#!/usr/bin/env bash

# import gentoo functions

source /lib/gentoo/functions.sh

# generic variables

export local releasename="redcore"
export local releasetarget="desktop"
export local releaseversion="1"

# kernel version && name from inside core squashfs

export local kernelver="4.8.5-"$releasename""

# core squahfs name and md5 checksum file

export local chrootx64=""$releasename"_"$releaseversion"_core_x64.squashfs"
export local chrootx64md5=""$chrootx64".md5"

# overlay mount variables

export local rodir="rodir"
export local rwdir="rwdir"
export local workdir="workdir" # only needed for overlayfs on kernel greather than 3.18
export local overlaydir="overlaydir"

# build variables and commands to run inside core squashfs when building packages

export local chrootuser="root"
export local chroottarget="${@:2}"
export local chrootbuildtarget="emerge -kav "$chroottarget""
export local chrootsrcmode="vasile --srcmode"

# iso variables and commands to run inside core squahfs when making iso image

export local isouser="root"
export local isomainarch="x86_64"
export local isobinmode="vasile --binmode"
export local isokernelname="kernel-genkernel-"$isomainarch"-"$kernelver""
export local isoramfscmd="dracut -N -a dmsquash-live -a pollcdrom -o systemd -o systemd-initrd -o systemd-networkd -o dracut-systemd --force --kver "$kernelver""
export local isoramfsname="initramfs-"$kernelver".img"
export local isoeficmd="grub2-mkimage -d /usr/lib64/grub/x86_64-efi -o bootx64.efi -O x86_64-efi ext2 fat udf btrfs ntfs reiserfs xfs hfsplus lvm ata part_msdos part_gpt part_apple bsd search_fs_uuid normal chain iso9660 configfile help loadenv reboot cat search memdisk tar boot linux chain"
export local isochainloadcmd="grub2-mkimage -d /usr/lib64/grub/i386-pc -o core.img -O i386-pc biosdisk part_msdos fat"

# iso image layout variables

export local bootloaderfetchpath="/tmp/bootcore"
export local bootloaderconfigs=""$bootloaderfetchpath"/cdroot/boot"
export local isorootdir=""$releasename"-"$releasetarget"-"$releaseversion"-"$isomainarch""
export local isogrubdir=""$isorootdir"/boot/grub"
export local isoefidir=""$isorootdir"/efi/boot"
export local isorsynctarget=""$isorootdir"/rootfs"
export local isorsyncsource="/tmp/"$isorootdir""
export local isocdrootdir=""$isorootdir"/CDroot"
export local isorealfsdir=""$isocdrootdir"/LiveOS"
export local isosquashfsdir=""$isorootdir"/LiveOS"

# modechange variables

export local portagedir="/usr/portage"
export local confdir="/etc/portage"
export local gitdir="/opt/redcore-build/conf/intel/portage"
export local clonedir="/opt/redcore-build"

# generic functions (used for both build && iso creation)

kernelconfig () {
	# check if the host kernel has needed modules for vasile to work properly...fail to start if it doesn't
	if [[ $(zgrep 'CONFIG_OVERLAY_FS=' /proc/config.gz) && $(zgrep "CONFIG_SQUASHFS=" /proc/config.gz) &&  $(zgrep "CONFIG_BLK_DEV_LOOP=" /proc/config.gz) ]] ; then
		einfo "Kernel configuration seems OK, moving on"
		sleep 1
	else
		eerror "Vasile needs OVERLAYFS && SQUASHFS && LOOP DEVICES to work"
		eerror "Please rebuild the kernel with those activated to use it"
		exit 1
	fi
}

checkroot () {
	# check for root privileges, needed for mount && chroot...fail to start if not root
	if [[ "$(whoami)" != root ]] ; then
		eerror "You're not root?...No cookies for you, go away !!!"
		exit 1
	fi
}

checkiflive () {
	# check if running in live mode...fail to start if so
	if [[ -L /dev/mapper/live-base ]] ; then
		eerror "Running in Live mode is unsupported"
		exit 1
	fi
}

chrootchecksum () {
	# check if core squashfs and md5 checksum file exists, verify core squashfs integrity against md5 checksum file
	# fail to start if core squashfs or md5 checksum file doesn't exist, or if core squashfs fails md5 verification
	while : true ; do
		if [[ -f "$chrootx64" && -f "$chrootx64md5" ]] ; then
			einfo "Squashed chroot && Checksum file found"
			if [[ "$(md5sum -c "$chrootx64md5")" ]] ; then
				einfo "Squashed chroot checksum passed"
				sleep 1
				break
			else
				eerror "Squashed chroot checksum failed"
				exit 1
			fi
		else
			eerror "Squashed chroot || Checksum file not found"
			exit 1
		fi
	done
}

