Implement reverse tag matchingv5.15.0_QtAS

Fixes: AUTOSUITE-1447
Change-Id: I7f8c3c83d49939962376c98a650b4ecb24f8e980
Reviewed-by: Nikolay Zamotaev <nzamotaev@luxoft.com>

12 files changed, 421 insertions, 272 deletions

diff --git a/appstore/settings.py b/appstore/settings.py
index 092ea09..b03e943 100644
--- a/appstore/settings.py
+++ b/appstore/settings.py
@@ -39,6 +39,7 @@ https://docs.djangoproject.com/en/1.7/topics/settings/
 For the full list of settings and their values, see
 https://docs.djangoproject.com/en/1.7/ref/settings/
 """
+import os
 
 APPSTORE_MAINTENANCE = False
 APPSTORE_PLATFORM_ID = 'NEPTUNE3'
@@ -50,10 +51,9 @@ APPSTORE_BIND_TO_DEVICE_ID = True # unique downloads for each device
 APPSTORE_NO_SECURITY = True       # ignore developer signatures and do not generate store signatures
 APPSTORE_STORE_SIGN_PKCS12_CERTIFICATE = 'certificates/store.p12'
 APPSTORE_STORE_SIGN_PKCS12_PASSWORD = 'password'
-APPSTORE_DEV_VERIFY_CA_CERTIFICATES = [ 'certificates/ca.crt', 'certificates/devca.crt' ]
+APPSTORE_DEV_VERIFY_CA_CERTIFICATES = ['certificates/ca.crt', 'certificates/devca.crt']
 
 # Build paths inside the project like this: os.path.join(BASE_DIR, ...)
-import os
 BASE_DIR = os.path.dirname(os.path.dirname(__file__))
 
 
diff --git a/appstore/urls.py b/appstore/urls.py
index 7c99a6a..1eb3d2c 100644
--- a/appstore/urls.py
+++ b/appstore/urls.py
@@ -33,7 +33,7 @@
 from django.conf.urls import include, url
 from django.contrib import admin
 from store import api as store_api
-import settings
+from appstore.settings import URL_PREFIX
 
 base_urlpatterns = [
     url(r'^admin/', include(admin.site.urls)),
@@ -42,6 +42,7 @@ base_urlpatterns = [
     url(r'^login$',             store_api.login),
     url(r'^logout$',            store_api.logout),
     url(r'^app/list$',          store_api.appList),
+    url(r'^app/icons/(.*)$',    store_api.appIconNew),
     url(r'^app/icon',           store_api.appIcon),
     url(r'^app/description',    store_api.appDescription),
     url(r'^app/purchase',       store_api.appPurchase),
@@ -53,8 +54,8 @@ base_urlpatterns = [
 
 
 prefix = '^'
-if settings.URL_PREFIX !='':
-    prefix = prefix + settings.URL_PREFIX + '/'
+if URL_PREFIX != '':
+    prefix = prefix + URL_PREFIX + '/'
 
 urlpatterns = [
     url(prefix, include(base_urlpatterns)),
diff --git a/appstore/wsgi.py b/appstore/wsgi.py
index 3f007d4..5ff13a6 100644
--- a/appstore/wsgi.py
+++ b/appstore/wsgi.py
@@ -40,7 +40,8 @@ https://docs.djangoproject.com/en/1.7/howto/deployment/wsgi/
 """
 
 import os
+from django.core.wsgi import get_wsgi_application
+
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "appstore.settings")
 
-from django.core.wsgi import get_wsgi_application
 application = get_wsgi_application()
diff --git a/doc/src/deployment-server-reference.qdoc b/doc/src/deployment-server-reference.qdoc
index 1ade88f..a8903de 100644
--- a/doc/src/deployment-server-reference.qdoc
+++ b/doc/src/deployment-server-reference.qdoc
@@ -55,15 +55,10 @@
             \li The Deployment Server's HTTP API version that you are using to communicate with the
                 server. For more information, see \c{settings.APPSTORE_VERSION}.
         \row
-            \li require_tag
+            \li require_tag (can also be passed as \c{tag} )
             \li An optional parameter used to filter packages by tags. Receives a comma-separated
-                list of tags; these tags must be alphanumeric. Only applications that contain any
-                of the specified tags should be listed.
-        \row
-            \li conflicts_tag
-            \li An optional parameter used to filter packages by tags. Receives a comma-separated
-                list of tags; these tags must be alphanumeric. Applications that contain any of the
-                speicifed tags should be excluded.
+                list of tags; these tags must be alphanumeric. Only applications that match any of the
+                specified tags (and not matching those in their conflicts list should be listed).
         \row
             \li architecture
             \li An optional parameter used to filter packages by architecture. Receives the CPU
@@ -190,7 +185,10 @@
             \li A category name for the app.
         \row
             \li tags
-            \li JSON array of app tags
+            \li JSON array of tags required for the app
+        \row
+            \li conflict_tags
+            \li JSON array of tags which will conflict with the app
         \row
             \li version
             \li The app's version, returned as a string. If the there is no version number, the
@@ -216,6 +214,14 @@
         \row
             \li category_id
             \li Numeric category ID that matches the app's category.
+        \row
+            \li purchaseId
+            \li Purchase identifier, freeform identifier of specific application on the server.
+            Used as an alternative to ID in \c{app/purchase} API call. This is a freeform string,
+            currently a UUID, but no assumptions should be made of the format.
+        \row
+            \li iconUrl
+            \li URL for the icon of this application
     \endtable
 
     \section2 app/icon
@@ -270,6 +276,10 @@
          \row
              \li id
              \li The app ID.
+         \row
+             \li purchaseId
+             \li Alternative app ID, to select specific app with tags and all (see \c{app/list} API description).
+             If both ID and purchaseId are specified, ID takes precedence.
      \endtable
      Returns a JSON object:
      \table
diff --git a/store/admin.py b/store/admin.py
index 2252af1..c55f6d4 100644
--- a/store/admin.py
+++ b/store/admin.py
@@ -30,7 +30,6 @@
 ##
 #############################################################################
 
-import os
 import StringIO
 from PIL import Image, ImageChops
 
@@ -42,7 +41,7 @@ from django.core.files.uploadedfile import InMemoryUploadedFile
 from ordered_model.admin import OrderedModelAdmin
 
 from store.models import *
-from utilities import parseAndValidatePackageMetadata, writeTempIcon, makeTagList
+from store.utilities import parseAndValidatePackageMetadata, writeTempIcon, makeTagList
 
 class CategoryAdminForm(forms.ModelForm):
     class Meta:
@@ -60,14 +59,14 @@ class CategoryAdminForm(forms.ModelForm):
                 # make image monochrome + alpha channel, this is done to compensate for
                 # how icons are treated in neptune3-ui
                 im = Image.open(cleaned_data['icon'])
-                grey, alpha = im.convert('LA').split()
+                grey, _ = im.convert('LA').split()
                 grey = ImageChops.invert(grey)
                 im.putalpha(grey)
                 im = im.convert('LA')
             else:
                 # No conversion, icons are uploaded as-is, only scaling is used.
                 im = Image.open(cleaned_data['icon'])
-            size = (settings.ICON_SIZE_X,settings.ICON_SIZE_Y,)
+            size = (settings.ICON_SIZE_X, settings.ICON_SIZE_Y)
             im.thumbnail(size, Image.ANTIALIAS)
             imagefile = StringIO.StringIO()
             im.save(imagefile, format='png')
@@ -100,41 +99,48 @@ class CategoryAdmin(OrderedModelAdmin):
 
 class AppAdminForm(forms.ModelForm):
     class Meta:
-        exclude = ["appid", "name", "tags", "architecture", 'version', 'pkgformat']
+        exclude = ["appid", "name", "tags", "tags_hash", "architecture", 'version', 'pkgformat']
 
     appId = ""
     name = ""
 
     def clean(self):
         cleaned_data = super(AppAdminForm, self).clean()
-        file = cleaned_data.get('file')
+        package_file = cleaned_data.get('file')
 
