# Parabola Install Wizard - common functions
#
# Copyright (C) 2020,2022 bill-auger <bill-auger@programmer.net>
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
# This file is part of Parabola Install Wizard.
#
# Parabola Install Wizard is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Parabola Install Wizard is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Parabola Install Wizard. If not, see <http://www.gnu.org/licenses/>.


cd $(dirname ${BASH_SOURCE[0]})
source ./constants.sh.inc


## sanity checks ##

if   (( ! IN_CHROOT ))
then which dialog &> /dev/null || ! echo "${DIALOG_ERR_MSG}"    || exit
     (( ! $EUID ))             || ! echo "${PRIVILEGE_ERR_MSG}" || exit
     [[ -w ./.session_state ]] || ! echo "${STATEFILE_ERR_MSG}" || exit
fi


## state helpers ##

SetStateVar() # (var_name value*)
{
  local var_name=$1 ; shift ;
  local value="$*"

  sed -i "/^${var_name}=.*/d"    ./.session_state
  echo "${var_name}=${value}" >> ./.session_state
}

GetStateVar() # (var_name [def_value])
{
  local var_name=$1
  local def_value=$2
  local stored_value=$(grep "${var_name}=" ./.session_state | cut -d '=' -f 2)

  if   [[ -n "${stored_value}" ]] && [[ "${stored_value}" != '_UNDEFINED_' ]]
  then echo ${stored_value}
  else echo ${def_value}
  fi
}

AreConfiguredStateVars() # ( state_var [ state_var ] ... )
{
# for state_var in $* ; do echo -n "AreConfiguredStateVars() state_var=${state_var}=$(GetStateVar ${state_var})=" ; [[ -n "$(GetStateVar ${state_var})" ]] && echo "OK" || ! echo "NFG" ; done ;

  # TODO: replace each call to this function with proper validations
  for state_var in $* ; do [[ -n "$(GetStateVar ${state_var})" ]] || return 1 ; done ;

  return 0
}


## dialog prompt helpers ##

# WizardDlg() notes:
# the primary purpose of the WizardDlg() function, is to simplify and normalize
#   creation of various dialog boxes, such that they can all be handled uniformly.
#
# in order for this to work properly, callers of WizardDlg() should pass the
# box-type argument (eg: --menu, --yesno, --inputbox) as positional parameter #2,
# followed by it's box-specific options. additional dialog options may be set
# via the 'DIALOGOPTS' environment variable.
#
# when the "Cancel" button or <ESC> key is pressed, in a 'msgbox',
#   'dialog' exits with a non-zero status; and no result is printed.
# install.sh runs under `set -e`; so we can not propogate the non-zero status,
#   otherwise, all callers of these helpers would need to supress it.
# callers should instead, exit upon the empty result, when a selection is mandatory.
#
# because an 'inputbox' may be blank, when the "OK" button is pressed, we emit a space,
#   in order to maintain the invariant, such that the "OK" result is never empty.
#
# 'dialog' is quirky; and it was difficult to acheive complete uniformity.
# so unfortunately, there are some caveats:
# * 'yesno' dialogs exit with a non-zero status upon the "No" button.
#   the "Cancel" and "No" buttons are identical, and indistinguishable at run-time.
#   the $YESNO_YES or $YESNO_NO values are printed explicitly for 'yesno' dialogs,
#   so that callers can handle the 'yesno' dialogs in the same way as 'msgbox' dialogs.
# * 'checklist' dialogs print no result if nothing was selected,
#   which would be indistinguishable from a cancel operation (eg: <ESC> key).
#   for that reason, $CANCEL_SENTINEL will be printed explicitly, upon a cancel operation
#   for 'checklist' dialogs, so that interested callers may handle it.
readonly CANCEL_STATUS=1
readonly CANCEL_SENTINEL='CANCEL'

