#!/usr/bin/env python3
#
# Copyright (C) 2019-2021, VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# File: check-qemu-install
# Purpose:
#  This script installs a system on a emulated qemu host to verify
#  that the iso produced is installable and boots.
#  after the iso is booted from disk it also tries to execute the
#  vyos-smoketest script to verify checks there.
#
#  For now it will not fail on failed smoketest but will fail on
#  install and boot errors.
#  Arguments:
#    iso            iso image to install
#    [disk]         disk filename to use, if none is provided it
#                   is autogenerated
#    [--keep]       Keep the disk image after completion
#    [--logfile]    name of logfile to save, defaulting to stdout
#    [--silent]     only print on errors
#    [--debug]      print all communication with the device

import pexpect
import sys
import os
import time
import argparse
import subprocess
import random
import traceback
import logging
import re
import json

from io import BytesIO
from io import StringIO
from datetime import datetime

EXCEPTION = 0
now = datetime.now()

parser = argparse.ArgumentParser(description='Install and start a test VyOS vm.')
parser.add_argument('iso', help='ISO file to install')
parser.add_argument('disk', help='name of disk image file', nargs='?',
                            default='testinstall-{}-{}.img'.format(now.strftime('%Y%m%d-%H%M%S'),
                                                                   "%04x" % random.randint(0,65535)))
parser.add_argument('--keep', help='Do not remove disk-image after installation',
                              action='store_true', default=False)
parser.add_argument('--silent', help='Do not show output on stdout unless an error has occured',
                              action='store_true', default=False)
parser.add_argument('--debug', help='Send all debug output to stdout',
                               action='store_true', default=False)
parser.add_argument('--logfile', help='Log to file')
parser.add_argument('--uefi', help='Boot using UEFI', action='store_true', default=False)
parser.add_argument('--raid', help='Perform a RAID-1 install', action='store_true', default=False)
parser.add_argument('--no-kvm', help='Disable use of kvm', action='store_true', default=False)
parser.add_argument('--configd', help='Execute testsuite with config daemon', action='store_true',
				default=False)
parser.add_argument('--no-interfaces', help='Execute testsuite without interface tests to save time',
                action='store_true', default=False)
parser.add_argument('--configtest', help='Execute load/commit config tests',
				action='store_true', default=False)

args = parser.parse_args()

with open('data/defaults.json') as f:
    vyos_defaults = json.load(f)

class StreamToLogger(object):
    """
    Fake file-like stream object that redirects writes to a logger instance.
    """
    def __init__(self, logger, log_level=logging.INFO):
        self.logger = logger
        self.log_level = log_level
        self.linebuf = b''
        self.ansi_escape = re.compile(r'\x1B[@-_][0-?]*[ -/]*[@-~]')

    def write(self, buf):
        self.linebuf += buf
        #print('.')
        while b'\n' in self.linebuf:
            f = self.linebuf.split(b'\n', 1)
            if len(f) == 2:
                self.logger.debug(self.ansi_escape.sub('', f[0].decode(errors="replace").rstrip()))
                self.linebuf = f[1]
            #print(f)


    def flush(self):
        pass

def get_half_cpus():
    """ return 1/2 of the numbers of available CPUs """
    cpu = os.cpu_count()
    if cpu > 1:
        cpu /= 2
    return int(cpu)

def get_qemu_cmd(name, enable_kvm, enable_uefi, disk_img, raid=None, iso_img=None):
    kvm = "-enable-kvm"
    cpu = "-cpu host"
    if not enable_kvm:
        kvm = "--no-kvm"
        cpu = ""

    uefi = ""
    uuid = "f48b60b2-e6ad-49ef-9d09-4245d0585e52"
    if enable_uefi:
        uefi = '-bios /usr/share/OVMF/OVMF_CODE.fd'
        name = f'{name}-UEFI'
        uuid = 'd27cf29e-4419-4407-8f82-dc73d1acd184'

    bootindex = '1'
    cdrom = ""
    if iso_img:
        cdrom = f' -boot d' \
                f' -drive file={iso_img},format=raw,if=none,media=cdrom,id=drive-cd1,readonly=on' \
                f' -device ahci,id=achi0' \
                f' -device ide-cd,bus=achi0.0,drive=drive-cd1,id=cd1,bootindex={bootindex}'