         # validate package
         try:
-            pkgdata = parseAndValidatePackageMetadata(file)
+            pkgdata = parseAndValidatePackageMetadata(package_file)
         except Exception as error:
             raise forms.ValidationError(_('Validation error: %s' % str(error)))
 
         self.appId = pkgdata['info']['id']
         self.name = pkgdata['storeName']
         self.architecture = pkgdata['architecture']
-        self.tags = makeTagList(pkgdata)
+        require_tags, conflict_tags, self.tags_hash = makeTagList(pkgdata)
 
         # check if this really is an update
         if hasattr(self, 'instance') and self.instance.appid:
             if self.appId != self.instance.appid:
-                raise forms.ValidationError(_('Validation error: an update cannot change the application id, tried to change from %s to %s' % (self.instance.appid, self.appId)))
+                raise forms.ValidationError(_('Validation error: an update cannot change the '
+                                              'application id, tried to change from %s to %s' %
+                                              (self.instance.appid, self.appId)))
             elif self.architecture != self.instance.architecture:
-                raise forms.ValidationError(_('Validation error: an update cannot change the application architecture from %s to %s' % (self.instance.architecture, self.architecture)))
+                raise forms.ValidationError(_('Validation error: an update cannot change the '
+                                              'application architecture from %s to %s' %
+                                              (self.instance.architecture, self.architecture)))
         else:
             try:
-                if App.objects.get(appid__exact = self.appId, architecture__exact = self.architecture, tags__exact = self.tags):
-                    raise forms.ValidationError(_('Validation error: another application with id %s , tags %s and architecture %s already exists' % (str(self.appId), str(self.tags), str(self.architecture))))
+                if App.objects.get(appid__exact=self.appId, architecture__exact=self.architecture, tags_hash__exact=self.tags_hash):
+                    raise forms.ValidationError(_('Validation error: another application with id'
+                                                  ' %s , tags %s and architecture %s already '
+                                                  'exists' % (str(self.appId), str(self.tags_hash),
+                                                              str(self.architecture))))
             except App.DoesNotExist:
                 pass
 
         # write icon into file to serve statically
-        success, error = writeTempIcon(self.appId, self.architecture, self.tags, pkgdata['icon'])
+        success, error = writeTempIcon(self.appId, self.architecture, self.tags_hash, pkgdata['icon'])
         if not success:
             raise forms.ValidationError(_(error))
 
@@ -148,19 +154,42 @@ class AppAdminForm(forms.ModelForm):
 
         m.file.seek(0)
         pkgdata = parseAndValidatePackageMetadata(m.file)
-        m.tags = makeTagList(pkgdata)
+        tags, conflict_tags, m.tags_hash = makeTagList(pkgdata)
+
+        # FIXME - add tags?
+        taglist = populateTagList(tags.list(),conflict_tags.list())
+
+        # FIXME: clean tags beforehand
         m.pkgformat = pkgdata['packageFormat']['formatVersion']
+        m.save()
+
+        for i in taglist:
+            # attach tags to app
+            m.tags.add(i)
+
         return m
 
 
 class AppAdmin(admin.ModelAdmin):
     form = AppAdminForm
-    list_display = ('name', 'appid', 'architecture', 'version', 'pkgformat', 'tags')
+    list_display = ('name', 'appid', 'architecture', 'version', 'pkgformat', 'tags_hash')
 
     def save_model(self, request, obj, form, change):
         obj.save()
 
+class TagAdmin(admin.ModelAdmin):
+    list_display = ('negative', 'name', 'version')
+
+    def has_add_permission(self, request, obj=None):
+        return False
+
+    def has_delete_permission(self, request, obj=None):
+        return False
+
+    def save_model(self, request, obj, form, change):
+        obj.save()
 
 admin.site.register(Category, CategoryAdmin)
 admin.site.register(Vendor)
+admin.site.register(Tag, TagAdmin)
 admin.site.register(App, AppAdmin)
diff --git a/store/api.py b/store/api.py
index fe8e25d..75e730f 100644
--- a/store/api.py
+++ b/store/api.py
@@ -39,14 +39,16 @@ from django.db.models import Q, Count
 from django.http import HttpResponse, HttpResponseForbidden, Http404, JsonResponse
 from django.contrib import auth
 from django.views.decorators.csrf import csrf_exempt
-from authdecorators import logged_in_or_basicauth, is_staff_member
+from django.core.exceptions import ValidationError
+from store.authdecorators import logged_in_or_basicauth, is_staff_member
 
-from models import App, Category, Vendor, savePackageFile
-from utilities import parsePackageMetadata, parseAndValidatePackageMetadata, addSignatureToPackage
-from utilities import packagePath, iconPath, downloadPath
-from utilities import getRequestDictionary
-from osandarch import normalizeArch
-from tags import SoftwareTagList
+from store.models import App, Category, Vendor, savePackageFile
+from store.utilities import parsePackageMetadata, parseAndValidatePackageMetadata, \
+    addSignatureToPackage
+from store.utilities import packagePath, iconPath, downloadPath
+from store.utilities import getRequestDictionary
+from store.osandarch import normalizeArch
+from store.tags import SoftwareTagList
 
 
 def hello(request):
@@ -66,16 +68,21 @@ def hello(request):
     elif not ((version) > 0 and (version <= settings.APPSTORE_PLATFORM_VERSION)):
         status = 'incompatible-version'
 
-    for j in ("require_tag", "conflicts_tag",):
-        if j in dictionary: #Tags are coma-separated,
-            versionmap = SoftwareTagList()
-            if not versionmap.parse(getRequestDictionary(request)[j]):
-                status = 'malformed-tag'
-                break
-            request.session[j] = str(versionmap)
+    # Tag parsing
+    temp_tags = []
+    for j in ("require_tag", "tag"):
+        if j in dictionary:
+            temp_tags.append(dictionary[j])
+    versionmap = SoftwareTagList()
+    #Tags are coma-separated, - so join them
+    if temp_tags:
+        if not versionmap.parse(','.join(temp_tags)):
+            status = 'malformed-tag'
+    request.session["tag"] = str(versionmap)
+    del temp_tags
 
     if 'architecture' in dictionary:
-        arch = normalizeArch(getRequestDictionary(request)['architecture'])
+        arch = normalizeArch(dictionary['architecture'])
         if arch == "":
             status = 'incompatible-architecture'
         request.session['architecture'] = arch
@@ -95,7 +102,7 @@ def login(request):
         except KeyError:
             raise Exception('missing-credentials')
 
