# -*- coding: utf-8 -*-
#
# Copyright (C) 2015 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# 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/>.

"""
VMware player/workstation server module.
"""

import os
import sys
import re
import shutil
import asyncio
import subprocess
import logging
import codecs

from collections import OrderedDict
from gns3server.utils.interfaces import interfaces
from gns3server.utils.asyncio import subprocess_check_output

log = logging.getLogger(__name__)

from ..base_manager import BaseManager
from .vmware_vm import VMwareVM
from .vmware_error import VMwareError
from .nio_vmnet import NIOVMNET


class VMware(BaseManager):

    _VM_CLASS = VMwareVM

    def __init__(self):

        super().__init__()
        self._execute_lock = asyncio.Lock()
        self._vmrun_path = None
        self._vmnets = []
        self._vmnet_start_range = 2
        if sys.platform.startswith("win"):
            self._vmnet_end_range = 19
        else:
            self._vmnet_end_range = 255

    @property
    def vmrun_path(self):
        """
        Returns the path vmrun utility.

        :returns: path
        """

        return self._vmrun_path

    @staticmethod
    def _find_vmrun_registry(regkey):

        import winreg
        try:
            # default path not used, let's look in the registry
            hkey = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, regkey)
            ws_install_path, _ = winreg.QueryValueEx(hkey, "InstallPath")
            vmrun_path = os.path.join(ws_install_path, "vmrun.exe")
            winreg.CloseKey(hkey)
            if os.path.exists(vmrun_path):
                return vmrun_path
        except OSError:
            pass
        return None

    def find_vmrun(self):
        """
        Searches for vmrun.

        :returns: path to vmrun
        """

        # look for vmrun
        vmrun_path = self.config.get_section_config("VMware").get("vmrun_path")
        if not vmrun_path:
            if sys.platform.startswith("win"):
                vmrun_path = shutil.which("vmrun")
                if vmrun_path is None:
                    # look for vmrun.exe in default VMware Workstation directory
                    vmrun_ws = os.path.expandvars(r"%PROGRAMFILES(X86)%\VMware\VMware Workstation\vmrun.exe")
                    if os.path.exists(vmrun_ws):
                        vmrun_path = vmrun_ws
                    else:
                        # look for vmrun.exe using the directory listed in the registry
                        vmrun_path = self._find_vmrun_registry(r"SOFTWARE\Wow6432Node\VMware, Inc.\VMware Workstation")
                    if vmrun_path is None:
                        # look for vmrun.exe in default VMware VIX directory
                        vmrun_vix = os.path.expandvars(r"%PROGRAMFILES(X86)%\VMware\VMware VIX\vmrun.exe")
                        if os.path.exists(vmrun_vix):
                            vmrun_path = vmrun_vix
                        else:
                            # look for vmrun.exe using the directory listed in the registry
                            vmrun_path = self._find_vmrun_registry(r"SOFTWARE\Wow6432Node\VMware, Inc.\VMware VIX")
            elif sys.platform.startswith("darwin"):
                vmrun_path = "/Applications/VMware Fusion.app/Contents/Library/vmrun"
            else:
                vmrun_path = shutil.which("vmrun")

        if not vmrun_path:
            raise VMwareError("Could not find vmrun")
        if not os.path.isfile(vmrun_path):
            raise VMwareError("vmrun {} is not accessible".format(vmrun_path))
        if not os.access(vmrun_path, os.X_OK):
            raise VMwareError("vmrun is not executable")
        if os.path.basename(vmrun_path) not in ["vmrun", "vmrun.exe"]:
            raise VMwareError("Invalid vmrun executable name {}".format(os.path.basename(vmrun_path)))

        self._vmrun_path = vmrun_path
        return vmrun_path

    @staticmethod
    def _find_vmware_version_registry(regkey):

        import winreg
        version = None
        try:
            # default path not used, let's look in the registry
            hkey = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, regkey)
            version, _ = winreg.QueryValueEx(hkey, "ProductVersion")
            winreg.CloseKey(hkey)
        except OSError:
            pass
        if version is not None:
            match = re.search("([0-9]+)\.", version)
            if match:
                version = match.group(1)
        return version

