From c586da1c3705746afe52fdb776c1862766a5579c Mon Sep 17 00:00:00 2001
From: Jan Kaluza <jkaluza@redhat.com>
Date: Jan 30 2018 10:17:00 +0000
Subject: Deduplicate the composes.odcs_compose_id before creating the unique index.


---

diff --git a/freshmaker/migrations/versions/e06434b3ef5e_add_unique_constraint_to_compose_odcs_.py b/freshmaker/migrations/versions/e06434b3ef5e_add_unique_constraint_to_compose_odcs_.py
index 73e7bc6..8f31159 100644
--- a/freshmaker/migrations/versions/e06434b3ef5e_add_unique_constraint_to_compose_odcs_.py
+++ b/freshmaker/migrations/versions/e06434b3ef5e_add_unique_constraint_to_compose_odcs_.py
@@ -12,15 +12,67 @@ down_revision = 'b17231ee8220'
 
 from alembic import op
 import sqlalchemy as sa
+from sqlalchemy import text
+
+from freshmaker import db
 
 
 def upgrade():
-    # ### commands auto generated by Alembic - please adjust! ###
+    connection = op.get_bind()
+
+    # There might be duplicated odcs_compose_ids in a composes table, so at
+    # first find them.
+    result = connection.execute(
+        text(
+            'SELECT odcs_compose_id FROM composes '
+            'GROUP BY odcs_compose_id HAVING COUNT(*) > 1'
+        )
+    )
+
+    # For every duplicate compose, merge the compose records together.
+    for row in result:
+        odcs_compose_id = row[0]
+
+        # Find out all the DB ids of duplicated this odcs_compose_id.
+        compose_ids = connection.execute(
+            text(
+                'SELECT id FROM composes '
+                'WHERE odcs_compose_id = :odcs_compose_id'
+            ).bindparams(odcs_compose_id=odcs_compose_id)
+        ).fetchall()
+
+        # compose_ids should be always have at least two rows here, because
+        # we have only duplicated composes here...
+        # Use the first compose id as a main one.
+        main_compose_id = compose_ids[0][0]
+        # Others will be merged with main compose and removed later.
+        composes_to_merge = [row[0] for row in compose_ids[1:]]
+
+        # For each ArtifactBuild, update the compose_id from id in
+        # "composes_to_merge" to "main_compose_id".
+        # Then remove the merged compose from 'composes' table
+        for compose_to_merge_id in composes_to_merge:
+            artifact_builds = connection.execute(
+                text(
+                    'UPDATE artifact_build_composes '
+                    'SET compose_id = :main_compose_id '
+                    'WHERE compose_id = :compose_to_merge_id'
+                ).bindparams(main_compose_id=main_compose_id,
+                             compose_to_merge_id=compose_to_merge_id)
+            )
+
+            connection.execute(
+                text(
+                    'DELETE FROM composes '
+                    'WHERE id = :compose_to_merge_id'
+                ).bindparams(compose_to_merge_id=compose_to_merge_id)
+            )
+
     op.create_index('idx_odcs_compose_id', 'composes', ['odcs_compose_id'], unique=True)
-    # ### end Alembic commands ###
 
 
 def downgrade():
-    # ### commands auto generated by Alembic - please adjust! ###
+    # We do not deduplicate data on downgrade, because we cannot get
+    # the original state and the duplicates were bug in database handling
+    # anyway.
     op.drop_index('idx_odcs_compose_id', table_name='composes')
-    # ### end Alembic commands ###