        # Set regular harddisk bootindex to 2 as we boot from a CDROM drive
        bootindex = '2'

    # test using half of the available CPUs on the system
    cpucount = get_half_cpus()

    macbase = '52:54:00:00:00'
    cmd = f'qemu-system-x86_64 \
        -name "{name}" \
        -smp sockets=1,cpus={cpucount},cores=1 \
        -cpu host \
        {uefi} \
        -m 1G \
        -vga none \
        -nographic \
        -machine accel=kvm \
        -uuid {uuid} \
        {cpu} \
        {cdrom} \
        {kvm} \
        -netdev user,id=n0 -device virtio-net-pci,netdev=n0,mac={macbase}:00,romfile="" \
        -netdev user,id=n1 -device virtio-net-pci,netdev=n1,mac={macbase}:01,romfile="" \
        -netdev user,id=n2 -device virtio-net-pci,netdev=n2,mac={macbase}:02,romfile="" \
        -netdev user,id=n3 -device virtio-net-pci,netdev=n3,mac={macbase}:03,romfile="" \
        -netdev user,id=n4 -device virtio-net-pci,netdev=n4,mac={macbase}:04,romfile="" \
        -netdev user,id=n5 -device virtio-net-pci,netdev=n5,mac={macbase}:05,romfile="" \
        -netdev user,id=n6 -device virtio-net-pci,netdev=n6,mac={macbase}:06,romfile="" \
        -netdev user,id=n7 -device virtio-net-pci,netdev=n7,mac={macbase}:07,romfile="" \
        -device virtio-scsi-pci,id=scsi0 \
        -drive format=raw,file={disk_img},if=none,media=disk,id=drive-hd1,readonly=off \
        -device scsi-hd,bus=scsi0.0,drive=drive-hd1,id=hd1,bootindex={bootindex}'

    # dynamically increment bootindex - required for RAID system
    bootindex = str(int(bootindex) + 1)
    if raid:
        cmd += f' -drive format=raw,file={raid},if=none,media=disk,id=drive-hd2,readonly=off' \
               f' -device scsi-hd,bus=scsi0.0,drive=drive-hd2,id=hd2,bootindex={bootindex}'

    return cmd

def shutdownVM(c, log, message=''):
    #################################################
    # Powering off system
    #################################################
    if message:
        log.info(message)

    c.sendline('poweroff now')
    log.info('Shutting down virtual machine')
    for i in range(30):
        log.info('Waiting for shutdown...')
        if not c.isalive():
            log.info('VM is shut down!')
            break
        time.sleep(10)
    else:
        tmp = 'VM Did not shut down after 300sec'
        log.error(tmp)
        raise Exception(tmp)

def loginVM(c, log):
    log.info('Waiting for login prompt')
    c.expect('[Ll]ogin:', timeout=600)
    c.sendline(default_user)
    c.expect('[Pp]assword:')
    c.sendline(default_password)
    c.expect(op_mode_prompt)
    log.info('Logged in!')

# Setting up logger
log = logging.getLogger()
log.setLevel(logging.DEBUG)

stl = StreamToLogger(log)
formatter = logging.Formatter('%(levelname)5s - %(message)s')

handler = logging.StreamHandler(sys.stdout)
if args.silent:
    handler.setLevel(logging.ERROR)
elif args.debug:
    handler.setLevel(logging.DEBUG)
else:
    handler.setLevel(logging.INFO)

handler.setFormatter(formatter)
log.addHandler(handler)

if args.logfile:
    filehandler = logging.FileHandler(args.logfile)
    filehandler.setLevel(logging.DEBUG)
    filehandler.setFormatter(formatter)
    log.addHandler(filehandler)

if args.silent:
    output = BytesIO()
else:
    output = sys.stdout.buffer

if not os.path.isfile(args.iso):
    log.error('Unable to find iso image to install')
    sys.exit(1)

if args.no_kvm:
    log.error('KVM forced off by command line')
    kvm=False
elif not os.path.exists('/dev/kvm'):
    log.error('KVM not enabled on host, proceeding with software emulation')
    kvm=False
else:
    kvm=True

# Creating diskimage!!
diskname_raid = None
def gen_disk(name):
    if not os.path.isfile(name):
        log.info(f'Creating Disk image {name}')
        c = subprocess.check_output(['qemu-img', 'create', name, '2G'])
        log.debug(c.decode())
    else:
        log.info(f'Diskimage "{name}" already exists, using the existing one.')

