#!/bin/bash

#SCREEN_X=3840; # horizontal resolution of the screen
#SCREEN_Y=2160; # vertical resolution of the screen
#SCREEN_X=1920; # horizontal resolution of the screen
#SCREEN_Y=1080; # vertical resolution of the screen
SCREEN_X=1600; # horizontal resolution of the screen
SCREEN_Y=900; # vertical resolution of the screen

SEGMENTS=2;    # how many xephyr sessions to merge (2 to 4)

WD_X=2;        # horizontal window decoration (left + right)(px)
WD_Y=2;        # vertical window decoration   (top + bottom + taskbar)(px)

XLSNORM="-*-neep-medium-r-semicondensed-*-13-*"
XLSBOLD="-*-neep-bold-r-semicondensed-*-13-*"
FONT_X=6;      # font width (px)
FONT_Y=13;     # font height (px)
# XLSNORM="-*-neep-medium-r-normal-*-20-*"
# XLSBOLD="-*-neep-bold-r-normal-*-20-*"
# FONT_X=10;     # font width (px)
# FONT_Y=20;     # font height (px)

# Verify that the needed applications are installed.
REKT="NO"
for PROGRAM in sleep wmctrl oclock Xephyr Xdmx xset fc-cache xterm END
do
  if [ "$PROGRAM" = "END" ]; then
    if [ "$REKT" = "YES" ]; then
      exit 1
    fi
  else
    TEMP_VAR=$(which $PROGRAM)
    if [ "${#TEMP_VAR}" -lt "2" ]; then
      echo $PROGRAM" is NOT installed or NOT available."
      REKT="YES"
    fi
  fi
done

# do some math

# max X / $COLUMNS per screen
MAX_X=$(( $(($SCREEN_X - $(($WD_X * $SEGMENTS)) )) / $FONT_X ))
# max X / $COLUMNS per segment
# man sure $COLUMNS is a multiple of 2 per segment (personal preference)
COL_X=$(( $(( $MAX_X / $SEGMENTS )) - $(( $(( $MAX_X / $SEGMENTS )) % 2 )) ))
# max X pixels per segment without window decoration
# (window decoration handled by environment / out of our control)
RES_X=$(( $COL_X * $FONT_X ))

# max Y / $LINES per screen
MAX_Y=$(( $(($SCREEN_Y - $WD_Y)) / $FONT_Y ))
# make sure $LINES is a multiple of 2 per segment (personal preference)
ROW_Y=$(( $MAX_Y - $(( $MAX_Y % 2 )) ))
# max Y / $LINES for the combined terminal
ROWS_Y=$(( $ROW_Y * $SEGMENTS ))
# max Y in pixels per segment without window decoration
# (window decoration handled by environment / out of our control)
RES_Y=$(( $ROW_Y * $FONT_Y ))

# where to place these segments
WIDTH=$(( $SCREEN_X / $SEGMENTS ))
OFFSET_X0=0
OFFSET_X1=0
OFFSET_X2=0
OFFSET_X3=0
if [ "$SEGMENTS" = "2" ]; then
OFFSET_X0=$(($(($WIDTH*0)) + 0))
OFFSET_X1=$(($(($WIDTH*1)) + $(($(($WIDTH-$WD_X))-$RES_X))))
fi
if [ "$SEGMENTS" = "3" ]; then
OFFSET_X0=$(($(($WIDTH*0)) + 0))
OFFSET_X1=$(($(($WIDTH*1)) + $(($(($(($WIDTH-$WD_X))-$RES_X))/2))))
OFFSET_X2=$(($(($WIDTH*2)) + $(($(($WIDTH-$WD_X))-$RES_X))))
fi
if [ "$SEGMENTS" = "4" ]; then
OFFSET_X0=$(($(($WIDTH*0)) + 0))
OFFSET_X1=$(($(($WIDTH*1)) + $(($(($(($(($WIDTH-$WD_X))-$RES_X))/3))*1))))
OFFSET_X2=$(($(($WIDTH*2)) + $(($(($(($(($WIDTH-$WD_X))-$RES_X))/3))*2))))
OFFSET_X3=$(($(($WIDTH*3)) + $(($(($WIDTH-$WD_X))-$RES_X))))
fi
# Some INFORMATION to validate our assumptions
echo "===== COLUMNS: "$COL_X" LINES: "$ROWS_Y" ROWS: "$ROW_Y
echo "====     px_X: "$RES_X" px_Y: "$RES_Y" "
echo "===    OFFSET: "$OFFSET_X0" "$OFFSET_X1" "$OFFSET_X2" "$OFFSET_X3" "
#exit 0; # ... verify the math for testing purposes

