#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright (C) 2023 New Vector, Ltd
#
# 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.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#
import logging
import os

import twisted.logger

from synapse.logging.context import LoggingContextFilter
from synapse.synapse_rust import reset_logging_config

# The maximum length of a single log line. Extremely long log lines aren't
# useful, and keeping them short also stays well under the limit that would
# otherwise break parallel test runs: under `trial -jN` worker log events are
# shipped to the manager process over trial's AMP, which raises `TooLong` for
# any value of 64KiB or more (e.g. a DEBUG dump of a large SQL query's values)
# (c.f. https://github.com/twisted/twisted/issues/12482).
_MAX_LOG_LINE_LENGTH = 60_000


class ToTwistedHandler(logging.Handler):
    """logging handler which sends the logs to the twisted log"""

    tx_log = twisted.logger.Logger()

    def emit(self, record: logging.LogRecord) -> None:
        log_entry = self.format(record)
        if len(log_entry) > _MAX_LOG_LINE_LENGTH:
            log_entry = (
                log_entry[:_MAX_LOG_LINE_LENGTH]
                + "... [truncated overly long log line]"
            )
        log_level = record.levelname.lower().replace("warning", "warn")
        self.tx_log.emit(
            twisted.logger.LogLevel.levelWithName(log_level), "{entry}", entry=log_entry
        )


def setup_logging() -> None:
    """Configure the python logging appropriately for the tests.

    (Logs will end up in _trial_temp.)
    """
    root_logger = logging.getLogger()

    # We exclude `%(asctime)s` from this format because the Twisted logger adds its own
    # timestamp
    log_format = "%(name)s - %(lineno)d - %(levelname)s - %(request)s - %(message)s"

    handler = ToTwistedHandler()
    formatter = logging.Formatter(log_format)
    handler.setFormatter(formatter)
    handler.addFilter(LoggingContextFilter())
    root_logger.addHandler(handler)

    log_level = os.environ.get("SYNAPSE_TEST_LOG_LEVEL", "ERROR")
    root_logger.setLevel(log_level)

    # In order to not add noise by default (since we only log ERROR messages for trial
    # tests as configured above), we only enable this for developers for looking for
    # more INFO or DEBUG.
    if root_logger.isEnabledFor(logging.INFO):
        # Log when events are (maybe unexpectedly) filtered out of responses in tests. It's
        # just nice to be able to look at the CI log and figure out why an event isn't being
        # returned.
        logging.getLogger("synapse.visibility.filtered_event_debug").setLevel(
            logging.DEBUG
        )

    # Blow away the pyo3-log cache so that it reloads the configuration.
    reset_logging_config()
