add estimated completion time for build tasks to the taskinfo page

www/kojiweb/index.py

@@ -500,9 +500,18 @@ def taskinfo(req, taskID):
 
     builds = server.listBuilds(taskID=task['id'])
     if builds:
-        values['taskBuild'] = builds[0]
+        taskBuild = builds[0]
     else:
-        values['taskBuild'] = None
+        taskBuild = None
+    values['taskBuild'] = taskBuild
+
+    values['estCompletion'] = None
+    if taskBuild and taskBuild['state'] == koji.BUILD_STATES['BUILDING']:
+        avgDuration = server.getAverageBuildDuration(taskBuild['package_id'])
+        if avgDuration != None:
+            avgDelta = datetime.timedelta(seconds=avgDuration)
+            startTime = datetime.datetime.fromtimestamp(taskBuild['creation_ts'])
+            values['estCompletion'] = startTime + avgDelta
 
     buildroots = server.listBuildroots(taskID=task['id'])
     values['buildroots'] = buildroots

www/kojiweb/taskinfo.chtml

@@ -199,9 +199,17 @@
     <tr>
       <th>Created</th><td>$util.formatTimeLong($task.create_time)</td>
     </tr>
+    #if $task.state == $koji.TASK_STATES.OPEN
+    #if $estCompletion
+    <tr>
+      <th>Est. Completion</th><td>$util.formatTimeLong($estCompletion)</td>
+    </tr>
+    #end if
+    #elif $task.completion_time
     <tr>
       <th>Completed</th><td>$util.formatTimeLong($task.completion_time)</td>
     </tr>
+    #end if
     <tr>
       <th>Owner</th>
       <td>