    @asyncio.coroutine
    def check_vmware_version(self):
        """
        Check VMware version
        """

        if sys.platform.startswith("win"):
            # look for vmrun.exe using the directory listed in the registry
            ws_version = self._find_vmware_version_registry(r"SOFTWARE\Wow6432Node\VMware, Inc.\VMware Workstation")
            if ws_version is None:
                player_version = self._find_vmware_version_registry(r"SOFTWARE\Wow6432Node\VMware, Inc.\VMware Player")
                if player_version:
                    log.debug("VMware Player version {} detected".format(player_version))
                    if int(player_version) < 6:
                        raise VMwareError("Using VMware Player requires version 6 or above")
                else:
                    log.warning("Could not find VMware version")
            else:
                log.debug("VMware Workstation version {} detected".format(ws_version))
                if int(ws_version) < 10:
                    raise VMwareError("Using VMware Workstation requires version 10 or above")
            return
        else:
            if sys.platform.startswith("darwin"):
                return  # FIXME: no version checking on Mac OS X
            else:
                vmware_path = shutil.which("vmware")

            if vmware_path is None:
                raise VMwareError("VMware is not installed (vmware executable could not be found in $PATH)")

            try:
                output = yield from subprocess_check_output(vmware_path, "-v")
                match = re.search("VMware Workstation ([0-9]+)\.", output)
                version = None
                if match:
                    version = match.group(1)
                    log.debug("VMware Workstation version {} detected".format(version))
                    if int(version) < 10:
                        raise VMwareError("Using VMware Workstation requires version 10 or above")
                match = re.search("VMware Player ([0-9]+)\.", output)
                if match:
                    version = match.group(1)
                    log.debug("VMware Player version {} detected".format(version))
                    if int(version) < 6:
                        raise VMwareError("Using VMware Player requires version 6 or above")
                if version is None:
                    log.warning("Could not find VMware version")
            except (OSError, subprocess.SubprocessError) as e:
                log.error("Error while looking for the VMware version: {}".format(e))

    @staticmethod
    def get_vmnet_interfaces():

        vmnet_interfaces = []
        for interface in interfaces():
            if sys.platform.startswith("win"):
                if "netcard" in interface:
                    windows_name = interface["netcard"]
                else:
                    windows_name = interface["name"]
                match = re.search("(VMnet[0-9]+)", windows_name)
                if match:
                    vmnet = match.group(1)
                    if vmnet not in ("VMnet1", "VMnet8"):
                        vmnet_interfaces.append(vmnet)
            elif interface["name"].startswith("vmnet"):
                vmnet = interface["name"]
                if vmnet not in ("vmnet1", "vmnet8"):
                    vmnet_interfaces.append(interface["name"])
        return vmnet_interfaces

    def is_managed_vmnet(self, vmnet):

        self._vmnet_start_range = self.config.get_section_config("VMware").getint("vmnet_start_range", self._vmnet_start_range)
        self._vmnet_end_range = self.config.get_section_config("VMware").getint("vmnet_end_range", self._vmnet_end_range)
        match = re.search("vmnet([0-9]+)$", vmnet, re.IGNORECASE)
        if match:
            vmnet_number = match.group(1)
            if self._vmnet_start_range <= int(vmnet_number) <= self._vmnet_end_range:
                return True
        return False

    def allocate_vmnet(self):

        if not self._vmnets:
            raise VMwareError("No VMnet interface available between vmnet{} and vmnet{}".format(self._vmnet_start_range,
                                                                                                self._vmnet_end_range))
        return self._vmnets.pop(0)

    def refresh_vmnet_list(self):

        vmnet_interfaces = self.get_vmnet_interfaces()

        # remove vmnets already in use
        for vm in self._vms.values():
            for used_vmnet in vm.vmnets:
                if used_vmnet in vmnet_interfaces:
                    log.debug("{} is already in use".format(used_vmnet))
                    vmnet_interfaces.remove(used_vmnet)

        # remove vmnets that are not managed
        for vmnet in vmnet_interfaces.copy():
            if vmnet in vmnet_interfaces and self.is_managed_vmnet(vmnet) is False:
                vmnet_interfaces.remove(vmnet)

        self._vmnets = vmnet_interfaces

    def create_nio(self, executable, nio_settings):

        if nio_settings["type"] == "nio_vmnet":
            return NIOVMNET(nio_settings["vmnet"])
        else:
            return super().create_nio(None, nio_settings)

    @property
    def host_type(self):
        """
        Returns the VMware host type.
        player = VMware player
        ws = VMware Workstation
        fusion = VMware Fusion