# dialog prompt for session-init.sh (with auto-accept timeout)
InitDlg() # (title prompt default_option options*)
{
  local title="$1"
  local prompt="$2"
  local default_option="$3"
  local options=("${@:4}")

  dialog --stdout --sleep 1 --no-tags --no-cancel --timeout 30 \
         --backtitle    "${title}"                             \
         --default-item "${default_option}"                    \
         --menu         "${prompt}" 15 42 10                   \
         "${options[@]}"
}

# dialog prompts for install.sh
WizardDlg() # ("title" box_type "boxargs"* options*)
{
  local title="$1"
  local dialog_type=$2
  local boxargs_and_options=("${@:3}")
  local opts=( $( [[ "${dialog_type}" == '--progressbox' ]] ||
                  [[ "${dialog_type}" == '--infobox'     ]] || echo '--erase-on-exit' ) )
  local result
  local status

  result=$( DIALOG_ESC=${CANCEL_STATUS}                       \
            dialog --stdout --insecure --sleep 1              \
                   --colors ${opts[*]}                        \
                   --backtitle    "${TR[wizard-${Lang}]}"     \
                   --title        "${title}"                  \
                   ${dialog_type} "${boxargs_and_options[@]}" ) && status=$? || status=$?

  # NOTE: a failure on the following LOC, indicates a bug in the caller code
  (( ! status || status == CANCEL_STATUS ))

  if   [[ "${dialog_type}" == '--menu' ]]
  then echo "${result}"

  elif [[ "${dialog_type}" == '--yesno' ]]
  then echo $(( ! status ))

  elif [[ "${dialog_type}" == '--inputbox'    ]] ||
       [[ "${dialog_type}" == '--passwordbox' ]]
  then if   (( status != CANCEL_STATUS ))
       then [[ -n "${result}" ]] && echo "${result}" || echo ' '
       fi

  elif [[ "${dialog_type}" == '--checklist' ]]
  then (( status != CANCEL_STATUS )) && echo "${result}" || echo ${CANCEL_SENTINEL}

  elif [[ "${dialog_type}" == '--infobox'     ]] ||
       [[ "${dialog_type}" == '--gauge'       ]] ||
       [[ "${dialog_type}" == '--msgbox'      ]] ||
       [[ "${dialog_type}" == '--progressbox' ]]
  then echo ''

  else echo "unhandled dialog_type: ${dialog_type}" >&2
  fi

  (( status == CANCEL_STATUS )) && status=0 || true ;

  return ${status}
}

ExitFail() # ("exit_msg")
{
  WizardDlg "${TR[exit_fail-${Lang}]}" --infobox "$(echo -e $@)" 0 0
  exit
}


## input validation helpers ##

ValidateId() # (login)
{
  local login="$*"

  [[ "${login}" =~ ^[[:space:]]*[^[:space:]]+[[:space:]]*$ ]] # TODO: improve this
}


## partitioning helpers ##

readonly DISK_RECORD_SEP='|'
readonly DISK_FIELD_SEP=':'

declare -A PartsData # raw data
declare -a DlgParams # dialog options

UnmountAll()
{
  mkdir -p /mnt
  umount /mnt/boot &> /dev/null || true
  umount /mnt/home &> /dev/null || true
  umount /mnt      &> /dev/null || true
}

GetDisksPartsData()
{
  local line
  local dev
  local size
  local part_n
  local format