-        user = auth.authenticate(username = username, password = password)
+        user = auth.authenticate(username=username, password=password)
         if user is None:
             raise Exception('authentication-failed')
 
@@ -147,9 +154,9 @@ def upload(request):
             myfile = request.FILES['package']
             category = Category.objects.all().filter(name__exact=category_name)
             vendor = Vendor.objects.all().filter(name__exact=vendor_name)
-            if len(category) == 0:
+            if not category:
                 raise Exception('Non-existing category')
-            if len(vendor) == 0:
+            if not vendor:
                 raise Exception('Non-existing vendor')
 
             try:
@@ -159,7 +166,11 @@ def upload(request):
 
             myfile.seek(0)
             try:
-                savePackageFile(pkgdata, myfile, category[0], vendor[0], description, shortdescription)
+                package_metadata = {'category':category[0],
+                                    'vendor':vendor[0],
+                                    'description':description,
+                                    'short_description':shortdescription}
+                savePackageFile(pkgdata, myfile, package_metadata)
             except Exception as error:
                 raise Exception(error)
         else:
@@ -174,29 +185,15 @@ def appList(request):
     apps = App.objects.all()
     dictionary = getRequestDictionary(request)
     if 'filter' in dictionary:
-        apps = apps.filter(name__contains = dictionary['filter'])
+        apps = apps.filter(name__contains=dictionary['filter'])
     if 'category_id' in dictionary:
         catId = dictionary['category_id']
         if catId != -1: # All metacategory
-            apps = apps.filter(category__exact = catId)
-
-    #Tag filtering
-    #"require_tag", "conflicts_tag"
-    # Tags are combined by logical AND (for require) and logical OR for conflicts
-    if 'require_tag' in request.session:
-        require_tags = SoftwareTagList()
-        require_tags.parse(request.session['require_tag'])
-        for i in require_tags.make_regex():
-            apps = apps.filter(Q(tags__regex = i))
-    if 'conflicts_tag' in request.session:
-        conflict_tags = SoftwareTagList()
-        conflict_tags.parse(request.session['conflicts_tag'])
-        for i in conflict_tags.make_regex():
-            apps = apps.filter(~Q(tags__regex=i))
+            apps = apps.filter(category__exact=catId)
 
     # Here goes the logic of listing packages when multiple architectures are available
-    # in /hello request, the target architecture is stored in the session. By definition target machine can support
-    # both "All" package architecture and it's native one.
+    # in /hello request, the target architecture is stored in the session. By definition
+    # target machine can support both "All" package architecture and it's native one.
     # So - here goes filtering by list of architectures
     archlist = ['All', ]
     if 'architecture' in request.session:
@@ -206,52 +203,93 @@ def appList(request):
     if 'pkgversions' in request.session:
         versionlist = request.session['pkgversions']
 
-    apps = apps.filter(architecture__in = archlist)
-    apps = apps.filter(pkgformat__in = versionlist)
-
-    # After filtering, there are potential duplicates in list. And we should prefer native applications to pure qml ones
-    # due to speedups offered.
-    # So - first applications are grouped by appid and numbers of same appids counted. In case where is more than one appid -
-    # there are two variants of application: for 'All' architecture, and for the architecture supported by the target machine.
-    # So, as native apps should be preferred
-    duplicates = (
-        apps.values('appid').order_by().annotate(count_id=Count('id')).filter(count_id__gt=1)
-    )
-    # Here we go over duplicates list and filter out 'All' architecture apps.
-    for duplicate in duplicates:
-        apps = apps.filter(~Q(appid__exact = duplicate['appid'], architecture__exact = 'All')) # if there is native - 'All' architecture apps are excluded
-
-    appList = list(apps.values('appid', 'name', 'vendor__name', 'briefDescription', 'category', 'tags', 'architecture', 'version').order_by('appid','architecture'))
+    apps = apps.filter(architecture__in=archlist)
+    apps = apps.filter(pkgformat__in=versionlist)
 
-    for app in appList:
+    #Tag filtering
+    #There is no search by version distance yet - this must be fixed
+    if 'tag' in request.session:
+        tags = SoftwareTagList()
+        tags.parse(request.session['tag'])
+        apps_ids = [app.id for app in apps if app.is_tagmatching(tags.list())]
+        apps = App.objects.filter(id__in=apps_ids)
+
+    # After filtering, there are potential duplicates in list. And we should prefer native
+    # applications to pure qml ones due to speedups offered.
+    # At this point - filtering duplicates is disabled, because it will be implemented with
+    # 'distance' between requested version and package version. Architecture will be also included
+    # in this metric (as native apps should be preferred)
+
+    selectedAppList = apps.values('id', 'appid', 'name', 'vendor__name', 'briefDescription',
+                                       'category', 'architecture',
+                                       'version', 'pkgformat', 'tags_hash').order_by('appid', 'architecture', 'tags_hash')
+
+    appList = []
+    for app in selectedAppList:
+        app['purchaseId'] = app['id']
         app['id'] = app['appid']
         app['category_id'] = app['category']
-        app['category'] = Category.objects.all().filter(id__exact = app['category_id'])[0].name
+        app['category'] = Category.objects.all().filter(id__exact=app['category_id'])[0].name
         app['vendor'] = app['vendor__name']
-        if app['tags'] != "":
-            app['tags'] = app['tags'].split(',')
+        app['tags'] = []
+        tags = list(App.objects.filter(appid=app['appid'], architecture=app['architecture'], tags_hash=app['tags_hash'], tags__negative=False).values('tags__name', 'tags__version'))
+        for i in tags:
+            app['tags'].append(i['tags__name'] if not i['tags__version'] else ':'.join((i['tags__name'],i['tags__version'])))
+        app['conflict_tags'] = []
+        conflict_tags = list(App.objects.filter(appid=app['appid'], architecture=app['architecture'], tags_hash=app['tags_hash'], tags__negative=True).values('tags__name', 'tags__version'))
+        for i in conflict_tags:
+            app['conflict_tags'].append(i['tags__name'] if not i['tags__version'] else ':'.join((i['tags__name'],i['tags__version'])))
+
+        toFile = '_'.join([app['appid'], app['architecture'], app['tags_hash']])
+        if settings.URL_PREFIX != '':
+            iconUri = '/' + settings.URL_PREFIX + '/app/icons/' + toFile
         else:
-            app['tags'] = []
+            iconUri = '/app/icons/' + toFile
+        app['iconUrl'] = request.build_absolute_uri(iconUri)
         del app['vendor__name']
         del app['appid']
+        del app['tags_hash']
+        appList.append(app)
 