if args.raid:
    filename, ext = os.path.splitext(args.disk)
    diskname_raid = f'{filename}_disk1{ext}'
    # change primary diskname, too
    args.disk = f'{filename}_disk0{ext}'
    gen_disk(diskname_raid)

# must be called after the raid disk as args.disk name is altered in the RAID path
gen_disk(args.disk)

test_timeout = 3 *3600 # 3 hours (in seconds)
try:
    #################################################
    # Installing image to disk
    #################################################
    log.info('Installing system')
    cmd = get_qemu_cmd('TESTVM', kvm, args.uefi, args.disk, diskname_raid, args.iso)
    log.debug(f'Executing command: {cmd}')
    c = pexpect.spawn(cmd, logfile=stl, timeout=60)

    #################################################
    # Logging into VyOS system
    #################################################
    op_mode_prompt = r'vyos@vyos:~\$'
    cfg_mode_prompt = r'vyos@vyos#'
    default_user = 'vyos'
    default_password = 'vyos'

    try:
        c.expect('Automatic boot in', timeout=10)
        c.sendline('')
    except pexpect.TIMEOUT:
        log.warning('Did not find GRUB countdown window, ignoring')

    loginVM(c, log)

    #################################################
    # Installing into VyOS system
    #################################################
    log.info('Starting installer')
    c.sendline('install image')
    c.expect('\nWould you like to continue?.*:')
    c.sendline('yes')

    if args.raid:
        c.expect('\nWould you like to configure RAID-1 mirroring on them?.*:')
        c.sendline('yes')
        # Erase all data on disks
        c.expect('\nAre you sure you want to do this?.*:')
        c.sendline('yes')
    else:
        log.info('Partitioning disk')
        c.expect('\nPartition.*:')
        c.sendline('')
        c.expect('\nInstall the image on.*:')
        c.sendline('')
        c.expect(r'\nContinue\?.*:')
        c.sendline('Yes')
        c.expect('\nHow big of a root partition should I create?.*:')
        c.sendline('')

    log.info('Disk(s) partitioned, installing...')
    c.expect('\nWhat would you like to name this image?.*:', timeout=600)
    c.sendline('')
    log.info('Copying files')
    c.expect('\nWhich one should I copy to.*:', timeout=600)
    c.sendline('')
    log.info('Files Copied!')
    c.expect('\nEnter password for user.*:')
    c.sendline(default_user)
    c.expect('\nRetype password for user.*:')
    c.sendline(default_password)

    if not args.raid:
        c.expect('\nWhich drive should GRUB modify the boot partition on.*:')
        c.sendline('')
        c.expect(op_mode_prompt)

    log.info('system installed, shutting down')

    #################################################
    # Powering down installer
    #################################################
    shutdownVM(c, log, 'Shutting down installation system')
    c.close()

    #################################################
    # Booting installed system
    #################################################
    log.info('Booting installed system')
    cmd = get_qemu_cmd('TESTVM', kvm, args.uefi, args.disk, diskname_raid)
    log.debug(f'Executing command: {cmd}')
    c = pexpect.spawn(cmd, logfile=stl)

    #################################################
    # Logging into VyOS system
    #################################################
    try:
        c.expect('The highlighted entry will be executed automatically in', timeout=10)
        c.sendline('')
    except pexpect.TIMEOUT:
        log.warning('Did not find GRUB countdown window, ignoring')

    loginVM(c, log)

    ################################################
    # Always load the WiFi simulation module
    ################################################
    c.sendline('sudo modprobe mac80211_hwsim')
    c.expect(op_mode_prompt)

    #################################################
    # Start/stop config daemon
    #################################################
    if args.configd:
        c.sendline('sudo systemctl start vyos-configd.service &> /dev/null')
    else:
        c.sendline('sudo systemctl stop vyos-configd.service &> /dev/null')
    c.expect(op_mode_prompt)

