"""
Use virt-install to create a VM suitable for installing a RHOSP/tripleo AIO
"""

import argparse
import pathlib
import subprocess
import sys

MD_PATH = "./meta-data"
UD_PATH = "./user-data"
ND_PATH = "./network-config"


def parse_args():
    """Parse the command line arguments"""
    template_path = pathlib.Path(__file__).parent.parent / "virt-install"
    parser = argparse.ArgumentParser()
    parser.add_argument("--password", required=True)
    parser.add_argument("--public-key", required=True, type=open)
    parser.add_argument("--local-hostname", required=True)
    parser.add_argument("--user-data", default=template_path / "user-data.tpl")
    parser.add_argument("--meta-data", default=template_path / "meta-data.tpl")
    parser.add_argument(
        "--network-data", default=template_path / "network-config.tpl"
    )
    parser.add_argument("--instance-id", required=True, help="Hostname for the new VM")
    parser.add_argument("--output-image", required=True)
    parser.add_argument("--image-size", default="100G")
    parser.add_argument("--input-image", required=True)
    parser.add_argument("--os-variant", required=True)
    parser.add_argument("--name", required=True)
    parser.add_argument("--memory", default=16384)  # , type="int")
    parser.add_argument("--cpus", default=4)  # , type="int")
    parser.add_argument("--gateway")
    parser.add_argument("--cidr-1")
    parser.add_argument("--cidr-2")
    parser.add_argument("--mac-1",default="RANDOM")
    parser.add_argument("--mac-2",default="RANDOM")
    parser.add_argument("--dns",)
    parser.add_argument("--search-domain")
    parser.add_argument("-v", "--verbose", action="store_true")
    parser.add_argument("--rhn-user", required=True)
    parser.add_argument("--rhn-password", required=True)

    args = parser.parse_args()

    if (args.cidr_1 or args.cidr_2) and not (args.cidr_1 and args.cidr_2):
        print("You must specify two addresses if you specify any addresses")
        sys.exit(1)

    if args.cidr_1 and not args.gateway:
        print("You must specify a gateway if you specify any addresses")
        sys.exit(1)

    if args.cidr_1 and not args.search_domain:
        print("You must specify a search domain if you specify any addresses")
        sys.exit(1)

    if args.cidr_1 and not args.dns:
        print("You must specify a DNS server if you specify any addresses")
        sys.exit(1)

    if not (args.cidr_1 or args.cidr_2) and (args.dns or args.gateway or args.search_domain):
        print("There's no point specifying DNS, gateway or search_domain if yoou don't specify addresses")
        sys.exit(1)

    args.public_key = args.public_key.read()

    with open(args.user_data) as user_data:
        args.user_data = user_data.read()
    generate_boot_cmd(args)
    args.user_data = args.user_data.format(data=args)

    with open(args.meta_data) as meta_data:
        args.meta_data = meta_data.read()
    args.meta_data = args.meta_data.format(data=args)

    with open(args.network_data) as network_data:
        args.network_data = network_data.read()
    args.network_data = args.network_data.format(data=args)

    output_image = pathlib.Path(args.output_image)
    if output_image.exists():
        raise ValueError(f"{args.output_image} already exists")
    args.output_image = output_image

    input_image = pathlib.Path(args.input_image)
    if not input_image.exists():
        raise ValueError(f"{args.input_image} not found")
    args.input_image = input_image

    return args

def generate_boot_cmd(data):
    data.bootcmd=""
    if data.cidr_1:
        data.bootcmd = (
            "bootcmd:\n"
            f'  - "nmcli con modify \'System eth0\' ipv4.address {data.cidr_1} ipv4.method static ipv4.gateway {data.gateway} ipv4.dns {data.dns}"\n'
            f'  - "nmcli con modify \'Wired connection 1\' ipv4.address {data.cidr_2} ipv4.method static ipv4.gateway {data.gateway} ipv4.dns {data.dns}"\n'
            '  - "nmcli networking off"\n'
            '  - "nmcli networking on"\n'
        )

def write_user_data(data):
    """Write out a temporary user data file"""

    with open(UD_PATH, "w", encoding="utf-8") as user_data_file:
        user_data_file.write(data)


def write_meta_data(meta_data):
    """Write out a temporary meta data file"""
    with open(MD_PATH, "w", encoding="utf-8") as meta_data_file:
        meta_data_file.write(meta_data)


def write_network_data(network_data):
    """Write out a temporary network data file"""
    with open(ND_PATH, "w", encoding="utf-8") as network_data_file:
        network_data_file.write(network_data)


def create_image(args):
    """
    Create a new image file bashed on the input image, resized to the 
    specified size.
    """

    print("creating image")
    cmd = (
        "qemu-img create -f qcow2 -o preallocation=metadata "
        f"{args.output_image} {args.image_size}"
        )

    result = subprocess.check_output(cmd, shell=True, universal_newlines=True)
    if args.verbose:
        print(result)

    print("Resizing image")
    cmd = f"virt-resize --expand /dev/sda3 {args.input_image} {args.output_image}"

    result = subprocess.check_output(cmd, shell=True, universal_newlines=True)

    if args.verbose:
        print(result)

    print("Image resized")

def virt_install_cmd(args):
    """Build and execute the virt-install command"""
    cmd = f"""
        sudo virt-install \\
            --os-variant {args.os_variant} \\
            --name {args.name} \\
            --memory {args.memory} \\
            --disk {args.output_image} \\
            --vcpus {args.cpus} \\
            --import \\
            --graphics spice,listen=127.0.0.1 \\
            --video virtio \\
            --channel spicevmc \\
            --wait 0 \\
            --cloud-init meta-data=./meta-data,user-data=./user-data \\
            --network bridge=bridge0,mac={args.mac_1} \\
            --network bridge=bridge0,mac={args.mac_2}
        """

    print("running virt-install")

    if args.verbose:
        print(cmd)

    result = subprocess.check_output(cmd, shell=True, universal_newlines=True)
    if args.verbose:
        print(result)


def delete_meta_data():
    """Delete the temporary metadata file"""
    pathlib.Path.unlink(pathlib.Path(MD_PATH))


def delete_user_data():
    """Delete the temporary userdata file"""
    pathlib.Path.unlink(pathlib.Path(UD_PATH))


def install_packages(args):
    """Install the packages needed for virt-install to work"""
    cmd = (
        "sudo dnf install -y virt-install virt-viewer qemu-img "
        "libguestfs.x86_64"
        )

    print("installing needed packages...")

    if args.verbose:
        print(
            subprocess.check_output(cmd, shell=True, universal_newlines=True)
        )


def main():
    """main function"""
    args = parse_args()

    if args.verbose:
        print(args)

    install_packages(args)
    create_image(args)
    write_meta_data(args.meta_data)
    write_user_data(args.user_data)

    virt_install_cmd(args)

    delete_meta_data()
    delete_user_data()


if __name__ == "__main__":
    main()