#!/bin/bash
# chmod +x mjpg-streamer.sh
# Crontab: @reboot /home/pi/mjpg-streamer/mjpg-streamer.sh start
# Crontab: @reboot /home/pi/mjpg-streamer/mjpg-streamer-experimental/mjpg-streamer.sh start

MJPG_STREAMER_BIN="/usr/local/bin/mjpg_streamer"  # "$(dirname $0)/mjpg_streamer"
MJPG_STREAMER_WWW="/usr/local/share/mjpg-streamer/www"
MJPG_STREAMER_LOG_FILE="${0%.*}.log"  # "$(dirname $0)/mjpg-streamer.log"
RUNNING_CHECK_INTERVAL="2" # how often to check to make sure the server is running (in seconds)
HANGING_CHECK_INTERVAL="3" # how often to check to make sure the server is not hanging (in seconds)

VIDEO_DEV="/dev/video0"
FRAME_RATE="5"
QUALITY="80"
RESOLUTION="1280x720"  # 160x120 176x144 320x240 352x288 424x240 432x240 640x360 640x480 800x448 800x600 960x544 1280x720 1920x1080 (QVGA, VGA, SVGA, WXGA)   #  lsusb -s 001:006 -v | egrep "Width|Height" # https://www.textfixer.com/tools/alphabetical-order.php  # v4l2-ctl --list-formats-ext  # Show Supported Video Formates
PORT="8081"
YUV="yes"

################INPUT_OPTIONS="-r ${RESOLUTION} -d ${VIDEO_DEV} -f ${FRAME_RATE} -q ${QUALITY} -pl 60hz"
INPUT_OPTIONS="-r ${RESOLUTION} -d ${VIDEO_DEV} -q ${QUALITY} -pl 60hz --every_frame 2"  # Limit Framerate with  "--every_frame ", ( mjpg_streamer --input "input_uvc.so --help" )


if [ "${YUV}" == "true" ]; then
	INPUT_OPTIONS+=" -y"
fi

OUTPUT_OPTIONS="-p ${PORT} -w ${MJPG_STREAMER_WWW}"

# ==========================================================
function running() {
    if ps aux | grep ${MJPG_STREAMER_BIN} | grep ${VIDEO_DEV} >/dev/null 2>&1; then
        return 0

    else
        return 1

    fi
}

function start() {
    if running; then
        echo "[$VIDEO_DEV] already started"
        return 1
    fi

    export LD_LIBRARY_PATH="$(dirname $MJPG_STREAMER_BIN):."

	echo "Starting: [$VIDEO_DEV] ${MJPG_STREAMER_BIN} -i \"input_uvc.so ${INPUT_OPTIONS}\" -o \"output_http.so ${OUTPUT_OPTIONS}\""
    ${MJPG_STREAMER_BIN} -i "input_uvc.so ${INPUT_OPTIONS}" -o "output_http.so ${OUTPUT_OPTIONS}" >> ${MJPG_STREAMER_LOG_FILE} 2>&1 &

    sleep 1

    if running; then
        if [ "$1" != "nocheck" ]; then
            check_running & > /dev/null 2>&1 # start the running checking task
            check_hanging & > /dev/null 2>&1 # start the hanging checking task
        fi

        echo "[$VIDEO_DEV] started"
        return 0

    else
        echo "[$VIDEO_DEV] failed to start"
        return 1

    fi
}

function stop() {
    if ! running; then
        echo "[$VIDEO_DEV] not running"
        return 1
    fi

    own_pid=$$

    if [ "$1" != "nocheck" ]; then
        # stop the script running check task
        ps aux | grep $0 | grep start | tr -s ' ' | cut -d ' ' -f 2 | grep -v ${own_pid} | xargs -r kill
        sleep 0.5
    fi

    # stop the server
    ps aux | grep ${MJPG_STREAMER_BIN} | grep ${VIDEO_DEV} | tr -s ' ' | cut -d ' ' -f 2 | grep -v ${own_pid} | xargs -r kill

    echo "[$VIDEO_DEV] stopped"
    return 0
}

function check_running() {
    echo "[$VIDEO_DEV] starting running check task" >> ${MJPG_STREAMER_LOG_FILE}

    while true; do
        sleep ${RUNNING_CHECK_INTERVAL}

        if ! running; then
            echo "[$VIDEO_DEV] server stopped, starting" >> ${MJPG_STREAMER_LOG_FILE}
            start nocheck
        fi
    done
}

function check_hanging() {
    echo "[$VIDEO_DEV] starting hanging check task" >> ${MJPG_STREAMER_LOG_FILE}

    while true; do
        sleep ${HANGING_CHECK_INTERVAL}

        # treat the "error grabbing frames" case
        if tail -n2 ${MJPG_STREAMER_LOG_FILE} | grep -i "error grabbing frames" > /dev/null; then
            echo "[$VIDEO_DEV] server is hanging, killing" >> ${MJPG_STREAMER_LOG_FILE}
            stop nocheck
        fi
    done
}

function help() {
    echo "Usage: $0 [start|stop|restart|status]"
    return 0
}

if [ "$1" == "start" ]; then
    start && exit 0 || exit -1

elif [ "$1" == "stop" ]; then
    stop && exit 0 || exit -1

elif [ "$1" == "restart" ]; then
    stop && sleep 1
    start && exit 0 || exit -1

elif [ "$1" == "status" ]; then
    if running; then
        echo "[$VIDEO_DEV] running"
        exit 0

    else
        echo "[$VIDEO_DEV] stopped"
        exit 1

    fi

else
    help

fi
