#
# Copyright (C) 2020-2021 Soleta Networks <info@soleta.eu>
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the
# Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.

from src.ogRest import ThreadState
from src.virtual import poweroffd
import socket
import errno
import select
import json
import subprocess
import shutil
import os
import guestfs
import hivex
import pathlib
import re
import math
import sys
import enum
import time
from src.log import OgError

class OgVM:
    DEFAULT_CPU = 'host'
    DEFAULT_VGA = 'virtio-vga'
    DEFAULT_QMP_IP = 'localhost'
    DEFAULT_QMP_PORT = 4444

    class State(enum.Enum):
        STOPPED = 0
        RUNNING = 1

    def __init__(self,
                 partition_path,
                 memory=None,
                 cpu=DEFAULT_CPU,
                 vga=DEFAULT_VGA,
                 qmp_ip=DEFAULT_QMP_IP,
                 qmp_port=DEFAULT_QMP_PORT,
                 vnc_params=None):
        self.partition_path = partition_path
        self.cpu = cpu
        self.vga = vga
        self.qmp_ip = qmp_ip
        self.qmp_port = qmp_port
        self.proc = None
        self.vnc_params = vnc_params

        if memory:
            self.mem = memory
        else:
            available_ram = os.sysconf('SC_PAGE_SIZE') * os.sysconf('SC_PHYS_PAGES')
            available_ram = available_ram / 2 ** 20
            # Calculate the lower power of 2 amout of RAM memory for the VM.
            self.mem = 2 ** math.floor(math.log(available_ram) / math.log(2))


    def run_vm(self):
        if self.vnc_params:
            vnc_str = f'-vnc 0.0.0.0:0,password'
        else:
            vnc_str = ''

        cmd = (f'qemu-system-x86_64 -accel kvm -cpu {self.cpu} -smp 4 '
               f'-drive file={self.partition_path},if=virtio '
               f'-qmp tcp:localhost:4444,server,nowait '
               f'-device {self.vga} -display gtk '
               f'-m {self.mem}M -boot c -full-screen {vnc_str}')
        self.proc = subprocess.Popen([cmd], shell=True)

        if self.vnc_params:
            # Wait for QMP to be available.
            time.sleep(20)
            cmd = { "execute": "change",
                    "arguments": { "device": "vnc",
                                   "target": "password",
                                   "arg": str(self.vnc_params['pass']) } }
            with OgQMP(self.qmp_ip, self.qmp_port) as qmp:
                qmp.talk(str(cmd))

class OgQMP:
    QMP_TIMEOUT = 5
    QMP_POWEROFF_TIMEOUT = 300

    def __init__(self, ip, port):
        self.ip = ip
        self.port = port

    def connect(self):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.sock.setblocking(0)
        try:
            self.sock.connect((self.ip, self.port))
        except socket.error as err:
            if err.errno == errno.ECONNREFUSED:
                raise OgError('Cannot connect to QEMU')
            elif err.errno == errno.EINPROGRESS:
                pass

        readset = [ self.sock ]
        readable, writable, exception = select.select(readset,
                                                      [],
                                                      [],
                                                      OgQMP.QMP_TIMEOUT)

        if self.sock in readable:
            try:
                out = self.recv()
            except:
                pass

        if 'QMP' not in out:
            raise OgError('Cannot handshake QEMU')

        out = self.talk(str({"execute": "qmp_capabilities"}))
        if 'return' not in out:
            raise OgError('Cannot handshake QEMU')

    def disconnect(self):
        try:
            self.sock.close()
        except:
            pass

    def __enter__(self):
        self.connect()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.disconnect()

    def talk(self, data, timeout=QMP_TIMEOUT):
        writeset = [ self.sock ]
        readable, writable, exception = select.select([],
                                                      writeset,
                                                      [],
                                                      timeout)
        if self.sock in writable:
            try:
                self.sock.send(bytes(data, 'utf-8'))
            except Exception as e:
                raise OgError('Cannot talk to QEMU') from e
        else:
            raise OgError('Timeout when talking to QEMU')

        return self.recv(timeout=timeout)

    def recv(self, timeout=QMP_TIMEOUT):
        readset = [self.sock]
        readable, _, _ = select.select(readset, [], [], timeout)