     # this is not valid JSON, since we are returning a list!
-    return JsonResponse(appList, safe = False)
+    return JsonResponse(appList, safe=False)
 
 
 def appDescription(request):
     archlist = ['All', ]
     if 'architecture' in request.session:
         archlist.append(request.session['architecture'])
+    versionlist = [1]
+    if 'pkgversions' in request.session:
+        versionlist = request.session['pkgversions']
     appId = getRequestDictionary(request)['id']
     try:
-        app = App.objects.get(appid__exact = appId, architecture__in = archlist).order_by('architecture')
+        app = App.objects.filter(appid__exact = appId, architecture__in = archlist).order_by('architecture','tags_hash')
+        app = app.filter(pkgformat__in=versionlist)
+        #Tag filtering
+        #There is no search by version distance yet - this must be fixed
+        if 'tag' in request.session:
+            tags = SoftwareTagList()
+            tags.parse(request.session['tag'])
+            app_ids = [x.id for x in app if x.is_tagmatching(tags.list())]
+            app = App.objects.filter(id__in=app_ids)
         app = app.last()
         return HttpResponse(app.description)
     except:
         raise Http404('no such application: %s' % appId)
 
 
+def appIconNew(request, path):
+    path=path.replace('/', '_').replace('\\', '_').replace(':', 'x3A').replace(',', 'x2C') + '.png'
+    try:
+        response = HttpResponse(content_type='image/png')
+        with open(iconPath() + path, 'rb') as pkg:
+            response.write(pkg.read())
+            response['Content-Length'] = pkg.tell()
+        return response
+    except:
+        raise Http404
+
 def appIcon(request):
     archlist = ['All', ]
     dictionary = getRequestDictionary(request)
@@ -259,12 +297,23 @@ def appIcon(request):
         archlist.append(normalizeArch(dictionary['architecture']))
     elif 'architecture' in request.session:
         archlist.append(request.session['architecture'])
+    versionlist = [1]
+    if 'pkgversions' in request.session:
+        versionlist = request.session['pkgversions']
     appId = dictionary['id']
     try:
-        app = App.objects.filter(appid__exact = appId, architecture__in = archlist).order_by('architecture')
+        app = App.objects.filter(appid__exact = appId, architecture__in = archlist).order_by('architecture','tags_hash')
+        app = app.filter(pkgformat__in=versionlist)
+        #Tag filtering
+        #There is no search by version distance yet - this must be fixed
+        if 'tag' in request.session:
+            tags = SoftwareTagList()
+            tags.parse(request.session['tag'])
+            app_ids = [x.id for x in app if x.is_tagmatching(tags.list())]
+            app = App.objects.filter(id__in=app_ids)
         app = app.last()
-        with open(iconPath(app.appid,app.architecture,app.tags), 'rb') as iconPng:
-            response = HttpResponse(content_type = 'image/png')
+        with open(iconPath(app.appid, app.architecture, app.tags_hash), 'rb') as iconPng:
+            response = HttpResponse(content_type='image/png')
             response.write(iconPng.read())
             return response
     except:
@@ -277,6 +326,10 @@ def appPurchase(request):
     archlist = ['All', ]
     if 'architecture' in request.session:
         archlist.append(request.session['architecture'])
+    versionlist = [1]
+    if 'pkgversions' in request.session:
+        versionlist = request.session['pkgversions']
+
     try:
         deviceId = str(getRequestDictionary(request).get("device_id", ""))
         if settings.APPSTORE_BIND_TO_DEVICE_ID:
@@ -285,13 +338,28 @@ def appPurchase(request):
         else:
             deviceId = ''
 
-        app = App.objects.filter(appid__exact = getRequestDictionary(request)['id'], architecture__in=archlist).order_by('architecture')
+        if 'id' in getRequestDictionary(request):
+            app = App.objects.filter(appid__exact = getRequestDictionary(request)['id'], architecture__in=archlist).order_by('architecture','tags_hash')
+        elif 'purchaseId' in getRequestDictionary(request):
+            app = App.objects.filter(id__exact = getRequestDictionary(request)['purchaseId'], architecture__in=archlist).order_by('architecture','tags_hash')
+        else:
+            raise ValidationError('id or purchaseId parameter required')
+        app = app.filter(pkgformat__in=versionlist)
+        #Tag filtering
+        #There is no search by version distance yet - this must be fixed
+        if 'tag' in request.session:
+            tags = SoftwareTagList()
+            tags.parse(request.session['tag'])
+            app_ids = [x.id for x in app if x.is_tagmatching(tags.list())]
+            app = App.objects.filter(id__in=app_ids)
+
         app = app.last()
-        fromFilePath = packagePath(app.appid, app.architecture, app.tags)
+        fromFilePath = packagePath(app.appid, app.architecture, app.tags_hash)
 
         # we should not use obvious names here, but just hash the string.
         # this would be a nightmare to debug though and this is a development server :)
-        toFile = str(app.appid) + '_' + str(request.user.id) + '_' + str(app.architecture) + '_' + str(app.tags) + '_'+ str(deviceId)
+        toFile = '_'.join((str(app.appid), str(request.user.id), str(app.architecture),
+                           str(app.tags_hash), str(deviceId)))
         if not settings.DEBUG:
             toFile = hashlib.sha256(toFile).hexdigest()
         toFile += '.appkg'
@@ -309,7 +377,7 @@ def appPurchase(request):
                 shutil.copyfile(fromFilePath, toPath + toFile)
             except Exception as error:
                 if type(error) == IOError:
-                    raise IOError(error.args[0],error.args[1], os.path.basename(fromFilePath))
+                    raise IOError(error.args[0], error.args[1], os.path.basename(fromFilePath))
                 else:
                     raise error
 
@@ -330,7 +398,7 @@ def appPurchase(request):
 
 def appDownload(request, path):
     try:
-        response = HttpResponse(content_type = 'application/octetstream')
+        response = HttpResponse(content_type='application/octetstream')
         with open(downloadPath() + path, 'rb') as pkg:
             response.write(pkg.read())
             response['Content-Length'] = pkg.tell()
diff --git a/store/management/commands/store-upload-package.py b/store/management/commands/store-upload-package.py
index 77286bc..7af866b 100644
--- a/store/management/commands/store-upload-package.py
+++ b/store/management/commands/store-upload-package.py
@@ -30,18 +30,22 @@
 ##
 #############################################################################
 
-import os
-
+from optparse import make_option
 from django.core.management.base import BaseCommand, CommandError
 from django.core.files.base import ContentFile
-from store.models import App, Category, Vendor, savePackageFile
+from store.models import Category, Vendor, savePackageFile
 from store.utilities import parseAndValidatePackageMetadata
-from optparse import make_option
+
 
 
 class Command(BaseCommand):
     help = 'Uploads a package to the deployment server. This can be used for batch uploading.'
-    option_list = BaseCommand.option_list + (
+    usage_string = 'Usage: manage.py store-upload-package --vendor <vendor> --category <category>' \
+                   ' [--description <short description>] <package>'
+
+    # FIXME: this doesn't work:
+    # see https://docs.djangoproject.com/en/1.8/howto/custom-management-commands/#django.core.management.BaseCommand.add_arguments
+    self.option_list = BaseCommand.option_list + (
         make_option('--vendor',
                     action='store',
                     type="string",
@@ -62,16 +66,14 @@ class Command(BaseCommand):
 