        :returns: host type (string)
        """

        if sys.platform.startswith("darwin"):
            host_type = "fusion"
        else:
            host_type = self.config.get_section_config("VMware").get("host_type", "ws")
        return host_type

    @asyncio.coroutine
    def execute(self, subcommand, args, timeout=60, host_type=None):

        with (yield from self._execute_lock):
            vmrun_path = self.vmrun_path
            if not vmrun_path:
                vmrun_path = self.find_vmrun()
            if host_type is None:
                host_type = self.host_type

            command = [vmrun_path, "-T", host_type, subcommand]
            command.extend(args)
            command_string = " ".join(command)
            log.info("Executing vmrun with command: {}".format(command_string))
            try:
                process = yield from asyncio.create_subprocess_exec(*command, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE)
            except (OSError, subprocess.SubprocessError) as e:
                raise VMwareError("Could not execute vmrun: {}".format(e))

            try:
                stdout_data, _ = yield from asyncio.wait_for(process.communicate(), timeout=timeout)
            except asyncio.TimeoutError:
                raise VMwareError("vmrun has timed out after {} seconds!".format(timeout))

            if process.returncode:
                # vmrun print errors on stdout
                vmrun_error = stdout_data.decode("utf-8", errors="ignore")
                raise VMwareError("vmrun has returned an error: {}".format(vmrun_error))

            return stdout_data.decode("utf-8", errors="ignore").splitlines()

    @staticmethod
    def parse_vmware_file(path):
        """
        Parses a VMware file (VMX, preferences or inventory).

        :param path: path to the VMware file

        :returns: dict
        """

        pairs = OrderedDict()
        encoding = "utf-8"
        # get the first line to read the .encoding value
        with open(path, "rb") as f:
            line = f.readline().decode(encoding, errors="ignore")
            if line.startswith("#!"):
                # skip the shebang
                line = f.readline().decode(encoding, errors="ignore")
            try:
                key, value = line.split('=', 1)
                if key.strip().lower() == ".encoding":
                    file_encoding = value.strip('" ')
                    try:
                        codecs.lookup(file_encoding)
                        encoding = file_encoding
                    except LookupError:
                        log.warning("Invalid file encoding detected in '{}': {}".format(path, file_encoding))
            except ValueError:
                log.warning("Couldn't find file encoding in {}, using {}...".format(path, encoding))

        # read the file with the correct encoding
        with open(path, encoding=encoding, errors="ignore") as f:
            for line in f.read().splitlines():
                try:
                    key, value = line.split('=', 1)
                    pairs[key.strip().lower()] = value.strip('" ')
                except ValueError:
                    continue
        return pairs

    @staticmethod
    def write_vmware_file(path, pairs):
        """
        Write a VMware file (excepting VMX file).

        :param path: path to the VMware file
        :param pairs: settings to write
        """

        encoding = "utf-8"
        if ".encoding" in pairs:
            file_encoding = pairs[".encoding"]
            try:
                codecs.lookup(file_encoding)
                encoding = file_encoding
            except LookupError:
                log.warning("Invalid file encoding detected in '{}': {}".format(path, file_encoding))
        with open(path, "w", encoding=encoding, errors="ignore") as f:
            for key, value in pairs.items():
                entry = '{} = "{}"\n'.format(key, value)
                f.write(entry)

    @staticmethod
    def write_vmx_file(path, pairs):
        """
        Write a VMware VMX file.

        :param path: path to the VMX file
        :param pairs: settings to write
        """

        encoding = "utf-8"
        if ".encoding" in pairs:
            file_encoding = pairs[".encoding"]
            try:
                codecs.lookup(file_encoding)
                encoding = file_encoding
            except LookupError:
                log.warning("Invalid file encoding detected in '{}': {}".format(path, file_encoding))
        with open(path, "w", encoding=encoding, errors="ignore") as f:
            if sys.platform.startswith("linux"):
                # write the shebang on the first line on Linux
                vmware_path = shutil.which("vmware")
                if vmware_path:
                    f.write("#!{}\n".format(vmware_path))
            for key, value in pairs.items():
                entry = '{} = "{}"\n'.format(key, value)
                f.write(entry)

    def _get_vms_from_inventory(self, inventory_path):
        """
        Searches for VMs by parsing a VMware inventory file.

