#!/bin/bash
####################################################################################
# File.......: /usr/lib/setup/INS-all-in-one
# Called from: Forked from /usr/lib/setup/SeTmedia
# Purpose....: Detect a partition labeled 'SLKins_aio-pkgs' and configure the
#              Installer to use it as the media source.
# Version....: 1.00
# Date.......: 22-Nov-2022
# Author.....: Stuart Winter <mozes@slackware.com>
###################################################################################
# Change log
# v1.00, 22-Nov-2022
# * Initial version
###################################################################################
#
# Copyright 2022  Stuart Winter, Earth, Milky Way, "".
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED
#  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
#  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
#  EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
#  OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
#  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
#  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
#  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# Exit codes
# 0 = Success (Install media dialog screen can exit cleanly)
# 1 = General failure. (Install media dialog needs to present the list of options)
# 2 = No media label found on any removable block device.
# 3 = Sanity checks failed.
# 4 = User chose not to use the bundled media, although the media passed sanity check.
# 10 = User configured not to use All-In-One feature.

# Check if the user has bypassed the all-in-one Installer functionality.
# This may be if they have the all-in-one Installer on the USB stick but want
# to install from another medium, and don't fancy re-deploying the standard USB
# Installer image to the USB stick.
[ -f /.no-allinone ] && exit 10

# Settings:
SLKINSMNT=/slack-all-in-one
TMP=/var/log/setup/tmp
[ ! -d $TMP ] && mkdir -pm755 $TMP

###################################################################################
################### Functions #####################################################
###################################################################################

# This code was copied in part from usr/lib/setup/INSUSB:
# Detect a device with a partition label 'SLKins_aio-pkgs'
# The MMC block devices aren't identified as 'removeable' so we don't filter on
# that attribute since this is the standard storage subsystem we use on ARM.
#lsblk -o name,label -ripn | grep -E 'SLKins_aio-pkgs$'
function media_scan(){
   local rdevice founddev
   for rdevice in $( ls --indicator-style none /sys/block | grep -Ev "loop|ram|^dm-|^sr|^md" ); do
         # Is it labeled 'SLKins_aio-pkgs'? If so we'll take the first one we find:
         founddev="$( lsblk -o name,label -ripn /dev/${rdevice} 2>/dev/null | grep -E 'SLKins_aio-pkgs$' | awk '{print $1}' )"
         [ ! -z "${founddev}" ] && break
   done
   # Report back if we found one:
   [ ! -z "${founddev}" ] && { echo "${founddev}" ; return 0 ;} || return 1
}

# Mount the specified block device under the known mount point:
function media_mount() {
   mount -o noatime -m "$1" $SLKINSMNT 2>/dev/null
   return $? ;}

# umount the media:
function media_umount() {
   umount $SLKINSMNT 2>/dev/null
   return $? ;}

# Check if the Slackware media partition is already mounted:
function media_ismounted() {
   findmnt -DRM ${SLKINSMNT} > /dev/null 2>&1
   return $?
}

# Sanity check the media:
# The directory layout is: '/slackware/<slackware-tree-name>'
# This is to enable users to add non-Slackware related assets to the partition upon installation
# of the OS, if they wish.
function media_sanity_check() {
   local slacktree=$( media_report_slacktree )
   [ -z "$slacktree" ] && return 1
   # Is the tree available? We'll check the 'A' series directory is present:
   [ ! -d $SLKINSMNT/slackware/$slacktree/a ] && return 1
   # Enough sanity checking, it's probably good!
   return 0
}

# Report the path to the configured Slackware media:
# Output is relative - e.g. doesn's include the mount point and parent 'slackware' directory.
function media_report_slacktree() {
   # The Slackware tree we're using is configured in this file.
   # This is placed by the script that creates the All-in-One Installer image.
   [ ! -f $SLKINSMNT/slackware/.slktree ] && return 1
   # Output content of the file which is a relative path: e.g. "slackwareaarch64-current/slackware"
   grep -Ev '^$' $SLKINSMNT/slackware/.slktree
}

# Inform the user that the All-in-One Installer is ready to go.
function offer_msg_ready() {
   local blockdev="$1" mntpnt="$2"
#      --msgbox "\nThe Slackware package directory has been found on $blockdev and is mounted on $mntpnt ready for use.\n
   dialog \
      --backtitle "Slackware Installer" \
      --title "INSTALLATION MEDIA SOURCE FOUND" --ok-button "OK" \
      --msgbox "\nThis edition of the Slackware Installer has the installation media bundled, and is ready to use.\n
      " 8 79
   clear
}

# Inform the user that the All-in-One Installer was detected but failed sanity check.
function offer_msg_failsanity() {
   local blockdev="$1" mntpnt="$2"
   dialog \
      --backtitle "Slackware Installer" \
      --title "INSTALLATION MEDIA SOURCE" --ok-button "OK" \
      --msgbox "\nThis edition of the Slackware Installer contains the installation media.\n\n
The media has been located on $blockdev but has failed the tests.\n\n
You will now be presented with the option to choose a different installation media source.\n" 12 79
   clear
}

# Offer the option to use the bundled media or pick the option manually:
# Y=return 0, N=1
function offer_chooseaio() {
   dialog \
      --backtitle "Slackware Installer" \
      --title "INSTALLATION MEDIA SOURCE" --yesno \
      "\nThis edition of the Slackware Installer contains the installation media.\n\n
Would you like to use this as the media source?\n\n
Answering 'No' provides a list of alternate installation media selection options.\n\n
Recommendation: Yes" 15 77
   return $?
}

# Configure the Slackware Installer to find the installation media on the All-in-One partition:
function installer_configure() {
   # An example of the entry in this file: /slack-all-in-one/slackware/slackwareaarch64-current/slackware
   echo "$SLKINSMNT/slackware/$( media_report_slacktree )" > $TMP/SeTDS # is $SLKINSMNT/slackware/[contents of file '.slktree']
   echo "-source_mounted" > $TMP/SeTmount
   echo "/dev/null" > $TMP/SeTsource
}

###################################################################################

# Try to locate the All-in-One Installer partition:
mediablockdev=$( media_scan )

# If we didn't find a block device with our label, bail out to enable the user to select
# one from the list presented by /usr/lib/setup/SeTmedia:
[ -z "${mediablockdev}" ] && exit 2

# If the media is already mounted and the sanity check passes, inform the user.
# This is to facilitate that the user may bounce through the main 'setup' menu and select
# the installation media chooser (/usr/lib/setup/SeTmedia) more than once.
# No, we're not going to offer them the option to pick a different installation source media:
# it might break something.  They can reboot.
if media_ismounted && media_sanity_check; then
   offer_msg_ready $mediablockdev $SLKINSMNT
   exit 0
fi

# It's not mounted, but we found a label on a removable block device.  Let's mount it,
# configure the Installer to find the package source media, and inform the user that it's
# ready to roll:
if media_mount $mediablockdev && media_sanity_check; then
   # Give the user the choice to use it.  At this point we know it's validated so is a viable option.
   # If the user chooses 'no', we umount the media and are returned to the '/usr/lib/setup/SeTmedia'
   # process to pick an option.
   offer_chooseaio || { media_umount ; clear ; exit 4 ;}
   installer_configure
   #offer_msg_ready $mediablockdev $SLKINSMNT
   exit 0
 else
   # umount the media. If it fails, no problem - we can ignore it. The Installer won't be configured
   # to use it unless the sanity check passed, so anything mounted isn't used nor is in the way.
   media_umount
   # Inform the user that they get to pick from the list of source media installation options:
   offer_msg_failsanity $mediablockdev
   exit 3
fi

clear
exit 0