#!/bin/bash
: '
 @vendor    Chorke Academia, Inc.
 @web       https://cdn.chorke.org/docs/academia
 @version   1.0.00
 @since     1.0.00
'

:<<EOF
if [ -x "$(command -v curl)" ];then \
sudo apt -qq update;\
bash <(curl -s 'https://cdn.chorke.org/exec/cli/bash/install/virtual-display/2023-02-06-debian.sh.txt')
else printf 'curl \033[0;31mnot found! \033[0m:(\n';fi
EOF


function validate(){
    # check existence of xdpyinfo
    if [ ! -x "$(command -v xdpyinfo)" ];then
        printf 'xdpyinfo \033[0;31mnot found! \033[0m:(\n';exit 1
    fi

    # check existence of x11vnc
    if [ ! -x "$(command -v x11vnc)" ];then
        printf 'x11vnc \033[0;31mnot found! \033[0m:(\n';exit 1
    fi

    # check existence of xrandr
    if [ ! -x "$(command -v xrandr)" ];then
        printf 'xrandr \033[0;31mnot found! \033[0m:(\n';exit 1
    fi

    # check existence of cvt
    if [ ! -x "$(command -v cvt)" ];then
        printf 'cvt \033[0;31mnot found! \033[0m:(\n';exit 1
    fi
}

function setting(){
    PRIMARY_DISPLAY=$(xrandr|sed -n "s/\(\w*\)\s*connected\s*primary.*/\1/p")
    VIRTUAL_HEIGHT=$(xdpyinfo|grep -oP 'dimensions:\s+\K\S+'|cut -d 'x' -f2)
    VIRTUAL_WIDTH=$(xdpyinfo|grep -oP 'dimensions:\s+\K\S+'|cut -d 'x' -f1)
    VIRTUAL_POSITION='--right-of'
    VIRTUAL_DISPLAY='VIRTUAL1'

    VIRTUAL_MODE_LINE=$(cvt  "${VIRTUAL_WIDTH}" "${VIRTUAL_HEIGHT}" 60)
    VIRTUAL_MODE_NAME=$(echo "${VIRTUAL_MODE_LINE}"|sed -n "s/^.*Modeline\s*\"\(.*\)\".*/\1/p")
    VIRTUAL_MODE_DESC=$(echo "${VIRTUAL_MODE_LINE}"|sed -n "s/^.*Modeline\s*\".*\"\s*//p")
}

function install(){
    if [[ ! -e /usr/share/X11/xorg.conf.d/30-virtscreen.conf ]];then
cat << EOF | sudo tee /usr/share/X11/xorg.conf.d/30-virtscreen.conf >/dev/null
# nvidia/nouveau/amdgpu device should be configured first before Intel GPU
Section "Device"
    Identifier "nvidiagpu0"
    Driver     "nvidia"
EndSection

# Then configure the Intel Internal GPU
Section "Device"
    Identifier "intelgpu0"
    Driver     "intel"
EndSection
EOF
fi
    xrandr --addmode ${VIRTUAL_DISPLAY} ${VIRTUAL_MODE_NAME} 2>/dev/null
    if [[ ! $? -eq 0 ]];then
        echo ${VIRTUAL_MODE_NAME} ${VIRTUAL_MODE_DESC}| xargs xrandr --newmode
        echo ${VIRTUAL_DISPLAY} ${VIRTUAL_MODE_NAME}  | xargs xrandr --addmode
    fi

    xrandr --output ${VIRTUAL_DISPLAY} --mode ${VIRTUAL_MODE_NAME} && sleep 5
    xrandr --output ${VIRTUAL_DISPLAY} ${VIRTUAL_POSITION} ${PRIMARY_DISPLAY}
}

function launch(){
    VIRTUAL_POSITION=$(xrandr|sed -n "s/^${VIRTUAL_DISPLAY}\s*connected\s*\([0-9]*x[0-9]*+[0-9]*+[0-9]*\).*/\1/p")
    x11vnc -multiptr -repeat -clip ${VIRTUAL_POSITION}
}

function finish(){
    xrandr --output  ${VIRTUAL_DISPLAY} --off 
    xrandr --delmode ${VIRTUAL_DISPLAY} ${VIRTUAL_MODE_NAME}
    printf '%s \033[0;31mdisplay disabled \033[0m:)\n' ${VIRTUAL_DISPLAY}
}

trap finish EXIT

function init(){
    validate
    setting
    install
    launch
}

init