#!/bin/sh
#
# Manage LeoFS servers.
#

#-------------------------------------------------------------------------------
# GLOBALS
#-------------------------------------------------------------------------------
LEOFS_SERVERS="
  gateway
  manager
  manager_slave
  storage
"

LEOFS_COMMANDS=
LEOFS_COMMANDS_MINIHELP=

PROGNAME=$(basename $0)
PROGPATH=$(realpath $0)

#-------------------------------------------------------------------------------
# Functions
#-------------------------------------------------------------------------------
in_list()
{
    local needle=$1
    local i

    shift

    for i
    do
        test "$i" = "$needle" && return 0
    done

    return 1
}

#-------------------------------------------------------------------------------
usage()
{
    local servers

    servers=$(echo $LEOFS_SERVERS | sed -e 's/ /|/g')

    echo "usage: ${PROGNAME} [help | -h | --help]"
    echo "       ${PROGNAME} ${servers} <command> [<args>]"
    echo
    echo "Commands:"
    echo "$LEOFS_COMMANDS_MINIHELP"
    echo
    echo "See '${PROGNAME} help <command>' for more information on a specific command."
}

#-------------------------------------------------------------------------------
# cmd utils
#-------------------------------------------------------------------------------
register_cmd()
{
    local cmd=$1

    LEOFS_COMMANDS="${LEOFS_COMMANDS} ${cmd}"
    LEOFS_COMMANDS_MINIHELP=$(printf "%s\n  %-16s%s" \
        "${LEOFS_COMMANDS_MINIHELP}" "${cmd}" "$(cmd_${cmd} help_summary)")
}

#-------------------------------------------------------------------------------
check_cmd()
{
    local cmd=$1

    if ! in_list "$cmd" $LEOFS_COMMANDS
    then
        echo "unknown command: $1" >&2
        echo  >&2
        usage >&2
        exit 1
    fi
}

#-------------------------------------------------------------------------------
run_cmd()
{
    local cmd=$1

    check_cmd "${cmd}"

    shift

    "cmd_${cmd}" "$@"
}

#-------------------------------------------------------------------------------
print_cmd_help()
{
    local cmd=$1
    local desc

    check_cmd "${cmd}"

    echo "NAME"
    echo "  ${cmd} - $(cmd_${cmd} help_summary)"
    echo
    echo "SYNOPSIS"
    echo "  $(cmd_${cmd} help_synopsis)"

    desc="$(cmd_${cmd} help_desc)"

    if [ -n "${desc}" ]
    then
        echo
        echo "DESCRIPTION"
        echo -n "${desc}" | sed -e 's/^/  /'
    fi

    opts="$(cmd_${cmd} help_opts)"

    if [ -n "${opts}" ]
    then
        echo
        echo "OPTIONS"
        echo -n "${opts}" | sed -e 's/^/  /'
    fi

    echo
}

#-------------------------------------------------------------------------------
# make ENV
#-------------------------------------------------------------------------------
check_app()
{
    local app=$1

    if ! in_list "${app}" $LEOFS_SERVERS
    then
        echo "unknown server: $1" >&2
        echo  >&2
        usage >&2
        exit 1
    fi
}

#-------------------------------------------------------------------------------
setusercontext()
{
    local cmd

    : ${LEOFS_USER=%%LEOFS_USER%%}

    user=`whoami`

    if [ ${user} = ${LEOFS_USER} ]
    then
        return
    fi

    if [ ${user} != root ]
    then
        echo "Must be run as ${LEOFS_USER} user or root (or set LEOFS_USER)" >&2
        exit 1
    fi

    # Restart as LEOFS_USER
   
    cmd="${PROGPATH} $@"

    exec /usr/bin/su -m ${LEOFS_USER} -c "${cmd}"
}

#-------------------------------------------------------------------------------
gen_config()
{
    local args cfg_dir app_config vm_args res snmp_cfg dir

    cfg_dir=${LEOFS_DBDIR}/etc

    mkdir -p ${cfg_dir}

    if [ ${LEOFS_ETCDIR}/${LEOFS_SERVER}.conf -ot ${cfg_dir}/app.config ]
    then
        return
    fi

    rm -f ${cfg_dir}/app.*.config ${cfg_dir}/vm.*.args

    args=`PATH=${ERTS_PATH}:${PATH} \
        ${LEOFS_BASEDIR}/bin/cuttlefish \
        -i ${LEOFS_BASEDIR}/etc/${LEOFS_SERVER}.schema \
        -c ${LEOFS_ETCDIR}/${LEOFS_SERVER}.conf \
        -d ${cfg_dir}`

    app_config=`echo ${args} | sed -nEe 's/^.*(app\.[0-9.]*\.config).*$/\1/p'`
    vm_args=`echo ${args} | sed -nEe 's/^.*(vm\.[0-9.]*\.args).*$/\1/p'`

    if [ -z "${app_config}" -o -z "${vm_args}" ]
    then
        echo "Failed to parse ${LEOFS_SERVER}.conf" >&2
        exit 1
    fi