XDMX_CONF_NAME="$HOME""/large_term_1x""$SEGMENTS""_""$FONT_X""x""$FONT_Y"".xdmx"

RES_OY0=$(( $RES_Y * 0 ))
RES_OY1=$(( $RES_Y * 1 ))
RES_OY2=$(( $RES_Y * 2 ))
RES_OY3=$(( $RES_Y * 3 ))
# create a configfile for Xdmx that meets our specifications
echo "virtual tiled1x"$SEGMENTS" {"                         > "$XDMX_CONF_NAME"
echo "  display \":11\" "$RES_X"x"$RES_Y"  @0x"$RES_OY0";" >> "$XDMX_CONF_NAME"
echo "  display \":12\" "$RES_X"x"$RES_Y"  @0x"$RES_OY1";" >> "$XDMX_CONF_NAME"
if [ "$SEGMENTS" -gt "2" ]; then
echo "  display \":13\" "$RES_X"x"$RES_Y"  @0x"$RES_OY2";" >> "$XDMX_CONF_NAME"
fi
if [ "$SEGMENTS" -gt "3" ]; then
echo "  display \":14\" "$RES_X"x"$RES_Y"  @0x"$RES_OY3";" >> "$XDMX_CONF_NAME"
fi
echo "}"                                                   >> "$XDMX_CONF_NAME"
echo "filename: "$XDMX_CONF_NAME
echo "========= "
cat $XDMX_CONF_NAME
#exit 0 # ... verify the conf for testing purposes

Xephyr :11 -screen "$RES_X"x"$RES_Y" -title Xephyr11 &
sleep 0.3; wmctrl -r Xephyr11 -e 0,"$OFFSET_X0",0,"$RES_X","$RES_Y"
Xephyr :12 -screen "$RES_X"x"$RES_Y" -title Xephyr12 &
sleep 0.3; wmctrl -r Xephyr12 -e 0,"$OFFSET_X1",0,"$RES_X","$RES_Y"
if [ "$SEGMENTS" -gt "2" ]; then
Xephyr :13 -screen "$RES_X"x"$RES_Y" -title Xephyr13 &
sleep 0.3; wmctrl -r Xephyr13 -e 0,"$OFFSET_X2",0,"$RES_X","$RES_Y"
fi
if [ "$SEGMENTS" -gt "3" ]; then
Xephyr :14 -screen "$RES_X"x"$RES_Y" -title Xephyr14 &
sleep 0.3; wmctrl -r Xephyr14 -e 0,"$OFFSET_X3",0,"$RES_X","$RES_Y"
fi

Xdmx :1 -configfile "$XDMX_CONF_NAME" \
        -config tiled1x"$SEGMENTS" -depth 24 -ignorebadfontpaths +xinerama &
sleep 4

# start with an oclock, since a wm/de is bloated and unnecessary
# when the last program ends in the Xdmx, then Xdmx restarts (annoying)
OC_SX=$(( $RES_X / 2 )); # pixels wide
OC_SY=$OC_SX
OC_OX=$(( $(($RES_X / 2)) - $(($OC_SX / 2)) ))
OC_OY=$(($RES_Y - $(($OC_OX+$OC_SX)) ))
oclock -fg rgb:00/00/aa -minute rgb:00/00/ff -bd rgb:00/00/aa \
       -transparent -shape -geometry "$OC_SX"x"$OC_SX"+"$OC_OX"+"$OC_OY" -display :1 &
sleep 1

# ensure that the custom fonts apply to the new environment
# could comment out this section if using neep or distro supplied font
xset -display :1 fp+ $HOME/.fonts/
sleep 0.3
xset -display :1 fp rehash
sleep 0.3
xterm -display :1 +hold -e fc-cache -f -v
sleep 0.3

# make that beautifully tall terminal
#urxvt -display :1 -b 0 -w 0 +sb \
xterm -display :1 -b 0 -bw 0 +sb \
      -fg rgb:99/99/99 -bg rgb:00/00/00 -cr rgb:ff/ff/00 \
      -fn "$XLSNORM" -fb "$XLSBOLD" -geometry "$COL_X"x"$ROWS_Y"+0+0 &

exit 0