#!/bin/sh

# EvoMaintenance script
# Dependencies (all OS): git postgresql-client
# Dependencies (Debian): sudo

# version 0.5.0.beta1
# Copyright 2007-2019 Evolix <info@evolix.fr>, Gregory Colpart <reg@evolix.fr>,
#                     Jérémy Lecour <jlecour@evolix.fr> and others.

VERSION="0.5.0.beta1"

show_version() {
    printf "%s\n" "evomaintenance version ${VERSION}"
}

show_help() {
    cat <<END
$(show_version)
Copyright 2007-2019 Evolix <info@evolix.fr>, Gregory Colpart <reg@evolix.fr>,
                    Jérémy Lecour <jlecour@evolix.fr> and others.

evomaintenance comes with ABSOLUTELY NO WARRANTY.  This is free software,
and you are welcome to redistribute it under certain conditions.
See the GNU General Public Licence for details.

evomaintenance is a program that helps reporting what you've done on a server

Usage: evomaintenance
  or   evomaintenance --message="add new host"
  or   evomaintenance --no-db --no-mail --no-commit
  or   echo "add new vhost | evomaintenance

Options
 -m, --message=MESSAGE       set the message from the command line
     --mail                  enable the mail hook
     --no-mail               disable the mail hook
     --db                    enable the database hook
     --no-db                 disable the database hook
     --commit                enable the commit hook
     --no-commit             disable the commit hook
 -v, --verbose               increase verbosity
 -n, --dry-run               actions are not executed
     --help                  print this message and exit
     --version               print version and exit
END
}

get_system() {
    uname -s
}

get_fqdn() {
    if [ "$(get_system)" = "Linux" ]; then
        hostname --fqdn
    elif [ "$(get_system)" = "OpenBSD" ]; then
        hostname
    else
        echo "OS not detected!"
        exit 1
    fi
}

get_tty() {
    if [ "$(get_system)" = "Linux" ]; then
        ps -o tty= | tail -1
    elif [ "$(get_system)" = "OpenBSD" ]; then
        env | grep SSH_TTY | cut -d"/" -f3
    else
        echo "OS not detected!"
        exit 1
    fi
}

get_who() {
    who=$(LC_ALL=C who -m)

    if [ -n "${who}" ]; then
        echo "${who}"
    else
        LC_ALL=C who | grep $(get_tty) | tr -s ' '
    fi
}

get_begin_date() {
    echo "$(date "+%Y") $(echo $(get_who) | cut -d" " -f3,4,5)"
}

get_ip() {
    ip=$(echo $(get_who) | cut -d" " -f6 | sed -e "s/^(// ; s/)$//")
    [ -z "${ip}" ] && ip="unknown (no tty)"
    [ "${ip}" = ":0" ] && ip="localhost"

    echo "${ip}"
}

get_end_date() {
    date +"%Y %b %d %H:%M"
}

get_now() {
    date +"%Y-%m-%dT%H:%M:%S%z"
}

get_complete_hostname() {
    REAL_HOSTNAME=$(get_fqdn)
    if [ "${HOSTNAME}" = "${REAL_HOSTNAME}" ]; then
        echo "${HOSTNAME}"
    else
        echo "${HOSTNAME} (${REAL_HOSTNAME})"
    fi
}

get_repository_status() {
    dir=$1
    # tell Git where to find the repository and the work tree (no need to `cd …` there)
    export GIT_DIR="${dir}/.git" GIT_WORK_TREE="${dir}"
    # If the repository and the work tree exist, try to commit changes
    if test -d "${GIT_DIR}" && test -d "${GIT_WORK_TREE}"; then
        CHANGED_LINES=$(${GIT_BIN} status --porcelain | wc -l | tr -d ' ')
        if [ "${CHANGED_LINES}" != "0" ]; then
            STATUS=$(${GIT_BIN} status --short | tail -n 10)
            printf "%s\n%s\n" "${GIT_DIR} (last 10 lines)" "${STATUS}" | sed -e '/^$/d'
        fi
    fi
    # unset environment variables to prevent accidental influence on other git commands
    unset GIT_DIR GIT_WORK_TREE
}

print_summary() {
  BLOB=$(cat <<END
Host      : $HOSTNAME_TEXT
User      : $USER
IP        : $IP
Begin     : $BEGIN_DATE
End       : $END_DATE
Message   : $MESSAGE
END
)
  printf "%s\n\n" "${BLOB}"
}

print_options() {
    cat <<END
********** Options ****************
MESSAGE: ${MESSAGE}
OPT_COMMIT: ${OPT_COMMIT}
OPT_DB: ${OPT_DB}
OPT_MAIL: ${OPT_MAIL}
DRY_RUN: ${DRY_RUN}
***********************************

