#!/bin/bash

API_BASE_URL=https://labmanager-api.edu-al.unipmn.it/api/1.0
MAX_RETRY=5
RETRY_DELAY=5
NORMAL_CONFIG_NAME=normale
DEBUG=0

# Sysadmin can override local vars here:
CONFFILE=/etc/sysconfig/labmanager

#  Load configuration override if present:
if [ -e ${CONFFILE} ]; then
    . ${CONFFILE}
fi

if [[ "-d" == "$2" ]]; then
    DEBUG=1
fi

# execute a task and on fail execute it again MAX_RETRY times every RETRY_DELAY seconds
function retry {
    local n=1
    local max=$MAX_RETRY
    local delay=$RETRY_DELAY
    while true; do
        "$@"
        if [[ $? == 0 ]]; then
            break
        else
            if [[ $n -lt $max ]]; then
                ((n++))
                echo "Failed. Attempt $n/$max..." >&2
                sleep $delay;
            else
                echo "Command failed after $n attempts." >&2
                exit 1
            fi
        fi
    done
}

function debug() {
    if [[ "${DEBUG}" == 1 ]]; then
        echo >&2 "$@"
    fi
}

# authenticate and get the token
function getTokenJSON() {
    # store the whole response with the status at the end
    HTTP_RESPONSE=$(curl -s -k -w "HTTPSTATUS:%{http_code}" --max-time 10 -X POST -H "Content-Type: application/json" -d "{\"login\":\"guest\",\"pwd\":\"\"}" ${API_BASE_URL}/login)
    ret=$?

    if [[ $ret != 0 ]]; then
        echo "Invalid authentication request!"
        return $ret
    fi

    # extract the status
    HTTP_STATUS=$(echo "$HTTP_RESPONSE" | tr -d '\n' | sed -e 's/.*HTTPSTATUS://')

    # check the status
    if [[ $HTTP_STATUS -ne 200  ]]; then
        echo "Authentication failed!"
        return 1
    else
        # extract the body
        HTTP_BODY=$(echo "$HTTP_RESPONSE" | sed -e 's/HTTPSTATUS\:.*//g')
        echo $HTTP_BODY
    fi
}


# extract a value from a JSON structure
function jsonValue() {
    KEY=$1
    num=$2
    awk -F"[,:}]" '{for(i=1;i<=NF;i++){if($i~/\042'$KEY'\042/){print $(i+1)}}}' | tr -d '"' | sed -n ${num}p
}


stop() {
    if [[ "$1" == "bootstop" ]]; then
        echo "STOP esame-get-config-boot"
    else
        echo "STOP esame-get-config"
    fi
}


# get configuration from WS
getConfigVars() {
    echo "Authenticating to WS..."
    TOKEN_JSON=`retry getTokenJSON`
    if [[ "$TOKEN_JSON" == "" ]]; then
        return 2
    fi
    TOKEN=`echo ${TOKEN_JSON} | jsonValue token 1`
    MACHINE_NAME=`hostname`
    echo "Getting machine configuration..."
    MACHINE_JSON=`retry /usr/bin/curl -s -k --max-time 10 -H "Authorization: Bearer ${TOKEN}" -X GET ${API_BASE_URL}/machines/name/${MACHINE_NAME}`
    MACHINE_ID=`echo $MACHINE_JSON | jsonValue id 1`
    MACHINE_CONFIGS_ID=`echo $MACHINE_JSON | jsonValue configs_id 1`
    CONFIG_NAME=`echo $MACHINE_JSON | jsonValue name 2`

    if [[ "$CONFIG_NAME" == "" ]]; then
        echo "Error fetching machine configuration!"
        return 1
    fi

