packages: Move checking for unavailable packages to component

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/package.py

@@ -6,6 +6,7 @@ Framework for installing and updating distribution packages
 import enum
 import json
 import logging
+import pathlib
 import subprocess
 import sys
 import threading
@@ -84,6 +85,25 @@ class Packages(app.FollowerComponent):
 
         return packages_installed(self.conflicts)
 
+    def has_unavailable_packages(self):
+        """Return whether any of the packages are not available.
+
+        Returns True if one or more of the packages is not available in the
+        user's Debian distribution or False otherwise. Returns None if it
+        cannot be reliably determined whether the packages are available or
+        not.
+        """
+        apt_lists_dir = pathlib.Path('/var/lib/apt/lists/')
+        num_files = len(
+            [child for child in apt_lists_dir.iterdir() if child.is_file()])
+        if num_files < 2:  # not counting the lock file
+            return None
+
+        # List of all packages from all Package components
+        cache = apt.Cache()
+        return any(package for package in self.packages
+                   if package not in cache)
+
 
 class PackageException(Exception):
     """A package operation has failed."""

plinth/setup.py

@@ -5,7 +5,6 @@ Utilities for performing application setup operations.
 
 import importlib
 import logging
-import os
 import threading
 import time
 from collections import defaultdict
@@ -159,34 +158,6 @@ class Helper(object):
         models.Module.objects.update_or_create(
             pk=self.module_name, defaults={'setup_version': version})
 
-    def has_unavailable_packages(self):
-        """Find if any of the packages managed by the module are not available.
-
-        Returns True if one or more of the packages is not available in the
-        user's Debian distribution or False otherwise.
-        Returns None if it cannot be reliably determined whether the
-        packages are available or not.
-        """
-        APT_LISTS_DIR = '/var/lib/apt/lists/'
-        num_files = len([
-            name for name in os.listdir(APT_LISTS_DIR)
-            if os.path.isfile(os.path.join(APT_LISTS_DIR, name))
-        ])
-        if num_files < 2:  # not counting the lock file
-            return None
-
-        pkg_components = list(self.module.app.get_components_of_type(Packages))
-        if not pkg_components:  # This app has no packages to install
-            return False
-
-        # List of all packages from all Package components
-        managed_pkgs = (package for component in pkg_components
-                        for package in component.packages)
-        cache = apt.Cache()
-        unavailable_pkgs = (pkg_name for pkg_name in managed_pkgs
-                            if pkg_name not in cache)
-        return any(unavailable_pkgs)
-
 
 def init(module_name, module):
     """Create a setup helper for a module for later use."""

plinth/templates/setup.html

@@ -41,7 +41,7 @@
             Please wait for a few moments before trying again.
           {% endblocktrans %}
         </div>
-      {% elif setup_helper.has_unavailable_packages %}
+      {% elif has_unavailable_packages %}
         <div class="alert alert-warning" role="alert">
           {% blocktrans trimmed %}
             This application is currently not available in your distribution.
@@ -64,7 +64,7 @@
       {% endif %}
 
       <input type="submit" class="btn btn-md btn-primary" name="install"
-             {% if package_manager_is_busy or setup_helper.has_unavailable_packages %}
+             {% if package_manager_is_busy or has_unavailable_packages %}
              disabled="disabled"
              {% endif %}
              {% if setup_state == 'needs-setup' %}

plinth/tests/test_package.py

@@ -80,6 +80,25 @@ def test_packages_find_conflicts(packages_installed_):
     assert component.find_conflicts() == ['package1', 'package2']
 
 
+@patch('apt.Cache')
+@patch('pathlib.Path')
+def test_packages_has_unavailable_packages(path_class, cache):
+    """Test checking for unavailable packages."""
+    path = Mock()
+    path_class.return_value = path
+    path.iterdir.return_value = [Mock()]
+
+    component = Packages('test-component', ['package1', 'package2'])
+    assert component.has_unavailable_packages() is None
+
+    path.iterdir.return_value = [Mock(), Mock()]
+    cache.return_value = ['package1', 'package2']
+    assert not component.has_unavailable_packages()
+
+    cache.return_value = ['package1']
+    assert component.has_unavailable_packages()
+
+
 def test_packages_installed():
     """Test packages_installed()."""
     # list as input

plinth/views.py

@@ -288,6 +288,9 @@ class SetupView(TemplateView):
         if not context['setup_current_operation']:
             context[
                 'package_manager_is_busy'] = package.is_package_manager_busy()
+            context[
+                'has_unavailable_packages'] = self._has_unavailable_packages(
+                    setup_helper.module.app)
 
         context['refresh_page_sec'] = None
         if context['setup_state'] == 'up-to-date':
@@ -335,6 +338,13 @@ class SetupView(TemplateView):
 
         return conflicts, conflicts_action
 
+    @staticmethod
+    def _has_unavailable_packages(app_):
+        """Return whether the app has unavailable packages."""
+        components = app_.get_components_of_type(Packages)
+        return any(component for component in components
+                   if component.has_unavailable_packages())
+
 
 def notification_dismiss(request, id):
     """Dismiss a notification."""