import getpass
import logging
import logging.config
import logging.handlers
import os
import sys
import time
import traceback
import uuid
from contextlib import contextmanager, suppress
from functools import lru_cache

import sentry_sdk
import yaml
from defence360agent.contracts import config, sentry
from defence360agent.contracts.config import AcronisBackup
from defence360agent.contracts.config import Logger as Config
from defence360agent.contracts.config import Sentry
from defence360agent.utils import antivirus_mode, is_root_user
from defence360agent.application import tags

PREFIX = os.environ.get("IMUNIFY360_LOGGING_PREFIX", "")
logger = logging.getLogger(__name__)


def _sentry_init(debug=False):
    # if config invalid, we still need to be able to configure logging
    try:
        error_reporting = Sentry.ENABLE
    except (KeyError, AssertionError):
        error_reporting = True

    if error_reporting:
        sentry_sdk.init(
            dsn=Sentry.DSN,
            debug=debug,
            release=config.Core.VERSION,
            attach_stacktrace="on",
        )
        with sentry_sdk.configure_scope() as scope:
            for tag, value in sentry.tags().items():
                scope.set_tag(tag, value)
            scope.user = {"id": sentry.tag("server_id")}
        return {
            "level": "ERROR",
            "class": "sentry_sdk.integrations.logging.SentryHandler",
        }
    else:
        return {
            "level": "NOTSET",
            "class": "logging.NullHandler",
        }


class _LoggerDynConfig:
    _ROOT_LOG_DIR = "/var/log/%s" % config.Core.PRODUCT

    @staticmethod
    def _user_log_dir():
        return "/var/log/%s_user_logs/%s" % (
            config.Core.PRODUCT,
            getpass.getuser() or os.getuid(),
        )

    def __init__(self):
        self.log_dir = (
            self._ROOT_LOG_DIR if is_root_user() else self._user_log_dir()
        )

        self.mutableDictConfig = {
            "loggers": {
                "network": {
                    "level": "DEBUG",
                    # network_log is disabled by default'
                    "handlers": [],
                },
                "defence360agent.internals.the_sink": {
                    "level": "DEBUG",
                    # process_message_log is disabled by default'
                    "handlers": [],
                },
                "event_hook": {
                    "level": "INFO",
                    "handlers": [],
                },
            },
            "version": 1,
            "handlers": {
                "sentry": _sentry_init(),
                "error_log": {
                    "level": "WARNING",
                    "formatter": "abstimestamp",
                    "filename": "%s/error.log" % self.log_dir,
                    "class": "logging.FileHandler",
                    "encoding": "utf8",
                },
                "network_log": {
                    "level": "DEBUG",
                    "formatter": "abstimestamp",
                    "filename": "%s/network.log" % self.log_dir,
                    "class": "logging.FileHandler",
                    "encoding": "utf8",
                },
                "debug_log": {
                    "level": "DEBUG",
                    "formatter": "abstimestamp",
                    "filename": "%s/debug.log" % self.log_dir,
                    "class": "logging.FileHandler",
                    "encoding": "utf8",
                },
                "console_log": {
                    "level": "INFO",
                    "formatter": "abstimestamp",
                    "filename": "%s/console.log" % self.log_dir,
                    "class": "logging.FileHandler",
                    "encoding": "utf8",
                },
                "hook_log": {
                    "level": "INFO",
                    "formatter": "eventhook",
                    "filename": "%s/hook.log" % self.log_dir,
                    "class": "logging.FileHandler",
                    "encoding": "utf8",
                },
                "console": {
                    "formatter": "abstimestamp",
                    "class": "logging.StreamHandler",
                    "stream": "ext://sys.stderr",
                    "level": "INFO",
                },
                "process_message_log": {
                    "formatter": "reltimestamp",
                    # DEF-26794: append mode (default). With logrotate's
                    # copytruncate, mode="w" would leave the fd offset past
                    # EOF after truncation and re-inflate the file with
                    # sparse zeros. O_APPEND seeks to the (now-zero) end
                    # before each write, so the file size resets cleanly.
                    "level": "DEBUG",
                    "filename": "%s/process_message.log" % self.log_dir,
                    "class": "logging.FileHandler",
                    "encoding": "utf8",
                },
            },
            "root": {
                "level": "NOTSET",
                "handlers": [
                    "console_log",
                    # 'debug_log' is disabled by default,
                    "error_log",
                    "sentry",
                ],
            },
            "mkdir": "logs",
            "formatters": {
                "reltimestamp": {
                    "format": (
                        "%(levelname)-7s [+%(relativeCreated)5dms] "
                        f"{PREFIX}%(name)50s|%(message)s"
                    )
                },
                "abstimestamp": {
                    "format": (
                        f"%(levelname)-7s [%(asctime)s] {PREFIX}%(name)s:"
                        " %(message)s"
                    )
                },
                "eventhook": {"format": "%(created)d : %(message)s"},
            },
            "disable_existing_loggers": False,
        }