    MACHINE_CONFIGS_ID_PREV=''
    CONFIG_NAME_PREV=''
    if [[ -e /local/config_name ]]
    then
        CONFIG_NAME_PREV=`cat /local/config_name`
    fi
}


getConfigFile() {
    echo "Downloading machine config file..."
    # get configuration file
    if [[ "${MACHINE_ID}" == "" ]]; then
        echo "Error downloading config file (machine_id empty, maybe it is not in LabManager's DB)"
        return 1
    fi
    HTTP_STATUS=`retry /usr/bin/curl -s -k -w "%{http_code}" -o /local/esame-machine.conf --max-time 10 --header "Authorization: Bearer ${TOKEN}" -X GET ${API_BASE_URL}/machines/${MACHINE_ID}/configfile`
    if [[ $HTTP_STATUS -ne 200 ]]
    then
        echo "Error downloading config file (http_status=$HTTP_STATUS)"
        return 1
    else
        echo "Downloaded config file (http_status=$HTTP_STATUS)"
    fi
}


getIpConfigFile() {
    echo "Downloading machine iptables config file..."
    # get ipconfig file
    HTTP_STATUS=`retry /usr/bin/curl -s -k -w "%{http_code}" -o /local/iptables --max-time 10 --header "Authorization: Bearer ${TOKEN}" -X GET ${API_BASE_URL}/machines/${MACHINE_ID}/ipconfigfile`
    if [[ $HTTP_STATUS -ne 200 ]]
    then
        echo "Error downloading iptables config file (http_status=$HTTP_STATUS)"
        return 1
    else
        echo "Downloaded iptables config file (http_status=$HTTP_STATUS)"
    fi
}


updateCurrentConfigId() {
    # Update this machine's current config id
    HTTP_STATUS=`/usr/bin/curl -s -k -w "%{http_code}" -o /dev/null --max-time 10 -H "Content-Type: application/json" -H "Authorization: Bearer ${TOKEN}" \
        -X PUT -d "{\"current_configs_id\":\"$MACHINE_CONFIGS_ID\"}" ${API_BASE_URL}/machines/${MACHINE_ID}/currentconfig`

    if [[ $HTTP_STATUS -ne 200 ]]
    then
        echo "Error updating current config (http_status=$HTTP_STATUS)"
        exit 1
    else
        echo "Updated current config (http_status=$HTTP_STATUS)"
    fi
}

function getConfig() {
    getConfigVars
    while [[ $? != 0 ]]; do
        echo "Error fetching machine info!"
        echo "If this is a new machine, did you add it into labmanager-admin?"
        sleep 30;
        getConfigVars
    done

    # back config files up
    cp -f /local/esame-machine.conf /local/esame-machine.conf.prev >/dev/null 2>&1
    cp -f /local/iptables /local/iptables.prev >/dev/null 2>&1

    getConfigFile
    if [[ $? != 0 ]]; then
        echo "Error fetching machine config file!"
        return 1
    fi

    getIpConfigFile
    if [[ $? != 0 ]]; then
        echo "Error fetching machine iptables file!"
        return 1
    fi
    return 0
}

start() {
    if [[ "$1" == "boot" ]]; then
        echo "START esame-get-config-boot"
    else
        echo "START esame-get-config"
    fi

    getConfig
    RESULT=$?

    #echo "TOKEN_JSON: $TOKEN_JSON"
    #echo "TOKEN: $TOKEN"
    #echo "MACHINE_NAME: $MACHINE_NAME"
    #echo "MACHINE_JSON: $MACHINE_JSON"
    #echo "MACHINE_ID: $MACHINE_ID"
    #echo "MACHINE_CONFIGS_ID: $MACHINE_CONFIGS_ID"
    #echo "MACHINE_CONFIGS_ID_PREV: $MACHINE_CONFIGS_ID_PREV"
    if [[ -n "$CONFIG_NAME" ]]; then
        echo "Configuration: $CONFIG_NAME"
    fi

    if [[ $RESULT != 0 ]]; then
        if [[ "$1" == "boot" ]]; then
            echo "Fatal error(s): aborting esame and switching machine to normal state..."
            # reset and remove exam configuration files
            echo "$NORMAL_CONFIG_NAME" > /local/config_name
            rm /local/esame-machine.conf >/dev/null 2>&1
            rm /local/esame-machine.conf.prev >/dev/null 2>&1
            rm /local/iptables >/dev/null 2>&1
            rm /local/iptables.prev >/dev/null 2>&1
            rm /local/mk-homedir >/dev/null 2>&1
            /usr/bin/systemctl start graphical.target && exit 0
        fi
        echo "Fatal error(s): missing or wrong web service reply, abort."
        exit 1
    fi