  # example parted output (GPT):
  #   BYT;
  #   /dev/sda:1074MB:scsi:512:512:gpt:ATA QEMU HARDDISK:; # QEMU device
  #   1:1049kB:106MB:105MB:ext4::;                         # EXT4 partition
  #   2:106MB:211MB:105MB:::;                              # un-formatted partition
  #   3:211MB:316MB:105MB:::swap;                          # un-formatted swap partition
  #   4:316MB:421MB:105MB:linux-swap(v1)::swap;            # formatted swap partition
  #                                                        # <-- ~600MB unallocated space
  #
  # example parted output (MBR):
  #   BYT;
  #   /dev/sdb:250GB:scsi:512:512:msdos:ATA ST3250318AS:; # hardware device
  #   1:1049kB:525MB:524MB:ntfs::boot;                    # windows boot partition
  #   2:525MB:20.5GB:20.0GB:ntfs::;                       # windows system partition
  #   4:20.5GB:249GB:228GB:::lvm;                         # LLVM partition
  #   3:249GB:250GB:1049MB:ntfs::msftres;                 # windows data partition
  #
  # NOTE: the example /dev/sdb is a typical windows partition scheme, where partition #2 was shrunken,
  #       partition #3 was deleted, and a *nix partition (#4) was added
  #
  # example parted output (multiple devices, no partition table on sdb):
  #   BYT;
  #   /dev/sda:42.9GB:scsi:512:512:msdos:ATA QEMU HARDDISK:;
  #   1:1049kB:42.9GB:42.9GB:ext4::;
  #
  #   BYT;                                                                      
  #   /dev/sdb:1074MB:scsi:512:512:unknown:ATA QEMU HARDDISK:;
  #
  # NOTE: in the 'BYT;' line of the example /dev/sdb,
  #       all of those spaces and a stray CR are present in the output
  #       '                                                                      \rBYT;'
  #
  # example GetDisksPartsData() output:
  #   /dev/sda:1074MB|/dev/sda1:105MB:ext4|/dev/sda2:105MB
  #   /dev/sdb:250GB|/dev/sdb1:524MB:ntfs|/dev/sdb2:20.0GB:ntfs|/dev/sdb4:228GB:|/dev/sdb3:1049MB:ntfs
  #
  # TODO: the above knowledge could be encapsulated as test mock data
  #       * make GetDisksPartsData() store into a cache instead of returning results
  #       * call GetDisksPartsData() only once
  #       * replace GetDisksPartsData() in callers with the cache
  #       * write a test suite against these partitioning helpers,
  #         mocking the GetDisksPartsData() cache with the data above
  #       * capture the 7th field (partition type)
  #       * allow automatically format un-formatted swap partitions in Partition()
  #
  # TODO: filter out mounted filesystems

  UnmountAll

  parted --list --machine 2> /dev/null | tr -d '\r' | \
  while read line
  do    if   [[ "$line" =~ ^BYT\;\ *$ ]]                              # device delimiter
        then echo ' '

        elif [[ "${line}" =~ ^(/dev/sd[a-z]):([^:]*): ]]              # device specifier
        then dev="${BASH_REMATCH[1]}"
                 size="${BASH_REMATCH[2]}"
             echo -n "${dev}${DISK_FIELD_SEP}${size}"

        elif [[ "${line}" =~ ^([0-9]):[^:]*:[^:]*:([^:]*):([^:]*): ]] # partition specifier
        then part_n=${BASH_REMATCH[1]}
             size=${BASH_REMATCH[2]}
             format=$( [[ -n "${BASH_REMATCH[3]}" ]] && echo ${BASH_REMATCH[3]} || : )
             echo -n "${DISK_RECORD_SEP}${dev}${part_n}"
             echo -n "${DISK_FIELD_SEP}${size}"
             echo -n "${DISK_FIELD_SEP}${format}"
        fi
  done
}

GetDiskData() # (disk_data_n)
{
  # example GetDiskData() output:
  #   /dev/sda 42.9GB

  if   [[ "$1" =~ ^[0-9]+$ ]]
  then local disk_data_n=$1
       local disks_parts_data=( $(GetDisksPartsData) )
       local disk_data=${disks_parts_data[${disk_data_n}]%%${DISK_RECORD_SEP}*}

       tr "${DISK_FIELD_SEP}" ' ' <<<${disk_data}
  fi
}

GetDiskPartsData() # (disk_data_n)
{
  # example GetDiskPartsData() output:
  #   /dev/sdb1:968MB:ext4 /dev/sdb2:105MB:linux-swap(v1)

  local disk_data_n=$1
  local disks_parts_data=( $(GetDisksPartsData) )
  local disk_parts_data=${disks_parts_data[${disk_data_n}]#*${DISK_RECORD_SEP}}