        if self.sock in readable:
            try:
                out = self.sock.recv(4096).decode('utf-8')
                out = json.loads(out)
            except socket.error as err:
                raise OgError('Cannot talk to QEMU') from err
        else:
            raise OgError('Timeout when talking to QEMU')
        return out

class OgVirtualOperations:
    def __init__(self):
        self.IP = '127.0.0.1'
        self.VIRTUAL_PORT = 4444
        self.USABLE_DISK = 0.75
        self.OG_PATH = os.path.dirname(os.path.realpath(sys.argv[0]))
        self.OG_IMAGES_PATH = f'{self.OG_PATH}/images'
        self.OG_PARTITIONS_PATH = f'{self.OG_PATH}/partitions'
        self.OG_PARTITIONS_CFG_PATH = f'{self.OG_PATH}/partitions.json'

        if not os.path.exists(self.OG_IMAGES_PATH):
            os.mkdir(self.OG_IMAGES_PATH, mode=0o755)
        if not os.path.exists(self.OG_PARTITIONS_PATH):
            os.mkdir(self.OG_PARTITIONS_PATH, mode=0o755)

    def poweroff_guest(self):
        try:
            with OgQMP(self.IP, self.VIRTUAL_PORT) as qmp:
                qmp.talk(str({"execute": "system_powerdown"}))
                out = qmp.recv()
                assert(out['event'] == 'POWERDOWN')
                out = qmp.recv(timeout=OgQMP.QMP_POWEROFF_TIMEOUT)
                assert(out['event'] == 'SHUTDOWN')
        except:
            return

    def poweroff_host(self):
        subprocess.run(['/sbin/poweroff'])

    def poweroff(self):
        self.poweroff_guest()
        self.poweroff_host()

    def reboot(self):
        try:
            with OgQMP(self.IP, self.VIRTUAL_PORT) as qmp:
                qmp.talk(str({"execute": "system_reset"}))
        except:
            pass

    def check_vm_state(self):
        try:
            with OgQMP(self.IP, self.VIRTUAL_PORT) as qmp:
                pass
            return OgVM.State.RUNNING
        except:
            return OgVM.State.STOPPED

    def get_installed_os(self):
        installed_os = {}
        try:
            with open(self.OG_PARTITIONS_CFG_PATH, 'r') as f:
                cfg = json.loads(f.read())
            for part in cfg['partition_setup']:
                if len(part['os']) > 0:
                    installed_os[part['os']] = (part['disk'], part['partition'])
        except:
            pass
        return installed_os

    def check_vm_state_loop(self, ogRest):
        # If we can't connect, wait until it's possible.
        while True:
            try:
                with socket.create_connection((poweroffd.QMP_DEFAULT_HOST,
                                               poweroffd.QMP_DEFAULT_PORT)):
                    break
            except ConnectionRefusedError:
                time.sleep(1)

        qmpconn = poweroffd.init()
        if poweroffd.run(qmpconn) < 0:
            return
        self.poweroff_host()

    def shellrun(self, request, ogRest):
        return

    def session(self, request, ogRest):
        disk = request.getDisk()
        partition = request.getPartition()

        part_path = f'{self.OG_PARTITIONS_PATH}/disk{disk}_part{partition}.qcow2'
        if ogRest.CONFIG['vnc']['activate']:
            qemu = OgVM(part_path, vnc_params=ogRest.CONFIG['vnc'])
        else:
            qemu = OgVM(part_path)
        qemu.run_vm()

    def partitions_cfg_to_json(self, data):
        for part in data['partition_setup']:
            part.pop('virt-drive')
            for k, v in part.items():
                part[k] = str(v)
        for disk in data['disk_setup']:
            for k, v in disk.items():
                disk[k] = str(v)
        return data

    def refresh(self, ogRest):
        try:
            # Return last partitions setup in case VM is running.
            with OgQMP(self.IP, self.VIRTUAL_PORT) as qmp:
                pass
            with open(self.OG_PARTITIONS_CFG_PATH, 'r') as f:
                data = json.loads(f.read())
            data = self.partitions_cfg_to_json(data)
            return data
        except:
            pass