        self.mutableDictConfig["loggers"]["AcronisClientInstaller"] = {
            "level": "INFO",
            "handlers": [],
        }
        self.mutableDictConfig["handlers"]["acronis_installer_log"] = {
            "formatter": "abstimestamp",
            # DEF-26794: append mode (default). See process_message_log
            # comment above for why mode="w" is unsafe with copytruncate.
            "level": "INFO",
            "filename": os.path.join(self.log_dir, AcronisBackup.LOG_NAME),
            "class": "logging.FileHandler",
            "encoding": "utf8",
        }


@lru_cache(1)
def _late_init():
    return _LoggerDynConfig()


def _we_are_in_cagefs():
    """
    :return bool: True if python interpreter is being run in CageFS container,
        otherwise False
    :raise: never

    Current implementation simply checks "/var/.cagefs" presence, as
    Anton Volkov consulted us to do.

    Placing this function not in 'subsys' package, because 'logger' module
    is one of cornerstones dependency for 'subsys' package as well.
    """
    with suppress(OSError):
        return os.path.exists("/var/.cagefs")


def _chmod_log_dirs(dirname, dir_perm, file_perm):
    """Change file/dir modes recursively.

    Starting at dirname, change all inner directory permissions to dir_perm,
    file permissions to file_perm

    Permission errors are logged to stderr and are ignored in any case.
    """

    def _os_chmod(file_dir_path, permission):
        try:
            os.chmod(file_dir_path, permission)
        except PermissionError as e:
            sys.stderr.write(
                "[WARNING] cannot chmod on {}: {}".format(file_dir_path, e)
            )

    _os_chmod(dirname, dir_perm)
    for path, dirs, files in os.walk(dirname):
        for directory in dirs:
            _os_chmod(os.path.join(path, directory), dir_perm)
        for name in files:
            _os_chmod(os.path.join(path, name), file_perm)


def reconfigure():
    """
    Re-catch with _LoggerDynConfig and re-open log files
    """
    if os.getenv("IMUNIFY360_DISABLE_LOGGING"):
        pass
    else:
        try:
            # Set sentry.TAGS from saved file
            tags.cached_fill()
            log_dir = _late_init().log_dir
            os.makedirs(log_dir, Config.LOG_DIR_PERM, exist_ok=True)
            _chmod_log_dirs(log_dir, Config.LOG_DIR_PERM, Config.LOG_FILE_PERM)
            logging.config.dictConfig(_late_init().mutableDictConfig)
        except OSError:
            # We do not create user logs to keep user isolation
            # level high.
            #
            # Another alternative is
            # cagefs.mp:%/var/log/imunify360_user_log
            # but it is not working for some reason, we need to find out
            # later why.

            if not _we_are_in_cagefs():
                traceback.print_exc(file=sys.stderr)
                sys.stderr.write(
                    "%s logger is not available.\n" % config.Core.PRODUCT
                )
        except Exception:
            # be robust: do not die if dictConfig fails
            traceback.print_exc(file=sys.stderr)
            sys.stderr.write(
                "%s logger is not available.\n" % config.Core.PRODUCT
            )
        else:  # logging is configured successfully
            sys.excepthook = _log_uncaught_exceptions


def _log_uncaught_exceptions(exc_type, exc_value, exc_traceback):
    if issubclass(exc_type, KeyboardInterrupt):
        sys.__excepthook__(exc_type, exc_value, exc_traceback)
        return

    logger.critical(
        "uncaught exception", exc_info=(exc_type, exc_value, exc_traceback)
    )


def update_logging_config_from_file(filename):
    with open(filename) as config_file:
        config = yaml.safe_load(config_file)
    _late_init().mutableDictConfig.update(config)

    reconfigure()


def get_fds():
    handlers = logging.root.handlers
    for _logger in _late_init().mutableDictConfig["loggers"].keys():
        handlers.extend(logging.getLogger(_logger).handlers)

    return [
        h.stream
        for h in handlers
        if hasattr(h, "stream")
        and hasattr(h.stream, "fileno")
        and h.stream != sys.stderr
    ]


def get_log_file_names():
    return [
        values["filename"]
        for _, values in _late_init().mutableDictConfig["handlers"].items()
        if "filename" in values
    ]


def getNetworkLogger(name):
    if name in sys.modules:
        return logging.getLogger("network." + sys.modules[name].__name__)
    else:
        return logging.getLogger("network." + name)


