#!/bin/bash
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-06-17; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.installer.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.installer
# SPDX-Security-Contact: security@coresecret.eu

guard_sourcing || return "${ERR_GUARD_SOURCE}"

#######################################
# Function to create the mount command, incl. mount path and options, and mount the respective device.
# Globals:
#   TARGET
# Arguments:
#   1: MOUNT_PATH
#   2: MOUNT_DEVICE
#   3: MOUNT_OPTIONS
#   4: MOUNT_FILESYSTEM
# Returns:
#   0: on success
#   ERR_MOUNTING_DEV: on failure
#######################################
mount_with_dir() {
  declare var_mount_path="${1}" var_mount_device="${2}" var_mount_options="${3:-}" var_mount_fs="${4:-}"
  declare -a ary_cmd=( mount )

  ### GPT-UUID conformity (RFC 4122).
  if [[ "${var_mount_device}" =~ ^[0-9a-fA-F]{8}-([0-9a-fA-F]{4}-){3}[0-9a-fA-F]{12}$ ]]; then

    if [[ -e "/dev/disk/by-uuid/${var_mount_device}" ]]; then

      var_mount_device="/dev/disk/by-uuid/${var_mount_device}"

    else

      do_log "error" "file_only" "3280() GPT-UUID for mount path: '${var_mount_path}' not found by '/dev/disk/by-uuid/${var_mount_device}'."
      return "${ERR_MOUNTING_DEV}"

    fi

  ### VFAT-UUID conformity.
  elif [[ "${var_mount_device}" =~ ^[0-9A-F]{4}-[0-9A-F]{4}$ ]]; then

    if [[ -e "/dev/disk/by-uuid/${var_mount_device}" ]]; then

      var_mount_device="/dev/disk/by-uuid/${var_mount_device}"

    else

      do_log "error" "file_only" "3280() FAT-UUID for mount path: '${var_mount_path}' not found by '/dev/disk/by-uuid/${var_mount_device}'."
      return "${ERR_MOUNTING_DEV}"

    fi

  ### Already absolute path.
  elif [[ "${var_mount_device}" == /dev/* ]]; then

    : ### Do nothing.

  ### Alternative checks for LABEL and PARTUUID.
  else

    if [[ -e "/dev/disk/by-label/${var_mount_device}" ]]; then

      var_mount_device="/dev/disk/by-label/${var_mount_device}"

    elif [[ -e "/dev/disk/by-partuuid/${var_mount_device}" ]]; then

      var_mount_device="/dev/disk/by-partuuid/${var_mount_device}"

    else

      do_log "error" "file_only" "3280() Mount path: '${var_mount_path}' could not be resolved by [UUID, LABEL, DEV, PARTUUID]'."
      return "${ERR_MOUNTING_DEV}"

    fi

  fi

  if [[ -z "${var_mount_fs:-}" ]]; then

    var_mount_fs=$(blkid -o value -s TYPE "${var_mount_device}" 2>/dev/null || true)

  fi

  [[ "${var_mount_path}" != "/" ]] && mkdir -p "${TARGET}${var_mount_path}"

  ### Build the command in an array to keep word boundaries intact.
  [[ -n "${var_mount_fs}" ]]      && ary_cmd+=( "-t" "${var_mount_fs}" )
  [[ -n "${var_mount_options}" ]] && ary_cmd+=( "-o" "${var_mount_options}" )

  ary_cmd+=( "${var_mount_device}" "${TARGET%/}${var_mount_path}" )

  safe_exec "${ary_cmd[@]}" "${ERR_MOUNTING_DEV}" || return

  do_log "debug" "file_only" "3280() [safe_exec ${ary_cmd[*]} ${ERR_MOUNTING_DEV}]."

  do_log "info" "file_only" "3280() Mounted: '${var_mount_device}' on: '${TARGET}${var_mount_path}' Options='${var_mount_options}'."

  return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f mount_with_dir

#######################################
# Device Path Resolver.
# Outputs '/dev/mapper/<encryption_label>'
# Outputs '/dev/<dev><partition>'
# Globals:
#   None
# Arguments:
#   1: Device
#   2: Partition
#   3: Boolean Encryption
#   4: Encryption Label
# Returns:
#   0: on success
#######################################
resolve_device() {
  declare local_var_dev="$1" local_var_partition="$2" local_var_enc_boolean="$3" local_var_enc_label="$4"

  if [[ "${local_var_enc_boolean,,}" == "true" ]]; then

    printf '/dev/mapper/%s' "${local_var_enc_label}"

  else

    printf '/dev/%s%s' "${local_var_dev}" "${local_var_partition}"

  fi

  return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f resolve_device

#######################################
# Validates btrfs compression algo and level.
# Globals:
#   None
# Arguments:
#   1: var_fs_btrfs_compress
#   2: var_fs_btrfs_level
# Returns:
#   0: Valid combination.
#   ERR_BTRFS_OPTION: on failure
#######################################
validate_btrfs_compression() {
  declare var_algo="$1" var_level="$2"

  case "${var_algo}:${var_level}" in

    zstd:|zstd:[0-9]|zstd:1[0-9]|zstd:2[0-2]|lzo:) return 0 ;;