    #################################################
    # Basic Configmode/Opmode switch
    #################################################
    log.info('Basic CLI configuration mode test')
    c.sendline('configure')
    c.expect(cfg_mode_prompt)
    c.sendline('exit')
    c.expect(op_mode_prompt)
    c.sendline('show version')
    c.expect(op_mode_prompt)
    c.sendline('show version kernel')
    c.expect(f'{vyos_defaults["kernel_version"]}-{vyos_defaults["kernel_flavor"]}')
    c.expect(op_mode_prompt)
    c.sendline('show version frr')
    c.expect(op_mode_prompt)
    c.sendline('show interfaces')
    c.expect(op_mode_prompt)

    #################################################
    # Executing test-suite
    #################################################
    if args.raid:
        # Verify RAID subsystem - by deleting a disk and re-create the array
        # from scratch
        c.sendline('cat /proc/mdstat')
        c.expect(op_mode_prompt)

        shutdownVM(c, log, f'Shutdown VM and start with empty RAID member "{args.disk}"')

        if os.path.exists(args.disk):
            os.unlink(args.disk)

        gen_disk(args.disk)

        #################################################
        # Booting RAID-1 system with one missing disk
        #################################################
        log.info('Booting RAID-1 system')
        cmd = get_qemu_cmd('TESTVM', kvm, args.uefi, args.disk, diskname_raid)

        # We need to swap boot indexes to boot from second harddisk so we can
        # recreate the RAID on the first disk
        cmd = cmd.replace('bootindex=1', 'bootindex=X')
        cmd = cmd.replace('bootindex=2', 'bootindex=1')
        cmd = cmd.replace('bootindex=X', 'bootindex=2')

        log.debug(f'Executing command: {cmd}')
        c = pexpect.spawn(cmd, logfile=stl)


        #################################################
        # Logging into VyOS system
        #################################################
        try:
            c.expect('The highlighted entry will be executed automatically in', timeout=10)
            c.sendline('')
        except pexpect.TIMEOUT:
            log.warning('Did not find GRUB countdown window, ignoring')

        loginVM(c, log)

        c.sendline('cat /proc/mdstat')
        c.expect(op_mode_prompt)

        log.info('Re-format new RAID member')
        c.sendline('format disk sda like sdb')
        c.sendline('yes')
        c.expect(op_mode_prompt)

        log.info('Add member to RAID1 (md0)')
        c.sendline('add raid md0 member sda1')
        c.expect(op_mode_prompt)

        log.info('Now we need to wait for re-sync to complete')

        start_time = time.time()
        timeout = 60
        while True:
            if (start_time + timeout) < time.time():
                break
            c.sendline('cat /proc/mdstat')
            c.expect(op_mode_prompt)
            time.sleep(20)

        # Reboot system with new primary RAID1 disk
        shutdownVM(c, log, f'Shutdown VM and start from recovered RAID member "{args.disk}"')

        log.info('Booting RAID-1 system')
        cmd = get_qemu_cmd('TESTVM', kvm, args.uefi, args.disk, diskname_raid)
        log.debug(f'Executing command: {cmd}')
        c = pexpect.spawn(cmd, logfile=stl)

        loginVM(c, log)

        c.sendline('cat /proc/mdstat')
        c.expect(op_mode_prompt)

    elif not args.configtest:
        # run default smoketest suite
        if args.no_interfaces:
            # remove interface tests as they consume a lot of time
            c.sendline('sudo rm -f /usr/libexec/vyos/tests/smoke/cli/test_interfaces_*')
            c.expect(op_mode_prompt)

        log.info('Executing VyOS smoketests')
        c.sendline('/usr/bin/vyos-smoketest')
        i = c.expect(['\n +Invalid command:', '\n +Set failed',
                      'No such file or directory', r'\n\S+@\S+[$#]'], timeout=test_timeout)

        if i == 0:
            raise Exception('Invalid command detected')
        elif i == 1:
            raise Exception('Set syntax failed :/')
        elif i == 2:
            tmp = '(W)hy (T)he (F)ace? VyOS smoketest not found!'
            log.error(tmp)
            raise Exception(tmp)

        c.sendline('echo EXITCODE:$\x16?')
        i = c.expect(['EXITCODE:0', 'EXITCODE:\d+'])
        if i == 0:
            log.info('Smoketest finished successfully!')
            pass
        elif i == 1:
            log.error('Smoketest failed :/')
            raise Exception("Smoketest-failed, please look into debug output")

