[API] New method Bug.details(). Refs #117

this method together with the underlying IssueTracker.details()
will be the foundation of how Kiwi TCMS fetches more details from
the bug tracking system.

At the moment the intention is for this information to be shown in
the UI but it can also be consumed independently via the API.

By default we're using OpenGraph protocol to collect the data that
will be shown. The details() method can be overriden for each bug
tracker that is supported and you may also override the entire class
with something you have created yourself.

requirements/base.txt

@@ -9,3 +9,4 @@ django-simple-history==2.7.3
 jira==2.0.0
 Markdown==3.1.1
 python-redmine==2.2.1
+topicaxis-opengraph==0.5

tcms/issuetracker/types.py

@@ -17,6 +17,7 @@
 import redminelib
 
 from django.conf import settings
+from opengraph.opengraph import OpenGraph
 
 from tcms.issuetracker import bugzilla_integration
 from tcms.issuetracker import jira_integration
@@ -63,6 +64,21 @@ def bug_id_from_url(cls, url):
         """
         return int(RE_ENDS_IN_INT.search(url.strip()).group(0))
 
+    def details(self, url):
+        """
+            Returns bug details to be used later. By default this method
+            returns OpenGraph metadata (dict) which is shown in the UI as tooltips.
+            You can override this method to provide different information.
+        """
+        result = OpenGraph(url, scrape=True)
+
+        # remove data which we don't need
+        for key in ['_url', 'url', 'scrape', 'type']:
+            if key in result:
+                del result[key]
+
+        return result
+
     def _report_comment(self, execution):  # pylint: disable=no-self-use
         """
             Returns the comment which is used in the original defect report.

tcms/xmlrpc/api/bug.py

@@ -6,13 +6,33 @@
 from tcms.testcases.models import BugSystem
 from tcms.testruns.models import TestExecution
 from tcms.issuetracker.types import IssueTrackerType
+from tcms.xmlrpc.api.utils import tracker_from_url
 
 
 __all__ = (
+    'details',
     'report',
 )
 
 
+@rpc_method(name='Bug.details')
+def details(url):
+    """
+    .. function:: XML-RPC Bug.details(url)
+
+        Returns details about bug at the given URL address. This method is
+        used when generating additional information which is shown in the UI.
+
+        :param url: URL address
+        :type url: str
+        :return: Detailed information about this URL. Depends on the underlying
+                 issue tracker.
+        :rtype: dict
+    """
+    tracker = tracker_from_url(url)
+    return tracker.details(url)
+
+
 @rpc_method(name='Bug.report')
 def report(execution_id, tracker_id):
     """