import argparse
import pathlib
import subprocess

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

def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument("--password", required=True)
    parser.add_argument("--public-key", required=True, type=open)
    parser.add_argument("--local-hostname", default="aio3.gpslab.cbr.redhat.com")
    parser.add_argument("--user-data", default="./user-data.tpl", type=open)
    parser.add_argument("--meta-data", default="./meta-data.tpl", type=open)
    parser.add_argument("--network-data", default="./network-config.tpl", type=open)
    parser.add_argument("--instance-id", default="aio3")
    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=2048) #, type="int")
    parser.add_argument("--gateway", required=True)
    parser.add_argument("--cidr-1", required=True)
    parser.add_argument("--cidr-2", required=True)
    parser.add_argument("--dns", required=True)
    parser.add_argument("--search-domain", required=True)
    parser.add_argument("-v", "--verbose", action="store_true")
    
    args = parser.parse_args()

    args.public_key = args.public_key.read()
    
    args.user_data = args.user_data.read()
    args.user_data = args.user_data.format(data=args)
    
    args.meta_data = args.meta_data.read()
    args.meta_data = args.meta_data.format(data=args)
    
    args.network_data = args.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 write_user_data(user_data):
    with open(UD_PATH, "w", encoding="utf-8") as user_data_file:
        user_data_file.write(user_data)

def write_meta_data(meta_data):
    with open(MD_PATH, "w", encoding="utf-8") as meta_data_file:
        meta_data_file.write(meta_data)

def write_network_data(network_data):
    with open(ND_PATH, "w", encoding="utf-8") as network_data_file:
        network_data_file.write(network_data)

def create_image(args):
    print("creating image")
    cmd = f"qemu-img create -f qcow2 -o preallocation=metadata {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)

def virt_install_cmd(args):
    cmd = f"""
        sudo virt-install \\
            --os-variant {args.os_variant} \\
            --name {args.name} \\
            --memory {args.memory} \\
            --disk {args.output_image} \\
            --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 \\
            --network bridge=bridge0
        """
    
    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():
    pathlib.Path.unlink(pathlib.Path(MD_PATH))
    
def delete_user_data():
    pathlib.Path.unlink(pathlib.Path(UD_PATH))

def install_packages(args):
    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():
    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()