  tr "${DISK_RECORD_SEP}" ' ' <<<${disk_parts_data}
}

GetDiskPartData() # (disk_data_n part_data_n)
{
  # example GetDiskPartData() output:
  #   /dev/sdb1 968MB ext4

  local disk_data_n=$1
  local part_data_n=$2
  local disk_parts_data=( $(GetDiskPartsData ${disk_data_n}) )
  local disk_part_data=${disk_parts_data[${part_data_n}]}

  tr "${DISK_FIELD_SEP}" ' ' <<<${disk_part_data}
}

GetDevice() # (disk_data_n)
{
  # example GetDevice() output:
  #   /dev/sda

  local disk_data_n=$1
  local disk_data=$(GetDiskData ${disk_data_n})
  local device=${disk_data/ *}

  echo ${device}
}

PopulatePartsData() # (disk_data_n) # sets $PartsData
{
  local disk_data_n=$(( $1 - 1 )) # dialog device_n is 1-based
  local disk_parts_data=( $(GetDiskPartsData ${disk_data_n}) )
  local part_data_n
  local disk_part_data
  local dlg_part_n
  PartsData=()

  # populate storage array for partition data - example PartsData:
  #   [1]="/dev/sdb1 9662MB ext4" [2]="/dev/sdb2 1048kB"
  for (( part_data_n=0 ; part_data_n < ${#disk_parts_data[@]} ; ++part_data_n ))
  do  disk_part_data="$(GetDiskPartData ${disk_data_n} ${part_data_n})"
      dlg_part_n=$(( ${part_data_n} + 1 )) # sparse array for selective deletion

      if ! [[ "${disk_part_data}" =~ linux-swap ]]           && # ignore swap
         ! mount | grep "^${disk_part_data/ *} " > /dev/null    # ignore mounted
      then PartsData[${dlg_part_n}]="${disk_part_data}"
      fi
  done
}

PopulateDisksOptions() # sets $DlgParams
{
  local disks_part_data=( $(GetDisksPartsData) )
  local disk_data_n
  DlgParams=()

  # populate params array for dialog - example DlgParams:
  #   ( 1 "/dev/sda 42.9GB" 2 "/dev/sdb 9664MB" )
  for (( disk_data_n=0 ; disk_data_n < ${#disks_part_data[@]} ; ++disk_data_n ))
  do  DlgParams+=( $(( ${disk_data_n} + 1 )) "$(GetDiskData ${disk_data_n})" )
  done
}

PopulatePartOptions() # sets $DlgParams, assumes $PartsData
{
  local part_data_n
  DlgParams=()

  # populate params array for dialog - example DlgParams:
  #   ( 1 "/dev/sdb1 9662MB ext4" 2 "/dev/sdb2 1048kB" )
  for part_data_n in $(tr ' ' '\n' <<<${!PartsData[@]} | sort)
  do  DlgParams+=( ${part_data_n} "${PartsData[${part_data_n}]}" )
  done
}

RemovePartOption() # (part_n) # modifies $PartsData
{
  local dlg_part_n=$1

  unset 'PartsData['"${dlg_part_n}"']'
  PopulatePartOptions
}


## error logging helpers ##

LogError() # (source_file func_name line_n)
{
  local SOURCE_FILE="${BASH_SOURCE[1]}"
  local FUNC_NAME="$( [[ -n "$1" ]] && echo "$1" || echo "FUNC_NAME" )"
  local LINE_N=$2
  local N_CONTEXT_LINES=3
  local N_LINES=$((      1 + (2 * N_CONTEXT_LINES) ))
  local BEGIN_LINE_N=$(( LINE_N - N_CONTEXT_LINES  ))
  local END_LINE_N=$((   LINE_N + N_CONTEXT_LINES  ))
  local marker line

