#!/bin/sh

# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2016-present Team LibreELEC (https://libreelec.tv)
#
# exit 1 = unsupported GPU
# exit 2 = dual boot system
# exit 3 = no backup for syslinux.cfg or extlinux.conf
# exit 4 = extlinux.conf and syslinux.cfg are available
# exit 5 = changes are already made either to extlinux.conf or syslinux.cfg
# exit 6 = xorg.conf already exists in /storage/.config
# exit 7 = more than a single device detected

# Help message and usage explanation
help() {
  echo "This script generates a custom EDID depending on your GPU"
  echo ""
  echo "To check which GPU you are using, use: getedid gpu"
  echo ""
  echo "To create a custom EDID, just use this script like: getedid create"
  echo ""
  echo "If you don't want to use the created EDID file anymore use: getedid delete"
  echo ""
  echo "If your hardware or kernel has changed and you want to have a custom EDID again, then you have to delete the old EDID first."
  echo "For this use: getedid delete "
  echo "And then use: getedid create"
}


# check for GPU and store string
check_gpu() {
  if lspci | grep -i vga | grep -i -q -E 'intel|amd' ; then
    gpu="intel/amd"
  elif lspci | grep -i vga | grep -i -q nvidia; then
    gpu="nvidia"
  else
    echo "GPU is not supported"
    exit 1
  fi
}


# run this first if the user already has a custom EDID but want to create a new one (TV or AVR change)
del_edid() {
  if [ "$gpu" = "intel/amd" ]; then
    check_file
    if [ -f "$file".old ];  then
      mount_rw
      rm "$file"
      mv "$file".old "$file"
      rm -f /flash/edid.cpio
      mount_ro
      sys_reboot
    else
      echo "You don't have a backup file for $file. You did not use this script to create the custom EDID"
      echo "Therefore we can't be sure the script is working properly. Exiting"
      exit 3
    fi
  else
    rm -f /storage/.config/xorg.conf
    rm -f /storage/.config/xorg.le.backup
    systemctl restart xorg.service
  fi   
}


# run main script depending on the GPU
run() {
  if [ "$gpu" = "intel/amd" ]; then
    intel_amd
  elif [ "$gpu" = "nvidia" ]; then
    nvidia
  fi
}


# mounting /flash to rw
mount_rw() {
  mount -o remount,rw /flash
}


# mounting /flash to ro
mount_ro() {
  mount -o remount,ro /flash
}


# remount /flash to ro and reboot
sys_reboot() {
  mount_ro
  echo "The system is rebooting in 15 seconds"
  sleep 15
  reboot
}


# check syslinux.cfg and/or extlinux.conf
check_file() {
  # check boot system
  if [ -d /sys/firmware/efi -a -f /flash/EFI/BOOT/syslinux.cfg ] ; then
    sys_boot="UEFI"
    sys_path="/flash/EFI/BOOT"
  else
    sys_boot="BIOS"
    sys_path="/flash"
  fi

  # check which file is available
  if [ -f "$sys_path/syslinux.cfg" -a -f "$sys_path/extlinux.conf" ]; then
    echo "Your system contains both a /flash/syslinux.cfg and a /flash/extlinux.conf file"
    echo "Something is wrong on your system. Exiting"
    exit 4
  elif [ -f "$sys_path/extlinux.conf" ]; then
    file="$sys_path/extlinux.conf"
  elif [ -f "$sys_path/syslinux.cfg" ]; then
    file="$sys_path/syslinux.cfg"
  else
    echo "You neither have a extlinux.conf nor do you have a syslinux.cfg."
    echo "Dual boot systems aren't supported"
    exit 2
  fi
}


check_content() {
  # check if changes are already made to $file and exit if yes
  if grep -q "initrd=/edid.cpio" $file ; then
    echo "$file has been modified. Please run 'getedid delete' first if you want to modify it again. Exiting."
    exit 5
  fi
}


check_kernel() {
  # determine which kernel is in use and store it in a compareable format. This will probably be deprecated for LE10
  kernel="$(uname -r | sed 's/[^0-9\.].*//g' | awk -F. '{ printf "%d%02d%03d\n",int($1),int($2),int($3) }')"
}


create_edid() {
  # create edid 
  mkdir -p /tmp/cpio/lib/firmware/edid
  cat "/sys/class/drm/$card/edid" > /tmp/cpio/lib/firmware/edid/edid.bin
  mkdir -p /storage/.config/firmware/edid
  cp /tmp/cpio/lib/firmware/edid/edid.bin /storage/.config/firmware/edid