END
}

hook_commit() {
    if test -x "${GIT_BIN}"; then
        # loop on possible directories managed by GIT
        for dir in ${GIT_REPOSITORIES}; do
            # tell Git where to find the repository and the work tree (no need to `cd …` there)
            export GIT_DIR="${dir}/.git" GIT_WORK_TREE="${dir}"
            # If the repository and the work tree exist, try to commit changes
            if test -d "${GIT_DIR}" && test -d "${GIT_WORK_TREE}"; then
                CHANGED_LINES=$(${GIT_BIN} status --porcelain | wc -l | tr -d ' ')
                if [ "${CHANGED_LINES}" != "0" ]; then
                    if [ "${DRY_RUN}" = "1" ]; then
                        STATS=$(${GIT_BIN} diff --stat | tail -1)
                        GIT_COMMITS=$(printf "%s\n%s : %s" "${GIT_COMMITS}" "${GIT_DIR}" "${STATS}" | sed -e '/^$/d')
                    else
                        ${GIT_BIN} add --all
                        ${GIT_BIN} commit --message "${MESSAGE}" --author="${USER} <${USER}@evolix.net>" --quiet
                        # Add the SHA to the log file if something has been committed
                        SHA=$(${GIT_BIN} rev-parse --short HEAD)
                        STATS=$(${GIT_BIN} show --stat | tail -1)
                        # append commit data, without empty lines
                        GIT_COMMITS=$(printf "%s\n%s : %s –%s" "${GIT_COMMITS}" "${GIT_DIR}" "${SHA}" "${STATS}" | sed -e '/^$/d')
                    fi
                fi
            fi
            # unset environment variables to prevent accidental influence on other git commands
            unset GIT_DIR GIT_WORK_TREE
        done
        if [ -n "${GIT_COMMITS}" ]; then
            if [ "${VERBOSE}" = "1" ]; then
                printf "\n\n********** Commits ****************\n%s\n***********************************\n" "${GIT_COMMITS}"
            fi
            if [ "${DRY_RUN}" != "1" ]; then
                echo "${GIT_COMMITS}" >> "${LOGFILE}"
            fi
        fi
    fi
}

hook_db() {
    SQL_DETAILS=$(echo "${MESSAGE}" | sed "s/'/''/g")
    PG_QUERY="INSERT INTO evomaint(hostname,userid,ipaddress,begin_date,end_date,details) VALUES ('${HOSTNAME}','${USER}','${IP}','${BEGIN_DATE}',now(),'${SQL_DETAILS}')"

    if [ "${VERBOSE}" = "1" ]; then
        printf "\n\n********** DB query **************\n%s\n***********************************\n" "${PG_QUERY}"
    fi
    if [ "${DRY_RUN}" != "1" ]; then
        echo "${PG_QUERY}" | psql "${PGDB}" "${PGTABLE}" -h "${PGHOST}"
    fi
}

