logger.py

# Copyright (C) 2017
#
# This file is part of Rogueinabox.
#
# Rogueinabox 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.
#
# Rogueinabox 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/>.

import time
from datetime import datetime


class Log:
    """Implements a log entry"""

    def __init__(self, name, text, depth=0, every=1, mean=None):
        """Constructor for log

        :param str name:
            log identification name.
            This is used as key in Logger.
        :param str text:
            log text
        :param int depth:
            logs are printed only if this value is lower than the log_depth of the Logger
        :param int every:
            how many logs with the given 'name' should be logged before printing one
        :param int mean:
            how many logs with the given 'name' use to average start/stop time.
            Useful only for logs used with Logger.start_log_timer() and Logger.stop_log_timer().
        """
        self.name = name
        self.text = text
        self.depth = depth
        self.every = every
        self.mean = mean


class Logger:
    """Implements a logger that supports conditions, timers and logging every X times"""

    def __init__(self, log_depth=0, log_targets=["terminal"], filepath="logfile.log", ui=None):
        """Constructor for Logger

        :param int log_depth:
            maximum depth that a log can have to be printed
        :param list[str] log_targets:
            media on which the logs will be printed.
            The list can contain:
                "terminal"
                    will print logs on terminal
                "file"
                    will append logs on the file named 'filepath'
                "ui"
                    will print logs on the gui 'ui'
        :param str filepath:
            log file path.
            N.B. Only used if parameter 'log_targets' contains "file".
        :param ui.UI ui:
            gui where to print logs.
            N.B. Only used if parameter 'log_targets' contains "ui".
        """
        self.depth = log_depth
        self.ui = ui
        self.targets = log_targets
        self.timers = {}
        self.every = {}
        self.means = {}
        if "file" in log_targets:
            self.log_file = open(filepath, "a+")
        current_time = datetime.now().isoformat()
        text = "\n\n[ Started session at {} ]\n\n ".format(current_time)
        self._print(text)

    def log(self, logs, condition=True):
        """Print the given log on the medium defined in the settings if the depth is right. An addition 'condition'
        gets evaluated before execution. It's possible to print the log text every 'log.every' cycle.

        :param list[Log] logs:
            list of logs to log
        :param condition:
            expression on which the printing is conditional. The given logs are processed only if 'condition' is truthy.
        """
        if condition:
            for log in logs:
                if log.depth <= self.depth:
                    if log.every > 1:
                        if log.name not in self.every:
                            self.every[log.name] = 1
                        else:
                            self.every[log.name] += 1
                            if self.every[log.name] >= log.every:
                                self.every[log.name] = 0
                                self._print(log.text)
                    else:
                        self._print(log.text)

    def start_log_timer(self, logs, condition=True):
        """Start a timer count on the given log if the depth is right. If log.mean is more than one
        a mean is started/updated.
        In addition 'condition' gets evaluated before execution.

        :param list[Log] logs:
            list of logs to log
        :param condition:
            expression on which the printing is conditional. The given logs are processed only if 'condition' is truthy.
        """
        if condition:
            for log in logs:
                if log.depth <= self.depth:
                    if log.mean > 1 and log.name not in self.means:
                        # very first time of a mean request
                        self.means[log.name] = [0, 0]
                    # init the timer
                    self.timers[log.name] = time.time()

    def stop_log_timer(self, logs, condition=True):
        """Stop a timer count on the given log if the depth is right. If log.mean is more than one a mean is
        updated/the relative log.text is printed on the medium specified in the settings.
        In addition 'condition' gets evaluated before execution.

        :param list[Log] logs:
            list of logs to log
        :param condition:
            expression on which the printing is conditional. The given logs are processed only if 'condition' is truthy.
        """
        if condition:
            for log in logs:
                if log.depth <= self.depth and log.name in self.timers:
                    elapsedTime = time.time() - self.timers[log.name]
                    self.timers.pop(log.name)  # reset the timer
                    if log.mean > 1 and log.name in self.means:
                        # update the timer mean
                        self.means[log.name][0] += elapsedTime
                        self.means[log.name][1] += 1
                        if self.means[log.name][1] >= log.mean:
                            mean = self.means[log.name][0] / log.mean
                            self.means.pop(log.name)
                            self._print('{} cycles of [{}] took a mean of {} ms to execute'.format(
                                log.mean, log.text, int(mean * 1000)))
                    else:
                        self._print('[{}] : {} ms'.format(
                            log.text, int(elapsedTime * 1000)))

    def _print(self, string):
        """Logs a string on the media provided during init

        :param str string:
            string to print
        """
        current_time = datetime.now().isoformat()
        formatted_str = "[{}] {}".format(current_time, string)
        for target in self.targets:
            if target == "terminal":
                print(formatted_str)
            elif target == "file":
                print(formatted_str, file=self.log_file)
            elif target == "ui" and self.ui is not None:
                self.ui.draw_log(string)