     def handle(self, *args, **options):
         if len(args) != 1:
-            raise CommandError(
-                'Usage: manage.py store-upload-package --vendor <vendor> --category <category> [--description <short description>] <package>')
+            raise CommandError(self.usage_string)
         if (not options['vendor']) or (not options['category']):
-            raise CommandError(
-                'Usage: manage.py store-upload-package --vendor <vendor> --category <category> [--description <short description>] <package>')
+            raise CommandError(self.usage_string)
         category = Category.objects.all().filter(name__exact=options['category'])
         vendor = Vendor.objects.all().filter(name__exact=options['vendor'])
-        if len(category) == 0:
+        if not category:
             raise CommandError('Non-existing category specified')
-        if len(vendor) == 0:
+        if not vendor:
             raise CommandError('Non-existing vendor specified')
 
         try:
@@ -86,7 +88,10 @@ class Command(BaseCommand):
         packagefile.seek(0)
         description = options['description']
         try:
-            savePackageFile(pkgdata, ContentFile(packagefile.read()), category[0], vendor[0], description, description)
+            package_metadata = {'category': category[0],
+                                'vendor': vendor[0],
+                                'description': description,
+                                'short_description': description}
+            savePackageFile(pkgdata, ContentFile(packagefile.read()), package_metadata)
         except Exception as error:
             raise CommandError(error)
-
diff --git a/store/migrations/0001_initial.py b/store/migrations/0001_initial.py
index f23c6bf..80d154c 100644
--- a/store/migrations/0001_initial.py
+++ b/store/migrations/0001_initial.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+# Generated by Django 1.11.27 on 2020-08-14 17:24
 #############################################################################
 ##
 ## Copyright (C) 2020 Luxoft Sweden AB
@@ -38,6 +39,7 @@ from django.conf import settings
 from django.db import migrations, models
 import django.db.models.deletion
 import store.models
+import uuid
 
 
 class Migration(migrations.Migration):
@@ -52,7 +54,7 @@ class Migration(migrations.Migration):
         migrations.CreateModel(
             name='App',
             fields=[
-                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('id', models.UUIDField(default=uuid.uuid4, editable=False, primary_key=True, serialize=False)),
                 ('appid', models.CharField(max_length=200)),
                 ('name', models.CharField(max_length=200)),
                 ('file', models.FileField(storage=store.models.OverwriteStorage(), upload_to=store.models.content_file_name)),
@@ -60,7 +62,7 @@ class Migration(migrations.Migration):
                 ('description', models.TextField()),
                 ('dateAdded', models.DateField(auto_now_add=True)),
                 ('dateModified', models.DateField(auto_now=True)),
-                ('tags', models.TextField(blank=True)),
+                ('tags_hash', models.CharField(default=b'', max_length=4096)),
                 ('architecture', models.CharField(default=b'All', max_length=20)),
                 ('version', models.CharField(default=b'0.0.0', max_length=20)),
                 ('pkgformat', models.IntegerField()),
@@ -80,6 +82,15 @@ class Migration(migrations.Migration):
             },
         ),
         migrations.CreateModel(
+            name='Tag',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('negative', models.BooleanField(default=False)),
+                ('name', models.CharField(max_length=200)),
+                ('version', models.CharField(blank=True, max_length=200)),
+            ],
+        ),
+        migrations.CreateModel(
             name='Vendor',
             fields=[
                 ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
@@ -88,6 +99,10 @@ class Migration(migrations.Migration):
                 ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
             ],
         ),
+        migrations.AlterUniqueTogether(
+            name='tag',
+            unique_together=set([('negative', 'name', 'version')]),
+        ),
         migrations.AddField(
             model_name='app',
             name='category',
@@ -95,11 +110,16 @@ class Migration(migrations.Migration):
         ),
         migrations.AddField(
             model_name='app',
+            name='tags',
+            field=models.ManyToManyField(to='store.Tag'),
+        ),
+        migrations.AddField(
+            model_name='app',
             name='vendor',
             field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='store.Vendor'),
         ),
         migrations.AlterUniqueTogether(
             name='app',
-            unique_together=set([('appid', 'architecture', 'tags')]),
+            unique_together=set([('appid', 'architecture', 'tags_hash')]),
         ),
     ]
diff --git a/store/models.py b/store/models.py
index 1cf8916..7e8751a 100644
--- a/store/models.py
+++ b/store/models.py
@@ -31,14 +31,16 @@
 #############################################################################
 
 import os
+import uuid
 
 from django.db import models
-from ordered_model.models import OrderedModel
 from django.conf import settings
 from django.contrib.auth.models import User
 from django.core.files.storage import FileSystemStorage
+from ordered_model.models import OrderedModel
 
-from utilities import packagePath, writeTempIcon, makeTagList
+from store.utilities import packagePath, writeTempIcon, makeTagList
+from store.tags import SoftwareTag
 
 def category_file_name(instance, filename):
     # filename parameter is unused. See django documentation for details:
@@ -66,8 +68,8 @@ class Category(OrderedModel):
             # This is a django hack. When category icon is saved and then later accessed,
             # category_id is used as a unique icon identifier. When category is first created,
             # but not saved yet, category_id is None. So this hack first saves category without icon
-            # and then saves the icon separately. This is done to prevent creation of category_None.png
-            # file, when the icon is saved.
+            # and then saves the icon separately. This is done to prevent creation of
+            # category_None.png file, when the icon is saved.
             saved_icon = self.icon
             self.icon = None
             super(Category, self).save(*args, **kwargs)
@@ -82,76 +84,133 @@ class Vendor(models.Model):
     def __unicode__(self):
         return self.name
 
+class Tag(models.Model):
+    negative = models.BooleanField(default=False)
+    name = models.CharField(max_length=200)
+    version = models.CharField(max_length=200, blank=True)
+
+    class Meta:
+        unique_together = (('negative', 'name', 'version'))
+
+    def __unicode__(self):
+        negative = '-' if self.negative else ''
+        if self.version:
+            return negative + self.name + ":" + self.version
+        return negative + self.name
 
 def content_file_name(instance, filename):
-    return packagePath(instance.appid, instance.architecture, instance.tags)
+    return packagePath(instance.appid, instance.architecture, instance.tags_hash)
 
 class App(models.Model):
-    appid = models.CharField(max_length = 200)
-    name = models.CharField(max_length = 200)
-    file = models.FileField(upload_to = content_file_name, storage = OverwriteStorage())
+    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
+    appid = models.CharField(max_length=200)
+    name = models.CharField(max_length=200)
+    file = models.FileField(upload_to=content_file_name, storage=OverwriteStorage())
     vendor = models.ForeignKey(Vendor)
     category = models.ForeignKey(Category)
     briefDescription = models.TextField()
     description = models.TextField()
-    dateAdded = models.DateField(auto_now_add = True)
-    dateModified = models.DateField(auto_now = True)
-    tags = models.TextField(blank=True)
+    dateAdded = models.DateField(auto_now_add=True)
+    dateModified = models.DateField(auto_now=True)
+    tags = models.ManyToManyField(Tag)
+    # Hash sum for sorted tag list, this is used to be able to distinguish different tag sets
+    tags_hash = models.CharField(max_length=4096, default='')
     architecture = models.CharField(max_length=20, default='All')
     version = models.CharField(max_length=20, default='0.0.0')
     pkgformat = models.IntegerField()
 