hook_mail() {
    MAIL_TEXTE=$(echo "${MESSAGE}" | sed -e "s@/@\\\\\/@g ; s@&@\\\\&@")
    MAIL_GIT_COMMITS=$(echo "${GIT_COMMITS}" | sed -e "s@/@\\\\\/@g ; s@&@\\\\&@")
    MAIL_CONTENT=$(sed -e "s/__TO__/${EVOMAINTMAIL}/" \
                       -e "s/__HOSTNAME__/${HOSTNAME_TEXT}/" \
                       -e "s/__USER__/${USER}/" \
                       -e "s/__BEGIN_DATE__/${BEGIN_DATE}/" \
                       -e "s/__END_DATE__/${END_DATE}/" \
                       -e "s/__GIT_COMMITS__/${MAIL_GIT_COMMITS}/" \
                       -e "s/__TEXTE__/${MAIL_TEXTE}/" \
                       -e "s/__IP__/${IP}/" \
                       -e "s/__FULLFROM__/${FULLFROM}/" \
                       -e "s/__FROM__/${FROM}/" \
                       -e "s/__URGENCYFROM__/${URGENCYFROM}/" \
                       -e "s/__URGENCYTEL__/${URGENCYTEL}/" \
                       /usr/share/scripts/evomaintenance.tpl)

    if [ "${VERBOSE}" = "1" ]; then
        printf "\n\n********** Mail *******************\n%s\n***********************************\n" "${MAIL_CONTENT}"
    fi
    if [ "${DRY_RUN}" != "1" ]; then
        echo "${MAIL_CONTENT}" | ${SENDMAIL_BIN} -oi -t -f "${FROM}"
    fi
}

hook_log() {
  echo "----------- $(get_now) ---------------" >> "${LOGFILE}"
  echo "${BLOB}" >> "${LOGFILE}"
}

# load configuration if present.
test -f /etc/evomaintenance.cf && . /etc/evomaintenance.cf

[ -n "${HOSTNAME}" ]     || HOSTNAME=$(get_fqdn)
[ -n "${EVOMAINTMAIL}" ] || EVOMAINTMAIL=evomaintenance-$(echo "${HOSTNAME}" | cut -d- -f1)@${REALM}
[ -n "${LOGFILE}" ]      || LOGFILE=/var/log/evomaintenance.log

[ -n "${OPT_COMMIT}" ]   || OPT_COMMIT=1
[ -n "${OPT_DB}" ]       || OPT_DB=1
[ -n "${OPT_MAIL}" ]     || OPT_MAIL=1
[ -n "${DRY_RUN}" ]      || DRY_RUN=0
[ -n "${VERBOSE}" ]      || VERBOSE=0

# initialize variables
MESSAGE=""
GIT_COMMITS=""

# Parse options
# based on https://gist.github.com/deshion/10d3cb5f88a21671e17a
while :; do
    case $1 in
        -h|-\?|--help)
            show_help
            exit 0
            ;;
        --version)
            show_version
            exit 0
            ;;
        -m|--message)
            # message options, with value speparated by space
            if [ -n "$2" ]; then
                MESSAGE=$2
                shift
            else
                printf 'ERROR: "--message" requires a non-empty option argument.\n' >&2
                exit 1
            fi
            ;;
        --message=?*)
            # message options, with value speparated by =
            MESSAGE=${1#*=}
            ;;
        --message=)
            # message options, without value
            printf 'ERROR: "--message" requires a non-empty option argument.\n' >&2
            exit 1
            ;;
        --no-commit)
            # disable commit hook
            OPT_COMMIT=0
            ;;
        --commit)
            # enable commit hook
            OPT_COMMIT=1
            ;;
        --no-db)
            # disable DB hook
            OPT_DB=0
            ;;
        --db)
            # enable DB hook
            OPT_DB=1
            ;;
        --no-mail)
            # disable mail hook
            OPT_MAIL=0
            ;;
        --mail)
            # enable mail hook
            OPT_MAIL=1
            ;;
        -n|--dry-run)
            # disable actual commands
            DRY_RUN=1
            ;;
        -v|--verbose)
            # print verbose information
            VERBOSE=1
            ;;
        --)
            # End of all options.
            shift
            break
            ;;
        -?*)
            # ignore unknown options
            printf 'WARN: Unknown option (ignored): %s\n' "$1" >&2
            ;;
        *)
            # Default case: If no more options then break out of the loop.
            break
    esac

    shift
done

if [ "${VERBOSE}" = "1" ]; then
    print_options
fi

# Treat unset variables as an error when substituting.
# Only after this line, because some config variables might be missing.
set -u

# Gather information
HOSTNAME_TEXT=$(get_complete_hostname)
# TTY=$(get_tty)
# WHO=$(get_who)
IP=$(get_ip)
BEGIN_DATE=$(get_begin_date)
END_DATE=$(get_end_date)
USER=$(logname)

