<gh_stars>1-10
# canaryd
# File: canaryd/util.py
# Desc: shared utilities for canaryd, mostly for plugins

import logging
import sys
import traceback

from datetime import datetime
from logging.handlers import SysLogHandler

from canaryd_packages import click
from canaryd_packages import six

STDOUT_LOG_LEVELS = (logging.DEBUG, logging.INFO)
STDERR_LOG_LEVELS = (logging.WARNING, logging.ERROR, logging.CRITICAL)

# Get the logger
logger = logging.getLogger('canaryd')


class LogFilter(logging.Filter):
    def __init__(self, *levels):
        self.levels = levels

    def filter(self, record):
        # Warnings only for vendored packages
        if record.name.startswith('canaryd.packages'):
            return record.levelno >= logging.WARNING

        return record.levelno in self.levels


class LogFormatter(logging.Formatter):
    level_to_format = {
        logging.DEBUG: lambda s: click.style(s, 'green'),
        logging.WARNING: lambda s: click.style(s, 'yellow'),
        logging.ERROR: lambda s: click.style(s, 'red'),
        logging.CRITICAL: lambda s: click.style(s, 'red', bold=True),
    }

    def format(self, record):
        message = record.msg

        if record.args:
            message = record.msg % record.args

        # We only handle strings here
        if isinstance(message, six.string_types):
            if record.levelno in self.level_to_format:
                message = self.level_to_format[record.levelno](message)

            now = datetime.now().replace(microsecond=0).isoformat()

            return '{0} {1} {2}'.format(now, record.levelname, message)

        # If not a string, pass to standard Formatter
        else:
            return super(LogFormatter, self).format(record)


def setup_logging(verbose, debug, default_level=logging.CRITICAL):
    log_level = default_level

    if verbose:
        log_level = logging.INFO

    if debug:
        log_level = logging.DEBUG

    # Set the log level
    logger.setLevel(log_level)

    # Setup a new handler for stdout & stderr
    stdout_handler = logging.StreamHandler(sys.stdout)
    stderr_handler = logging.StreamHandler(sys.stderr)

    # Setup filters to push different levels to different streams
    stdout_filter = LogFilter(*STDOUT_LOG_LEVELS)
    stdout_handler.addFilter(stdout_filter)

    stderr_filter = LogFilter(*STDERR_LOG_LEVELS)
    stderr_handler.addFilter(stderr_filter)

    # Setup a formatter
    formatter = LogFormatter()
    stdout_handler.setFormatter(formatter)
    stderr_handler.setFormatter(formatter)

    # Add the handlers
    logger.addHandler(stdout_handler)
    logger.addHandler(stderr_handler)

    return log_level


def setup_logging_from_settings(settings):
    if settings.debug == 'true':
        logger.setLevel(logging.DEBUG)

    if settings.log_file:
        rotation = settings.log_file_rotation
        count = settings.log_file_rotation_count

        try:
            rotation = int(rotation)
        except (TypeError, ValueError):
            pass

        if isinstance(rotation, int):
            handler = logging.handlers.RotatingFileHandler(
                settings.log_file,
                maxBytes=rotation,
                backupCount=count,
            )

        elif isinstance(rotation, six.string_types):
            handler = logging.handlers.TimedRotatingFileHandler(
                settings.log_file,
                when=rotation,
                backupCount=count,
            )

        else:
            handler = logging.FileHandler(settings.log_file)

        formatter = LogFormatter()
        handler.setFormatter(formatter)
        logger.addHandler(handler)

    if settings.syslog_facility:
        handler = SysLogHandler(facility=settings.syslog_facility)
        logger.addHandler(handler)


def print_exception(debug_only=False):
    if debug_only and logger.level != logging.DEBUG:
        return

    traceback.print_exc()
