#!/bin/sh

fullPage=6 # How many pages before a full refresh?

### Do not edit below this line unless you know what you are doing ###

read cvmPid < /var/run/cvm.pid
pCount=0
fullPage="$(($fullPage-1))"

trap "echo 0 > /sys/devices/platform/eink_fb.0/override_upd_mode ; echo 19 0 > /proc/eink_fb/update_display ; rm /var/run/flashdis.pid ; exit" SIGINT SIGTERM

if [[ ! -e "/var/run/flashdis.pid" ]]; then
    echo $$ > "/var/run/flashdis.pid"
else
    echo "Flash disabler is already running"
    exit 1
fi

update() {
    let pCount+=1
    ## Do a bunch of refreshes
    for i in 1 2 3 4 5 ; do
        echo 19 0 > /proc/eink_fb/update_display
        echo 0 > /sys/devices/platform/eink_fb.0/override_upd_mode
        echo 18 0 > /proc/eink_fb/update_display
        echo 1 > /sys/devices/platform/eink_fb.0/override_upd_mode
        echo 19 4 > /proc/eink_fb/update_display
        usleep 75000
    done

    ## Sets the next page turn to be a full refresh
    if [[ "$pCount" -ge "$fullPage" ]]; then
        echo 0 > /sys/devices/platform/eink_fb.0/override_upd_mode
        echo 19 0 > /proc/eink_fb/update_display
        pCount=0
    fi
}

bookCheck() {
    ## Check if cvm has a open file descriptor for a file in /mnt/us/documents/
    if [[ "$(realpath /proc/$cvmPid/fd/* 2> /dev/null | grep -c /mnt/us/documents/)" != "0" ]]; then
        update
    else
        echo 0 > /sys/devices/platform/eink_fb.0/override_upd_mode
        echo 19 0 > /proc/eink_fb/update_display
    fi
}

## Wait for page turn
while :; do
    case "$(waitforkey)" in
        191*|109*|104*|193*)
            bookCheck
        ;;
    esac
done