Remove dependency on xdg package

Implements and improves the functionality provided by the `xdg` package
in `getenv_dir()` and `get_cache_dir()`.

pyproject.toml

@@ -34,7 +34,6 @@ include = ["generate_completions.sh"]
 python = "^3.10.4"
 click = "^8.1.3"
 click-help-colors = "^0.9.1"
-xdg = "^5.1.1"
 requests = "^2.28.1"
 
 [build-system]

src/tldr_man/languages.py

@@ -19,7 +19,7 @@
 
 from click import Context
 
-from tldr_man.pages import TLDR_CACHE_HOME, language_directory_to_code
+from tldr_man.pages import CACHE_DIR, language_directory_to_code
 from tldr_man.util import exit_with
 
 
@@ -32,7 +32,7 @@ def all_language_codes() -> Iterator[str]:
     """Returns an iterator of all language codes, based on all language directories."""
     return (
         language_directory_to_code(pages_dir)
-        for pages_dir in TLDR_CACHE_HOME.iterdir()
+        for pages_dir in CACHE_DIR.iterdir()
         if pages_dir.is_dir()
     )
 
@@ -83,7 +83,7 @@ def get_language_directory(language_code: str) -> str:
         return 'pages'
     else:
         full_locale = f'pages.{language}_{region}'
-        if (TLDR_CACHE_HOME / full_locale).is_dir():
+        if (CACHE_DIR / full_locale).is_dir():
             return full_locale
         else:
             return f'pages.{language}'

src/tldr_man/pages.py

@@ -19,19 +19,18 @@
 from concurrent.futures import ThreadPoolExecutor
 from contextlib import suppress
 from pathlib import Path
-from os import remove, makedirs
+from os import remove, makedirs, getenv
 from shutil import rmtree, move
 from subprocess import run, PIPE, DEVNULL
 from typing import Optional
 from collections.abc import Iterable
 
 import requests
 from click import secho, progressbar, style, echo
-from xdg import XDG_CACHE_HOME
 
 from tldr_man.util import mkstemp_path, mkdtemp_path, eprint, exit_with
 
-TLDR_CACHE_DIR_NAME = 'tldr-man'
+CACHE_DIR_NAME = 'tldr-man'
 
 ZIP_ARCHIVE_URL = "https://tldr.sh/assets/tldr.zip"
 
@@ -78,11 +77,19 @@
 """[1:-1]
 
 
-def tldr_cache_home(location: Path = XDG_CACHE_HOME) -> Path:
-    return location / TLDR_CACHE_DIR_NAME
+def getenv_dir(key: str, default: Optional[Path] = None) -> Optional[Path]:
+    if value := getenv(key):
+        path = Path(value)
+        if path.is_absolute():
+            return path.resolve()
+    return default
 
 
-TLDR_CACHE_HOME: Path = tldr_cache_home()
+def get_cache_dir() -> Path:
+    return getenv_dir('XDG_CACHE_HOME', Path.home() / '.cache') / CACHE_DIR_NAME
+
+
+CACHE_DIR: Path = get_cache_dir()
 
 
 def download_archive(location: Path, url: str = ZIP_ARCHIVE_URL) -> None:
@@ -138,8 +145,8 @@ def update_cache() -> None:
                 # Get the directory where the old versions of the manpages are located,
                 # to compare it with the new versions that are generated:
                 original_dir = (
-                    TLDR_CACHE_HOME / language_dir.name / sections_dir.name / ('man' + MANPAGE_SECTION)
-                    if TLDR_CACHE_HOME.exists() else None
+                    CACHE_DIR / language_dir.name / sections_dir.name / ('man' + MANPAGE_SECTION)
+                    if CACHE_DIR.exists() else None
                 )
 
                 # Create the label for the progress bars that are shown.
@@ -194,10 +201,10 @@ def to_manpage(tldr_page: zipfile.Path) -> tuple[str, str]:
         # and move the new cache into the correct directory from the temporary directory.
 
         with suppress(FileNotFoundError):
-            rmtree(TLDR_CACHE_HOME)
+            rmtree(CACHE_DIR)
 
-        makedirs(TLDR_CACHE_HOME.parent, exist_ok=True)
-        move(temp_cache_dir, TLDR_CACHE_HOME)
+        makedirs(CACHE_DIR.parent, exist_ok=True)
+        move(temp_cache_dir, CACHE_DIR)
 
     finally:
         # Clean up any temporary files that aren't gone.
@@ -266,7 +273,7 @@ def pandoc_exists() -> bool:
 
 def verify_tldr_cache_exists():
     """Display a specific message if the tldr manpage cache doesn't exist yet, and then exit."""
-    if not TLDR_CACHE_HOME.exists():
+    if not CACHE_DIR.exists():
         exit_with(CACHE_DOES_NOT_EXIST_MESSAGE)
 
 
@@ -292,7 +299,7 @@ def find_page(page_name: str, /, locales: Iterable[str], page_sections: Iterable
 
 def get_dir_search_order(locales: Iterable[str], page_sections: Iterable[str]) -> Iterable[Path]:
     return (
-        TLDR_CACHE_HOME / locale / section / ('man' + MANPAGE_SECTION)
+        CACHE_DIR / locale / section / ('man' + MANPAGE_SECTION)
         for locale in locales
         for section in page_sections
     )

src/tldr_man/shell_completion.py

@@ -17,13 +17,13 @@
 from click import Context, Parameter
 from click.shell_completion import CompletionItem
 
-from tldr_man.pages import TLDR_CACHE_HOME, get_dir_search_order
+from tldr_man.pages import CACHE_DIR, get_dir_search_order
 from tldr_man.languages import get_locales, all_language_codes
 from tldr_man.platforms import get_page_sections
 
 
 def page_shell_complete(ctx: Context, param: Parameter, incomplete: str) -> list[CompletionItem]:
-    if not TLDR_CACHE_HOME.exists() or param.name is None: # the `param.name is None` check makes the type checker happy
+    if not CACHE_DIR.exists() or param.name is None: # the `param.name is None` check makes the type checker happy
         return []
 
     locales: list[str] = get_locales(ctx)
@@ -41,6 +41,6 @@ def page_shell_complete(ctx: Context, param: Parameter, incomplete: str) -> list
 
 
 def language_shell_complete(_ctx: Context, _param: Parameter, _incomplete: str) -> list[CompletionItem]:
-    if not TLDR_CACHE_HOME.exists():
+    if not CACHE_DIR.exists():
         return []
     return [CompletionItem(code) for code in all_language_codes()]