#! /bin/sh -e

# @configure_input@

# Licensed 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.

SCRIPT_OK=0
SCRIPT_ERROR=1

INTERACTIVE_BOOLEAN=false
BACKGROUND_BOOLEAN=false
KILL_BOOLEAN=false
SHUTDOWN_BOOLEAN=false
RECURSED_BOOLEAN=false

RESPAWN_TIMEOUT=0

LIB_DIRECTORY=%pkgstatelibdir%
LOG_DIRECTORY=%pkgstatelogdir%

INI_FILE=%pkgconfdir%/couch.ini
PID_FILE=%localstatedir%/run/couchdb.pid

STDOUT_FILE=couchdb.stdout
STDERR_FILE=couchdb.stderr

HEART_COMMAND="%bindir%/%couchdb_command_name% -k"
HEART_BEAT_TIMEOUT=11

basename=$(basename $0)

display_version () {
    # Display version and copyright information.

    cat << EOF
$basename - %package_name% %version%

Licensed 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.
EOF
 }

display_help () {
    # Display a short description of the script's behaviour.

    cat << EOF
Usage: $basename [OPTION]

The $basename command runs the %package_name% server.

Erlang inherits the environment of this command.

The exit status is 0 for success or 1 for failure.

The \`-s' option will exit 0 for running and 1 for not running.

Options:

  -h          display a short help message and exit
  -V          display version information and exit
  -c FILE     set the configuration FILE (defaults to $INI_FILE)
  -i          use the interactive Erlang shell
  -b          spawn as a background process
  -p FILE     set the background PID FILE (defaults to $PID_FILE)
  -r SECONDS  respawn background process after SECONDS (defaults to no respawn)
  -o FILE     redirect background stdout to FILE (defaults to $STDOUT_FILE)
  -e FILE     redirect background stderr to FILE (defaults to $STDERR_FILE)
  -s          display the status of the background process
  -k          kill the background process, will respawn if needed
  -d          shutdown the background process

Report bugs at <%bug_uri%>.
EOF
}

display_error () {
    # Display a short instruction referring users to further documentation.

    if test -n "$1"; then
        echo $1 >&2
    fi
    echo >&2
    echo "Try \`"$basename" -h' for more information." >&2
    exit $SCRIPT_ERROR
}

_load_configuration () {
    # Load ini configuration and overwrite default variables.

    dbrootdir_ini_value=$(awk -F = "/^DbRootDir=/{print \$2}" < $INI_FILE)
    if test -n "$dbrootdir_ini_value"; then
        LIB_DIRECTORY=$dbrootdir_ini_value
    fi
    logfile_ini_value=$(awk -F = "/^LogFile=/{print \$2}" < $INI_FILE)
    if test -n "$logfile_ini_value"; then
        LOG_DIRECTORY=$(dirname $logfile_ini_value)
    fi
}

_get_pid () {
    if test -f $PID_FILE; then
        PID=$(cat $PID_FILE)
    fi
    echo $PID
}

check_status () {
    # Check the status of the running Apache CouchDB process.

    PID=$(_get_pid)
    if test -n "$PID"; then
        if kill -0 $PID 2> /dev/null; then
            echo "Apache CouchDB is running as process $PID. Time to relax."
            return $SCRIPT_OK
        else
            echo >&2 << EOF
Apache CouchDB is not running but a stale PID file exists: $PID_FILE"
EOF
        fi
    else
        echo "Apache CouchDB is not running." >&2
    fi
    return $SCRIPT_ERROR
}

check_environment () {
    # Check the environment for common problems to prevent nasty backtraces.

    message_prefix="Apache CouchDB needs write permission on the"
    if test ! -w $LIB_DIRECTORY; then
        echo "$message_prefix data directory: $LIB_DIRECTORY" >&2
        exit $SCRIPT_ERROR
    fi
    if test ! -w $LOG_DIRECTORY; then
        echo "$message_prefix log directory: $LOG_DIRECTORY" >&2
        exit $SCRIPT_ERROR
    fi
    message_prefix="Apache CouchDB needs write permission on data file"
    for file in $(find $LIB_DIRECTORY -type f); do
        if test ! -w $file; then
            echo "$message_prefix: $file" >&2
            exit $SCRIPT_ERROR
        fi
    done
    message_prefix="Apache CouchDB needs write permission on log file"
    for file in $(find $LOG_DIRECTORY -type f); do
        if test ! -w $file; then
            echo "$message_prefix: $file" >&2
            exit $SCRIPT_ERROR
        fi
    done
    if test "$BACKGROUND_BOOLEAN" = "true"; then
        touch $PID_FILE 2> /dev/null || true
        touch $STDOUT_FILE 2> /dev/null || true
        touch $STDERR_FILE 2> /dev/null || true
        message_prefix="Apache CouchDB needs write permission on the"
        if test ! -w $PID_FILE; then
            echo "$message_prefix PID file: $PID_FILE" >&2
            exit $SCRIPT_ERROR
        fi
        if test ! -w $STDOUT_FILE; then
            echo "$message_prefix STDOUT file: $STDOUT_FILE" >&2
            exit $SCRIPT_ERROR
        fi
        if test ! -w $STDERR_FILE; then
            echo "$message_prefix STDERR file: $STDERR_FILE" >&2
            exit $SCRIPT_ERROR
        fi
        message_prefix="Apache CouchDB needs a regular"
        if ! echo 2> /dev/null >> $PID_FILE; then
            echo "$message_prefix PID file: $PID_FILE" >&2
            exit $SCRIPT_ERROR
        fi
        if ! echo 2> /dev/null >> $STDOUT_FILE; then
            echo "$message_prefix STDOUT file: $STDOUT_FILE" >&2
            exit $SCRIPT_ERROR
        fi
        if ! echo 2> /dev/null >> $STDERR_FILE; then
            echo "$message_prefix STDERR file: $STDERR_FILE" >&2
            exit $SCRIPT_ERROR
        fi
    fi
}

start_couchdb () {
    # Start Apache CouchDB with the Erlang interpreter.

