#!/usr/bin/env bash

set -e -o errexit
set -o pipefail
if [[ "${DEBUG}" == 'true' ]]; then
  set -o xtrace
else
  export DEBUG=
fi
set -o nounset
####
# script bol vygenerovany s nasledovnymi parametrami
# ?render=sh
###
_hello() {
  echo "Linux Boot v0.1.0"
}

_export_info() {
  export BIOS=$([ -d /sys/firmware/efi/efivars ] && echo "UEFI" || echo "Legacy")
  export SIZE_MEM=4
  export FS=xfs
  export SOURCE_QUERY="?render=sh"
}

export _ADD_PARAMS=()

_join() {
  (($#)) || return 1 # At least delimiter required
  local -- delim="$1" str IFS=
  shift
  str="${*/#/$delim}" # Expand arguments with prefixed delimiter (Empty IFS)
  echo "${str:${#delim}}" # Echo without first delimiter
}

_download() {
  if [[ $# -ne 2 ]]; then
    echo 'missing parameters source and target'
    exit 1
  fi

  local srcName=$1
  local dstName=$2
  local add=""
  if [ ${#_ADD_PARAMS[@]} -gt 0 ]; then
    add=$(_join '&' "${_ADD_PARAMS[@]}")
  fi

  # TODO test that local files work
  # TODO should dstName contain the /mnt prefix or should we test if we are in installation mode?
  _log "INFO kopirujem ${srcName} do $dstName"
  curl -sL "linux.curo.sk/d/${srcName}?render=sh&${add}" -o "${dstName}"
}

_source() {
  if [[ $# -eq 0 ]]; then
    echo 'missing parameter what to source'
    exit 1
  fi

  local scriptName=$1
  source <(curl -sL "linux.curo.sk/${scriptName}?render=sh")
}

REVERT_COUNT=0

_revert() {
  if [[ $# -eq 0 ]]; then
    echo 'nothing to add to revert stack'
  else
    # reset revert on first call
    if [[ $REVERT_COUNT -eq 0 ]]; then
      _log "DEBUG reseting revert stack on: $1"
#      rm -f /tmp/revert.sh
    fi

    echo $1 >>/tmp/revert.sh
  fi
}

_log() {
  local text=$1
  echo ": ${text}"
  #  >&2
}

_requireRoot() {
  if [ $UID != 0 ]; then
    echo "fist execute: sudo -i"
    exit 1
  fi
}
isNixOS() {
  if [ -f /etc/NIXOS ]; then
    echo 1
  else
    echo 0
  fi
}

assertIsNixOS() {
  MESSAGE="${1:-Program vyžaduje prostedie Linux distribúcie NixOS.}"
  if [ "x$(isNixOS)" == "x0" ]; then
    echo "ERROR: $MESSAGE" >/dev/stderr
    exit 1
  fi
}

assertIsSupportedNixOS() {
  REQUIRED_VER="${1:-22.05}"
  assertIsNixOS
  source /etc/os-release
  if [ "${VERSION_ID}" != "${REQUIRED_VER}" ]; then
    echo "ERROR: Vyžaduje sa verzia NixOS ${REQUIRED_VER}. Aktuálne máš spustenú verziu ${VERSION_ID}." >/dev/stderr
    exit 1
  fi
}
isNixInstaller() {
  if grep -q "imports = \[ <nixpkgs/nixos/modules/installer" /etc/nixos/configuration.nix; then
    echo 1
  else
    echo 0
  fi
}

assertIsNixInstaller() {
  MESSAGE="${1:-Program vyžaduje prostredie Linux distribúcie NixOS spustenej z inštalačného média.}"
  if [ "x$(isNixInstaller)" == "x0" ]; then
    echo "ERROR: $MESSAGE" >/dev/stderr
    exit 1
  fi
}

assertIsNotNixInstaller() {
  MESSAGE="${1:-Program nie je možné spustiť v prostredí NixOS inštalačného média.}"
  if [ "x$(isNixInstaller)" != "x0" ]; then
    echo "ERROR: $MESSAGE" >/dev/stderr
    exit 1
  fi
}

# kontrola prostredia instalacie
assertIsSupportedNixOS
assertIsNixInstaller
# pozdravime pouzivatela a vypiseme aktualnu verziu
_hello
# zmazeme script, ktory sa da pouzit na vratenie do vychodzieho stavu pocas instalacie
# toto je skor vhodne pre vyvoj scriptu a v praxi je lepsie PC restartnut a zacat s instalaciou od znova
# script /tmp/revert.sh by si mal spustat len, ak rozumies prikazom, ktore do neho pocas instalacie pribudnu 
rm -f /tmp/revert.sh
# mozno si spustil tento script bez dostatocneho opravnenia pre instalaciu
# instalacia ma za nasledok moznu stratu dat, takze nebudem pokracovat, pokial sa sam nerozhodnes
_requireRoot
# pripravime si niektore dolezite premenne, ktore sa pocas instalacie ocakavaju
_export_info
if [ "$BIOS" = "Legacy" ] ; then
  _log "INFO: going to prepare disk with script partition layout suitable for Legacy BIOS and MBR partition table"
### will partition disk as msdos
### if PartBootSize>0 then it will create boot partition
### calling template should:
###   1. format and mount $PART_BOOT
###   2. call lib_partition_mbr_mount.sh template to mount rest of the partitioned disks

export DISK=/dev/sda
DISKSEP=""
if [[ $DISK == /dev/nvme* ]]; then
  DISKSEP="p"
fi
export DISKSEP
PART=1
PART_BOOT=
PART_SWAP=
PART_ROOT=
SIZE_BOOT=0
START_ROOT=$(expr $SIZE_MEM + $SIZE_BOOT)

#set +e
_log "INFO: disk ${DISK} will be initialized with legacy msdos partition"
parted -s ${DISK} -- mklabel msdos
#set -e

if [[ $SIZE_BOOT -gt 0 ]]; then
  PART_BOOT=${DISK}${DISKSEP}${PART}
  PART=$(expr $PART + 1)
  _log "INFO: creating boot partition as ${PART_BOOT} of size ${SIZE_BOOT} GB"
  parted -s ${DISK} -- mkpart primary 1MiB ${SIZE_BOOT}GiB
else
  _log "INFO: will not use boot partition"
fi

PART_SWAP=${DISK}${DISKSEP}${PART}
PART=$(expr $PART + 1)
_log "INFO: creating swap partition on ${PART_SWAP} of size ${SIZE_MEM} GB"
if [[ $SIZE_BOOT -eq 0 ]]; then
  START=1MiB
else
  START=${SIZE_BOOT}GiB
fi
parted -s ${DISK} -- mkpart primary linux-swap ${START} ${SIZE_MEM}GiB
PART_ROOT=${DISK}${DISKSEP}${PART}
PART=$(expr $PART + 1)
_log "INFO: creating main partition on ${PART_ROOT} where size is disk size minus ${START_ROOT} GB"
parted -s ${DISK} -- mkpart primary ${START_ROOT}GiB 100%
### XFS related code
_log "INFO: formatting main partition on ${PART_ROOT} to xfs"
wipefs -a ${PART_ROOT} # needed to if the partition was zfs before
mkfs.xfs -f -L nixos ${PART_ROOT}
xfs_admin -L nixos ${PART_ROOT}
#mount /dev/disk/by-label/nixos /mnt
mount ${PART_ROOT} /mnt

### will mount /boot partition if needed
### will mount and activate swap if defined
if [ ! -z "$PART_BOOT" ]; then
  # needed for legacy bios
  mkfs.fat -F 32 -n boot ${PART_BOOT}
  mkdir -p /mnt/boot
  mount ${PART_BOOT} /mnt/boot
  _revert "umount /mnt/boot"
fi

if [ ! -z "$PART_SWAP" ]; then
  _log "INFO: formatting swap partition on ${PART_SWAP}"
  mkswap -L swap $PART_SWAP
  swapon $PART_SWAP
  _revert "swapoff $PART_SWAP"
fi

_revert "umount -a"

export BOOT_CONFIGURATION_DOWNLOAD=nixos-configuration-mbr.nix

export PART_BOOT
export PART_SWAP
export PART_ROOT
export SIZE_BOOT
export START_ROOT
else
### will partition disk as msdos
### if PartBootSize>0 then it will create boot partition
### calling template should:
###   1. format and mount $PART_BOOT
###   2. call lib_partition_mbr_mount.sh template to mount rest of the partitioned disks

export DISK=/dev/sda
DISKSEP=""
if [[ $DISK == /dev/nvme* ]]; then
  DISKSEP="p"
fi
export DISKSEP
PART=1
PART_BOOT=
PART_SWAP=
PART_ROOT=
SIZE_BOOT=0
START_ROOT=$(expr $SIZE_MEM + $SIZE_BOOT)

#set +e
_log "INFO: disk ${DISK} will be initialized with GPT partition"
parted -s ${DISK} -- mklabel gpt
#set -e

parted ${DISK} -- mkpart primary 512MiB -8GiB
parted ${DISK} -- mkpart primary linux-swap -8GiB 100%
parted ${DISK} -- mkpart ESP fat32 1MiB 512MiB
parted ${DISK} -- set 3 esp on
PART_BOOT=${DISK}${DISKSEP}3
PART_SWAP=${DISK}${DISKSEP}2
PART_ROOT=${DISK}${DISKSEP}1

#parted ${DISK} print > /tmp/parts.txt
#curl -LX PUT linux.curo.sk --data-binary @"/tmp/parts.txt" 
### XFS related code
_log "INFO: formatting main partition on ${PART_ROOT} to xfs"
mkfs.fat -F 32 -n boot ${PART_BOOT}
wipefs -a ${PART_ROOT} # needed to if the partition was zfs before
mkfs.xfs -f -L nixos ${PART_ROOT}
xfs_admin -L nixos ${PART_ROOT}

sleep 3
mount /dev/disk/by-label/nixos /mnt
# mount ${PART_ROOT} /mnt
mkdir -p /mnt/boot
mount /dev/disk/by-label/boot /mnt/boot

export BOOT_CONFIGURATION_DOWNLOAD=nixos-configuration-uefi.nix

export PART_BOOT
export PART_SWAP
export PART_ROOT
export SIZE_BOOT
export START_ROOT
fi
nixos-generate-config --root /mnt


# extract detected network interface name
NET=$(sed -n -e 's/.*networking.interfaces\.\([a-z0-9]\+\)\.useDHCP = true;.*/\1/p' /mnt/etc/nixos/configuration.nix)
_ADD_PARAMS+=("net=${NET}")

mv /mnt/etc/nixos/configuration.nix /mnt/etc/nixos/configuration.nix-DELETE
_download nixos-configuration.nix /mnt/etc/nixos/configuration.nix
_download nixos-configuration-users.nix /mnt/etc/nixos/users.nix
_download ${BOOT_CONFIGURATION_DOWNLOAD} /mnt/etc/nixos/boot-configuration.nix
_download nixos-configuration-empty.nix /mnt/etc/nixos/custom-configuration.nix
STATE_VER=$(cat /mnt/etc/nixos/configuration.nix-DELETE | sed -n 's/^.*system.stateVersion\s*=\s*"\s*\([^"]*\).*$/\1/p')
sed -i "s/system.stateVersion =.*/system.stateVersion = \"${STATE_VER}\"; # Did you read the comment?/" /mnt/etc/nixos/configuration.nix
# TODO this may fail on low memory HW !!!
# nix-channel --update
# nixos-rebuild switch
nixos-install --show-trace --root /mnt --no-root-password
# TODO do this based on curomd and/or curoui flags
# we boot with basic config
# but we already copy configs which should finish the configuration
_download nixos-curo-base.nix /mnt/etc/nixos/curo-base.nix
_download nixos-configuration-empty.nix /mnt/etc/nixos/curo-vpn.nix
_download nixos-configuration-empty.nix /mnt/etc/nixos/curo-md.nix
_download nixos-configuration-empty.nix /mnt/etc/nixos/curo-ui.nix
_download nixos-configuration-empty.nix /mnt/etc/nixos/backup.nix
_download nixos-configuration-empty.nix /mnt/etc/nixos/samba.nix
# TODO we need to be able to edit this
_download nixos-custom-configuration-curo.nix /mnt/etc/nixos/custom-configuration.nix
cat <<EOF

██╗  ██╗ ██████╗ ████████╗ ██████╗ ██╗   ██╗ ██████╗          
██║  ██║██╔═══██╗╚══██╔══╝██╔═══██╗██║   ██║██╔═══██╗         
███████║██║   ██║   ██║   ██║   ██║██║   ██║██║   ██║         
██╔══██║██║   ██║   ██║   ██║   ██║╚██╗ ██╔╝██║   ██║         
██║  ██║╚██████╔╝   ██║   ╚██████╔╝ ╚████╔╝ ╚██████╔╝██╗██╗██╗
╚═╝  ╚═╝ ╚═════╝    ╚═╝    ╚═════╝   ╚═══╝   ╚═════╝ ╚═╝╚═╝╚═╝
                                                              
EOF
_log "INFO: Reštartuj počítač (príkaz 'sudo reboot') a naštartuj ho z pevného disku."