    *) do_log "error" "file_only" "3280() Invalid btrfs compression: '${var_algo}:${var_level}'"; return "${ERR_BTRFS_OPTION}" ;;

  esac
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f validate_btrfs_compression

#######################################
# Function for mounting all partitions for debootstrap, including the generation of btrfs subvolumes.
# Globals:
#   ARY_CRYPT_MOUNT_PATHS
#   ARY_PATHS_SORTED
#   DIR_LOG
#   HMP_FSTAB_MOUNT_OPTS
#   HMP_PATH_DEV_PART
#   HMP_PATH_FSUUID
#   HMP_PATH_PARTUUID
#   NL
#   TARGET
#   VAR_RECIPE_STRING
#   VAR_SAFE_MNT_BASE
#   VAR_SETUP_PART
# Arguments:
#   None
# Returns:
#   0: on success
#   ERR_BTRFS_INITPH: on failure
#   ERR_BTRFS_OPTION: on failure
#   ERR_BTRFS_SUBVOL: on failure
#   ERR_MOUNTING_DEV: on failure
#######################################
mount_partition() {
  ### Declare Arrays, HashMaps, and Variables.
  # shellcheck disable=SC2034
  declare -Ag HMP_FSTAB_MOUNT_OPTS   # Used in: 4200() - [Mount Path:Mount Options].

  declare     var_mount_path="" var_dev_part="" var_dev="" var_btrfs_options="" \
              var_encryption_label="" var_fs_btrfs_compress="" var_fs_btrfs_level="" var_fs_btrfs_snapshot="" \
              var_fs_btrfs_subvolume="" var_fs_version="" var_mount_options="" var_mount_optsnap="" var_mount_path="" \
              var_snapshot="" var_fs_uuid="" var_partuuid=""

  declare -a  ary_cmd=() ary_cmd_mount=()

  for var_mount_path in "${ARY_PATHS_SORTED[@]}"; do

    ### Initialize Arrays and Variables
    ary_cmd=(); ary_cmd_mount=(); var_btrfs_options=""

    ### Generates physical device location.
    var_dev_part="${HMP_PATH_DEV_PART["${var_mount_path}"]}"
    var_dev="${var_dev_part//./}"

    ### Extract parameters from YAML.
    var_fs_btrfs_compress=$(yq_val ".recipe.${VAR_RECIPE_STRING}.dev.${var_dev_part}.filesystem.btrfs.compress" "${VAR_SETUP_PART}")
    var_fs_btrfs_level=$(yq_val ".recipe.${VAR_RECIPE_STRING}.dev.${var_dev_part}.filesystem.btrfs.level"       "${VAR_SETUP_PART}")
    var_fs_btrfs_snapshot=$(yq_val ".recipe.${VAR_RECIPE_STRING}.dev.${var_dev_part}.filesystem.btrfs.snapshot" "${VAR_SETUP_PART}")
    var_fs_version=$(yq_val ".recipe.${VAR_RECIPE_STRING}.dev.${var_dev_part}.filesystem.version"               "${VAR_SETUP_PART}")
    var_mount_options=$(yq_val ".recipe.${VAR_RECIPE_STRING}.dev.${var_dev_part}.mount.options"                 "${VAR_SETUP_PART}")
    var_mount_optsnap=$(yq_val ".recipe.${VAR_RECIPE_STRING}.dev.${var_dev_part}.mount.optsnap"                 "${VAR_SETUP_PART}")

    if [[ "${ARY_CRYPT_MOUNT_PATHS[*]}" == *"${var_mount_path}"* ]]; then
      var_encryption_label=$(get_label "${var_mount_path}" "${var_fs_version}" "luks")
    fi

    ### Mounting of Ephemeral 'SWAP' and '/tmp' as per https://wiki.archlinux.org/title/Dm-crypt/Swap_encryption#UUID_and_LABEL
    if [[ "${var_mount_path,,}" == "swap" ]]; then

      var_partuuid="${HMP_PATH_PARTUUID["${var_mount_path}"]}"

      ### Gathering information for '/etc/fstab'-generation in 4040().
      HMP_FSTAB_MOUNT_OPTS["SWAP"]="${var_mount_options}"

      cryptsetup open --type plain \
        --key-file /dev/urandom \
        --cipher aes-xts-plain64 --key-size 512 \
        "/dev/disk/by-partuuid/${var_partuuid}" "${var_encryption_label}"

      mkswap "/dev/mapper/${var_encryption_label}"
      do_log "debug" "file_only" "3280() [mkswap /dev/mapper/${var_encryption_label}]."

      swapon "/dev/mapper/${var_encryption_label}"
      do_log "debug" "file_only" "3280() [swapon /dev/mapper/${var_encryption_label}]."

      do_log "info" "file_only" "3280() Mounted: '${var_mount_path}' on: '/dev/mapper/${var_encryption_label}'."