        try:
            with open(self.OG_PARTITIONS_CFG_PATH, 'r+') as f:
                data = json.loads(f.read())
                for part in data['partition_setup']:
                    if len(part['virt-drive']) > 0:
                        if not os.path.exists(part['virt-drive']):
                            part['code'] = '',
                            part['filesystem'] = 'EMPTY'
                            part['os'] = ''
                            part['size'] = 0
                            part['used_size'] = 0
                            part['virt-drive'] = ''
                            continue
                        g = guestfs.GuestFS(python_return_dict=True)
                        g.add_drive_opts(part['virt-drive'],
                                         format="qcow2",
                                         readonly=1)
                        g.launch()
                        devices = g.list_devices()
                        assert(len(devices) == 1)
                        partitions = g.list_partitions()
                        assert(len(partitions) == 1)
                        filesystems_dict = g.list_filesystems()
                        assert(len(filesystems_dict) == 1)
                        g.mount(partitions[0], '/')
                        used_disk = g.du('/')
                        g.umount_all()
                        total_size = g.disk_virtual_size(part['virt-drive']) / 1024

                        part['used_size'] = int(100 * used_disk / total_size)
                        part['size'] = total_size
                        root = g.inspect_os()
                        if len(root) == 1:
                            part['os'] = f'{g.inspect_get_distro(root[0])} ' \
                                         f'{g.inspect_get_product_name(root[0])}'
                        else:
                            part['os'] = ''
                        filesystem = [fs for fs in filesystems_dict.values()][0]
                        part['filesystem'] = filesystem.upper()
                        if filesystem == 'ext4':
                            part['code'] = '0083'
                        elif filesystem == 'ntfs':
                            part['code'] = '0007'
                        g.close()
                f.seek(0)
                f.write(json.dumps(data, indent=4))
                f.truncate()
        except FileNotFoundError:
            total_disk, used_disk, free_disk = shutil.disk_usage("/")
            free_disk = int(free_disk * self.USABLE_DISK)
            data = {'serial_number': '',
                    'disk_setup': [{'disk': 1,
                                   'partition': 0,
                                   'code': '0',
                                   'filesystem': '',
                                   'os': '',
                                   'size': int(free_disk / 1024),
                                   'used_size': int(100 * used_disk / total_disk)}],
                    'partition_setup': []}
            for i in range(4):
                part_json = {'disk': 1,
                             'partition': i + 1,
                             'code': '',
                             'filesystem': 'EMPTY',
                             'os': '',
                             'size': 0,
                             'used_size': 0,
                             'virt-drive': ''}
                data['partition_setup'].append(part_json)
            with open(self.OG_PARTITIONS_CFG_PATH, 'w+') as f:
                f.write(json.dumps(data, indent=4))
        except:
            with open(self.OG_PARTITIONS_CFG_PATH, 'r') as f:
                data = json.load(f)

        data = self.partitions_cfg_to_json(data)

        return data

    def setup(self, request, ogRest):
        self.poweroff_guest()
        self.refresh(ogRest)

        part_setup = request.getPartitionSetup()
        disk = request.getDisk()

        for i, part in enumerate(part_setup):
            if int(part['format']) == 0:
                continue

            drive_path = f'{self.OG_PARTITIONS_PATH}/disk{disk}_part{part["partition"]}.qcow2'
            g = guestfs.GuestFS(python_return_dict=True)
            g.disk_create(drive_path, "qcow2", int(part['size']) * 1024)
            g.add_drive_opts(drive_path, format="qcow2", readonly=0)
            g.launch()
            devices = g.list_devices()
            assert(len(devices) == 1)
            g.part_disk(devices[0], "gpt")
            partitions = g.list_partitions()
            assert(len(partitions) == 1)
            g.mkfs(part["filesystem"].lower(), partitions[0])
            g.close()

            with open(self.OG_PARTITIONS_CFG_PATH, 'r+') as f:
                data = json.loads(f.read())
                if part['code'] == 'LINUX':
                    data['partition_setup'][i]['code'] = '0083'
                elif part['code'] == 'NTFS':
                    data['partition_setup'][i]['code'] = '0007'
                elif part['code'] == 'DATA':
                    data['partition_setup'][i]['code'] = '00da'
                data['partition_setup'][i]['filesystem'] = part['filesystem']
                data['partition_setup'][i]['size'] = int(part['size'])
                data['partition_setup'][i]['virt-drive'] = drive_path
                f.seek(0)
                f.write(json.dumps(data, indent=4))
                f.truncate()

