#!/usr/bin/env bash

# Add the current ejabberd node in a cluster

# copyright (c) 2010-2015 ProcessOne

# Return Code:
#  0 : groovy baby
# 10 : ejabberdctl not found
# 11 : erl not found
# 12 : erlc not found
# 20 : database dir can not be created 
# 21 : database dir not writable
# 22 : temporary dir can not be created
# 30 : network issue
# 31 : node names incompatibility

function error
{
    echo "Error: $1" >&2
    exit $2
}

[ -z $NO_WARNINGS ] && {
    echo "--------------------------------------------------------------------"
    echo ""
    echo "ejabberd cluster configuration"
    echo ""
    echo "This ejabberd node will be configured for use in an ejabberd cluster."
    echo "IMPORTANT: all local data from the database will be lost, and"
    echo "cluster database will be initialized. All data from the master"
    echo "node will be replicated to this one."
    echo ""
    echo "--------------------------------------------------------------------"
    echo "Press any key to continue, or Ctrl+C to stop now"
    read foo
    echo ""
}

[ $# -eq 0 ] && {
    echo "Make sure you have a running remote master ejabberd node"
    echo "Before continuing, you must copy the ~/.erlang.cookie file from"
    echo "remote master node and check ejabberd.cfg compatibility."
    echo "e.g. hosts definition must match on all nodes"
    echo ""
    echo "The remote master node name is defined as ERLANG_NODE into"
    echo "ejabberdctl.cfg on that remote node."
    echo ""
    echo -n "Remote master node name: "
    read REMOTE
    echo ""
} || {
    echo "Using passed parameter for remote master node name: $1"
    REMOTE=$1
}

PA=/tmp/clustersetup_$$
CTL=$(which ejabberdctl)
[ -x "$CTL" ] || {
  HERE=`which "$0"`
  BASE=`dirname $HERE`/..
  ROOTDIR=`cd $BASE; pwd`
  PATH=$ROOTDIR/bin:$PATH
  PA=$ROOTDIR/clustersetup_$$
  CTL=$(which ejabberdctl)
}
echo "Using commands:"
[ -x "$CTL" ] && echo $CTL || error "can't find ejabberdctl" 10

. $CTL stop 2>/dev/null >/dev/null
ERLC=${ERL}c

[ -x $ERL ] && echo $ERL || error "can't find erl"  11
[ -x $ERLC ] && echo $ERLC || error "can't find erlc" 12
echo ""

NAME=-name
[ "$ERLANG_NODE" = "${ERLANG_NODE%.*}" ] && NAME=-sname
CLUSTERSETUP=clustersetup
CLUSTERSETUP_ERL=$PA/$CLUSTERSETUP.erl

REMOTENAME=-name
[ "$REMOTE" = "${REMOTE%.*}" ] && REMOTENAME=-sname
[ "$REMOTENAME" = "$NAME" ] || {
    echo "IMPORTANT!: node names are incompatible"
    echo "Remote node name is $REMOTE"
    echo "Local node name is $ERLANG_NODE"
    echo ""
    echo "Both node names must be short or fqdn names."
    echo "Using short and fqdn names is impossible."
    echo ""
    error "incompatible node names" 31
}

set -o errexit
set -o nounset

[ -d $SPOOL_DIR ] && rm -Rf $SPOOL_DIR/* || mkdir -p $SPOOL_DIR || error "$SPOOL_DIR cannot be created" 20
[ -w $SPOOL_DIR ] || error "$SPOOL_DIR directory is not writable" 21
mkdir -p $PA || error "$PA cannot be created" 22
cd $PA
cat <<EOF > $CLUSTERSETUP_ERL
-module($CLUSTERSETUP).

-export([start/0]).

set_table_copy(Table, _Node, {badrpc, Reason}) ->
    io:format("Error: cannot get storage type for table ~p on node $REMOTE:~n ~p~n",[Table, Reason]);
set_table_copy(Table, Node, Type) ->
    io:format("setting table ~p to mode ~p~n",[Table, Type]),
    case mnesia:add_table_copy(Table, Node, Type) of
    {aborted, _} ->
        mnesia:change_table_copy_type(Table, Node, Type);
    _ ->
        ok
    end.

set_tables({badrpc, Reason}) ->
    io:format("ERROR: cannot get tables list on $REMOTE : ~p~n",[Reason]);
set_tables([]) ->
    ok;
set_tables([schema | Tables]) ->
    set_tables(Tables);
set_tables([s2s | Tables]) ->
    set_tables(Tables);
set_tables([session | Tables]) ->
    set_tables(Tables);
set_tables([Table | Tables]) ->
    set_table_copy(Table, node(),
                   rpc:call('$REMOTE', mnesia, table_info, [Table, storage_type])),
    set_tables(Tables).

start() ->
    io:format("~n",[]),
    R = case net_adm:ping('$REMOTE') of
        pong ->
            set_table_copy(schema, node(), disc_copies),
            set_tables(rpc:call('$REMOTE', mnesia, system_info, [tables])),
            0;
        pang ->
            io:format("node ~p is not reachable, please check epmd port, and FIREWALL_WINDOW ports~n", ['$REMOTE']),
            1
    end,
    halt(R).
EOF

$ERLC -o $PA $CLUSTERSETUP_ERL
$ERL $NAME $ERLANG_NODE -pa $PA $KERNEL_OPTS -mnesia extra_db_nodes "['$REMOTE']" dir "\"$SPOOL_DIR\"" -s mnesia -s $CLUSTERSETUP start
cd -
rm -Rf $PA

echo "End."
echo "Check that there is no error in the above messages."