version(*vnums)