    # Sanity check the app.config file
    res=`${ERTS_PATH}/escript \
        ${ERTS_PATH}/nodetool chkconfig ${cfg_dir}/${app_config}`
    if [ "${res}" != "ok" ]
    then
        echo "Error reading ${app_config}: ${res}" >&2 
        exit 1
    fi

    mv ${cfg_dir}/$app_config ${cfg_dir}/app.config
    mv ${cfg_dir}/$vm_args ${cfg_dir}/vm.args
}


#-------------------------------------------------------------------------------
make_env()
{
    local app=${1#leo_} # Remove 'leo_' prefix in server name if present.
    local user

    check_app "${app}"

    LEOFS_SERVER=leo_${app}

    LEOFS_ETCDIR=%%LEOFS_ETCDIR%%
    LEOFS_BASEDIR=%%LEOFS_BASEDIR%%
    LEOFS_DBDIR=%%LEOFS_DBDIR%%/${LEOFS_SERVER}
    LEOFS_RUNDIR=%%LEOFS_RUNDIR%%
    LEOFS_PIPE=${LEOFS_RUNDIR}/${LEOFS_SERVER}.pipe
    LEOFS_LOGDIR=%%LEOFS_LOGDIR%%/${LEOFS_SERVER}

    START_ERL=`cat ${LEOFS_BASEDIR}/releases/${LEOFS_SERVER%_slave}/start_erl.data`
    ERTS_VSN=${START_ERL% *}
    APP_VSN=${START_ERL#* }
    ERTS_PATH=${LEOFS_BASEDIR}/erts-${ERTS_VSN}/bin

    : ${ERLEXEC_MODE=embedded}

    LEOFS_BOOT=${LEOFS_BASEDIR}/releases/${LEOFS_SERVER%_slave}/${APP_VSN}/${LEOFS_SERVER%_slave}

    HOME=%%LEOFS_DBDIR%%
    cd ${HOME}

    setusercontext "$@"

    gen_config

    snmp_cfg=`sed -nEe 's/^-config *(.*)$/\1.config/p' ${LEOFS_DBDIR}/etc/vm.args`

    sed -nEe 's:^.*dir, *"((%%LEOFS_DBDIR%%|%%LEOFS_LOGDIR%%)[^"]*)".*$:\1:p' \
        ${LEOFS_DBDIR}/etc/app.config ${snmp_cfg} | sort -u |
    while read dir
    do
        mkdir -p "${dir}"
    done
}

#-------------------------------------------------------------------------------
# Erlang tools
#-------------------------------------------------------------------------------
nodetool()
{
    local cmd=$1 ; shift
    local vmargs_path name_arg cookie_arg

    vmargs_path=${LEOFS_DBDIR}/etc/vm.args

    name_arg=`egrep '^-s?name' ${vmargs_path}`
    if [ -z "${name_arg}" ]
    then
        echo "vm.args needs either -name or -sname parameter" >&2 
        exit 1
    fi

    cookie_arg=`grep '^-setcookie' ${vmargs_path}`
    if [ -z "${cookie_arg}" ]
    then
        echo "vm.args needs a -setcookie parameter" 2>&2
        exit 1
    fi

    ${ERTS_PATH}/escript ${ERTS_PATH}/nodetool ${name_arg} ${cookie_arg} ${cmd}
}

#-------------------------------------------------------------------------------
check_node()
{
    local expected_state=$1
    local status

    nodetool ping >/dev/null 2>&1
    status=$?
     
    if [ "${expected_state}" = DOWN ]
    then
        if [ ${status} -eq 0 ]
        then
            echo "Node is already running" >&2
            exit 1
        fi
    else
        if [ ${status} -ne 0 ]
        then
            echo "Node is not running" >&2
            exit 1
        fi
    fi
}

#-------------------------------------------------------------------------------
remsh()
{
    local vmargs_path name_arg cookie_arg
    local remsh_type remsh_name remsh_name_arg remsh_remsh_arg

    vmargs_path=${LEOFS_DBDIR}/etc/vm.args

    name_arg=`egrep '^-s?name' ${vmargs_path}`
    if [ -z "${name_arg}" ]
    then
        echo "vm.args needs either -name or -sname parameter" >&2 
        exit 1
    fi

    cookie_arg=`grep '^-setcookie' ${vmargs_path}`
    if [ -z "${cookie_arg}" ]
    then
        echo "vm.args needs a -setcookie parameter" 2>&2
        exit 1
    fi

    # Extract the name type and name from the name_arg for remsh
    remsh_type=${name_arg% *}
    remsh_name=${name_arg#* }

    # `date +%s` is used to allow multiple remsh to the same node transparently
    remsh_name_arg="${remsh_type} remsh$(date +%s)@${remsh_name#*@}"
    remsh_remsh_arg="-remsh ${remsh_name}"