  # create cpio archive
  cd /tmp/cpio/
  find . -print | cpio -ov -H newc > /storage/edid.cpio
}


intel_amd() {
  # check which output is connnected:
  counter=0
  for i in /sys/class/drm/*; do
    if [ "$(cat "$i"/status 2>/dev/null)" = "connected" ]; then
      counter=$((counter + 1))
      if [ $counter -gt 0 -a $counter -lt 2 ]; then
        card="$(echo "$i" | cut -d / -f 5)"
        hdmi="$(echo "$i" | cut -d / -f 5 | sed 's/card[0-9]-//g')"
      else
        echo "More than a single device connected. Probably enable \"Disable all other monitors\" at Kodi settings. Aborting!"
        exit 7
      fi
    fi
  done

  # create the edid 
  create_edid

  # check extlinux.conf and syslinux.cfg
  check_file
  check_content

  # remount /flash to rw
  mount_rw
  mv /storage/edid.cpio /flash

  # make a backup of $file
  cp "$file" "$file".old
  
  #check kernel version
  check_kernel

  # add boot parameters to $file
  sed -i "/ APPEND/s/$/ initrd=\/edid.cpio drm.edid_firmware=edid\/edid.bin video=$hdmi:D/" "$file"

  # reboot
  sys_reboot
}


nvidia() {
  # check if xorg.conf already exists
  if [ -f /storage/.config/xorg.conf -o -f /storage/.config/xorg-nvidia.conf ]; then
    echo "Existing /storage/.config/xorg.conf detected. Aborting!"
    exit 6
  fi


  # check for multi-montior setup
  monitors="$(grep -i -w "connected" /var/log/Xorg.0.log | grep -i -o "dfp-[0-9]" | sort -u | wc -l)"
  if [ "$monitors" -gt "1" ]; then
    echo "You have more than a single monitor connected. The script doesn't support a multi-monitor setup. Aborting!"
    exit 7
  fi


  # set debug and restart Xorg
  cp /etc/X11/xorg-nvidia.conf /storage/.config/xorg.conf
  sed -i 's/"ModeDebug" "false"/"ModeDebug" "true"/g' /storage/.config/xorg.conf
  systemctl restart xorg.service
  

  # get port
  nv_port="$(grep -i -w connected /var/log/Xorg.0.log | grep -i -o "dfp-[0-9]" | sort -u)"
  nvidia-xconfig --extract-edids-from-file=/var/log/Xorg.0.log --extract-edids-output-file=/storage/.config/edid.bin 1>/dev/null

  # set mode debug back to false
  sed -i 's/"ModeDebug" "true"/"ModeDebug" "false"/g' /storage/.config/xorg.conf
  
  # set port and uncomment lines
  sed -i "s/#    Option         \"ConnectedMonitor\" \"DFP-0\"/    Option         \"ConnectedMonitor\" \"$nv_port\"/g" /storage/.config/xorg.conf
  sed -i "s/#    Option         \"CustomEDID\" \"DFP-0:\/storage\/.config\/edid.bin\"/    Option         \"CustomEDID\" \"$nv_port:\/storage\/.config\/edid.bin\"/g" /storage/.config/xorg.conf
  sed -i "s/#    Option         \"IgnoreEDID\" \"false\"/    Option         \"IgnoreEDID\" \"false\"/g" /storage/.config/xorg.conf
  sed -i "s/#    Option         \"UseEDID\" \"true\"/    Option         \"UseEDID\" \"true\"/g" /storage/.config/xorg.conf

  # restart xorg.service
  systemctl restart xorg.service
}


# start script from here
case "$1" in
  'create')
    check_gpu
    run
    ;;
  'gpu')
    check_gpu
    echo "$gpu"
    ;;
  'delete')
    check_gpu
    del_edid
    ;;
  'help')
    help
    ;;
  *)
    echo "Usage $0 { create | gpu | delete | help }"
    ;;
esac