#!/bin/bash

printf "welcome to portable linux creation tool v1.0p2\n"
printf "available distros: debian\n\n"

while true; do
	read -rp "distro: " distro
	distro=${distro,,}
	if  [ "$distro" = "debian" ] || \
	    [ "$distro" = "alpine" ]; then
		break
	fi
	echo "pls choose distro from list"
done

read -rp "choose mountpoint (/mnt/install): " mount
if [ ! -n "$mount" ]; then
	mount="/mnt/install"
fi

read -rp "disk (e.g. /dev/sdX) or skip to install to $mount: " disk

while true; do
	read -rp "gpt/mbr: " table
	table=${table,,}
	if [ "$table" = "gpt" ] || [ "$table" = "mbr" ]; then
		break
	fi
	echo "pls choose gpt or mbr"
done

while true; do
	read -rp "efi? (yes/no): " efi
	efi=${efi,,}
	if [ "$efi" = "yes" ] || [ "$efi" = "no" ]; then
		break
	fi
	echo "pls choose yes or no"
done

if [[ $disk =~ nvme[0-9]+n[0-9]+$ ]] || [[ $disk =~ mmcblk[0-9]+$ ]] || [[ $disk =~ loop[0-9]+$ ]]; then
    prefix="p"
else
    prefix=""
fi

prepare_debian() {
	declare -A need=(
		[debootstrap --help]=debootstrap
		[parted --help]=parted
		[mkfs.fat --help]=e2fsprogs
		[which mkfs.ext4]=mkfs.ext4
		[blkid]=blkid
	)

	missing=()
	
	read -rp "choose debian mirror (https://deb.debian.org/debian): " mirror
	if [ ! -n "$mirror" ]; then
		mirror="https://deb.debian.org/debian"
	fi

	# prompt for debian version
	read -rp "choose debian version (bookworm): " choice
	if [ ! -n "$choice" ]; then
		choice="bookworm"
	fi

	# checking if version of debian exists
	while true; do
		if curl -sS -o /dev/null -w "%{http_code}" -L "$mirror/dists/$choice" | grep -q "200"; then
			break
		fi
		echo "debian $choice was not found at $mirror/dists/$choice"
		read -rp "choose debian version (bookworm): " choice
	done

	if [ ! -n "$choice" ]; then
		choice="bookworm"
	fi

	echo "found debian $choice"
	for cmd in "${!need[@]}"; do
		if ! $cmd >/dev/null 2>&1; then
			missing+=("${need[$cmd]:-$cmd}")
		fi
	done

	if ((${#missing[@]})); then
		echo "missing this things: ${missing[*]}" >&2
		echo "pls install them or run the script as root" >&2
		exit 1
	fi

	if [ -n $disk ]; then
		while true; do
			read -rp "everything is ok, type 'no' to cancel or 'yes' to preceed installation of debian $choice to $disk with $table table (DATA ON $disk WILL BE LOST): " proceeding
			if [ "$proceeding" = "no" ]; then
				echo "ok aborting"
				exit
			fi
			if [ "$proceeding" = "yes" ]; then
				echo "ok starting the installation"
				break
			fi
		done
	else
		while true; do
			read -rp "everything is ok, type 'no' to cancel or 'yes' to preceed installation of debian $choice to $mount with $table table: " proceeding
			if [ "$proceeding" = "no" ]; then
				echo "ok aborting"
				exit
			fi
			if [ "$proceeding" = "yes" ]; then
				echo "ok starting the installation"
				break
			fi
		done
	fi

	install_debian
}

install_debian() {
	if [ -n "$disk" ]; then
		echo "unmounting $disk"
		umount $disk*

		umount -R $mount
		rm -rf $mount
		mkdir $mount

		echo "making $table table"
		if [ $table = "mbr" ]; then
			parted $disk --script mklabel msdos
		fi
		
		if [ $table = "gpt" ]; then
			parted $disk --script mklabel gpt
		fi
		
		echo "making partitions"
		if [ $efi = "yes" ]; then
		    parted $disk --script \
		        mkpart primary fat32 1MiB 513MiB \
		        set 1 esp on \
		        mkpart primary ext4 513MiB 100%
		    
		    mkfs.fat -F 32 ${disk}${prefix}1
		    mkfs.ext4 ${disk}${prefix}2

		    echo "mounting"

		    mount ${disk}${prefix}2 $mount
		    mkdir $mount/boot
		    mount ${disk}${prefix}1 $mount/boot
		fi
		
		if [ $efi = "no" ]; then
		    parted $disk --script \
		        mkpart primary ext4 1MiB 100%
		    mkfs.ext4 ${disk}${prefix}1
		    
		    mount ${disk}${prefix}1 $mount
		fi
	fi

    debootstrap $choice $mount $mirror

    mount --bind /dev $mount/dev
    mount --bind /dev/pts $mount/dev/pts
    mount --bind /proc $mount/proc
    mount --bind /sys $mount/sys

    RUN="chroot $mount"
    
    $RUN apt update && $RUN apt install -y locales tzdata network-manager linux-image-amd64
    $RUN dpkg-reconfigure locales
	$RUN dpkg-reconfigure tzdata

	while true; do
		read -rp "hostname: " hostname
		if [ -n "$hostname" ]; then
			break
		fi
		echo "pls set hostname"
	done
	echo $hostname > $mount/etc/hostname
	echo "updating root password"
	$RUN passwd root

	if [ $efi = "yes" ]; then
		$RUN apt install -y grub-efi-amd64
		mkdir $mount/boot/efi
		$RUN grub-install --target=x86_64-efi --efi-directory=/boot --removable
		$RUN update-grub
		
		if [ -n "$disk" ]; then
			efi_uuid=$(blkid -s UUID -o value ${disk}${prefix}1)
			root_uuid=$(blkid -s UUID -o value ${disk}${prefix}2)
			echo "UUID=$efi_uuid /boot/ vfat umask=0077 0 1" >> $mount/etc/fstab
			echo "UUID=$root_uuid / ext4 defaults,noatime 0 1" >> $mount/etc/fstab
		fi
    fi
    if [ $efi = "no" ]; then
		$RUN apt-get install -y grub-pc
		$RUN grub-install $disk
		$RUN update-grub
		
		if [ -n "$disk" ]; then
			root_uuid=$(blkid -s UUID -o value ${disk}${prefix}1)
			echo "UUID=$root_uuid / ext4 defaults,noatime 0 1" >> $mount/etc/fstab
		fi
    fi

	echo 'done! chrooted you into installed system. type "exit" to finish the installation'
	if [ ! -n "$disk" ]; then
		echo "pls generate fstab manually"
	fi
	$RUN /bin/bash
	
	umount -R $mount
}



if [ $distro = "debian" ]; then
	prepare_debian
	exit
fi

echo "bye!"