#!/bin/bash

[[ -z "$DISPLAY" ]] && export DISPLAY=:0
CONFIGFOLDER=$HOME/.config/q-tools-disp/
CONFIG=${CONFIGFOLDER}disp
TEMPLATE='# configure the display names with "xrandr"
MAIN=eDP-1
ANALOG=VGA-1
DIGITAL=DP-1

# You hay have to change ANALOG/DIGITAL in the outputs, 
# especially for Workstation choices
# If you want a single display as your workstation setup, 
# leave WORKSTATIONRIGHT empty
WORKSTATIONLEFT=$MAIN
WORKSTATIONRIGHT=$DIGITAL
'

_display_main() {
    [[ -f "$CONFIG" ]] || {
        echo "ERROR: You do not have configuration yet"
        _help
    }
    _isconnected "$MAIN" || {
        echo "Display MAIN=$MAIN is not connected, trying to turn all on. Please check your setup: $CONFIG"
        _allon
    }
    _xrandr --output "$MAIN" --auto --gamma $g:$g:$g
    xrandr | grep " connected" | awk '{ print $1 }' | grep -v "$MAIN" | while read display; do
        _xrandr --output $display --off
    done
    
}

_display_presentation() {
    _isconnected "$MAIN" || {
        echo "Display MAIN=$MAIN is not connected, trying to turn all on. Please check your setup: $CONFIG"
        _allon
    }
    xrandr | grep " connected" | awk '{ print $1 }' | while read display; do
        _xrandr --output $display --mode 1024x768 --pos 0x0 --gamma $g:$g:$g 
    done
}
_display_workstation() {
    [[ -f "$CONFIG" ]] || {
        echo "ERROR: You do not have configuration yet"
        _help
    }
    if [ -z "$WORKSTATIONLEFT" ];then 
        echo "WORKSTATIONLEFT not defined, turning everything on"
        _allon
    fi
    _isconnected "$WORKSTATIONLEFT" || {
        echo "WORKSTATIONLEFT=$WORKSTATIONLEFT is not connected, turning everything on"
        _allon
    }
    if [ -z "$WORKSTATIONRIGHT" ];then 
        # Single display setup
        _xrandr --output "$WORKSTATIONLEFT" --auto --gamma $g:$g:$g
        xrandr | grep " connected" | awk '{ print $1 }' | grep -v "$WORKSTATIONLEFT" | while read display; do
            _xrandr --output $display --off
        done
        return
    fi
    # Two display setup
    _isconnected "$WORKSTATIONRIGHT" || {
        echo "WORKSTATIONRIGHT=$WORKSTATIONRIGHT is not connected, turning everything on"
        _allon
    }
    _xrandr --output "$WORKSTATIONLEFT" --auto --gamma $g:$g:$g --output "$WORKSTATIONRIGHT" --auto --gamma $g:$g:$g --right-of "$WORKSTATIONLEFT"
    xrandr | grep " connected" | awk '{ print $1 }' | grep -v "$WORKSTATIONLEFT" | grep -v "$WORKSTATIONRIGHT" | while read display; do
        _xrandr --output $display --off
    done
    
}
_isconnected() {
    xrandr | grep -q "${1} connected"
}
_allon() {
    xrandr | grep " connected" | awk '{ print $1 }' | while read display; do
        _xrandr --output $display --auto
    done
    exit
}

_setup() {
    # config
    mkdir -p "$CONFIGFOLDER"
    [[ -f "$CONFIG" ]] || {
        echo "$TEMPLATE" > "$CONFIG"
        FIRST=$( xrandr | grep connected | head -n1 | awk '{ print $1 }' )
        sed -i 's,^MAIN=.*,MAIN='$FIRST',' "$CONFIG"
    }
    echo '# Current configuration:'
    echo $CONFIG
    echo ======================
    cat "$CONFIG"
    echo ======================
    . "$CONFIG"
    echo '# Displays at this computer:'
    xrandr | grep -e '.*connected' -e '.*\*' --color=always
    xdg-open "$CONFIG"
    echo "Add something to your LXPanel to create the configuration (launcher icon etc...)"
    exit
}
_xrandr() {
    echo xrandr "$@"
    xrandr "$@"
}
_help() {
    echo 'SBL-DISP
    
    Running without arguments shows display configuration choices
    
    help    Get this help message
    setup   Setup display names
    all     Try to turn all displays on
    
    Following arguments require "setup"

    0       Run "arandr" to setup manually
    1       Main display only
    2       Presentation: Main and external screen clones
    3       Workstation: Run your workstation mode, setup in the configuration file
    
    Second argument to any previous sets the gamma correction value
    Configuration file: '$CONFIG'
    '
    exit
}

[[ -f "$CONFIG" ]] && . "$CONFIG"

# Sub functions exit on their own
[[ "$1" = "help" ]] && _help
[[ "$1" = "--help" ]] && _help
[[ "$1" = "-h" ]] && _help
g=1
[[ -z "$2" ]] || g=$2
i=$1
if [ -z "$1" ]; then
   echo "Currently connected displays:"
   xrandr | grep --color=always -e ".* connected" -e '.*\*' | awk '{ print $1,$2,$3} '
   echo 'Menu choices:
   
   0       Run "arandr" to setup manually
   1       Main display only ('$MAIN')
   2       Presentation: Main and all external screen clones (1024x768)
   3       Workstation: Your personal configration ('$WORKSTATIONLEFT + $WORKSTATIONRIGHT', panel on '$PANEL')
   
   See further help by running with argument: -h
   '
   read -N 1 i
   echo ""
fi

case $i in
    all)    _allon; ;;
    setup)  _setup; ;;
    0)      arandr; ;;
    1)      _display_main; ;;
    2)      _display_presentation; ;;
    3)      _display_workstation; ;;
esac