%% -------------------------------------------------------------------
%%
%% Copyright (c) 2012 Basho Technologies, Inc.
%%
%% Newer versions of Riak may use different on-disk formats of riak.
%% When performing a rolling downgrade, the downgraded nodes may not
%% be able to read the newer on-disk format. This tests that riak_kv_format
%% correctly downgrades the on-disk format on a node while performing a
%% rolling downgrade.
%%
%% This file is provided to you under the Apache License,
%% Version 2.0 (the "License"); you may not use this file
%% except in compliance with the License.  You may obtain
%% a copy of the License at
%%
%%   http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing,
%% software distributed under the License is distributed on an
%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
%% KIND, either express or implied.  See the License for the
%% specific language governing permissions and limitations
%% under the License.
%%
%% -------------------------------------------------------------------
-module(verify_riak_object_reformat).
-behaviour(riak_test).
-export([confirm/0]).
-include_lib("eunit/include/eunit.hrl").

-define(N, 3).

confirm() ->
    rt:update_app_config(all, [{riak_kv, [{object_format, v1}]}]),
    TestMetaData = riak_test_runner:metadata(),
    DowngradeVsn = proplists:get_value(upgrade_version, TestMetaData, previous),
    Nodes = [Node1|_] = rt:build_cluster(?N),

    [rt:wait_until_capability(N, {riak_kv, object_format}, v1, v0) || N <- Nodes],

    lager:info("Writing 100 keys in format v1 to ~p", [Node1]),
    rt:systest_write(Node1, 100, ?N),
    ?assertEqual([], rt:systest_read(Node1, 100, ?N)),
    lager:info("100 keys successfully written to ~p", [Node1]),

    %% TODO: introduce some handoff
    [begin
         lager:info("Reformatting objects and downgrading ~p", [Node]),
         run_reformat(Node, Node =:= Node1), %% wait for handoffs on one node, kill on rest
         [rt:wait_until_capability(N, {riak_kv, object_format}, v0, v0) || N <- Nodes],
         rt:upgrade(Node, DowngradeVsn), %% use upgrade to downgrade
         rt:wait_for_service(Node, riak_kv),
         lager:info("Ensuring keys still readable on ~p", [Node]),
         ?assertEqual([], rt:systest_read(Node, 100, ?N))
     end || Node <- Nodes],
    ok.

run_reformat(Node, KillHandoffs) ->
    {_Success, _Ignore, Error} = rpc:call(Node,
                                          riak_kv_reformat,
                                          run,
                                          [v0, [{kill_handoffs, KillHandoffs}]]),
    ?assertEqual(0, Error),
    ok.