      ### Ephemeral 'SWAP' finally mounted. Skip all other steps.
      continue

    elif [[ "${var_mount_path,,}" == "/tmp" ]]; then

      var_partuuid="${HMP_PATH_PARTUUID["${var_mount_path}"]}"

      cryptsetup open --type plain \
        --key-file /dev/urandom \
        --cipher aes-xts-plain64 --key-size 512 \
        "/dev/disk/by-partuuid/${var_partuuid}" "${var_encryption_label}"

      mkdir -p "${TARGET}/tmp"

      safe_exec mkfs.ext4 -E lazy_itable_init=1,lazy_journal_init=1 "/dev/mapper/${var_encryption_label}" "${ERR_MOUNTING_DEV}" || return "${ERR_MOUNTING_DEV}"

      ### Gathering information for '/etc/fstab'-generation in 4040().
      HMP_FSTAB_MOUNT_OPTS["${var_mount_path}"]="${var_mount_options}"

      ### Build the command in an array to keep word boundaries intact
      ary_cmd=( mount )
      ary_cmd+=( "/dev/mapper/${var_encryption_label}" "${TARGET}${var_mount_path}" )

      safe_exec "${ary_cmd[@]}" "${ERR_MOUNTING_DEV}" || return "${ERR_MOUNTING_DEV}"
      do_log "info" "file_only" "3280() Mounted: '${var_mount_path}' on: '/dev/mapper/${var_encryption_label}'."

      ### Ephemeral '/tmp' finally mounted. Skip all other steps.
      continue

    fi

    var_fs_uuid="${HMP_PATH_FSUUID["${var_mount_path}"]}"

    if [[ "${var_fs_version,,}" == "btrfs" ]]; then

      var_fs_btrfs_subvolume=$(get_label "${var_mount_path}" "${var_fs_version}" "sub")

      ### Mount toplevel (subvolid=0) without extra options.
      ary_cmd_mount=( mount -o "subvolid=0" "/dev/disk/by-uuid/${var_fs_uuid}" "${VAR_SAFE_MNT_BASE}" )
      safe_exec "${ary_cmd_mount[@]}" "${ERR_BTRFS_INITPH}" || return "${ERR_BTRFS_INITPH}"

      btrfs subvolume create "${VAR_SAFE_MNT_BASE}/${var_fs_btrfs_subvolume}"
      do_log "debug" "file_only" "3280() [btrfs subvolume create ${VAR_SAFE_MNT_BASE}/${var_fs_btrfs_subvolume}]."
      do_log "info" "file_only" "3280() btrfs subvolid=0 created: '${var_mount_path}' on: '/dev/disk/by-uuid/${var_fs_uuid}'."

      if [[ "${var_fs_btrfs_snapshot}" == "true" ]]; then

        var_snapshot=$(get_label "${var_mount_path}" "${var_fs_version}" "snap")

        btrfs subvolume create "${VAR_SAFE_MNT_BASE}/${var_snapshot}" || return "${ERR_BTRFS_SUBVOL}"
        do_log "debug" "file_only" "3280() [btrfs subvolume create ${VAR_SAFE_MNT_BASE}/${var_snapshot}]."
        do_log "info" "file_only" "3280() btrfs subvolid=${var_snapshot} created: '${var_mount_path}' on: '/dev/disk/by-uuid/${var_fs_uuid}'."

      fi

      umount "${VAR_SAFE_MNT_BASE}"
      do_log "info" "file_only" "3280() btrfs subvolume umount: '${var_mount_path}' on: '/dev/disk/by-uuid/${var_fs_uuid}'."

    fi

    case "${var_fs_version,,}" in

      btrfs)

        validate_btrfs_compression "${var_fs_btrfs_compress}" "${var_fs_btrfs_level}" || return "${ERR_BTRFS_OPTION}"

        if [[ -n "${var_mount_options}" ]]; then
          var_btrfs_options="subvol=${var_fs_btrfs_subvolume},compress=${var_fs_btrfs_compress}:${var_fs_btrfs_level},${var_mount_options}"
        else
          var_btrfs_options="subvol=${var_fs_btrfs_subvolume},compress=${var_fs_btrfs_compress}:${var_fs_btrfs_level}"
        fi

