✨ add local cache support

nb_cli/handlers/__init__.py

@@ -29,6 +29,13 @@
 
 # isort: split
 
+# data
+from .data import DATA_DIR as DATA_DIR
+from .data import CACHE_DIR as CACHE_DIR
+from .data import CONFIG_DIR as CONFIG_DIR
+
+# isort: split
+
 # package
 from .store import load_module_data as load_module_data
 from .store import format_package_results as format_package_results

nb_cli/handlers/data.py

@@ -0,0 +1,79 @@
+import os
+import sys
+from pathlib import Path
+from typing import Literal
+
+WINDOWS = sys.platform.startswith("win") or (sys.platform == "cli" and os.name == "nt")
+
+
+# -- Windows support functions --
+def _get_win_folder_from_registry(
+    csidl_name: Literal["CSIDL_APPDATA", "CSIDL_COMMON_APPDATA", "CSIDL_LOCAL_APPDATA"]
+) -> Path:
+    """
+    This is a fallback technique at best. I'm not sure if using the
+    registry for this guarantees us the correct answer for all CSIDL_*
+    names.
+    """
+    import winreg
+
+    shell_folder_name = {
+        "CSIDL_APPDATA": "AppData",
+        "CSIDL_COMMON_APPDATA": "Common AppData",
+        "CSIDL_LOCAL_APPDATA": "Local AppData",
+    }[csidl_name]
+
+    key = winreg.OpenKey(
+        winreg.HKEY_CURRENT_USER,
+        r"Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders",
+    )
+    directory, _type = winreg.QueryValueEx(key, shell_folder_name)
+    return Path(directory)
+
+
+def _get_win_folder_with_ctypes(
+    csidl_name: Literal["CSIDL_APPDATA", "CSIDL_COMMON_APPDATA", "CSIDL_LOCAL_APPDATA"]
+) -> Path:
+    csidl_const = {
+        "CSIDL_APPDATA": 26,
+        "CSIDL_COMMON_APPDATA": 35,
+        "CSIDL_LOCAL_APPDATA": 28,
+    }[csidl_name]
+
+    buf = ctypes.create_unicode_buffer(1024)
+    ctypes.windll.shell32.SHGetFolderPathW(None, csidl_const, None, 0, buf)
+
+    # Downgrade to short path name if have highbit chars. See
+    # <http://bugs.activestate.com/show_bug.cgi?id=85099>.
+    has_high_char = any(ord(c) > 255 for c in buf)
+    if has_high_char:
+        buf2 = ctypes.create_unicode_buffer(1024)
+        if ctypes.windll.kernel32.GetShortPathNameW(buf.value, buf2, 1024):
+            buf = buf2
+
+    return Path(buf.value)
+
+
+if WINDOWS:
+    try:
+        import ctypes
+
+        _get_win_folder = _get_win_folder_with_ctypes
+    except ImportError:
+        _get_win_folder = _get_win_folder_from_registry
+
+    CACHE_DIR = _get_win_folder("CSIDL_LOCAL_APPDATA") / "nb-cli" / "Cache"
+    DATA_DIR = _get_win_folder("CSIDL_LOCAL_APPDATA") / "nb-cli"
+    CONFIG_DIR = DATA_DIR
+
+elif sys.platform == "darwin":
+    CACHE_DIR = Path("~/Library/Caches/nb-cli").expanduser()
+    DATA_DIR = Path("~/Library/Application Support/nb-cli").expanduser()
+    CONFIG_DIR = DATA_DIR
+
+else:
+    CACHE_DIR = Path(os.getenv("XDG_CACHE_HOME", "~/.cache")).expanduser() / "nb-cli"
+    DATA_DIR = (
+        Path(os.getenv("XDG_DATA_HOME", "~/.local/share")).expanduser() / "nb-cli"
+    )
+    CONFIG_DIR = Path(os.getenv("XDG_CONFIG_HOME", "~/.config")).expanduser() / "nb-cli"