        :param inventory_path: path to the inventory file

        :returns: list of VMs
        """

        vm_entries = {}
        vms = []
        try:
            log.debug('Reading VMware inventory file "{}"'.format(inventory_path))
            pairs = self.parse_vmware_file(inventory_path)
            for key, value in pairs.items():
                if key.startswith("vmlist"):
                    try:
                        vm_entry, variable_name = key.split('.', 1)
                    except ValueError:
                        continue
                    if vm_entry not in vm_entries:
                        vm_entries[vm_entry] = {}
                    vm_entries[vm_entry][variable_name.strip()] = value
        except OSError as e:
            log.warning("Could not read VMware inventory file {}: {}".format(inventory_path, e))

        for vm_settings in vm_entries.values():
            if "displayname" in vm_settings and "config" in vm_settings:
                log.debug('Found VM named "{}" with VMX file "{}"'.format(vm_settings["displayname"], vm_settings["config"]))
                vms.append({"vmname": vm_settings["displayname"], "vmx_path": vm_settings["config"]})
        return vms

    def _get_vms_from_directory(self, directory):
        """
        Searches for VMs in a given directory.

        :param directory: path to the directory

        :returns: list of VMs
        """

        vms = []
        for path, _, filenames in os.walk(directory):
            for filename in filenames:
                if os.path.splitext(filename)[1] == ".vmx":
                    vmx_path = os.path.join(path, filename)
                    log.debug('Reading VMware VMX file "{}"'.format(vmx_path))
                    try:
                        pairs = self.parse_vmware_file(vmx_path)
                        if "displayname" in pairs:
                            log.debug('Found VM named "{}"'.format(pairs["displayname"]))
                            vms.append({"vmname": pairs["displayname"], "vmx_path": vmx_path})
                    except OSError as e:
                        log.warning('Could not read VMware VMX file "{}": {}'.format(vmx_path, e))
                        continue
        return vms

    @staticmethod
    def get_vmware_inventory_path():
        """
        Returns VMware inventory file path.

        :returns: path to the inventory file
        """

        if sys.platform.startswith("win"):
            return os.path.expandvars(r"%APPDATA%\Vmware\Inventory.vmls")
        elif sys.platform.startswith("darwin"):
            return os.path.expanduser("~/Library/Application\ Support/VMware Fusion/vmInventory")
        else:
            return os.path.expanduser("~/.vmware/inventory.vmls")

    @staticmethod
    def get_vmware_preferences_path():
        """
        Returns VMware preferences file path.

        :returns: path to the preferences file
        """

        if sys.platform.startswith("win"):
            return os.path.expandvars(r"%APPDATA%\VMware\preferences.ini")
        elif sys.platform.startswith("darwin"):
            return os.path.expanduser("~/Library/Preferences/VMware Fusion/preferences")
        else:
            return os.path.expanduser("~/.vmware/preferences")

    @staticmethod
    def get_vmware_default_vm_path():
        """
        Returns VMware default VM directory path.

        :returns: path to the default VM directory
        """

        if sys.platform.startswith("win"):
            return os.path.expandvars(r"%USERPROFILE%\Documents\Virtual Machines")
        elif sys.platform.startswith("darwin"):
            return os.path.expanduser("~/Documents/Virtual Machines.localized")
        else:
            return os.path.expanduser("~/vmware")

    @asyncio.coroutine
    def list_vms(self):
        """
        Gets VMware VM list.
        """

        # check for the right VMware version
        yield from self.check_vmware_version()

        inventory_path = self.get_vmware_inventory_path()
        if os.path.exists(inventory_path):
            #FIXME: inventory may exist if VMware workstation has not been fully uninstalled, therefore VMware player VMs are not searched
            return self._get_vms_from_inventory(inventory_path)
        else:
            # VMware player has no inventory file, let's search the default location for VMs.
            vmware_preferences_path = self.get_vmware_preferences_path()
            default_vm_path = self.get_vmware_default_vm_path()

            if os.path.exists(vmware_preferences_path):
                # the default vm path may be present in VMware preferences file.
                try:
                    pairs = self.parse_vmware_file(vmware_preferences_path)
                    if "prefvmx.defaultvmpath" in pairs:
                        default_vm_path = pairs["prefvmx.defaultvmpath"]
                except OSError as e:
                    log.warning('Could not read VMware preferences file "{}": {}'.format(vmware_preferences_path, e))

            if not os.path.isdir(default_vm_path):
                raise VMwareError('Could not find the default VM directory: "{}"'.format(default_vm_path))
            return self._get_vms_from_directory(default_vm_path)