# NOTE: client expects that this function will return
# the same value always - /var/log/imunify360. They base their logrotate
# configs on this value. In case of some updates, corresponding teams
# should be notified before update to update their logrotate configs.
def log_dir() -> str:
    """
    Return base log directory for the product.
    Supposed to be used by clients to build the path to their own logs.
    """
    return _late_init().log_dir


def setLogLevel(verbose):
    # FIXME
    if antivirus_mode.disabled:
        _late_init().mutableDictConfig["loggers"]["AcronisClientInstaller"][
            "handlers"
        ].append("acronis_installer_log")
    if verbose >= 2:
        _late_init().mutableDictConfig["loggers"]["network"][
            "handlers"
        ].append("network_log")
    if verbose >= 3:
        _late_init().mutableDictConfig["loggers"][
            "defence360agent.internals.the_sink"
        ]["handlers"].append("process_message_log")
    if verbose >= 4:
        _late_init().mutableDictConfig["root"]["handlers"].append("debug_log")
    _late_init().mutableDictConfig["loggers"]["event_hook"]["handlers"].append(
        "hook_log"
    )

    reconfigure()


def setConsoleLogLevel(newloglevel):
    """
    also results in reconfigure()
    """
    _late_init().mutableDictConfig["handlers"]["console"][
        "level"
    ] = newloglevel
    reconfigure()


# openAibolitActionsLog and openMdsActionsLog are deprecated and should be removed
# after release of https://gerrit.cloudlinux.com/c/defence360/+/225868
@contextmanager
def openAibolitActionsLog(scan_id: str):
    path = os.path.join(_late_init().log_dir, "aibolit_actions.log")
    with open(path, "a") as f:
        f.write(f'{time.strftime("%Y-%m-%d %H:%M:%S")} | {scan_id} | ')
        yield f
        f.write("\n\n")


# openAibolitActionsLog and openMdsActionsLog are deprecated and should be removed
# after release of https://gerrit.cloudlinux.com/c/defence360/+/225868
@contextmanager
def openMdsActionsLog(scan_id: str):
    log_dir = _late_init().log_dir
    os.makedirs(log_dir, exist_ok=True)
    path = os.path.join(log_dir, "mds_actions.log")
    with open(path, "a") as f:
        f.write(f'{time.strftime("%Y-%m-%d %H:%M:%S")} | {scan_id} | ')
        yield f
        f.write("\n\n")


class EventHookLogger:
    class _EventLogger:
        class _HookLogger:
            tpl = (
                "{uuid:s} : {action:s} {native:s}: "
                "{event:s} : {subtype:s} : {path:s}"
            )

            def __init__(self, parent, path, native):
                self.path = path
                self.event = parent.event
                self.subtype = parent.subtype
                self.uuid = parent.uuid
                self.log = parent.log
                self.native = native

            def __enter__(self):
                return self

            def __exit__(self, exc_type, exc_val, exc_tb):
                pass

            def _log(self, action, message=""):
                data = {
                    "uuid": str(self.uuid),
                    "action": action,
                    "native": "native " if self.native else "",
                    "event": self.event,
                    "subtype": self.subtype,
                    "path": self.path,
                }
                msg = self.tpl.format(**data)

                if message:
                    msg = " : ".join([msg, message])

                self.log(msg)

            def begin(self):
                self._log("started")

            def finish(self, exit_code, err):
                message = "OK" if exit_code == 0 else "ERROR"
                if exit_code:
                    message = ":".join([message, str(exit_code)])
                if err:
                    if isinstance(err, bytes):
                        err = err.decode(errors="backslashreplace")
                    message = "\n".join([message, err])

                self._log("done", message)

        def __init__(self, parent, event, subtype):
            self.event = event
            self.subtype = subtype
            self.uuid = uuid.uuid4()
            self.log = parent.log

        def __call__(self, path, native=False):
            return self._HookLogger(self, path, native=native)

        def __enter__(self):
            return self

        def __exit__(self, exc_type, exc_val, exc_tb):
            pass

    def __init__(self):
        logger = logging.getLogger("event_hook")
        self.log = logger.info

    def __call__(self, event, subtype):
        return self._EventLogger(self, event, subtype)