    # configuration profile is changed
    if [[ "$CONFIG_NAME" != "$CONFIG_NAME_PREV" ]]
    then
        # update config_name file
        echo "${CONFIG_NAME}" > /local/config_name

        # no exam, set normal target
        if [[ "$CONFIG_NAME" == "$NORMAL_CONFIG_NAME" ]]
        then
            # stop some services to revert system files
            rm /local/esame-machine.conf >/dev/null 2>&1
            rm /local/esame-machine.conf.prev >/dev/null 2>&1
            rm /local/iptables >/dev/null 2>&1
            rm /local/iptables.prev >/dev/null 2>&1
            rm /local/mk-homedir >/dev/null 2>&1
	    echo "Normal!"
            #systemctl isolate graphical && exit 0
            /usr/bin/systemctl reboot
            #--force
        else
            echo "Exam!"
            touch /local/mk-homedir
	          #systemctl isolate esame.target && exit 0
            /usr/bin/systemctl reboot
            #--force
        fi
    else
        # at boot time choose the correct target
        if [[ "$1" == "boot" ]]
        then
            # we have just rebooted, update the current configuration via web service
            updateCurrentConfigId
            case "$CONFIG_NAME" in
                $NORMAL_CONFIG_NAME) # normal
                    systemctl start graphical.target && exit 0
                    ;;
                'kiosk-dir' | 'kiosk-dir-esami' | 'kiosk-escher' | 'kiosk-freebrowsing' | 'kiosk-teco') # kiosk mode
                    systemctl start esamekiosk.target && exit 0
                    ;;
                'show') # show mode, an exam mode with no limitations on USB ports and network
                    systemctl start esameshow.target && exit 0
                    ;;
                *) # all full desktop exams
                    systemctl start esame.target && exit 0
                    ;;
            esac
        fi
    fi

    # Runtime parameters
    if [[ "$CONFIG_NAME" != "$NORMAL_CONFIG_NAME" ]]
    then
        # check if parameters are changed
        cmp --silent /local/esame-machine.conf /local/esame-machine.conf.prev
        if [[ $? -ne 0 ]]
        then
            /usr/bin/systemctl daemon-reload
            echo "Configuration parameters changed: restart some services... "
            # restart some exam services
            #echo -n "USB..."
            #/usr/bin/systemctl restart esame-usb
            #echo " done."
            KIOSK_URL_CHANGED=$(diff /local/esame-machine.conf /local/esame-machine.conf.prev  | grep ESAME_KIOSK_URL -c)
            if [[ $KIOSK_URL_CHANGED -ne 0 ]]
            then
                echo -n "Firefox Home..."
                FIREFOX_PID=$(pgrep firefox)
                if [[ "${FIREFOX_PID}" != "" ]]
                then
                    FIREFOX_USER=$(ps -o user= -p ${FIREFOX_PID})
                    rm -f /local/${FIREFOX_USER}/.mozilla/firefox/44bu2eyb.default/lock
                    pkill firefox
                    sleep 2
                    /usr/bin/systemctl restart esame-firefox-home
                    echo " done."
                    # no way to restart firefox, I must miss something :(
                    #echo -n "Restarting Firefox..."
                    #su - ${FIREFOX_USER} -c 'nohup /usr/bin/firefox --display=:0.0 &'
                    #echo " done."
                else
                    /usr/bin/systemctl restart esame-firefox-home
                    echo " done."
                fi
            fi
            echo
            echo "All done."
        fi
    fi
}


args=("$@")

case "$1" in
'bootstart')
    start "boot"
    ;;
'bootstop')
    stop "boot"
    ;;
'start')
    start
    ;;
'stop')
    stop
    ;;
'restart')
    stop
    start
    ;;
*)
    echo "Usage: $0 { bootstart | bootstop | start | stop | restart }";
    exit 1;
    ;;
esac
exit 0