"""This file contains the Winlogon Registry plugin."""

from plaso.containers import events
from plaso.parsers import winreg_parser
from plaso.parsers.winreg_plugins import interface


class WinlogonEventData(events.EventData):
    """Winlogon event data attribute container.

    Attributes:
      application (str): Winlogon application.
      command (str): Winlogon command.
      handler (str): Winlogon handler.
      key_path (str): Windows Registry key path.
      last_written_time (dfdatetime.DateTimeValues): entry last written date and
          time.
      trigger (str): Winlogon trigger.
    """

    DATA_TYPE = "windows:registry:winlogon"

    def __init__(self):
        """Initializes event data."""
        super().__init__(data_type=self.DATA_TYPE)
        self.application = None
        self.command = None
        self.handler = None
        self.key_path = None
        self.last_written_time = None
        self.trigger = None


class WinlogonPlugin(interface.WindowsRegistryPlugin):
    """Windows Registry plugin for parsing the Winlogon key."""

    NAME = "winlogon"
    DATA_FORMAT = "Windows log-on Registry data"

    FILTERS = frozenset(
        [
            interface.WindowsRegistryKeyPathFilter(
                "HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows NT\\CurrentVersion"
                "\\Winlogon"
            )
        ]
    )

    # Sort the value names to ensure event_data is generated in a deterministic
    # manner.
    _LOGON_APPLICATIONS = sorted(
        [
            "Shell",
            "Userinit",
            "AppSetup",
            "GinaDLL",
            "System",
            "VmApplet",
            "taskman",
            "UIHost",
        ]
    )

    _TRIGGER_VALUE_NAMES = sorted(
        [
            "Lock",
            "Logoff",
            "Logon",
            "Shutdown",
            "SmartCardLogonNotify",
            "StartScreenSaver",
            "StartShell",
            "Startup",
            "StopScreenSaver",
            "Unlock",
        ]
    )

    def _ParseRegisteredDLLs(self, parser_mediator, notify_subkey):
        """Parses the registered DLLs that receive event notifications.

        Args:
          parser_mediator (ParserMediator): mediates interactions between parsers
              and other components, such as storage and dfVFS.
          notify_subkey (dfwinreg.WinRegistryKey): Notify Windows Registry subkey.
        """
        for subkey in notify_subkey.GetSubkeys():
            for value_name in self._TRIGGER_VALUE_NAMES:
                handler_value = subkey.GetValueByName(value_name)
                if not handler_value:
                    # TODO: generate extraction warning.
                    continue

                # TODO: check data type handler.

                event_data = WinlogonEventData()
                event_data.application = subkey.name
                event_data.command = self._GetValueFromKey(subkey, "DllName")
                event_data.handler = handler_value.GetDataAsObject()
                event_data.key_path = subkey.path
                event_data.last_written_time = subkey.last_written_time
                # TODO: refactor make trigger a list of value names.
                event_data.trigger = value_name

                parser_mediator.ProduceEventData(event_data)

    def _ParseLogonApplications(self, parser_mediator, registry_key):
        """Parses the registered logon applications.

        Args:
          parser_mediator (ParserMediator): mediates interactions between parsers
              and other components, such as storage and dfVFS.
          registry_key (dfwinreg.WinRegistryKey): Windows Registry key.
        """
        for application in self._LOGON_APPLICATIONS:
            command_value = registry_key.GetValueByName(application)
            if not command_value:
                # TODO: generate extraction warning.
                continue

            event_data = WinlogonEventData()
            event_data.application = application
            # TODO: refactor make command a list of command values.
            event_data.command = command_value.GetDataAsObject()
            event_data.key_path = registry_key.path
            event_data.last_written_time = registry_key.last_written_time
            event_data.trigger = "Logon"

            parser_mediator.ProduceEventData(event_data)

    def ExtractEvents(self, parser_mediator, registry_key, **kwargs):
        """Extracts events from a Windows Registry key.

        Args:
          parser_mediator (ParserMediator): mediates interactions between parsers
              and other components, such as storage and dfVFS.
          registry_key (dfwinreg.WinRegistryKey): Windows Registry key.
        """
        self._ParseLogonApplications(parser_mediator, registry_key)

        notify_subkey = registry_key.GetSubkeyByName("Notify")
        if notify_subkey:
            self._ParseRegisteredDLLs(parser_mediator, notify_subkey)


winreg_parser.WinRegistryParser.RegisterPlugin(WinlogonPlugin)
