#!/usr/bin/sh
#----------------------------------------------------------------------------
# /usr/sbin/service - system service control wrapper
#
# Creation:     2022-10-01  dv
# Last Update:  $Id$
#
# Copyright (c) 2003-@@YEAR@@ the eisfair team, team(at)eisfair(dot)org
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#----------------------------------------------------------------------------

# include eislib
. /var/install/include/eislib

SYSTEMCTL="/usr/bin/systemctl"
RCDIR="/etc/rc2.d"
INITDIR="/etc/init.d"

# system V management functions

is_sysvscript()
{
    test -f "/etc/init.d/${1}"
    return $?
}

sysv_is_enabled()
{
    local package="${1}"
    local start_script=$(ls ${RCDIR}/S??${package} 2>/dev/null)
    test -n "${start_script}"
    return $?
}

sysv_is_active()
{
    local package="${1}"
    sysv_command "${package}" "status" > /dev/null
    return $?
}

sysv_enable()
{
    local package="${1}"
    if ! sysv_is_enabled ${package}
    then
        local kill_script=$(ls ${RCDIR}/K??${package} 2>/dev/null)

        if [ -z "${kill_script}" ]
        then
            # failed to enable sysv script
            return 1
        fi

        local stop_seq=$(basename "${kill_script}" | grep -o -E '[0-9]+' | head -n1)
        local start_seq=$((100 - stop_seq))

        local start_script="${RCDIR}/S${start_seq}${package}"

        ln -sr "${INITDIR}/${package}" "${start_script}"
        return $?
    fi
    return 0
}

sysv_disable()
{
    local package="${1}"
    if sysv_is_enabled "${package}"
    then
        local start_script=$(ls ${RCDIR}/S??${package} 2>/dev/null)
        rm -f "${start_script}"
        return $?
    fi
    return 0
}

sysv_command()
{
    "${INITDIR}/${1}" "${2}"
    return $?
}


# systemd management functions

is_systemd_installed()
{
    test -f "${SYSTEMCTL}"
    return $?
}

is_systemd_service()
{
    if is_systemd_installed
    then
        local state=$(${SYSTEMCTL} --full --no-legend --no-pager --type=service --property=LoadState show "${1}" 2>/dev/null)
        test "$state" = "LoadState=loaded"
        return $?
    fi
    return 1
}

systemd_is_enabled()
{
    ${SYSTEMCTL} is-enabled "${1}" >/dev/null 2>&1
    return $?
}

systemd_is_active()
{
    ${SYSTEMCTL} is-active "${1}" >/dev/null 2>&1
    return $?
}

systemd_enable()
{
    local package="${1}"
    if ! systemd_is_enabled ${package}
    then
        ${SYSTEMCTL} enable "${package}" >/dev/null 2>&1
        return $?
    fi
    return 0
}

systemd_disable()
{
    local package="${1}"
    if systemd_is_enabled "${package}"
    then
        ${SYSTEMCTL} disable "${package}" >/dev/null 2>&1
        return $?
    fi
    return 0
}

systemd_command()
{
    ${SYSTEMCTL} ${no_pager} "${2}" "${1}"
    return $?
}

systemd_get_service_description()
{
    if is_systemd_service "${package}"
    then
        local desc="$(${SYSTEMCTL} cat ${package} | grep Description | cut -f2 -d= | sed 's/^LSB: //1')"
        if [ -z "${desc}" ]
        then
            case "${package}" in
            *.*)
                echo "${package}"
                ;;
            *)
                echo "${package}.service"
                ;;
            esac
        else
            echo "${desc}"
        fi
    fi
}


# general command handlers

enable()
{
    local packages="${1}"
    local package
    local result=0

    for package in ${packages}
    do
        if is_sysvscript "${package}"
        then
            if ! sysv_enable "${package}"
            then
                result=1
            fi
        fi

        if is_systemd_service "${package}"
        then
            if ! systemd_enable "${package}"
            then
                result=1
            fi
        fi
    done

    return ${result}
}

disable()
{
    local packages="${1}"
    local package
    local result=0

    for package in ${packages}
    do
        if is_sysvscript "${package}"
        then
            if ! sysv_disable "${package}"
            then
                result=1
            fi
        fi

        if is_systemd_service "${package}"
        then
            if ! systemd_disable "${package}"
            then
                result=1
            fi
        fi
    done

    return ${result}
}

issue_command()
{
    local package="${1}"
    local command="${2}"
    local result=0

    if is_sysvscript "${package}"
    then
        if ! sysv_command "${package}" "${command}"
        then
            result=1
        fi
    else
        if is_systemd_service "${package}" &&
           ! systemd_command "${package}" "${command}"
        then
            result=1
        fi
    fi
    return ${result}
}

issue_commands()
{
    local packages="${1}"
    local command="${2}"
    local verbose="${3}"
    local action="${4}"
    local package
    local result=0

    for package in ${packages}
    do
        local desc="$(systemd_get_service_description ${package})"

        if [ "${verbose}" = true ] && [ -n "${desc}" ]
        then
            echo " * ${action} ${desc} ..."

            if ! issue_command "${package}" "${command}"
            then
                mecho --fail
                result=1
            else
                mecho --ok
            fi
        else
            if ! issue_command "${package}" "${command}"
            then
                result=1
            fi
        fi
    done
    return ${result}
}

issue_sysv_command()
{
    local packages="${1}"
    local command="${2}"
    local package
    local result=0

    for package in ${packages}
    do
        if is_sysvscript "${package}"
        then
            if ! sysv_command "${package}" "${command}"
            then
                result=1
            fi
        else
            if is_systemd_service "${package}"
            then
                echo "\"${command}\" is invalid for \"${package}\"!" >&2
            else
                echo "\"${package}\" is not a valid service!" >&2
            fi
            result=1
        fi
    done
    return ${result}
}