  (( BEGIN_LINE_N < 0 )) && BEGIN_LINE_N=0

  echo "ERROR: in ${SOURCE_FILE} ${FUNC_NAME}()::${LINE_N}" >&2
  sed 's|\\$||' "${SOURCE_FILE}" | pr -tn                      | \
  tail -n +${BEGIN_LINE_N} | head -n ${N_LINES} | tr '\n' '\n' | \
  while read line
  do    line_n=$(sed -E 's|([0-9]+).*|\1|' <<<${line})
        (( line_n == LINE_N )) && marker='==>' || marker='   '
        printf "%s %s\n" "${marker}" "${line}" >&2
  done
}


## debugging helpers ##

MOCK_INIT()              { SetStateVar 'XKBMAP' ${DEF_KEYMAP} ; SetStateVar 'LANG' ${DEF_LANG} ; SetStateVar 'TR_KEY' ${DEF_TRKEY} ; SetStateVar 'INSTALL' ${DEF_INSTALL} ; }
MOCK_SELECTDEFAULTS()    { SetStateVar 'INSTALL' ${DEF_INSTALL} ; SetStateVar 'BASE' ${DEF_PKG_SET} ; SetStateVar 'INIT' ${DEF_INIT} ; SetStateVar 'WMDE' ${DEF_WMDE} ; SetStateVar 'HOSTNAME' ${DEF_HOSTNAME} ; SetStateVar 'TIMEZONE' ${DEF_TIMEZONE} ; SetStateVar 'KEYMAP' $(GetStateVar 'XKBMAP') ; SetStateVar 'LOCALES' $(GetStateVar 'LANG') ; }
MOCK_SELECTDEFAULTS_NO() { : ; }
MOCK_SELECTLOGINS()      { SetStateVar 'ROOT_PASS' ROOT_PASS ; MOCK_SELECTLOGINS_USER ; }
MOCK_SELECTLOGINS_USER() { SetStateVar 'USER_LOGIN' USER_LOGIN ; SetStateVar 'USER_PASS' USER_PASS ; }
MOCK_SELECTBASE()        { SetStateVar 'INSTALL' ${DEF_INSTALL} ; SetStateVar 'BASE' ${DEF_PKG_SET} ; SetStateVar 'INIT' ${DEF_INIT} ; }
MOCK_SELECTBOOT()        { SetStateVar 'BOOT' 'grub' ; }
MOCK_SELECTWMDE()        { [[ -n "$(GetStateVar 'WMDE')" ]] || SetStateVar 'WMDE' 'cli' ; }
MOCK_SELECTENV()         { SetStateVar 'HOSTNAME' ${DEF_HOSTNAME} ; SetStateVar 'TIMEZONE' ${DEF_TIMEZONE} ; SetStateVar 'KEYMAP' $(GetStateVar 'XKBMAP') ; SetStateVar 'LOCALES' $(GetStateVar 'LANG') ; }


## translations for user-facing strings ##

readonly SWAP_SED_RX='/(\[part_auto-[a-z][a-z]\]=".*) [^ ]+ ([^ ]+\)")/{s//\1 '$((SWAP_MB / 1000))'GB \2/ ; h} ; ${x ; /./{x ; q0} ; x ; q1} ;'
readonly SWAP_SED_ERR_MSG="SWAP_SED_RX failed on translations.sh.inc"
readonly TRANSLATIONS_ERR_MSG="failed to source translations.sh.inc"

if   (( ! IN_CHROOT ))
then # inject size of automatic swap partition into translations, then load the translations
     sed -i -E "${SWAP_SED_RX}" ./translations.sh.inc || ! echo "${SWAP_SED_ERR_MSG}"     || exit 1
     source ./translations.sh.inc                     || ! echo "${TRANSLATIONS_ERR_MSG}" || exit 1
fi


# helper for install.sh
SetLang() { Lang=$( (( ${TRANSLATIONS[$1]} )) && echo $1 || echo ${DEF_TRKEY} ) ; }


# set initial installer language
Lang='' ; SetLang $(GetStateVar 'TR_KEY' ${DEF_TRKEY}) ;