From 3be91bb320695ba24d6488cf6fb9ddde4853f030 Mon Sep 17 00:00:00 2001
From: Ant Zucaro <azucaro@gmail.com>
Date: Fri, 25 Nov 2016 09:15:18 -0500
Subject: [PATCH] Add a merge_servers function.

---
 functions/merge_servers.sql | 52 +++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 functions/merge_servers.sql

diff --git a/functions/merge_servers.sql b/functions/merge_servers.sql
new file mode 100644
index 0000000..f929064
--- /dev/null
+++ b/functions/merge_servers.sql
@@ -0,0 +1,52 @@
+create or replace function merge_servers(p_winner_server_id servers.server_id%TYPE, p_loser_server_id servers.server_id%TYPE) 
+RETURNS void as
+$$
+declare
+    rowcount integer;
+    w_server record;
+    l_server record;
+begin
+    raise notice 'Merging servers % and %', p_winner_server_id, p_loser_server_id;
+
+    select * into w_server from servers where server_id = p_winner_server_id;
+    select * into l_server from servers where server_id = p_loser_server_id;
+
+    -- hashkey check: if both have hashkeys and they are different, we
+    -- shouldn't merge them!
+    if w_server.hashkey is not null and l_server.hashkey is not null and w_server.hashkey != l_server.hashkey then
+        raise exception 'Both servers have hashkeys and they are different! Not merging.';
+    end if;
+
+    -- fill in the "important" missing attributes
+    if w_server.ip_addr is null and l_server.ip_addr is not null then
+        w_server.ip_addr := l_server.ip_addr;
+    end if;
+
+    if w_server.hashkey is null and l_server.hashkey is not null then
+        w_server.hashkey := l_server.hashkey;
+    end if;
+
+    if w_server.revision is null and l_server.revision is not null then
+        w_server.revision := l_server.revsion;
+    end if;
+
+    -- games get moved to the new server
+    update games set server_id = p_winner_server_id where server_id = p_loser_server_id;
+
+    get diagnostics rowcount = ROW_COUNT;
+    raise notice '% game rows updated.', rowcount;
+
+    -- update attributes rescued from the losing server
+    update servers set
+        ip_addr = w_server.ip_addr,
+        hashkey = w_server.hashkey,
+        revision = w_server.revision
+    where server_id = p_winner_server_id;
+
+    -- now deactivate the old server
+    update servers set active_ind = false where server_id = p_loser_server_id;
+
+    raise notice 'Server #% deactivated.', p_loser_server_id;
+end;
+$$
+language plpgsql;
-- 
2.39.2