PATH=${PATH}:/usr/sbin

SENDMAIL_BIN=$(command -v sendmail)
GIT_BIN=$(command -v git)

GIT_REPOSITORIES="/etc /etc/bind"

# initialize variable
GIT_STATUSES=""
# git statuses
if test -x "${GIT_BIN}"; then
    # loop on possible directories managed by GIT
    for dir in ${GIT_REPOSITORIES}; do
        RESULT=$(get_repository_status "${dir}")
        if test -n "${RESULT}"; then
            # append diff data, without empty lines
            GIT_STATUSES=$(printf "%s\n%s\n" "${GIT_STATUSES}" "${RESULT}" | sed -e '/^$/d')
        fi
        unset RESULT
    done
fi

# find out if running in interactive mode, or not
if [ -t 0 ]; then
    INTERACTIVE=1
else
    INTERACTIVE=0
fi

if [ -z "${MESSAGE}" ] && [ "${INTERACTIVE}" = "1" ]; then
    # get input from stdin
    printf "> Please, enter details about your maintenance:\n"
    read -r MESSAGE
fi

if test -z "${MESSAGE}"; then
    echo "no value..."
    exit 1
fi

print_summary

# Log hook
if [ "${DRY_RUN}" != "1" ]; then
    hook_log
fi

# Commit hook
if [ "${INTERACTIVE}" = "1" ]; then
    if test -n "${GIT_STATUSES}" && [ "${OPT_COMMIT}" = "1" ]; then
        echo "/!\ There are some uncommited changes."
        echo "${GIT_STATUSES}"
        echo ""

        y="Y"; n="n"
        answer=""
        while true; do
            printf "> Do you want to commit the changes? [%s] " "${y}${n}"
            read -r answer
            case $answer in
                [Yy] )
                    hook_commit;
                    break
                    ;;
                [Nn] )
                    break
                    ;;
                "" )
                    if [ "${OPT_COMMIT}" = "1" ]; then
                      hook_commit
                    fi
                    break
                    ;;
                * )
                    echo "answer with a valid choice"
                    ;;
            esac
        done
    fi
else
    if [ "${OPT_COMMIT}" = "1" ]; then
        hook_commit
    fi
fi

# Database hook
if [ "${INTERACTIVE}" = "1" ]; then
    if [ "${OPT_DB}" = "1" ]; then
        y="Y"; n="n"
    else
        y="y"; n="N"
    fi
    answer=""
    while true; do
        printf "> Do you want to insert your message into the database? [%s] " "${y}${n}"
        read -r answer
        case $answer in
            [Yy] )
                hook_db;
                break
                ;;
            [Nn] )
                break
                ;;
            "" )
                if [ "${OPT_DB}" = "1" ]; then
                  hook_db
                fi
                break
                ;;
            * )
                echo "answer with a valid choice"
                ;;
        esac
    done
else
    if [ "${OPT_DB}" = "1" ]; then
        hook_db
    fi
fi

# Mail hook
if [ "${INTERACTIVE}" = "1" ]; then
    if [ "${OPT_MAIL}" = "1" ]; then
        y="Y"; n="n"
    else
        y="y"; n="N"
    fi
    answer=""
    while true; do
        printf "> Do you want to send an email to <%s>? [%s] " "${EVOMAINTMAIL}" "${y}${n}e"
        read -r answer
        case $answer in
            [Yy] )
                hook_mail;
                break
                ;;
            [Nn] )
                break
                ;;
            [Ee] )
                printf "> To: [%s] " "${EVOMAINTMAIL}"
                read -r mail_recipient
                if [ -n "${mail_recipient}" ]; then
                    EVOMAINTMAIL="${mail_recipient}"
                fi
                ;;
            "" )
                if [ "${OPT_MAIL}" = "1" ]; then
                    hook_mail
                fi
                break
                ;;
            * )
                echo "answer with a valid choice"
                ;;
        esac
    done
else
    if [ "${OPT_MAIL}" = "1" ]; then
        hook_mail
    fi
fi

exit 0