        return self.refresh(ogRest)

    def image_create(self, path, request, ogRest):
        disk = request.getDisk()
        partition = request.getPartition()
        name = request.getName()
        repo = request.getRepo()
        samba_config = ogRest.samba_config

        self.poweroff_guest()

        self.refresh(ogRest)

        drive_path = f'{self.OG_PARTITIONS_PATH}/disk{disk}_part{partition}.qcow2'

        cmd = f'mount -t cifs //{repo}/ogimages {self.OG_IMAGES_PATH} -o ' \
              f'rw,nolock,serverino,acl,' \
              f'username={samba_config["user"]},' \
              f'password={samba_config["pass"]}'
        subprocess.run([cmd], shell=True)

        try:
            shutil.copy(drive_path, f'{self.OG_IMAGES_PATH}/{name}')
        except:
            return None

        subprocess.run([f'umount {self.OG_IMAGES_PATH}'], shell=True, check=True)

        return True

    def image_restore(self, request, ogRest):
        disk = request.getDisk()
        partition = request.getPartition()
        name = request.getName()
        repo = request.getRepo()
        # TODO Multicast? Unicast? Solo copia con samba.
        ctype = request.getType()
        profile = request.getProfile()
        cid = request.getId()
        samba_config = ogRest.samba_config

        self.poweroff_guest()
        self.refresh(ogRest)

        drive_path = f'{self.OG_PARTITIONS_PATH}/disk{disk}_part{partition}.qcow2'

        if os.path.exists(drive_path):
            os.remove(drive_path)

        cmd = f'mount -t cifs //{repo}/ogimages {self.OG_IMAGES_PATH} -o ' \
              f'ro,nolock,serverino,acl,' \
              f'username={samba_config["user"]},' \
              f'password={samba_config["pass"]}'
        subprocess.run([cmd], shell=True, check=True)

        try:
            shutil.copy(f'{self.OG_IMAGES_PATH}/{name}', drive_path)
        except:
            return None

        subprocess.run([f'umount {self.OG_IMAGES_PATH}'], shell=True)
        self.refresh(ogRest)

        return True

    def cache_delete(self, request, ogRest):
        raise NotImplementedError

    def software(self, request, path, ogRest):
        DPKG_PATH = '/var/lib/dpkg/status'

        disk = request.getDisk()
        partition = request.getPartition()
        drive_path = f'{self.OG_PARTITIONS_PATH}/disk{disk}_part{partition}.qcow2'
        g = guestfs.GuestFS(python_return_dict=True)
        g.add_drive_opts(drive_path, readonly=1)
        g.launch()
        root = g.inspect_os()[0]

        os_type = g.inspect_get_type(root)
        os_major_version = g.inspect_get_major_version(root)
        os_minor_version = g.inspect_get_minor_version(root)
        os_distro = g.inspect_get_distro(root)

        software = []

        if 'linux' in os_type:
            g.mount_ro(g.list_partitions()[0], '/')
            try:
                g.download('/' + DPKG_PATH, 'dpkg_list')
            except:
                pass
            g.umount_all()
            if os.path.isfile('dpkg_list'):
                pkg_pattern = re.compile('Package: (.+)')
                version_pattern = re.compile('Version: (.+)')
                with open('dpkg_list', 'r') as f:
                    for line in f:
                        pkg_match = pkg_pattern.match(line)
                        version_match = version_pattern.match(line)
                        if pkg_match:
                            pkg = pkg_match.group(1)
                        elif version_match:
                            version = version_match.group(1)
                        elif line == '\n':
                            software.append(pkg + ' ' + version)
                        else:
                            continue
                os.remove('dpkg_list')
        elif 'windows' in os_type:
            g.mount_ro(g.list_partitions()[0], '/')
            hive_file_path = g.inspect_get_windows_software_hive(root)
            g.download('/' + hive_file_path, 'win_reg')
            g.umount_all()
            h = hivex.Hivex('win_reg')
            key = h.root()
            key = h.node_get_child (key, 'Microsoft')
            key = h.node_get_child (key, 'Windows')
            key = h.node_get_child (key, 'CurrentVersion')
            key = h.node_get_child (key, 'Uninstall')
            software += [h.node_name(x) for x in h.node_children(key)]
            # Just for 64 bit Windows versions, check for 32 bit software.
            if (os_major_version == 5 and os_minor_version >= 2) or \
               (os_major_version >= 6):
                key = h.root()
                key = h.node_get_child (key, 'Wow6432Node')
                key = h.node_get_child (key, 'Microsoft')
                key = h.node_get_child (key, 'Windows')
                key = h.node_get_child (key, 'CurrentVersion')
                key = h.node_get_child (key, 'Uninstall')
                software += [h.node_name(x) for x in h.node_children(key)]
            os.remove('win_reg')