# build functions

chrootprepare () {
	# always start from fresh overlay mount path, if previous exists, remove it and start over
	while : true ; do
		if [[ ! -d "$rodir" && ! -d "$rwdir" && ! -d "$workdir" && ! -d "$overlaydir" ]] ; then
			for i in "$rodir" "$rwdir" "$workdir" "$overlaydir" ; do
				mkdir "$i"
			done
			chrootstart
			break
		elif [[ -d "$rodir" && -d "$rwdir" && -d "$workdir" && -d "$overlaydir" ]] ; then
			chrootstop
			for i in "$rodir" "$rwdir" "$workdir" "$overlaydir" ; do
				rm -rf "$i"
			done
			continue
		fi
	done

}

chrootstop () {
	# umount core squashfs overlay mount
	umount -l "$overlaydir"/proc > /dev/null 2>&1
	umount -l "$overlaydir"/sys > /dev/null 2>&1
	umount -l "$overlaydir"/dev/pts > /dev/null 2>&1
	umount -l "$overlaydir"/dev/shm > /dev/null 2>&1
	umount -l "$overlaydir"/dev > /dev/null 2>&1
	umount -l "$overlaydir"/tmp > /dev/null 2>&1
	umount -l "$overlaydir"/usr/portage/packages > /dev/null 2>&1
	umount -l "$overlaydir"/usr/portage/distfiles > /dev/null 2>&1
	umount -l "$overlaydir" > /dev/null 2>&1
	umount -l "$rodir" > /dev/null 2>&1
}

chrootstart () {
	# mount core squashfs in overlay
	mount -t squashfs "$chrootx64" "$rodir"
	mount -t overlay -o lowerdir="$rodir",upperdir="$rwdir",workdir="$workdir" overlay "$overlaydir"
	mount -o bind packages "$overlaydir"/usr/portage/packages
	mount -o bind distfiles "$overlaydir"/usr/portage/distfiles
	mount -t proc proc "$overlaydir"/proc
	mount -t sysfs sysfs "$overlaydir"/sys
	mount -t devtmpfs -o relatime,size=3055348k,nr_inodes=763837,mode=755 none "$overlaydir"/dev
	mount -t devpts -o nosuid,noexec,relatime,gid=5,mode=620 none "$overlaydir"/dev/pts
	mount -t tmpfs -o nosuid,nodev none "$overlaydir"/dev/shm
	mount -t tmpfs -o nosuid,nodev,noexec none  "$overlaydir"/tmp
}

chrootdevtree () {
	# inject portage tree, redcore overlay && redcore buildsystem (portage config)
	chroot "$overlaydir" su - "$chrootuser" -c "$chrootsrcmode"
}

chrootbuild () {
	# build and install package(s) given as argument...if is already built, install it
	einfo "All systems are go!"
	sleep 1
	chroot "$overlaydir" su - "$chrootuser" -c "$chrootbuildtarget"
}

chrootx64 () {
	# land into a chroot env into overlay mounted core squashfs and make build adjustments, if needed
	einfo "DROPPING YOU TO A ROOT SHELL INTO BUILD ENVIRONMENT"
	einfo "FIX FAILURES && ADJUST PORTAGE CONFIGURATION FILES"
	einfo "TEST USEFLAGS && KEYWORDS && MASKS IF REQUIRED"
	einfo "IN THE END : DO NOT FORGET TO COMMIT YOUR CHANGES"
	chroot "$overlaydir" su - "$chrootuser"
}

makepkg () {
	chrootchecksum
	chrootprepare
	chrootdevtree
	chrootbuild
	chrootx64
	chrootstop
}

# iso functions

isostart () {
	# mount iso image core
	mount -o bind packages "$isorsynctarget"/usr/portage/packages
	mount -t proc proc "$isorsynctarget"/proc
	mount -t sysfs sysfs "$isorsynctarget"/sys
	mount -t devtmpfs -o relatime,size=3055348k,nr_inodes=763837,mode=755 none "$isorsynctarget"/dev
	mount -t devpts -o nosuid,noexec,relatime,gid=5,mode=620 none "$isorsynctarget"/dev/pts
	mount -t tmpfs -o nosuid,nodev none "$isorsynctarget"/dev/shm
	mount -t tmpfs -o nosuid,nodev,noexec none  "$isorsynctarget"/tmp
}

isostop () {
	# umount iso image core
	umount -l "$isorsynctarget"/proc > /dev/null 2>&1
	umount -l "$isorsynctarget"/sys > /dev/null 2>&1
	umount -l "$isorsynctarget"/dev/pts > /dev/null 2>&1
	umount -l "$isorsynctarget"/dev/shm > /dev/null 2>&1
	umount -l "$isorsynctarget"/dev > /dev/null 2>&1
	umount -l "$isorsynctarget"/tmp > /dev/null 2>&1
	umount -l "$isorsynctarget"/usr/portage/packages > /dev/null 2>&1
}