    ${ERTS_PATH}/erl ${remsh_name_arg} ${remsh_remsh_arg} ${cookie_arg}
}

#-------------------------------------------------------------------------------
# Commands
#-------------------------------------------------------------------------------
cmd_help()
{
    case "$1" in
        help_summary)
            echo "Display help information about ${PROGNAME}"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} help [<command>]"
            exit
            ;;
        help_desc)
            echo "With no command given, the synopsis of the ${PROGNAME} command"
            echo "and a list of possible ${PROGNAME} commands are printed on the"
            echo "standard output."
            echo
            echo "If a ${PROGNAME} command is named, a mini help for that command is"
            echo "brought up."
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    if [ -n "$1" ]
    then
        print_cmd_help "$1"
    else
        usage
    fi
}

register_cmd help

#-------------------------------------------------------------------------------
cmd_attach()
{
    case "$1" in
        help_summary)
            echo "Attach to the running node"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} <server> attach"
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    check_node UP

    ${ERTS_PATH}/to_erl ${LEOFS_PIPE}
}

register_cmd attach

#-------------------------------------------------------------------------------
cmd_console()
{
    local config_path vmargs_path cmd

    case "$1" in
        help_summary)
            echo "Start the server in console"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} <server> console"
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    export ROOTDIR=${LEOFS_BASEDIR}
    export BINDIR=${ERTS_PATH}
    export EMU=beam
    export PROGNAME=${PROGNAME}

    config_path=${LEOFS_DBDIR}/etc/app.config
    vmargs_path=${LEOFS_DBDIR}/etc/vm.args

    cmd="${BINDIR}/erlexec -boot ${LEOFS_BOOT} -mode ${ERLEXEC_MODE} \
        -config ${config_path} -args_file ${vmargs_path} -- console $@"

    # Dump environment info for logging purposes
    echo Exec: ${cmd}
    echo Root: ${ROOTDIR}

    ${cmd}
}

register_cmd console

#-------------------------------------------------------------------------------
cmd_console_clean()
{
    case "$1" in
        help_summary)
            echo "Start the VM in console using start_clean.boot"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} <server> cosole_clean"
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    LEOFS_BOOT=$(dirname ${LEOFS_BOOT})/start_clean

    cmd_console
}

register_cmd console_clean

#-------------------------------------------------------------------------------
cmd_ping()
{
    case "$1" in
        help_summary)
            echo "See if the VM is alive"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} <server> ping"
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    nodetool ping
}

register_cmd ping

#-------------------------------------------------------------------------------
cmd_reboot()
{
    case "$1" in
        help_summary)
            echo "Restart the VM completely (uses heart to restart it)"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} <server> reboot"
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    nodetool reboot
}

register_cmd reboot

#-------------------------------------------------------------------------------
cmd_remote_console()
{
    case "$1" in
        help_summary)
            echo "Run remote shell command to control node"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} <server> remote_console"
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    check_node UP

    remsh "$@"
}

register_cmd remote_console

#-------------------------------------------------------------------------------
cmd_restart()
{
    case "$1" in
        help_summary)
            echo "Restart the VM without exiting the process"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} <server> restart"
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    nodetool restart
}

register_cmd restart

#-------------------------------------------------------------------------------
cmd_start()
{
    local i res

    case "$1" in
        help_summary)
            echo "Launch the application"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} <server> start"
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    check_node DOWN

    export HEART_COMMAND="${PROGPATH} ${LEOFS_SERVER} start"

    ${ERTS_PATH}/run_erl -daemon ${LEOFS_PIPE} ${LEOFS_LOGDIR} \
        "exec ${PROGPATH} ${LEOFS_SERVER} console $@" 2>&1
    res=$?

    if [ "${res}" -ne 0 ]
    then
        exit ${res}
    fi

    # Wait up to 1 minute for the node to start responding on ping.
    for i in `jot 60`
    do
        nodetool ping >/dev/null 2>&1 || exit 0
        sleep 1
    done
    exit 1
}

register_cmd start

#-------------------------------------------------------------------------------
cmd_stop()
{
    local pid res i

    case "$1" in
        help_summary)
            echo "Stop the application"
            exit
            ;;
        help_synopsis)
            echo "${PROGNAME} <server> stop"
            exit
            ;;
        help_*)
            exit
            ;;
    esac

    pid=`ps xww -o pid= -o command= |
        grep "${LEOFS_BASEDIR}.*/[b]eam.*${LEOFS_SERVER}" |
        awk '{print $1}'`

    nodetool stop > /dev/null
    res=$?

    if [ "${res}" -ne 0 ]
    then
        if [ -z "${pid}" ]
        then
            echo "${LEOFS_SERVER} is not running"
        else
            echo "Failed to stop ${LEOFS_SERVER}"
        fi
        exit ${res}
    fi

    # Wait up to 1 minute for the process to terminate.
    for i in `jot 60`
    do
        kill -0 ${pid} 2>/dev/null || exit 0
        sleep 1
    done
    echo "Failed to terminate the ${LEOFS_SERVER} process (pid ${pid})"
    exit 1
}

register_cmd stop

#-------------------------------------------------------------------------------
# Main
#-------------------------------------------------------------------------------
if in_list "$1" "" "help" "-h" "--help" || test -z "$2"
then
    cmd=help ; shift
else
    make_env "$@"

    app="$1" ; shift
    cmd="$1" ; shift
fi

run_cmd "${cmd}" "$@"