     class Meta:
         """Makes the group of id and arch - a unique identifier"""
-        unique_together = (('appid', 'architecture', 'tags'),)
+        unique_together = (('appid', 'architecture', 'tags_hash'),)
 
     def __unicode__(self):
-        return self.name + " [" + " ".join([self.appid, self.version, self.architecture, self.tags]) + "]"
+        return self.name + " [" + " ".join([self.appid, self.version, self.architecture,
+                                            self.tags_hash]) + "]"
+
+    def is_tagmatching(self, tagstring):
+        temp = self.tags.all()
+        if not temp: #App with tags does not require anything
+            return True
+        for i in temp:
+            if not any(j.match(SoftwareTag(str(i))) for j in tagstring):
+                return False
+        return True
 
     def save(self, *args, **kwargs):
         try:
-            this = App.objects.get(appid=self.appid,architecture=self.architecture,tags=self.tags) #FIXME: This should be 'tags match, not exact same tags'
+            this = App.objects.get(appid=self.appid, architecture=self.architecture, tags_hash=self.tags_hash)
             if this.file != self.file:
                 this.file.delete(save=False)
         except:
             pass
         super(App, self).save(*args, **kwargs)
 
-
-def savePackageFile(pkgdata, pkgfile, category, vendor, description, shortdescription):
+def populateTagList(tags, conflict_tags):
+    taglist = []
+    for i in tags:
+        # Add tag to database
+        version = "" if i.version is None else i.version
+        tag, created = Tag.objects.get_or_create(name=i.tag, version=version, negative=False)
+        if created:
+            tag.save()
+        taglist.append(tag)
+    for i in conflict_tags:
+        # Add tag to database
+        version = "" if i.version is None else i.version
+        tag, created = Tag.objects.get_or_create(name=i.tag, version=version, negative=True)
+        if created:
+            tag.save()
+    return taglist
+
+
+def savePackageFile(pkgdata, pkgfile, package_metadata):
     appId = pkgdata['info']['id']
     name = pkgdata['storeName']
     architecture = pkgdata['architecture']
     pkgformat = pkgdata['packageFormat']['formatVersion']
-    tags = makeTagList(pkgdata)
-    success, error = writeTempIcon(appId, architecture, tags, pkgdata['icon'])
+    tags, conflict_tags, tags_hash = makeTagList(pkgdata)
+    category = package_metadata['category']
+    vendor = package_metadata['vendor']
+    description = package_metadata['description']
+    shortdescription = package_metadata['short_description']
+
+    success, error = writeTempIcon(appId, architecture, tags_hash, pkgdata['icon'])
     if not success:
         raise Exception(error)
 
     exists = False
     app = None
     try:
-        app = App.objects.get(appid__exact=appId, architecture__exact=architecture, tags__exact=tags)
+        app = App.objects.get(appid__exact=appId, architecture__exact=architecture,
+                              tags_hash__exact=tags_hash)
         exists = True
     except App.DoesNotExist:
         pass
 
+    taglist = populateTagList(tags.list(), conflict_tags.list())
+
     if exists:
         app.appid = appId
         app.category = category
         app.vendor = vendor
         app.name = name
-        app.tags = tags
+        app.tags_hash = tags_hash
         app.description = description
         app.briefDescription = shortdescription
         app.architecture = architecture
         app.pkgformat = pkgformat
-        app.file.save(packagePath(appId, architecture, tags), pkgfile)
+        app.file.save(packagePath(appId, architecture, tags_hash), pkgfile)
         app.save()
     else:
-        app, _ = App.objects.get_or_create(name=name, tags=tags, vendor=vendor,
-                                           category=category, appid=appId,
-                                           briefDescription=shortdescription, description=description,
-                                           pkgformat = pkgformat, architecture=architecture)
-        app.file.save(packagePath(appId, architecture, tags), pkgfile)
+        app, _ = App.objects.get_or_create(name=name, tags_hash=tags_hash,
+                                           vendor=vendor, category=category, appid=appId,
+                                           briefDescription=shortdescription,
+                                           description=description, pkgformat=pkgformat,
+                                           architecture=architecture) #FIXME
+        app.file.save(packagePath(appId, architecture, tags_hash), pkgfile)
         app.save()
+
+    for i in taglist:
+        # attach tags to app
+        app.tags.add(i)
+
diff --git a/store/osandarch.py b/store/osandarch.py
index 7b833d3..5668b48 100644
--- a/store/osandarch.py
+++ b/store/osandarch.py
@@ -32,12 +32,14 @@
 
 # check for file type here.
 # those are expected types
-# ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.18, not stripped
+# ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked,
+#            interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.18, not stripped
 # ELF 64-bit LSB shared object, x86-64, version 1 (GNU/Linux), dynamically linked, not stripped
 # ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, not stripped
 # Mach-O 64-bit x86_64 dynamically linked shared library
 # Mach-O 64-bit x86_64 executable
-# Mach-O universal binary with 2 architectures: [x86_64: Mach-O 64-bit x86_64 bundle] [i386: Mach-O i386 bundle] []
+# Mach-O universal binary with 2 architectures:
+#        [x86_64: Mach-O 64-bit x86_64 bundle] [i386: Mach-O i386 bundle] []
 # PE32+ executable (console) x86-64, for MS Windows
 # PE32+ executable (DLL) (console) x86-64, for MS Windows
 # PE32+ executable (DLL) (GUI) x86-64, for MS Windows
@@ -45,21 +47,21 @@
 
 import re
 
-def parseMachO(str):  # os, arch, bits, endianness
-    if " universal " in str:
+def parseMachO(string_data):  # os, arch, bits, endianness
+    if " universal " in string_data:
         # Universal binary - not supported
         raise Exception("Universal binaries are not supported in packages")
     os = "macOS"
-    arch = str.split(' ')
+    arch = string_data.split(' ')
     arch = arch[2]
-    bits = str.split(' ')[1].replace('-bit', '')
+    bits = string_data.split(' ')[1].replace('-bit', '')
     endianness = "little_endian"
     return [os, arch, bits, endianness]
 
 
-def parsePE32(str):
+def parsePE32(string_data):
     os = "Windows"
-    arch = str.split(',')
+    arch = string_data.split(',')
     arch = arch[0]  # Take first part
     arch = arch.split(' ')
     arch = arch[-1]  # Take last element
@@ -72,12 +74,13 @@ def parsePE32(str):
     return [os, arch, bits, endianness]
 
 
-def parseElfArch(str, architecture, bits):
+def parseElfArch(string_data, architecture, bits):
     architecture = architecture.strip()
     if architecture.startswith("ARM"):
         if 'aarch64' in architecture:
             return 'arm64'
-        if 'armhf' in str:  # this does not work for some reason - from_file() returns longer data than from_buffer() - needs fix
+        if 'armhf' in string_data:  # this does not work for some reason - from_file() returns
+                                    # longer data than from_buffer() - needs fix
             return 'arm'    # because qt does not report it directly
     elif architecture.startswith("Intel"):
         if '80386' in architecture:
@@ -93,13 +96,13 @@ def parseElfArch(str, architecture, bits):
     return architecture.lower()
 