isousertree () {
	# inject portage tree, redcore overlay && redcore buildsystem (portage config)
	chroot "$isorsynctarget" su - "$isouser" -c "$isobinmode"
}

isoramfs () {
	# generate iso initramfs with required modules for live boot
	chroot "$isorsynctarget" su - "$isouser" -c "$isoramfscmd"
}

isoefiimg () {
	# generate efi bootloader
	chroot "$isorsynctarget" su - "$isouser" -c "$isoeficmd"
}

isochainloader () {
	# generate syslinux -> grub chainloader for unetbootin compatibility
	chroot "$isorsynctarget" su - "$isouser" -c "$isochainloadcmd"
}

isoservices () {
	# enable live iso image system services
	for service in avahi-daemon cups connman dkms dm-event redcorelive lightdm lvm2-lvmetad lvm2-monitor NetworkManager ModemManager virtualbox-guest-additions ; do
		chroot "$isorsynctarget" su - "$isouser" -c "systemctl enable "$service""
	done
}

isochroot () {
	# land into a chroot env into iso image core and make adjustments, if needed
	einfo "DROPPING YOU TO A ROOT SHELL INTO ISO ENVIRONMENT"
	einfo "INSTALL APPS & TARGETS & DES YOU WANT INSIDE ISO"
	einfo "EXIT WHEN YOU'RE DONE AND I'LL CREATE THE IMAGE"
	chroot "$isorsynctarget" su - "$isouser"
}

prepareiso () {
	# prepare iso image layout
	mkdir -p "$isorsynctarget"
	dd if=/dev/zero of=""$isorsynctarget".img" bs=50M count=400
	mkfs.ext4 ""$isorsynctarget".img"
	mkdir -p "$isorsyncsource"
	mkdir -p "$isocdrootdir"
	mkdir -p "$isosquashfsdir"
	mkdir -p "$isorealfsdir"
	mkdir -p "$isogrubdir"
	mkdir -p "$isoefidir"
	# mount core squashfs and rsync it's contents into core iso image
	mount -t squashfs "$chrootx64" "$isorsyncsource"
	mount -t ext4 ""$isorsynctarget".img" "$isorsynctarget"
	rsync -aHAXr --progress "$isorsyncsource/" "$isorsynctarget/"
	# copy the kernel for live boot
	cp -avx ""$isorsynctarget"/boot/"$isokernelname"" ""$isorootdir"/boot/vmlinuz"
	# generate and copy initramfs for live boot
	isostart
	isoramfs
	isostop
	mv ""$isorsynctarget"/boot/"$isoramfsname"" ""$isorootdir"/boot/initrd"
	# generate and copy efi bootloader for live boot
	isostart
	isoefiimg
	isostop
	mv ""$isorsynctarget"/root/bootx64.efi" "$isoefidir"
	chmod 755 ""$isoefidir"/bootx64.efi"
	# generate and copy syslinux -> grub chainloader for unetbootin compatibility
	isostart
	isochainloader
	isostop
	mv ""$isorsynctarget"/root/core.img" "$isogrubdir"
	cp -avx ""$isorsynctarget"/usr/lib64/grub/i386-pc/lnxboot.img" "$isogrubdir"
	# enable live iso image system services
	isostart
	isousertree
	isochroot
	isostop
	isostart
	isoservices
	isostop
	umount -l "$isorsynctarget" > /dev/null 2>&1
	# move "real" live filesystem into right place
	mv ""$isorsynctarget".img"  "$isorealfsdir"
	# compress "fake" live filesystem
	mksquashfs "$isocdrootdir" ""$isorootdir"/squashfs.img" -b 1048576 -comp xz -Xdict-size 100%
	mv ""$isorootdir/"squashfs.img" "$isosquashfsdir"
	# dracut requires "real" ext4 live filesystem to be placed 
	# into a "fake" squashfs live filesystem as bellow :
	# /cdroot/LiveOS/squashfs.img/LiveOS/rootfs.img 
	# squashfs.img is the "fake" squashfs live filesystem
	# rootfs.img is the "real" ext4 live filesystem
}

bootloaderiso () {
	# get grub2 live boot configs and place them into right place
	git clone https://gitlab.com/"$releasename"/boot-core.git "$bootloaderfetchpath"
	cp -avx "$bootloaderconfigs" "$isorootdir"
}

cleanupiso () {
	# cleanup temporary files used during iso image layout preparation
	umount "$isorsyncsource"
	rm -rf "$isorsynctarget"
	rm -rf "$isorsyncsource"
	rm -rf "$isocdrootdir"
	rm -rf "$bootloaderfetchpath"
}

makeisoimg () {
	# create iso image
	grub2-mkrescue -o ""$releasename"-"$releasetarget"-"$releaseversion"-"$isomainarch".iso" "$isorootdir"
}

makeiso () {
	chrootchecksum
	prepareiso
	bootloaderiso
	cleanupiso
	makeisoimg
}

