Refactor Properties into several files for better maintainability

src/hexdoc/core/properties/__init__.py

@@ -0,0 +1,30 @@
+__all__ = [
+    "JINJA_NAMESPACE_ALIASES",
+    "AnimatedTexturesProps",
+    "AnimationFormat",
+    "BaseProperties",
+    "EnvironmentVariableProps",
+    "LangProps",
+    "PNGTextureOverride",
+    "Properties",
+    "TemplateProps",
+    "TextureTextureOverride",
+    "TexturesProps",
+    "env",
+    "lang",
+    "properties",
+    "template",
+    "textures",
+]
+
+from .env import EnvironmentVariableProps
+from .lang import LangProps
+from .properties import BaseProperties, Properties
+from .template import JINJA_NAMESPACE_ALIASES, TemplateProps
+from .textures import (
+    AnimatedTexturesProps,
+    AnimationFormat,
+    PNGTextureOverride,
+    TexturesProps,
+    TextureTextureOverride,
+)

src/hexdoc/core/properties/env.py

@@ -0,0 +1,55 @@
+from __future__ import annotations
+
+from typing import Self
+
+from pydantic import model_validator
+from yarl import URL
+
+from hexdoc.model.base import HexdocSettings
+from hexdoc.utils.types import PydanticURL
+
+
+class EnvironmentVariableProps(HexdocSettings):
+    # default Actions environment variables
+    github_repository: str
+    github_sha: str
+
+    # set by CI
+    github_pages_url: PydanticURL
+
+    # for putting books somewhere other than the site root
+    hexdoc_subdirectory: str | None = None
+
+    # optional for debugging
+    debug_githubusercontent: PydanticURL | None = None
+
+    @property
+    def asset_url(self) -> URL:
+        if self.debug_githubusercontent is not None:
+            return URL(str(self.debug_githubusercontent))
+
+        return (
+            URL("https://raw.githubusercontent.com")
+            / self.repo_owner
+            / self.repo_name
+            / self.github_sha
+        )
+
+    @property
+    def repo_owner(self):
+        return self._github_repository_parts[0]
+
+    @property
+    def repo_name(self):
+        return self._github_repository_parts[1]
+
+    @property
+    def _github_repository_parts(self):
+        owner, repo_name = self.github_repository.split("/", maxsplit=1)
+        return owner, repo_name
+
+    @model_validator(mode="after")
+    def _append_subdirectory(self) -> Self:
+        if self.hexdoc_subdirectory:
+            self.github_pages_url /= self.hexdoc_subdirectory
+        return self