    if test ! "$RECURSED_BOOLEAN" = "true"; then
        if check_status 2> /dev/null; then
            exit $SCRIPT_OK
        fi
        check_environment
    fi
    interactive_option="+Bd -noinput"
    if test "$INTERACTIVE_BOOLEAN" = "true"; then
        interactive_option=""
    fi
    if test "$BACKGROUND_BOOLEAN" = "true"; then
        touch $PID_FILE
        interactive_option="+Bd -noinput"
    fi
    command="`%ICU_CONFIG% --invoke` \
        %ERL% $interactive_option -smp auto -sasl errlog_type error \
        -pa %erlanglibdir%/couch-%version%/ebin \
            %erlanglibdir%/mochiweb-r76/ebin \
        -eval \"application:load(inets)\" \
        -eval \"application:load(crypto)\" \
        -eval \"application:load(couch)\" \
        -eval \"crypto:start()\" \
        -eval \"inets:start()\" \
        -eval \"couch_server:start(), receive done -> done end.\" \
        -couchini $INI_FILE"
    if test "$BACKGROUND_BOOLEAN" = "true" \
        -a "$RECURSED_BOOLEAN" = "false"; then
        # Recursively call and detach a duplicate couchdb command.
        $0 -c $INI_FILE -b -r $RESPAWN_TIMEOUT -p $PID_FILE \
            -o $STDOUT_FILE -e $STDERR_FILE -R &
        echo "Apache CouchDB has started. Time to relax."
    else
        if test "$RECURSED_BOOLEAN" = "true"; then
            while true; do
                export HEART_COMMAND
                export HEART_BEAT_TIMEOUT
                $(eval $command -pidfile $PID_FILE -heart \
                    > $STDOUT_FILE 2> $STDERR_FILE) || true
                PID=$(_get_pid)
                if test -n "$PID"; then
                    if kill -0 $PID 2> /dev/null; then
                        # Found an existing process, do not respawn.
                        return $SCRIPT_ERROR
                    fi
                    # Stale PID file, we should respawn.
                else
                    # No PID file, do not respawn.
                    return $SCRIPT_OK
                fi
                if test "$RESPAWN_TIMEOUT" = "0"; then
                    # RESPAWN_TIMEOUT is zero, do not respawn.
                    return $SCRIPT_OK
                fi
                if test "$RESPAWN_TIMEOUT" != "1"; then
                    plural_ending="s"
                fi
                cat << EOF
Apache CouchDB crashed, restarting in $RESPAWN_TIMEOUT second$plural_ending.
EOF
                sleep $RESPAWN_TIMEOUT
            done
        else
            eval exec $command
        fi
    fi
}

stop_couchdb () {
    # Send SIGHUP to the running Apache CouchDB process.

    PID=$(_get_pid)
    if test -n "$PID"; then
        # Clean up PID file or leave stale for respawn.
        if test "$1" = "false"; then
            echo > $PID_FILE
        fi
        if kill -0 $PID 2> /dev/null; then
            if kill -1 $PID 2> /dev/null; then
                if test "$1" = "false"; then
                    echo "Apache CouchDB has been shutdown."
                else
                    echo "Apache CouchDB has been killed."
                fi
                return $SCRIPT_OK
            else
                echo "Apache CouchDB could not be killed." >&2
                return $SCRIPT_ERROR
            fi
            if test "$1" = "false"; then
                echo "Stale PID file exists but Apache CouchDB is not running."
            else
                echo "Stale PID file existed but Apache CouchDB is not running."
            fi
        fi
    else
        echo "Apache CouchDB is not running."
    fi
}

parse_script_option_list () {
    # Parse the script option list and take the appropriate action.

    if ! argument_list=$(getopt hVc:ibp:r:Ro:e:skd $@); then
        display_error
    fi
    eval set -- "$argument_list"
    while [ $# -gt 0 ]; do
        case "$1" in
            -h) shift; display_help; exit $SCRIPT_OK;;
            -V) shift; display_version; exit $SCRIPT_OK;;
            -c) shift; INI_FILE=$1; shift;;
            -i) shift; INTERACTIVE_BOOLEAN=true;;
            -b) shift; BACKGROUND_BOOLEAN=true;;
            -r) shift; RESPAWN_TIMEOUT=$1; shift;;
            -R) shift; RECURSED_BOOLEAN=true;;
            -p) shift; PID_FILE=$1; shift;;
            -o) shift; STDOUT_FILE=$1; shift;;
            -e) shift; STDERR_FILE=$1; shift;;
            -s) shift; check_status; exit $SCRIPT_OK;;
            -k) shift; KILL_BOOLEAN=true;;
            -d) shift; SHUTDOWN_BOOLEAN=true;;
            --) shift; break;;
            *) display_error "Unknown option: $1" >&2;;
        esac
    done
    _load_configuration
    if test "$KILL_BOOLEAN" = "true" -o "$SHUTDOWN_BOOLEAN" = "true"; then
        stop_couchdb $KILL_BOOLEAN
    else
        start_couchdb
    fi
}

parse_script_option_list $@