# modechange functions

removeportagetree() {
	# remove portage tree, but leave packages and distfiles directories intact
	if [ -d ""$portagedir"/.git" ] ; then
		einfo "Removing gentoo portage tree"
		find "$portagedir" -mindepth 1 -name "packages" -prune -o -name "distfiles" -prune -o -exec rm -rf {} \; > /dev/null 2>&1
	fi
}

removeoverlays() {
	# remove redcore overlay
	einfo "Removing "$releasename"-"$releasetarget" overlay"
	layman -d "$releasename"-"$releasetarget" > /dev/null 2>&1
}

removeportageconfig() {
	# remove redcore buildsystem (portage configuration)
	einfo "Removing "$releasename"-"$releasetarget" buildsystem"
	rm ""$confdir"/make.conf" > /dev/null 2>&1
	rm ""$confdir"/make.profile" > /dev/null 2>&1
	rm "$confdir" > /dev/null 2>&1
	rm -rf "$clonedir" > /dev/null 2>&1
}

resetmode () {
	removeportagetree
	removeoverlays
	removeportageconfig
}

fetchportageconfig() {
	# fetch redcore buildsystem (portage configuration)
	pushd /opt > /dev/null 2>&1
	einfo "Injecting "$releasename"-"$releasetarget" buildsystem"
	git clone https://gitlab.com/redcore/redcore-build.git
	popd > /dev/null 2>&1
}

fetchfullportagetree() {
	# fetch full portage tree
	if [[ ! -d "$portagedir"/.git ]] ; then
		einfo "Injecting mixedmode/srcmode (full) gentoo portage tree"
		cd "$portagedir" && git init > /dev/null 2>&1
		git remote add origin https://gitlab.com/redcore/portage.git
		git pull --depth=1 origin master
		git branch -u origin/master master
		rm -rf ""$portagedir"/profiles/updates"
	fi
}

fetchminimalportagetree() {
	# fetch minimal portage tree
	# in binmode we don't want the whole tree of gentoo ebuilds
	# but we need portage profiles portage metadata && portage eclasses
	# so make a sparse-checkout, to fetch only what we need
	if [[ ! -d "$portagedir"/.git ]] ; then
		einfo "Injecting binmode (minimal) gentoo portage tree"
		cd "$portagedir" && git init > /dev/null 2>&1
		git remote add origin https://gitlab.com/redcore/portage.git
		git config core.sparsecheckout true
		echo "profiles/*" >> .git/info/sparse-checkout
		echo "metadata/*" >> .git/info/sparse-checkout
		echo "eclass/*" >> .git/info/sparse-checkout
		echo ".gitignore" >> .git/info/sparse-checkout
		git pull --depth=1 origin master
		git branch -u origin/master master
		rm -rf ""$portagedir"/profiles/updates"
	fi
}

fetchoverlays () {
	# fetch redcore overlay
	einfo "Injecting "$releasename"-"$releasetarget" overlay"
	layman -f -a "$releasename"-"$releasetarget" -o https://gitlab.com/"$releasename"/"$releasename"-"$releasetarget"/raw/master/overlay.xml
}

setbinmodeconfig() {
	# set make.conf to binmode, portage will always use binary packages from binhost
	ln -sf "$gitdir" "$confdir"
	ln -sf "$confdir"/make.conf.amd64-binmode "$confdir"/make.conf
	eselect profile set 1
	env-update
	. /etc/profile
}

setmixedmodeconfig() {
	# set make.conf to mixedmode, portage will prefer binary packages over ebuilds
	# but will use ebuilds if they are newer than binary packages from binhost
	# or if the binary package is not available in binhost
	ln -sf "$gitdir" "$confdir"
	ln -sf "$confdir"/make.conf.amd64-mixedmode "$confdir"/make.conf
	eselect profile set 1
	env-update
	. /etc/profile
}

setsrcmodeconfig () {
	# set make.conf to srcmode, portage will always use ebuilds
	ln -sf "$gitdir" "$confdir"
	ln -sf "$confdir"/make.conf.amd64-srcmode "$confdir"/make.conf
	eselect profile set 1
	env-update
	. /etc/profile
}

binmode() {
	resetmode
	fetchminimalportagetree
	fetchoverlays
	fetchportageconfig
	setbinmodeconfig
}

mixedmode() {
	resetmode
	fetchfullportagetree
	fetchoverlays
	fetchportageconfig
	setmixedconfig
}

srcmode() {
	resetmode
	fetchfullportagetree
	fetchoverlays
	fetchportageconfig
	setsrcmodeconfig
}