        return '\n'.join(software)

    def parse_pci(self, path='/usr/share/misc/pci.ids'):
        data = {}
        with open(path, 'r') as f:
            for line in f:
                if line[0] == '#':
                    continue
                elif len(line.strip()) == 0:
                    continue
                else:
                    if line[:2] == '\t\t':
                        fields = line.strip().split(maxsplit=2)
                        data[last_vendor][last_device][(fields[0], fields[1])] = fields[2]
                    elif line[:1] == '\t':
                        fields = line.strip().split(maxsplit=1)
                        last_device = fields[0]
                        data[last_vendor][fields[0]] = {'name': fields[1]}
                    else:
                        fields = line.strip().split(maxsplit=1)
                        if fields[0] == 'ffff':
                            break
                        last_vendor = fields[0]
                        data[fields[0]] = {'name': fields[1]}
        return data

    def hardware(self, path, ogRest):
        try:
            with OgQMP(self.IP, self.VIRTUAL_PORT) as qmp:
                pci_data = qmp.talk(str({"execute": "query-pci"}))
                mem_data = qmp.talk(str({"execute": "query-memory-size-summary"}))
                cpu_data = qmp.talk(str({"execute": "query-cpus-fast"}))
        except:
            return

        pci_data = pci_data['return'][0]['devices']
        pci_list = self.parse_pci()
        device_names = {}
        for device in pci_data:
            vendor_id = hex(device['id']['vendor'])[2:]
            device_id = hex(device['id']['device'])[2:]
            subvendor_id = hex(device['id']['subsystem-vendor'])[2:]
            subdevice_id = hex(device['id']['subsystem'])[2:]
            description = device['class_info']['desc'].lower()
            name = ''
            try:
                name = pci_list[vendor_id]['name']
                name += ' ' + pci_list[vendor_id][device_id]['name']
                name += ' ' + pci_list[vendor_id][device_id][(subvendor_id, subdevice_id)]
            except KeyError:
                if vendor_id == '1234':
                    name = 'VGA Cirrus Logic GD 5446'
                else:
                    pass

            if 'usb' in description:
                device_names['usb'] = name
            elif 'ide' in description:
                device_names['ide'] = name
            elif 'ethernet' in description:
                device_names['net'] = name
            elif 'vga' in description:
                device_names['vga'] = name

            elif 'audio' in description or 'sound' in description:
                device_names['aud'] = name
            elif 'dvd' in description:
                device_names['cdr'] = name

        ram_size = int(mem_data['return']['base-memory']) * 2 ** -20
        device_names['mem'] = f'QEMU {int(ram_size)}MiB'

        cpu_arch = cpu_data['return'][0]['arch']
        cpu_target = cpu_data['return'][0]['target']
        cpu_cores = len(cpu_data['return'])
        device_names['cpu'] = f'CPU arch:{cpu_arch} target:{cpu_target} ' \
                              f'cores:{cpu_cores}'

        with open(path, 'w+') as f:
            f.seek(0)
            for k, v in device_names.items():
                f.write(f'{k}={v}\n')
            f.truncate()

    def probe(self, ogRest):
        return {'status': 'VDI' if ogRest.state != ThreadState.BUSY else 'BSY'}