        ### Gathering information for '/etc/fstab'-generation in 4040().
        HMP_FSTAB_MOUNT_OPTS["${var_mount_path}"]="${var_btrfs_options}"
        do_log "debug" "file_only" "3280() [HMP_FSTAB_MOUNT_OPTS] : '${var_mount_path}' -> '${HMP_FSTAB_MOUNT_OPTS["${var_mount_path}"]}'."

        mount_with_dir "${var_mount_path}" "${var_fs_uuid}" "${var_btrfs_options}" "btrfs" || return "${ERR_MOUNTING_DEV}"
        do_log "info" "file_only" "3280() Mounted: '${var_fs_uuid}' on: '${TARGET}${var_mount_path}' Options='${var_btrfs_options}'."

        if [[ "${var_fs_btrfs_snapshot}" == "true" ]]; then

          ### Preparing "/.snapshot"-directory
          mkdir -p "${TARGET}${var_mount_path}/.snapshots"
          do_log "info" "file_only" "3280() Created: '${TARGET}${var_mount_path}/.snapshots'."

          if [[ -n "${var_mount_optsnap}" ]]; then
            var_mount_optsnap+=",subvol=${var_snapshot}"
          else
            var_mount_optsnap="subvol=${var_snapshot}"
          fi

          ### Gathering information for '/etc/fstab'-generation in 4040().
          HMP_FSTAB_MOUNT_OPTS["${var_mount_path}/.snapshots"]="${var_mount_optsnap}"
          do_log "debug" "file_only" "3280() [HMP_FSTAB_MOUNT_OPTS] : '${var_mount_path}/.snapshots' -> '${HMP_FSTAB_MOUNT_OPTS["${var_mount_path}/.snapshots"]}'."

          mount_with_dir "${var_mount_path}/.snapshots" "${var_fs_uuid}" "${var_mount_optsnap}" "btrfs"
          do_log "info" "file_only" "3280() Mounted: '${var_fs_uuid}' on: '${TARGET}${var_mount_path}/.snapshots' Options='${var_mount_optsnap}'."

        fi
        ;;

      ext4)

        ### Gathering information for '/etc/fstab'-generation in 4040().
        HMP_FSTAB_MOUNT_OPTS["${var_mount_path}"]="${var_mount_options}"
        do_log "debug" "file_only" "3280() [HMP_FSTAB_MOUNT_OPTS] : '${var_mount_path}' -> '${HMP_FSTAB_MOUNT_OPTS["${var_mount_path}"]}'."

        mount_with_dir "${var_mount_path}" "${var_fs_uuid}" "${var_mount_options}" "ext4" || return "${ERR_MOUNTING_DEV}"
        do_log "info" "file_only" "3280() Mounted: '${var_fs_uuid}' on: '${TARGET}${var_mount_path}' Options='${var_mount_options}'."
        ;;

      fat32)

        ### Gathering information for '/etc/fstab'-generation in 4040().
        HMP_FSTAB_MOUNT_OPTS["${var_mount_path}"]="${var_mount_options}"
        do_log "debug" "file_only" "3280() [HMP_FSTAB_MOUNT_OPTS] : '${var_mount_path}' -> '${HMP_FSTAB_MOUNT_OPTS["${var_mount_path}"]}'."

        mount_with_dir "${var_mount_path}" "${var_fs_uuid}" "${var_mount_options}" "vfat" || return "${ERR_MOUNTING_DEV}"
        do_log "info" "file_only" "3280() Mounted: '${var_fs_uuid}' on: '${TARGET}${var_mount_path}' Options='${var_mount_options}'."
        ;;

      *)
        do_log "info" "file_only" "3280() No valid FS found for: '${var_mount_path}'."
        ;;

      esac

    var_dev="${var_dev_part%.*}"
    lsblk -o NAME,MAJ:MIN,FSTYPE,FSVER,SIZE,UUID,MOUNTPOINT,PATH "/dev/${var_dev}" >| "${DIR_LOG}/3280_${var_dev}_overview.log"
    lsblk -o NAME,PARTTYPE,FSTYPE,FSVER,UUID,MOUNTPOINT,PATH "/dev/${var_dev}" >| "${DIR_LOG}/3280_${var_dev}_parttype.log"
    {
      printf "%b" "${NL}"
      lsblk "/dev/${var_dev}"
      printf "%b" "${NL}"
      lsblk -t "/dev/${var_dev}"
    } >> "${DIR_LOG}/3280_${var_dev}_overview.log"

  done

  guard_dir; return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f mount_partition
# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh