#!/usr/bin/env bash

###
##
## Novos Install script
##
###

###
## Definitions
###

# Checks
readonly CHECK_INTERNET_URL='www.alpinelinux.org'

# Installation
readonly INSTALLATION_LOCK_FILE='/root/.installation.lock'
readonly INSTALLATION_LOGFILE='/root/installation.log'
readonly INSTALLATION_PARTLABEL_ESP="ESP"
readonly INSTALLATION_PARTLABEL_ROOT="ROOT"
readonly INSTALLATION_ESP_PARTITION_SIZE=4
readonly INSTALLATION_MOUNTPOINT='/mnt'
readonly INSTALLATION_NOVERIA_BIN='/usr/local/noveria/bin'
readonly INSTALLATION_SECRETS_FILE="/root/installation.secrets"
readonly INSTALLATION_ANSIBLE_ROOT="srv/ansible"
readonly INSTALLATION_ANSIBLE_GIT="https://git.noveria.org/Novos/ansible-playbooks.git"
readonly INSTALLATION_ALPINE_VERSION=$(cat /etc/os-release | grep VERSION_ID | cut -d= -f2)
readonly INSTALLATION_REL_VERSION=%REL_VER%

# Colors
readonly RED='\033[0;31m'
readonly NC='\033[0m' # No Color

###
## Errorhandling
###
# set -e                exit script when a command fails
# set -o pipefail       check any command in pipeline for error, not just last one
# set -eo pipefail

# catch ^C and other signals and clean up
trap "errorHardExit 'Interrupted with CTRL+C'" SIGINT SIGHUP SIGTERM SIGABRT

###
## Helper Functions
###

##
#   Run commands in chroot
#   - $1: command
##
function runInChroot() {
  chroot "${INSTALLATION_MOUNTPOINT}" /bin/ash -c "$1"
}

##
#   Installation subtask title output
#   - $1: subtask title
##
function installationSubtaskTitle() {
  echo -e "\n=> $1"
}

##
#   Random password generator (alphanumeric)
#   - $1: password length (default 11)
#   - $2: avoid poorly readable characters: l/I/1, O/0 (default false)
##
function randomPasswordGen() {
  # character set
  if ${2:-false}; then
    local character_set='a-km-zA-HJ-NP-Z2-9'
  else
    local character_set='a-zA-Z0-9'
  fi

  # https://en.wikipedia.org/wiki/randomPasswordGen#Bash
  LC_ALL=C tr -dc "$character_set" </dev/urandom | head -c "${1:-11}"
  echo
}


##
#   Hard exit with console error message
##
function errorHardExit() {
  echo -e "${RED}$1${NC} \nAborting \n"
  exit 1
}

###
## Functions
###

##
#   Pre checks
##

function preChecks() {
  # Check if another installation is in progress
  if [ -f $INSTALLATION_LOCK_FILE ]; then
    dialog --stdout --clear --no-collapse --yes-label "Exit" --no-label "Start anyway" --yesno "     Another installation is in progress" 6 50
    case $? in
    0)
      clear
      exit
      ;;
    1) rm "$INSTALLATION_LOCK_FILE" ;;
    255)
      clear
      exit
      ;;
    esac
  fi

  # Check if booted in UEFI
  if [ ! -d /sys/firmware/efi ]; then
    dialog --stdout --clear --no-collapse --yes-label "Shutdown" --nolabel "Alpine shell" --yesno "The ISO hasn't been booted in UEFI mode. Please boot the ISO in UEFI to proceed installation" 6 50
    case $? in
    0)
      clear
      COUNTER=5
      echo "Novos is shutting down in: "
      while [ 1 ]; do
          if [ ${COUNTER} -eq 0 ]; then
              break
          fi
          echo -n "${COUNTER}"
          COUNTER=$( echo "${COUNTER}-1" | bc )
          sleep 0.2
          for (( i=0; i<4; i++ )); do
              echo -n "."
              sleep 0.2
          done
      done
      poweroff
      ;;
    1)
      clear
      exit 0
      ;;
    255)
      clear
      exit
      ;;
    esac
  fi

  introDialogue
}

##
#   Introduction dialog
##
function introDialogue() {
  local introtext="\n\n\n
                                     Velkommen til
                               _   _\n
                              | \ | | _____   _____  ___\n
                              |  \| |/ _ \ \ / / _ \/ __|\n
                              | |\  | (_) \ V / (_) \__ \ \n
                              |_| \_|\___/ \_/ \___/|___/\n\n
                            OS: Novos
                            Version: $INSTALLATION_REL_VERSION
                            IP: $(ifconfig eth0 | grep "inet addr" | awk '{$1=$1};1' | awk '{print $2}' | cut -d: -f2)