# function returns success if at least one of the packages is a service
is_service()
{
    local packages="${1}"
    local package

    for package in ${packages}
    do
        if is_sysvscript "${package}"
        then
            return 0
        fi

        if is_systemd_service "${package}"
        then
            return 0
        fi
    done
    return 1
}

# function returns success if at least one of the packages is enabled
is_enabled()
{
    local packages="${1}"
    local package

    for package in ${packages}
    do
        if is_sysvscript "${package}" &&
           sysv_is_enabled "${package}"
        then
            return 0
        fi

        if is_systemd_service "${package}" &&
           systemd_is_enabled "${package}"
        then
            return 0
        fi
    done

    return 1
}

# function returns success if at least one of the packages is active
is_active()
{
    local packages="${1}"
    local package

    for package in ${packages}
    do
        if is_sysvscript "${package}" &&
           sysv_is_active "${package}"
        then
            return 0
        fi

        if is_systemd_service "${package}" &&
           systemd_is_active "${package}"
        then
            return 0
        fi
    done

    return 1
}

show_message()
{
    if [ -n "${1}" ]
    then
        mecho --info "$1 ..."
    fi
}

# command line help

show_help()
{
cat <<EOF

Control system services

usage:
    service [OPTIONS] COMMAND PACKAGE [PACKAGE]*

options:
    --quiet           don't show text output (only effective for
                      systemd's start, stop, restart ... commands)
    --msg=<msg>       message to be displayed
    --help            show this help screen

possible values for COMMAND:
    is-service    check whether a package name denotes a service
    is-enabled    check whether a service is enabled
    is-active     check whether a service is running / active
    enable        enable a service for autostart
    disable       disable a service for autostart
    start         manually start a service
    stop          manually stop a service
    restart       manually stop and restart a service
    try-restart   restart service only if it is already running
    status        show status of a service
    reload        reload configuration files
    daemon-reload reloads unit files (only effective when
                  systemd is installed)
EOF
}

main()
{
    local verbose=false
    local message=""
    no_pager=''

    # since systemctl prints no output by itself, we do it locally
    # when systemd is installed. This default behaviour can be changed
    # using --quiet switch
    if is_systemd_installed
    then
        verbose=true
    fi

    # read option switches
    while [ "${1:0:2}" = "--" ]
    do
        case ${1} in
        --help)
            shift
            show_help
            exit 0
            ;;
        --quiet)
            shift
            verbose=false
            ;;
        --msg)
            shift
            if [ "${1}" != "" -a "${1:0:2}" != "--" ]
            then
                message="${1}"
                shift
            else
                echo 'error: missing argument for --msg!' >&2
                show_help
                exit 1
            fi
            ;;
        --msg=*)
            message="${1:6}"
            shift
            ;;
        *)
            echo "error: invalid command line switch \"$1\"!" >&2
            show_help
            exit 1
            ;;
        esac
    done

    # check for sufficient command line arguments
    local action="${1}"
    if [ "${action}" = "daemon-reload" ] && [ "$#" -ne 1 ]
    then
        show_help
        exit 1
    elif [ "${action}" != "daemon-reload" ] && [ "$#" -lt 2 ]
    then
        show_help
        exit 1
    fi

    shift

    local packages=""
    while [ "$#" -gt 0 ]
    do
        packages="${packages} ${1}"
        shift
    done

    case "${action}" in
    "daemon-reload")
        if is_systemd_installed
        then
            show_message "${message}"
            ${SYSTEMCTL} daemon-reload >/dev/null 2>&1
            exit $?
        fi
        ;;
    "is-service")
        show_message "${message}"
        if is_service "${packages}"
        then
            exit 0
        fi
        exit 1
        ;;
    "is-enabled")
        show_message "${message}"
        if is_enabled "${packages}"
        then
            exit 0
        fi
        exit 1
        ;;
    "is-active")
        show_message "${message}"
        if is_active "${packages}"
        then
            exit 0
        fi
        exit 1
        ;;
    "start")
        show_message "${message}"
        issue_commands "${packages}" "start" "${verbose}" "Starting"
        ;;
    "stop")
        show_message "${message}"
        issue_commands "${packages}" "stop" "${verbose}" "Stopping"
        ;;
    "restart")
        show_message "${message}"
        issue_commands "${packages}" "restart" "${verbose}" "Restarting"
        ;;
    "try-restart")
        show_message "${message}"
        issue_commands "${packages}" "try-restart" "${verbose}" "Restarting (try)"
        ;;
    "status")
        no_pager='--no-pager --full'
        show_message "${message}"
        issue_commands "${packages}" "status" "false" ""
        ;;
    "reload")
        show_message "${message}"
        issue_commands "${packages}" "reload" "${verbose}" "Reloading"
        ;;
    "force-reload")
        show_message "${message}"
        issue_commands "${packages}" "force-reload" "${verbose}" "Reloading (forced)"
        ;;
    "enable")
        show_message "${message}"
        enable "${packages}"
        ;;
    "disable")
        show_message "${message}"
        disable "${packages}"
        ;;
    *)
        show_message "${message}"
        issue_sysv_command "${packages}" "${action}"
        ;;
    esac
}

main "${@}"