From e721c83e7b8744dae54878ab50ca495b2ff1f251 Mon Sep 17 00:00:00 2001
From: Tim Flink <tflink@fedoraproject.org>
Date: May 25 2016 06:18:58 +0000
Subject: make lookup of previous build more generic


---

diff --git a/libtaskotron/directives/koji_directive.py b/libtaskotron/directives/koji_directive.py
index be8d1b7..ea0f1f7 100644
--- a/libtaskotron/directives/koji_directive.py
+++ b/libtaskotron/directives/koji_directive.py
@@ -207,15 +207,17 @@ class KojiDirective(BaseDirective):
                     "The koji directive requires 'koji_build' for the 'download_latest_stable' "
                     "action. Detected arguments: %s" % detected_args)
 
-            name = rpm_utils.rpmformat(params['koji_build'], 'n')
-            disttag = rpm_utils.get_dist_tag(params['koji_build'])
-            # we need to do 'fc22' -> 'f22' conversion
-            tag = disttag.replace('c', '')
-
-            # first we need to check updates tag and if that fails, the latest
-            # stable nvr is in the base repo
-            tags = ['%s-updates' % tag, tag]
-            latest_stable_nvr = self.koji.latest_by_tag(tags, name)
+            #name = rpm_utils.rpmformat(params['koji_build'], 'n')
+            #disttag = rpm_utils.get_dist_tag(params['koji_build'])
+            ## we need to do 'fc22' -> 'f22' conversion
+            #tag = disttag.replace('c', '')
+
+            ## first we need to check updates tag and if that fails, the latest
+            ## stable nvr is in the base repo
+            #tags = ['%s-updates' % tag, tag]
+            #latest_stable_nvr = self.koji.latest_by_tag(tags, name)
+
+            latest_stable_nvr = self.koji.get_previous_build(params['koji_build'])
 
             output_data['downloaded_rpms'] = self.koji.get_nvr_rpms(
                 latest_stable_nvr, self.target_dir, arch_exclude=self.arch_exclude,
diff --git a/libtaskotron/ext/fedora/koji_utils.py b/libtaskotron/ext/fedora/koji_utils.py
index 3f7c54e..2bd447c 100644
--- a/libtaskotron/ext/fedora/koji_utils.py
+++ b/libtaskotron/ext/fedora/koji_utils.py
@@ -268,6 +268,43 @@ class KojiClient(object):
 
         return rpms
 
+    def get_previous_build(self, nvr):
+        '''The idea here is to find the previous build using a few assumptions
+        which I hope are valid.
+
+          1. there is a parent tag
+          2. the latest build in that parent tag is "the last build"
+
+        so we find the tag of input build, look for the parent tag of that build
+        and get the latest build in that tag for the same package.
+
+        This appears to work but has not been reviewed or hevily tested'''
+
+
+        build_info = self.session.getBuild(nvr)
+        build_tags = self.session.listTags(nvr)
+        # assuming that if there are multiple tags, they have the same parent
+
+        tagname = build_tags[0]['name']
+        buildnvr = None
+        while buildnvr is None:
+            parent_tags = self.session.getInheritanceData(tagname)
+
+            if len(parent_tags) == 0:
+                raise Exception("there were no parent tags!")
+
+            parent_tag = parent_tags[0]['name']
+
+            history = self.session.queryHistory(None, package=build_info['name'], tag=parent_tag)
+
+            # assuming these are sorted in reverse chronological order
+            if len(history['tag_listing']) > 0:
+                buildnvr = history['tag_listing'][0]
+                continue
+            tagname = parent_tag
+
+        return "{}-{}-{}".format(buildnvr['name'], buildnvr['version'], buildnvr['release'])
+
 
 def getNEVR(build):
     '''Extract RPM version identifier in NEVR format from Koji build object