Major refactor to move away from glade file

src/libs/desktop_parsing/app_finder.py

@@ -0,0 +1,147 @@
+# Python imports
+import os
+import logging
+from collections import OrderedDict
+from itertools import chain
+from typing import Generator, List
+
+# Lib imports
+from gi.repository import Gio
+from xdg.BaseDirectory import xdg_config_home, xdg_cache_home, xdg_data_dirs, xdg_data_home
+
+
+# Application imports
+from .file_finder import find_files
+from .db.KeyValueDb import KeyValueDb
+
+
+
+
+DEFAULT_BLACKLISTED_DIRS = [
+    '/usr/share/locale',
+    '/usr/share/app-install',
+    '/usr/share/kservices5',
+    '/usr/share/fk5',
+    '/usr/share/kservicetypes5',
+    '/usr/share/applications/screensavers',
+    '/usr/share/kde4',
+    '/usr/share/mimelnk'
+]
+
+# Use utop_cache dir because of the WebKit bug
+# https://bugs.webkit.org/show_bug.cgi?id=151646
+CACHE_DIR = os.path.join(xdg_cache_home, 'utop_cache')
+
+# Spec: https://specifications.freedesktop.org/menu-spec/latest/ar01s02.html
+DESKTOP_DIRS = list(filter(os.path.exists, [os.path.join(dir, "applications") for dir in xdg_data_dirs]))
+
+logger = logging.getLogger(__name__)
+
+
+
+
+def find_desktop_files(dirs: List[str] = None, pattern: str = "*.desktop") -> Generator[str, None, None]:
+    """
+        Returns deduped list of .desktop files (full paths)
+
+        :param list dirs:
+        :rtype: list
+    """
+
+    if dirs is None:
+        dirs = DESKTOP_DIRS
+
+    all_files = chain.from_iterable(
+                    map(lambda f: os.path.join(f_path, f), find_files(f_path, pattern)) for f_path in dirs
+                )
+
+    # NOTE: Dedup desktop file according to follow XDG data dir order.
+    #       Specifically the first file name (i.e. firefox.desktop) take precedence
+    #       and other files with the same name should be ignored
+    deduped_file_dict = OrderedDict()
+    for file_path in all_files:
+        file_name = os.path.basename(file_path)
+        if file_name not in deduped_file_dict:
+            deduped_file_dict[file_name] = file_path
+
+    deduped_files = deduped_file_dict.values()
+
+    blacklisted_dirs = DEFAULT_BLACKLISTED_DIRS
+    for file in deduped_files:
+        try:
+            if any([file.startswith(dir) for dir in blacklisted_dirs]):
+                continue
+        except UnicodeDecodeError:
+            continue
+
+        yield file
+
+
+def filter_app(app):
+    """
+        :param Gio.DesktopAppInfo app:
+        :returns: True if app can be added to the database
+    """
+    return app and not (app.get_is_hidden() or app.get_nodisplay()
+                                            or app.get_string('Type') != 'Application'
+                                            or not app.get_string('Name'))
+
+
+def read_desktop_file(file):
+    """
+        :param str file: path to .desktop
+        :rtype: :class:`Gio.DesktopAppInfo` or :code:`None`
+    """
+    try:
+        return Gio.DesktopAppInfo.new_from_filename(file)
+    except Exception as e:
+        logger.info('Could not read "%s": %s', file, e)
+        return None
+
+
+def find_apps(dirs=None):
+    """
+        :param list dirs: list of paths to `*.desktop` files
+        :returns: list of :class:`Gio.DesktopAppInfo` objects
+    """
+    if dirs is None:
+        dirs = DESKTOP_DIRS
+
+    return list(filter(filter_app, map(read_desktop_file, find_desktop_files(dirs))))
+
+
+def find_apps_cached(dirs=None):
+    """
+        :param list dirs: list of paths to `*.desktop` files
+        :returns: list of :class:`Gio.DesktopAppInfo` objects
+
+        Pseudo code:
+        >>> if cache hit:
+        >>>     take list of paths from cache
+        >>>     yield from filter(filter_app, map(read_desktop_file, cached_paths))
+        >>> yield from find_apps()
+        >>> save new paths to the cache
+    """
+    if dirs is None:
+        dirs = DESKTOP_DIRS
+
+    desktop_file_cache_dir = os.path.join(CACHE_DIR, 'desktop_dirs.db')
+    cache = KeyValueDb(desktop_file_cache_dir).open()
+    desktop_dirs = cache.find('desktop_dirs')
+
+    if desktop_dirs:
+        for dir in desktop_dirs:
+            app_info = read_desktop_file(dir)
+            if filter_app(app_info):
+                yield app_info
+        logger.info('Found %s apps in cache', len(desktop_dirs))
+
+    new_desktop_dirs = []
+
+    for app_info in find_apps(DESKTOP_DIRS):
+        yield app_info
+        new_desktop_dirs.append(app_info.get_filename())
+
+    cache.put('desktop_dirs', new_desktop_dirs)
+    cache.commit()
+    logger.info('Found %s apps in the system', len(new_desktop_dirs))