 
-def parseElf(str):
+def parseElf(string_data):
     os = "Linux"
-    arch = str.split(',')
+    arch = string_data.split(',')
     arch = arch[1]
-    bits = str.split(' ')[1].replace('-bit', '')
-    arch = parseElfArch(str, arch, bits)
-    endian = str.split(' ')[2].lower()
+    bits = string_data.split(' ')[1].replace('-bit', '')
+    arch = parseElfArch(string_data, arch, bits)
+    endian = string_data.split(' ')[2].lower()
     if endian == "msb":
         endianness = "big_endian"
     elif endian == "lsb":
@@ -109,21 +112,21 @@ def parseElf(str):
     return [os, arch, bits, endianness]
 
 
-def getOsArch(str):
+def getOsArch(string_data):
     os = None
     arch = None
     bits = None
     endianness = None
     fmt = None
-    if str.startswith("ELF "):
+    if string_data.startswith("ELF "):
         fmt = "elf"
-        os, arch, bits, endianness = parseElf(str)
-    elif str.startswith("Mach-O "):
+        os, arch, bits, endianness = parseElf(string_data)
+    elif string_data.startswith("Mach-O "):
         fmt = "mach_o"
-        os, arch, bits, endianness = parseMachO(str)
-    elif str.startswith("PE32+ ") or str.startswith("PE32 "):
+        os, arch, bits, endianness = parseMachO(string_data)
+    elif string_data.startswith("PE32+ ") or string_data.startswith("PE32 "):
         fmt = "pe32"
-        os, arch, bits, endianness = parsePE32(str)
+        os, arch, bits, endianness = parsePE32(string_data)
     if arch:
         arch = arch.replace('-', '_')
     result = [os, arch, endianness, bits, fmt]
@@ -133,9 +136,10 @@ def getOsArch(str):
 
 def normalizeArch(inputArch):
     """
-        This function brings requested architecture to common form (currently just parses the bits part and turns it into 32/64)
-        Input string format is: arch-endianness-word_size-optional_ABI-kernelType
-        Output string format is: arch-endianness-word_size-kernelType
+    This function brings requested architecture to common form (currently just parses the bits
+        part and turns it into 32/64)
+    Input string format is: arch-endianness-word_size-optional_ABI-kernelType
+    Output string format is: arch-endianness-word_size-kernelType
 
     """
     parts = inputArch.split('-')
diff --git a/store/tags.py b/store/tags.py
index aa73006..e906684 100644
--- a/store/tags.py
+++ b/store/tags.py
@@ -37,6 +37,10 @@ import re
 
 
 def validateTagVersion(version):
+    """
+    Validates tag version, in string form
+    :type tag: str
+    """
     for i in version:
         if not i.isalnum():
             if not ((i == "_") or (i == ".")):
@@ -45,7 +49,11 @@ def validateTagVersion(version):
 
 
 def validateTag(tag):
-    if len(tag) == 0:
+    """
+    Validates tag (with version), in string form
+    :type tag: str
+    """
+    if not tag:
         return False
     lst = tag.split(':')
     if len(lst) > 2:
@@ -60,14 +68,21 @@ def validateTag(tag):
 
 
 class SoftwareTag:
+    """
+    This class represents one tag instance. Tag is formatted in string form as two parts:
+    * tag itself, which is supposed to contain only alphanumeric symbols and _
+    * optional tag version, which consists of any non-zero number of alphanumeric parts,
+      separated by dots.
+"""
+
     def __init__(self, tag):
         """ Takes tag and parses it. If it can't parse - raises exception of invalid value
         :type tag: str
         """
-        if not ((type(tag) == str) or (type(tag) == unicode)):
-            raise (BaseException("Invalid input data-type"))
+        if not isinstance(tag, (str, unicode)):
+            raise BaseException("Invalid input data-type")
         if not validateTag(tag):
-            raise (BaseException("Malformed tag"))
+            raise BaseException("Malformed tag")
         tag_version = tag.split(':')
         self.tag = tag_version[0].lower()  # No, this should be lowercase
         self.version = None if len(tag_version) == 1 else tag_version[1]
@@ -78,37 +93,27 @@ class SoftwareTag:
     def __str__(self):
         if self.version:
             return "%s:%s" % (self.tag, self.version)
-        else:
-            return self.tag
+        return self.tag
 
     def has_version(self):
         return self.version is not None
 
     def match(self, tag):  # self is "on server", tag is "request"
+        """
+        Does tag matching for tag string/tag list minimisation
+        :param tag: tags.SoftwareTag
+        :return: Returns true, if self is more specific (or equal) than tag
+        """
         if self.tag == tag.tag:
             # Names are the same, that is good, matching versions now.
             if self.version == tag.version:
                 return True
-            else:
-                if tag.version is None:
-                    return True  # qt in request, anything else on server - True
-                if self.version is not None and self.version.startswith(tag.version + "."):
-                    return True
-                return False
+            if tag.version is None:
+                return True
+            if self.version is not None and self.version.startswith(tag.version + "."):
+                return True
         return False
 
-    def make_regex(self):
-        if self.version is None:
-            # versionless tag
-            temp_string = re.escape(self.tag)
-            regex = "(%s:[a-z0-9_.]*)|(%s)" % (temp_string, temp_string,)
-        else:
-            # tag with versions
-            temp_string = re.escape("%s:%s" % (self.tag, self.version))
-            regex = "(%s\.[a-z0-9_.]*)|(%s)" % (temp_string, temp_string)
-        return regex
-
-
 class SoftwareTagList:
     def __init__(self):
         # dictionary of tags, key is - tag name
@@ -116,7 +121,7 @@ class SoftwareTagList:
 
     def __str__(self):
         lst = list()
-        for key, value in self.taglist.items():
+        for _, value in self.taglist.items():
             lst += [str(i) for i in value]
         lst.sort()
         return ",".join(lst)
@@ -136,7 +141,8 @@ class SoftwareTagList:
 
     def has_version(self, tag_name):
         if tag_name in self.taglist:
-            # This check is possible, because, when there is tag without version - it is the only tag in the list
+            # This check is possible, because, when there is tag without version -
+            # it is the only tag in the list
             if self.taglist[tag_name][0].has_version():
                 return True
         return False
@@ -160,41 +166,13 @@ class SoftwareTagList:
     def is_empty(self):
         return len(self.taglist) == 0
 
-    def make_regex(self):
+    def list(self):
         lst = list()
-        for key, value in self.taglist.items():
-            regex = "(^|,)%s(,|$)" % "|".join([i.make_regex() for i in value])
-            lst.append(regex)
+        for _, value in self.taglist.items():
+            for i in value:
+                lst.append(i)
         return lst
 
