#!/bin/bash

check() {
    if ! type -f qemu-nbd >/dev/null; then
        echo "'qemu-nbd' not found on this system, install it to use this module."
        return 1
    fi
    if ! type -f qemu-img >/dev/null; then
        echo "'qemu-img' not found on this system, install it to use this module."
        return 1
    fi
    if ! type -f nbd-client >/dev/null; then
        echo "'nbd-client' not found on this system, install it to use this module."
        return 1
    else
        # check version
        local nbd_client_version="$(nbd-client --help 2>&1 | grep -oE '3\.[0-9]+')"
        local nbd_client_version_major="${nbd_client_version%.*}"
        local nbd_client_version_minor="${nbd_client_version#*.}"
        if [ "${nbd_client_version_major}" -ne 3 ]; then
            # nbd-client probably too old
            echo "The nbd-client major version is not 3, meaning its probably too old."
            return 1
        fi
        if [ "${nbd_client_version_minor}" -gt 8 ]; then
            # TODO check if ver = 3.9 has the same new syntax...
            echo "The nbd-client minor version is greater than 8. A new syntax has been
                    introduced starting with 3.10 which we do not support."
            return 1
        fi
        return 0
    fi
}

depends() {
    echo base network bash kernel-modules
    return 0
}

installkernel() {
    instmods ext4
}

install() {
    # cause we need reboots
    inst "$moddir/scripts/r" /usr/bin/r
    # Needed to mount remote dnbd3 filesystem.
    inst "$moddir/binaries/dnbd3-client" /usr/bin/dnbd3-client
    inst "$moddir/binaries/busybox" /usr/bin/busybox
    # A generic wrapper program to prepend a "@" to each process spawned by
    # given nested programs.
    inst "$moddir/binaries/systemd-preserve-process-marker" \
        /usr/bin/systemd-preserve-process-marker

    # NOTE: These modules are build again Kernel: 3.10.0-229.1.2.el7.x86_64
    inst "$moddir/kernel_modules/dnbd3.ko" \
        /usr/lib/modules/current/extra/dnbd3.ko
    inst "$moddir/kernel_modules/nbd.ko" \
        /usr/lib/modules/current/extra/nbd.ko

    # NOTE: Priority has to be lower than the network cmdline parsing hooks
    # since we have to modify the some kernel parameter before.
    inst_hook cmdline 00 "$moddir/hooks/cmdline.sh"
    inst_hook cmdline 90 "$moddir/hooks/nbd-cmdline.sh"
    inst_hook pre-udev 00 "$moddir/hooks/pre-udev.sh"
    inst_hook pre-mount 10 "$moddir/hooks/pre-mount.sh"
    inst_hook mount 10 "$moddir/hooks/mount.sh"
    inst "$moddir/scripts/setup-qcow2" /sbin/setup-qcow2
    inst "$moddir/scripts/setup-nbdroot" /sbin/setup-nbdroot


    # Debugging Uncomment this version if you need some useful debugging tools
    # in your iniramfs.
    inst_multiple lsblk ping ip ifconfig sshd htop tail head cat vim \
        touch sed lsmod insmod qemu-img sleep route wget find lsof strace \
        chroot switch_root pivot_root qemu-nbd mount nbd-client fdisk
    # Production:
    # inst_multiple insmod qemu-img qemu-nbd
    return 0
}