#!/usr/bin/env bash
# 
# Script to build Kogaion Linux packages in a clean squashfs + overlayfs chroot
# Using predefined targets : kernel.target, libs.target, x11.target, sound.target, artwork.target etc
# Targets are passed as arguments, and will remain private...for now (not all of them are stable yet)
# Author	: V3n3RiX @ RogentOS
# Deps		: squashfs + overlayfs kernel support
# Todo		: add squashfs portage tree && overlays sync && build.git sync && profile setup
# Todo		: auto push built packages to repos (maybe, really needed?!?)

export local sqfsroot="kogaiondevelx64.squashfs"
export local sqfsroothash="fb2afc5f3b387412a0954f242df54927"
export local rodir="rodir"
export local rwdir="rwdir"
export local overlaydir="overlaydir"
export local envuser="root"
export local envtargets="$@"
export local envbuildcmd="emerge -av "$envtargets""


envintegrity() {
	# check if our squashfs chroot somehow got corrupted, abort if so
	while : true ; do
		if [[ "$(md5sum "$sqfsroot" | awk {'print $1'})" = "$sqfsroothash" ]]; then
			break
		else
			exit 1
		fi
	done
}

envstart () {
	# mount ro squashfs + add rw overlayfs layer to enable clean package building
	mount -t squashfs "$sqfsroot" "$rodir"
	mount -t overlayfs -o lowerdir="$rodir",upperdir="$rwdir" overlayfs "$overlaydir"
	mount -o bind /proc "$overlaydir"/proc
	mount -o bind /sys "$overlaydir"/sys
	mount -o bind /dev "$overlaydir"/dev
	mount -o bind /dev/pts "$overlaydir"/dev/pts
	mount -o bind /dev/shm "$overlaydir"/dev/shm
	mount -o bind /tmp "$overlaydir"/tmp
}

envstop () {
	# umount squashfs + overlayfs chroot
	umount -l "$overlaydir"/proc
	umount -l "$overlaydir"/sys
	umount -l "$overlaydir"/dev/pts
	umount -l "$overlaydir"/dev/shm
	umount -l "$overlaydir"/dev
	umount -l "$overlaydir"/tmp
	umount -l "$overlaydir"
	umount -l "$rodir"
}

envbuild () {
	# build packages in squashfs + overlayfs chroot
	chroot "$overlaydir" su - "$envuser" -c "$envbuildcmd"
}

envchroot() {
	# enter squashfs + overlayfs chroot to push packages, or debug build errors
	echo -e ""
	echo -e "#################################################################"
	echo -e "#       ENTERING CHROOT ENV FOR YOU TO PUSH BUILT PACKAGES      #"
	echo -e "#               OR TO FIX EVENTUAL BUILD ERRORS                 #"
	echo -e "#################################################################"
	echo -e "#            !!! WARNING !!! WARNING !!! WARNING !!!            #"
	echo -e "#################################################################"
	echo -e "#       NEXT RUN OF THIS SCRIPT WILL DESTROY ALL YOUR WORK      #"
	echo -e "#   DO NOT EXIT CHROOT UNTIL ALL PACKAGES ARE PUSHED TO REPOS   #"
	echo -e "#  OR, IN CASE OF BUILD FAILURES, UNTIL ALL FIXES ARE COMMITED  #"
	echo -e "#################################################################"
	echo -e "#            !!! WARNING !!! WARNING !!! WARNING !!!            #"	
	echo -e "#################################################################"
	echo -e ""
	echo -e ""
	chroot "$overlaydir" su - "$envuser"
}

envprepare () {
	# first let's check our environment for sanity
	# if safe, trigger start && break the loop to build packages
	# else trigger stop && cleanup && check again
	while : true ; do
		if [[ ! -d "$rodir" && ! -d "$rwdir" && ! -d "$overlaydir" ]]; then
			for i in "$rodir" "$rwdir" "$overlaydir" ; do
				mkdir "$i"
			done
			envstart
			break
		elif [[ -d "$overlaydir" && -f "$overlaydir/usr/bin/emerge" ]] ; then
			envstop
			for i in "$rodir" "$rwdir" "$overlaydir" ; do
				rm -rf "$i"
			done
			continue
		fi
	done
}

main () {
	envintegrity
	envprepare
	envbuild
	envchroot
}

main 
exit 0