                            How do you want to continue?
  "
  dialog --stdout --clear --cr-wrap --no-collapse --yes-label "Graphical Guide" --no-label "Alpine shell" --yesno "$introtext" 31 93
  case $? in
  1)
    clear
    exit
    ;;
  255)
    clear
    exit
    ;;
  esac

  checkInternetConnection
}

##
#   Internet connection
##
function checkInternetConnection() {
  dialog --no-collapse --infobox "\n   Check internet connection" 5 35

  # wait 5 seconds to give some more time for network initialization
  sleep 5

  while ! ping -c 1 "$CHECK_INTERNET_URL" >/dev/null 2>&1; do
    dialog --clear --title "No internet connection" --msgbox "
  Insert network cable, wait 5 seconds and press 'OK'" 7 65
  done

  prepareInstallation
}

##
#   Installation preparation
##
function prepareInstallation() {

  # disk
  readonly AVAILABLE_DISKS=($(lsblk | grep -vE "p[0-9]+" | grep -vE "[s,v]d[a-z][0-9]+" | grep -v "luks" | grep -v "rom" | grep -vE "sd[a-z][0-9]+" | grep -v "/" | tail -n +2 | awk '{print $1}'))
  for available_disk in ${AVAILABLE_DISKS[@]}; do
    if [[ -z "$diskString" ]]; then
      diskString="$available_disk /dev/$available_disk off"
    else
      diskString="$diskString $available_disk /dev/$available_disk off"
    fi
  done

  INSTALLATION_DISK=$(dialog --clear --radiolist "Select Disk to install the system" 10 70 3 $(echo $diskString) 3>&1 1>&2 2>&3 3>&-)
  INSTALLATION_DISK_BYID=$(lshw -class disk | grep ${INSTALLATION_DISK} | tr -d "[:space:]" | cut -d: -f2)

  # root password
  INSTALLATION_ROOT_PW=$(randomPasswordGen 5)
  for _ in {0..2}; do
    INSTALLATION_ROOT_PW="${INSTALLATION_ROOT_PW}-$(randomPasswordGen 5)"
  done

  # hostname
  INSTALLATION_HOSTNAME=$(dialog --clear --title "What's the hostname of this device?" --inputbox "Enter hostname" 10 70 3>&1 1>&2 2>&3 3>&-)

  # domain
  INSTALLATION_DOMAIN=$(dialog --clear --title "What's the domain of this device?" --inputbox "Enter domain (leave empty for localhost)" 10 70 3>&1 1>&2 2>&3 3>&-)
  [[ -z "$INSTALLATION_DOMAIN" ]] && INSTALLATION_DOMAIN="localhost"

  # installation type
  INSTALLATION_TYPE=$(dialog --clear --title "Choose the main installation type of this host" --radiolist "Select one" 10 70 3 gaming Game-Server false proxy Proxy-Server false build Build-Server false 3>&1 1>&2 2>&3 3>&-)

  # show summary
  summary
}

##
#   Summary to confirm
##
function summary() {
  dialog --stdout --clear --title "Summary" --yes-label "Confirm" --no-label "Abort" --yesno "\n
Hostname:       ${INSTALLATION_HOSTNAME}.${INSTALLATION_DOMAIN}\n
Type:           ${INSTALLATION_TYPE}\n
Disk:           ${INSTALLATION_DISK}
  " 9 60

  case $? in
  0) installation ;;
  1)
    clear
    errorHardExit "Abort on summary dialog"
    ;;
  255)
    clear
    errorHardExit "Abort on summary dialog"
    ;;
  esac
}

##
#   Installation
##
function installation() {
  # clear display
  clear

  # lock file
  touch "$INSTALLATION_LOCK_FILE" || installationFailed

  # log all output to logfile
  rm -f "$INSTALLATION_LOGFILE" || installationFailed
  exec &> >(tee -a "$INSTALLATION_LOGFILE")

  # create boot environment timestamp
  START_TIMESTAMP=$(date +"%Y-%m-%d_%H-%M-%S") || installationFailed

  echo ""
  echo "┌──────────────────────────────────────────┐"
  echo "│        Swipe and repartition disk        │"
  echo "└──────────────────────────────────────────┘"

  installationSubtaskTitle "Wipe disk"
  blkdiscard -f "${INSTALLATION_DISK_BYID}" || installationFailed

  installationSubtaskTitle "Repartitioning disk"
  parted -s "${INSTALLATION_DISK_BYID}" mklabel gpt || installationFailed
  parted -s "${INSTALLATION_DISK_BYID}" mkpart "${INSTALLATION_PARTLABEL_ESP}" fat32 1MiB ${INSTALLATION_ESP_PARTITION_SIZE}GiB || installationFailed
  parted -s "${INSTALLATION_DISK_BYID}" set 1 esp on || installationFailed
  parted -s "${INSTALLATION_DISK_BYID}" mkpart "${INSTALLATION_PARTLABEL_ROOT}" btrfs ${INSTALLATION_ESP_PARTITION_SIZE}GiB 100% || installationFailed

  # Informing the Kernel of the changes.
  sleep 0.1
  partprobe "${INSTALLATION_DISK_BYID}" || installationFailed

  # loop until lsblk is updated and gives the partition back
  while
    sleep 0.1
    ESP_PARTITION="/dev/$(lsblk "${INSTALLATION_DISK_BYID}" -o NAME,PARTLABEL | grep "${INSTALLATION_PARTLABEL_ESP}" | cut -d " " -f1 | cut -c7-)" || installationFailed
    ROOT_PARTITION="/dev/$(lsblk "${INSTALLATION_DISK_BYID}" -o NAME,PARTLABEL | grep "${INSTALLATION_PARTLABEL_ROOT}" | cut -d " " -f1 | cut -c7-)" || installationFailed
    [[ "${ESP_PARTITION}" == '/dev/' || "${ROOT_PARTITION}" == '/dev/' ]]
  do :; done

  installationSubtaskTitle "File system creation"
  mkfs.vfat -F 32 -n EFI "${ESP_PARTITION}" || installationFailed
  mkfs.btrfs -f -L ROOT "${ROOT_PARTITION}" || installationFailed

  installationSubtaskTitle "Create btrfs subvolumes"
  mount -t btrfs "${ROOT_PARTITION}" "${INSTALLATION_MOUNTPOINT}" || installationFailed
  btrfs sub create "${INSTALLATION_MOUNTPOINT}/@root_${START_TIMESTAMP}" || installationFailed
  btrfs sub create "${INSTALLATION_MOUNTPOINT}/@home" || installationFailed
  btrfs sub create "${INSTALLATION_MOUNTPOINT}/@podman" || installationFailed
  btrfs sub create "${INSTALLATION_MOUNTPOINT}/@mysql" || installationFailed
  umount "${INSTALLATION_MOUNTPOINT}" || installationFailed

  echo ""
  echo "┌──────────────────────────────────────────┐"
  echo "│             Mount filesystems            │"
  echo "└──────────────────────────────────────────┘"

  installationSubtaskTitle "Mount btrfs subvolumes"
  mount -o noatime,nodiratime,discard=async,space_cache=v2,subvol=@root_"${START_TIMESTAMP}" "${ROOT_PARTITION}" "${INSTALLATION_MOUNTPOINT}" || installationFailed
  mkdir -p ${INSTALLATION_MOUNTPOINT}/{efi,home,btrfs,var/lib/mysql,opt/podman,sys/firmware/efi/efivars} || installationFailed
  mount -o noatime,nodiratime,discard=async,space_cache=v2,subvol=@home "${ROOT_PARTITION}" "${INSTALLATION_MOUNTPOINT}/home" || installationFailed
  mount -o noatime,nodiratime,discard=async,space_cache=v2,subvol=@podman "${ROOT_PARTITION}" "${INSTALLATION_MOUNTPOINT}/opt/podman" || installationFailed
  mount -o noatime,nodiratime,discard=async,space_cache=v2,subvol=@mysql "${ROOT_PARTITION}" "${INSTALLATION_MOUNTPOINT}/var/lib/mysql" || installationFailed
  mount -o noatime,nodiratime,discard=async,space_cache=v2,subvol=/ "${ROOT_PARTITION}" "${INSTALLATION_MOUNTPOINT}/btrfs" || installationFailed

  installationSubtaskTitle "Mount ESP"
  mount -o nodev,nosuid,noexec "${ESP_PARTITION}" "${INSTALLATION_MOUNTPOINT}/efi" || installationFailed

  echo ""
  echo "┌──────────────────────────────────────────┐"
  echo "│         Install and configure OS         │"
  echo "└──────────────────────────────────────────┘"

  installationSubtaskTitle "Install base packages"
  wget https://raw.githubusercontent.com/alpinelinux/alpine-make-rootfs/v0.7.0/alpine-make-rootfs
  chmod u+x alpine-make-rootfs
  ./alpine-make-rootfs --no-cleanup --branch 'v'$(echo ${INSTALLATION_ALPINE_VERSION} | rev | cut -d. -f2- | rev) --packages "apk-tools alpine-base linux-lts linux-firmware-none zsh vim btrfs-progs dialog wget git mkinitfs lsblk parted lshw shadow" ${INSTALLATION_MOUNTPOINT}

  installationSubtaskTitle "Setup resolv.conf"
  if [[ -f "${INSTALLATION_MOUNTPOINT}/etc/resolv.conf" ]]; then
    rm -f "${INSTALLATION_MOUNTPOINT}/etc/resolv.conf"
  fi
  cp /etc/resolv.conf "${INSTALLATION_MOUNTPOINT}/etc/resolv.conf" || installationFailed

  installationSubtaskTitle "Setup PATH"
  runInChroot "export PATH='/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin'" || installationFailed

  installationSubtaskTitle "Mount extra mounts for chroot"
  mount -t proc /proc "${INSTALLATION_MOUNTPOINT}/proc" || installationFailed
  mount -t sysfs /sys "${INSTALLATION_MOUNTPOINT}/sys" || installationFailed
  mount -t efivarfs efivarfs "${INSTALLATION_MOUNTPOINT}/sys/firmware/efi/efivars" || installationFailed
  mount -o bind /dev "${INSTALLATION_MOUNTPOINT}/dev" || installationFailed
  mount -o bind /run "${INSTALLATION_MOUNTPOINT}/run" || installationFailed


  installationSubtaskTitle "Install base-packages"
  runInChroot "apk add alpine-base tzdata eudev udev-init-scripts --no-cache" || installationFailed

  installationSubtaskTitle "Overwrite default repositories"
  cp /etc/apk/repositories "${INSTALLATION_MOUNTPOINT}/etc/apk/repositories" || installationFailed

  installationSubtaskTitle "Install Ansible"
  runInChroot "apk add ansible envsubst" || installationFailed

  installationSubtaskTitle "Setup keymap"
  runInChroot "setup-keymap ch ch" || installationFailed

  installationSubtaskTitle "Setting localtime to Europe/Zurich"
  runInChroot "ln -s /usr/share/zoneinfo/Europe/Zurich /etc/localtime" || installationFailed

  installationSubtaskTitle "Time sync"
  runInChroot "hwclock --systohc" || installationFailed

  installationSubtaskTitle "Setup hostname"
  runInChroot "echo '${INSTALLATION_HOSTNAME}.${INSTALLATION_DOMAIN}' > /etc/hostname" || installationFailed
  runInChroot "hostname -F /etc/hostname" || installationFailed
  runInChroot "rc-update add hostname" || installationFailed

  installationSubtaskTitle "Setup hosts"
  cp /etc/hosts "${INSTALLATION_MOUNTPOINT}/etc/hosts" || installationFailed

  installationSubtaskTitle "Set root password"
  runInChroot "echo -e \"${INSTALLATION_ROOT_PW}\n${INSTALLATION_ROOT_PW}\" | passwd" || installationFailed

  installationSubtaskTitle "Enable btrfs module"
  runInChroot "echo 'btrfs' >> /etc/modules"
  runInChroot "echo 'efivarfs' >> /etc/modules"

  installationSubtaskTitle "Enable udev services"
  runInChroot "rc-update add udev sysinit"
  runInChroot "rc-update add udev-trigger sysinit"
  runInChroot "rc-update add udev-settle sysinit"
  runInChroot "rc-update add udev-postmount default"

  echo ""
  echo "┌──────────────────────────────────────────┐"
  echo "│    Configure Ansible and playbook-run    │"
  echo "└──────────────────────────────────────────┘"

  installationSubtaskTitle "Clone Playbook-repo"
  mkdir -p ${INSTALLATION_MOUNTPOINT}/${INSTALLATION_ANSIBLE_ROOT}/playbooks
  git clone ${INSTALLATION_ANSIBLE_GIT} ${INSTALLATION_MOUNTPOINT}/${INSTALLATION_ANSIBLE_ROOT}/playbooks

  mkdir -p ${INSTALLATION_MOUNTPOINT}/etc/ansible
  cat >"${INSTALLATION_MOUNTPOINT}/etc/ansible/ansible.cfg" <<EOT || installationFailed
[defaults]
inventory=/${INSTALLATION_ANSIBLE_ROOT}/inventory.yml
EOT

  cat >"${INSTALLATION_MOUNTPOINT}/${INSTALLATION_ANSIBLE_ROOT}/inventory.yml" <<EOT
ungrouped:
  hosts:
    localhost
  vars:
    ansible_connection: local
    start_timestamp: ${START_TIMESTAMP}
    tmpfs_size: 4G
    installation_type: ${INSTALLATION_TYPE}
    mysql_root_password: $(randomPasswordGen 32)
    release_version: %REL_VER%
    alpine_version: %ALP_VER%
EOT

  installationSubtaskTitle "Execute Ansible playbooks"
  runInChroot "ansible-playbook /${INSTALLATION_ANSIBLE_ROOT}/playbooks/top.ansible.yml" || installationFailed

  echo ""
  echo "┌──────────────────────────────────────────┐"
  echo "│                   Boot                   │"
  echo "└──────────────────────────────────────────┘"

  installationSubtaskTitle "Make EFI boot image with mkinitfs"
  latest_kernel="$(chroot $INSTALLATION_MOUNTPOINT /bin/ash -c 'echo $(apk search linux-lts | head -n1 | cut -d- -f3- | sed "s|r||")-lts')"
  runInChroot "mkinitfs $latest_kernel" || installationFailed

  installationSubtaskTitle "Installing grub to /efi"
  runInChroot "grub-install --target=x86_64-efi --efi-directory=/efi --bootloader-id=alpine" || installationFailed

  installationSubtaskTitle "Generating Bootmenu entries"
  chroot "${INSTALLATION_MOUNTPOINT}" /bin/bash -c "/usr/local/noveria/bin/noveriablcgen --noconfirm" || installationFailed

  installationSubtaskTitle "Generating motd"
  chroot "${INSTALLATION_MOUNTPOINT}" /bin/bash -c "/usr/local/noveria/bin/generate_motd" || installationFailed
  chroot "${INSTALLATION_MOUNTPOINT}" /bin/bash -c "/usr/local/noveria/bin/nsm check remote" || installationFailed

  echo ""
  echo "┌──────────────────────────────────────────┐"
  echo "│                Finishing                 │"
  echo "└──────────────────────────────────────────┘"

  #installationSubtaskTitle "Unmount"
  #umount -l ${INSTALLATION_MOUNTPOINT} || installationFailed

  installationSubtaskTitle "End of installation"

  # end log all output to logfile
  exec &>"$(tty)"

  # write secrets file
  writeInstallationSecretsToFile

  # remove installation lock file
  rm -f "$INSTALLATION_LOCK_FILE"

  # remove shell histories
  rm -f /root/.zsh_history

  selected_option=$(dialog --output-fd 1 --menu "What would you like to do?" 10 70 5 reboot "Reboot into your newly installed system" poweroff "Shut down the current live system" alpine-shell "Switch to an interactive shell")
  case "$selected_option" in
    "reboot")
        reboot
        ;;
    "poweroff")
        poweroff
        ;;
    "alpine-shell")
        clear
        exit
        ;;
  esac
}

##
#   Write installation secrets to file
##
writeInstallationSecretsToFile() {
  rm -f "$INSTALLATION_SECRETS_FILE"
  {
    echo "# Installation secrets from $START_TIMESTAMP"
    echo ""
    echo "FQDN: $(cat /mnt/etc/hostname)"
    echo ""
    echo "root_pw: ${INSTALLATION_ROOT_PW}"
    echo ""
  } >>"$INSTALLATION_SECRETS_FILE"
}

##
#   Installation failed
#   - $1: comment
##
installationFailed() {
  # log error
  echo -e "\n=> ERROR"
  if [ -n "$1" ]; then
    echo -e "=> Comment: $1"
  fi

  # end log all output to logfile
  exec &>"$(tty)"

  # Remove lock file
  rm -f $INSTALLATION_LOCK_FILE

  dialog --no-collapse --ok-label "Exit" --msgbox "\n   Installation failed\n\nLog: ${INSTALLATION_LOGFILE} " 9 32
  clear
  exit 1
}


###
## Script Start
###

preChecks

###
## Script End
###