-    def match_positive(self, taglist):
-        # checks that everything from tag list matches current tags
-        # Start checking with checking if all requested tags in taglist are present in self.taglist
-        for i in taglist.taglist:
-            if i not in self.taglist:
-                return False
-        # Now we need to check if versions are matching
-        for tag in taglist.taglist:
-            if not self.has_version(tag):
-                # If package tag accepts anything - it already matches, next please
-                continue
-            if taglist.has_version(tag) and not any(v1.match(v) for v in taglist[tag] for v1 in self[tag]):
-                return False
-        return True
-
-    def match_negative(self, taglist):
-        # checks that nothing from taglist matches current tags
-        for i in taglist.taglist:
-            if i in self.taglist:
-                if (not taglist.has_version(i)) or (not self.has_version(i)):
-                    return False
-                # Tag found, version list is present. check if it matches, if it does - check is failed
-                for version in taglist[i]:
-                    for version1 in self[i]:
-                        if version1.match(version):
-                            return False
-        return True
-
     def hash(self):
         # Looks like the list is sorted, but well...
         return hashlib.md5(str(self)).hexdigest()
@@ -247,43 +225,6 @@ class TestSoftwareTagListMethods(unittest.TestCase):
         lst.append(SoftwareTag('qt'))
         self.assertFalse(lst.is_empty())
 
-    def test_empty_matches_everything(self):
-        empty_list = SoftwareTagList()
-        test_list = SoftwareTagList()
-        test_list.append(SoftwareTag('qt'))
-        self.assertTrue(test_list.match_positive(empty_list))
-        self.assertTrue(test_list.match_negative(empty_list))
-
-    def test_match_positive(self):
-        list_to_test = SoftwareTagList()
-        list_to_test.parse("qt:5.1,neptune,test:1,second_test")
-        matching_list = SoftwareTagList()
-        matching_list.parse("qt")
-        self.assertTrue(list_to_test.match_positive(matching_list))
-        matching_list.parse("qt:5.1")
-        self.assertTrue(list_to_test.match_positive(matching_list))
-        matching_list.parse("qt:5.1,qt:5.2,neptune:1")
-        self.assertTrue(list_to_test.match_positive(matching_list))
-        matching_list.parse("qt:5.1,test:2")
-        self.assertFalse(list_to_test.match_positive(matching_list))
-        matching_list.parse("qt:5.1.1")
-        self.assertFalse(list_to_test.match_positive(matching_list))
-
-    def test_match_negative(self):
-        list_to_test = SoftwareTagList()
-        list_to_test.parse("qt:5.1,neptune")
-        matching_list = SoftwareTagList()
-        matching_list.parse("qt")
-        self.assertFalse(list_to_test.match_negative(matching_list))
-        matching_list.parse("qt:5.1")
-        self.assertFalse(list_to_test.match_negative(matching_list))
-        matching_list.parse("qt:5.1,qt:5.2,neptune:1")
-        self.assertFalse(list_to_test.match_negative(matching_list))
-        matching_list.parse("qt:5.1,qt:5.2")
-        self.assertFalse(list_to_test.match_negative(matching_list))
-        matching_list.parse("test")
-        self.assertTrue(list_to_test.match_negative(matching_list))
-
     def test_append_invalid(self):
         lst = SoftwareTagList()
         with self.assertRaisesRegexp(BaseException, "Malformed tag"):
diff --git a/store/utilities.py b/store/utilities.py
index 1205f1b..74ffc98 100644
--- a/store/utilities.py
+++ b/store/utilities.py
@@ -43,38 +43,48 @@ from django.conf import settings
 from OpenSSL.crypto import load_pkcs12, FILETYPE_PEM, dump_privatekey, dump_certificate
 from M2Crypto import SMIME, BIO, X509
 
-from tags import SoftwareTagList, SoftwareTag
-import osandarch
+from store.tags import SoftwareTagList, SoftwareTag
+import store.osandarch
 
 def makeTagList(pkgdata):
+    """Generates tag lists out of package data
+       First list - required tags, second list - conflicting tags
+    """
     taglist = SoftwareTagList()
+    tagconflicts = SoftwareTagList()
     for fields in ('extra', 'extraSigned'):
         if fields in pkgdata['header']:
             if 'tags' in pkgdata['header'][fields]:
                 for i in list(pkgdata['header'][fields]['tags']):  # Fill tags list then add them
                     taglist.append(SoftwareTag(i))
-    return str(taglist)
+            if 'conflicts' in pkgdata['header'][fields]:
+                for i in list(pkgdata['header'][fields]['conflicts']):
+                    tagconflicts.append(SoftwareTag(i))
+
+    tags_hash = str(taglist) + str(tagconflicts)
+    return taglist, tagconflicts, tags_hash
 
 def getRequestDictionary(request):
     if request.method == "POST":
         return request.POST
-    else:
-        return request.GET
+    return request.GET
 
-def packagePath(appId = None, architecture = None, tags = None):
+def packagePath(appId=None, architecture=None, tags=None):
     path = settings.MEDIA_ROOT + 'packages/'
     if tags is None:
         tags = ""
     if (appId is not None) and (architecture is not None):
-        path = path + '_'.join([appId, architecture, tags]).replace('/','_').replace('\\','_').replace(':','x3A').replace(',','x2C')
+        path = path + '_'.join([appId, architecture, tags]).replace('/', '_').\
+            replace('\\', '_').replace(':', 'x3A').replace(',', 'x2C')
     return path
 
-def iconPath(appId = None, architecture = None, tags = None):
+def iconPath(appId=None, architecture=None, tags=None):
     path = settings.MEDIA_ROOT + 'icons/'
     if tags is None:
         tags = ""
     if (appId is not None) and (architecture is not None):
-        return path + '_'.join([appId, architecture, tags]).replace('/','_').replace('\\','_').replace(':','x3A').replace(',','x2C') + '.png'
+        return path + '_'.join([appId, architecture, tags]).replace('/', '_').\
+            replace('\\', '_').replace(':', 'x3A').replace(',', 'x2C') + '.png'
     return path
 
 def writeTempIcon(appId, architecture, tags, icon):
@@ -87,7 +97,8 @@ def writeTempIcon(appId, architecture, tags, icon):
         tempicon.close()
         return True, None
     except IOError as error:
-        return False, 'Validation error: could not write icon file to media directory: %s' % str(error)
+        return False, 'Validation error: could not write icon file to media directory: %s' % \
+            str(error)
 
 def downloadPath():
     return settings.MEDIA_ROOT + 'downloads/'
@@ -300,7 +311,7 @@ def parsePackageMetadata(packageFile):
                 fil.seek(0)                         #from_buffer instead of from_file
                 filemagic = ms.from_file(fil.name)
                 fil.close()
-                osarch = osandarch.getOsArch(filemagic)
+                osarch = store.osandarch.getOsArch(filemagic)
                 if osarch: #[os, arch, endianness, bits, fmt]
                     architecture = '-'.join(osarch[1:])
                     osset.add(osarch[0])
@@ -416,7 +427,7 @@ def parseAndValidatePackageMetadata(packageFile, certificates = []):
         certificates = []
         for certFile in settings.APPSTORE_DEV_VERIFY_CA_CERTIFICATES:
             with open(certFile, 'rb') as cert:
-               certificates.append(cert.read())
+                certificates.append(cert.read())
 
         verifySignature(pkgdata['footer']['developerSignature'], pkgdata['rawDigest'], certificates)