    # else, run configtest suite
    else:
        log.info('Adding a legacy WireGuard default keypair for migrations')
        c.sendline('sudo mkdir -p /config/auth/wireguard/default')
        c.expect(op_mode_prompt)
        c.sendline('echo "aGx+fvW916Ej7QRnBbW3QMoldhNv1u95/WHz45zDmF0=" | sudo tee /config/auth/wireguard/default/private.key')
        c.expect(op_mode_prompt)
        c.sendline('echo "x39C77eavJNpvYbNzPSG3n1D68rHYei6q3AEBEyL1z8=" | sudo tee /config/auth/wireguard/default/public.key')
        c.expect(op_mode_prompt)

        log.info('Generating some OpenVPN keys')
        subject = '/C=DE/ST=BY/O=VyOS/localityName=Cloud/commonName=vyos/' \
                  'organizationalUnitName=VyOS/emailAddress=maintainers@vyos.io/'
        ca_cert  = '/config/auth/ovpn_test_ca.pem'
        ssl_cert = '/config/auth/ovpn_test_server.pem'
        ssl_key  = '/config/auth/ovpn_test_server.key'
        dh_pem   = '/config/auth/ovpn_test_dh.pem'
        s2s_key  = '/config/auth/ovpn_test_site2site.key'
        auth_key = '/config/auth/ovpn_test_tls_auth.key'

        c.sendline(f'openssl req -newkey rsa:4096 -new -nodes -x509 -days 3650 '\
                   f'-keyout {ssl_key} -out {ssl_cert} -subj {subject}')
        c.expect(op_mode_prompt, timeout=600)
        c.sendline(f'openssl req -new -x509 -key {ssl_key} -out {ca_cert} -subj {subject}')
        c.expect(op_mode_prompt, timeout=600)
        c.sendline(f'openssl dhparam -out {dh_pem} 2048')
        c.expect(op_mode_prompt, timeout=600)
        c.sendline(f'openvpn --genkey secret {s2s_key}')
        c.expect(op_mode_prompt)
        c.sendline(f'openvpn --genkey secret {auth_key}')
        c.expect(op_mode_prompt)

        script_file = '/config/scripts/vyos-foo-update.script'
        c.sendline(f'echo "#!/bin/sh" > {script_file}; chmod 775 {script_file}')
        c.expect(op_mode_prompt)

        for file in [ca_cert, ssl_cert, ssl_key, dh_pem, s2s_key, auth_key]:
            c.sendline(f'sudo chown openvpn:openvpn {file}')
            c.expect(op_mode_prompt)

        log.info('Executing load config tests')
        c.sendline('/usr/bin/vyos-configtest')
        i = c.expect(['\n +Invalid command:', 'No such file or directory',
                     r'\n\S+@\S+[$#]'], timeout=test_timeout)

        if i==0:
            raise Exception('Invalid command detected')
        elif i==1:
            tmp = '(W)hy (T)he (F)ace? VyOS smoketest not found!'
            log.error(tmp)
            raise Exception(tmp)

        c.sendline('echo EXITCODE:$\x16?')
        i = c.expect(['EXITCODE:0', 'EXITCODE:\d+'])
        if i == 0:
            log.info('Configtest finished successfully!')
            pass
        elif i == 1:
            tmp = 'Configtest failed :/ - check debug output'
            log.error(tmp)
            raise Exception(tmp)

    shutdownVM(c, log, 'Powering off system')
    c.close()

except pexpect.exceptions.TIMEOUT:
    log.error('Timeout waiting for VyOS system')
    log.error(traceback.format_exc())
    EXCEPTION = 1

except pexpect.exceptions.ExceptionPexpect:
    log.error('Exeption while executing QEMU')
    log.error('Is qemu working on this system?')
    log.error(traceback.format_exc())
    EXCEPTION = 1

except Exception:
    log.error('Unknown error occured while VyOS!')
    traceback.print_exc()
    EXCEPTION = 1

#################################################
# Cleaning up
#################################################
log.info("Cleaning up")

if not args.keep:
    log.info(f'Removing disk file: {args.disk}')
    try:
        os.remove(args.disk)
        if diskname_raid:
            os.remove(diskname_raid)
    except Exception:
        log.error('Exception while removing diskimage!')
        log.error(traceback.format_exc())
        EXCEPTION = 1

if EXCEPTION:
    log.error('Hmm... system got an exception while processing.')
    log.error('The ISO image is not considered usable!')
    sys.exit(1)