Added automatic version mechanism and moved pyinstaller spec to gener…

…ic location.

imagecolorpicker/version.py

@@ -0,0 +1,115 @@
+from typing import (
+    Self,
+    Optional,
+)
+from types import ModuleType
+from pygit2 import (
+    Repository,
+    GIT_DESCRIBE_TAGS,
+)
+from pathlib import Path
+from enum import Enum
+from importlib.util import (
+    spec_from_file_location,
+    module_from_spec,
+)
+from importlib.machinery import ModuleSpec
+from importlib.resources import files
+import imagecolorpicker
+
+
+class VersionType(Enum):
+    Unavailable = 0x0
+    GitTag = 0x1
+    GeneratedModule = 0x2
+
+
+class Version:
+    GitRepositorySuffix = '.git'
+    NoVCSDescription = "novcs"
+    ImportAttemptDescription = "imported"
+    DirtySuffix = "-dirty"
+    VersionModuleName = 'generated_version'
+
+    def __init__(self: Self) -> None:
+        self._repositoryPath: Optional[Path] = self._findRepositoryPath()
+        self._versionType: VersionType = VersionType.Unavailable
+
+        if self.hasRepository:
+            self._versionType = VersionType.GitTag
+            self._repository: Repository = Repository(self.repositoryPath)
+
+        self._versionModule: ModuleType = self._findVersionModule()
+        if self.hasVersionModule:
+            self.versionType = VersionType.GeneratedModule
+
+    def _findRepositoryPath(self: Self) -> Optional[Path]:
+        """
+            Return nearest git repository's path above __file__, or None
+            if there is none available.
+        """
+        path = Path(__file__)
+        while path.parent != path:
+            repoPath: Path = path / Version.GitRepositorySuffix
+
+            if(repoPath.exists()):
+                return repoPath
+
+            path = path.parent
+
+        return None
+
+    @property
+    def repositoryPath(self: Self) -> Optional[Path]:
+        return self._repositoryPath
+
+    @property
+    def hasRepository(self: Self) -> bool:
+        return self._repositoryPath is not None
+
+    def _findVersionModule(self: Self) -> Optional[ModuleType]:
+        """
+            Try to load the version number from a module
+            which was generated at build time using `generateVersionModule`.
+        """
+        try:
+            path: Path = Path(files(imagecolorpicker)) / '{}.py'.format(Version.VersionModuleName)
+            spec: ModuleSpec = spec_from_file_location(path.name, path)
+            module: Optional[ModuleType] = module_from_spec(spec)
+            spec.loader.exec_module(module)
+            return module
+        except:
+            return None
+
+    @property
+    def versionModule(self: Self) -> Optional[ModuleType]:
+        return self._versionModule
+
+    @property
+    def hasVersionModule(self: Self) -> bool:
+        return self._versionModule is not None
+
+    def describe(self: Self) -> str:
+        """
+            Returns a str containing the most appropriate version description available.
+        """
+        if self.hasRepository:
+            return self._repository.describe(
+                describe_strategy=GIT_DESCRIBE_TAGS,
+                show_commit_oid_as_fallback=True,
+                dirty_suffix=Version.DirtySuffix,
+            )
+
+        if self.hasVersionModule:
+            return self._versionModule.__version__
+
+        return Version.NoVCSDescription
+
+    def generateVersionModule(self: Self, path: str) -> None:
+        """
+            Generates a module containing the most appropriate version string.
+            Use this for example from pyinstaller spec files.
+        """
+        (Path(path) / (Version.VersionModuleName + '.py')).write_text("""
+__version__ = '{}'
+""".format(self.describe()))