--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/backend/core/log_config.py	Fri Jun 02 11:49:51 2023 +0200
@@ -0,0 +1,411 @@
+#!/usr/bin/env python3
+
+
+# Libervia: an XMPP client
+# Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)
+
+# 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.
+
+# This program 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 Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""High level logging functions"""
+# XXX: this module use standard logging module when possible, but as SàT can work in different cases where logging is not the best choice (twisted, pyjamas, etc), it is necessary to have a dedicated module. Additional feature like environment variables and colors are also managed.
+
+from libervia.backend.core.constants import Const as C
+from libervia.backend.core import log
+
+
+class TwistedLogger(log.Logger):
+    colors = True
+    force_colors = False
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        from twisted.logger import Logger
+        self.twisted_log = Logger()
+
+    def out(self, message, level=None, **kwargs):
+        """Actually log the message
+
+        @param message: formatted message
+        """
+        self.twisted_log.emit(
+            level=self.level_map[level],
+            format=message,
+            sat_logged=True,
+            **kwargs,
+        )
+
+
+class ConfigureBasic(log.ConfigureBase):
+    def configure_colors(self, colors, force_colors, levels_taints_dict):
+        super(ConfigureBasic, self).configure_colors(
+            colors, force_colors, levels_taints_dict
+        )
+        if colors:
+            import sys
+
+            try:
+                isatty = sys.stdout.isatty()
+            except AttributeError:
+                isatty = False
+            # FIXME: isatty should be tested on each handler, not globaly
+            if (force_colors or isatty):
+                # we need colors
+                log.Logger.post_treat = lambda logger, level, message: self.ansi_colors(
+                    level, message
+                )
+        elif force_colors:
+            raise ValueError("force_colors can't be used if colors is False")
+
+    @staticmethod
+    def get_profile():
+        """Try to find profile value using introspection"""
+        import inspect
+
+        stack = inspect.stack()
+        current_path = stack[0][1]
+        for frame_data in stack[:-1]:
+            if frame_data[1] != current_path:
+                if (
+                    log.backend == C.LOG_BACKEND_STANDARD
+                    and "/logging/__init__.py" in frame_data[1]
+                ):
+                    continue
+                break
+
+        frame = frame_data[0]
+        args = inspect.getargvalues(frame)
+        try:
+            profile = args.locals.get("profile") or args.locals["profile_key"]
+        except (TypeError, KeyError):
+            try:
+                try:
+                    profile = args.locals["self"].profile
+                except AttributeError:
+                    try:
+                        profile = args.locals["self"].parent.profile
+                    except AttributeError:
+                        profile = args.locals[
+                            "self"
+                        ].host.profile  # used in quick_frontend for single profile configuration
+            except Exception:
+                # we can't find profile, we return an empty value
+                profile = ""
+        return profile
+
+
+class ConfigureTwisted(ConfigureBasic):
+    LOGGER_CLASS = TwistedLogger
+
+    def pre_treatment(self):
+        from twisted import logger
+        global logger
+        self.level_map = {
+            C.LOG_LVL_DEBUG: logger.LogLevel.debug,
+            C.LOG_LVL_INFO: logger.LogLevel.info,
+            C.LOG_LVL_WARNING: logger.LogLevel.warn,
+            C.LOG_LVL_ERROR: logger.LogLevel.error,
+            C.LOG_LVL_CRITICAL: logger.LogLevel.critical,
+        }
+        self.LOGGER_CLASS.level_map = self.level_map
+
+    def configure_level(self, level):
+        self.level = self.level_map[level]
+
+    def configure_output(self, output):
+        import sys
+        from twisted.python import logfile
+        self.log_publisher = logger.LogPublisher()
+
+        if output is None:
+            output = C.LOG_OPT_OUTPUT_SEP + C.LOG_OPT_OUTPUT_DEFAULT
+        self.manage_outputs(output)
+
+        if C.LOG_OPT_OUTPUT_DEFAULT in log.handlers:
+            if self.backend_data is None:
+                raise ValueError(
+                    "You must pass options as backend_data with Twisted backend"
+                )
+            options = self.backend_data
+            log_file = logfile.LogFile.fromFullPath(options['logfile'])
+            self.log_publisher.addObserver(
+                logger.FileLogObserver(log_file, self.text_formatter))
+            # we also want output to stdout if we are in debug or nodaemon mode
+            if options.get("nodaemon", False) or options.get("debug", False):
+                self.log_publisher.addObserver(
+                    logger.FileLogObserver(sys.stdout, self.text_formatter))
+
+        if C.LOG_OPT_OUTPUT_FILE in log.handlers:
+
+            for path in log.handlers[C.LOG_OPT_OUTPUT_FILE]:
+                log_file = (
+                    sys.stdout if path == "-" else logfile.LogFile.fromFullPath(path)
+                )
+                self.log_publisher.addObserver(
+                    logger.FileLogObserver(log_file, self.text_formatter))
+
+        if C.LOG_OPT_OUTPUT_MEMORY in log.handlers:
+            raise NotImplementedError(
+                "Memory observer is not implemented in Twisted backend"
+            )
+
+    def configure_colors(self, colors, force_colors, levels_taints_dict):
+        super(ConfigureTwisted, self).configure_colors(
+            colors, force_colors, levels_taints_dict
+        )
+        self.LOGGER_CLASS.colors = colors
+        self.LOGGER_CLASS.force_colors = force_colors
+        if force_colors and not colors:
+            raise ValueError("colors must be True if force_colors is True")
+
+    def post_treatment(self):
+        """Install twistedObserver which manage non SàT logs"""
+        # from twisted import logger
+        import sys
+        filtering_obs = logger.FilteringLogObserver(
+            observer=self.log_publisher,
+            predicates=[
+                logger.LogLevelFilterPredicate(self.level),
+                ]
+        )
+        logger.globalLogBeginner.beginLoggingTo([filtering_obs])
+
+    def text_formatter(self, event):
+        if event.get('sat_logged', False):
+            timestamp = ''.join([logger.formatTime(event.get("log_time", None)), " "])
+            return f"{timestamp}{event.get('log_format', '')}\n"
+        else:
+            eventText = logger.eventAsText(
+                event, includeSystem=True)
+            if not eventText:
+                return None
+            return eventText.replace("\n", "\n\t") + "\n"
+
+
+class ConfigureStandard(ConfigureBasic):
+    def __init__(
+        self,
+        level=None,
+        fmt=None,
+        output=None,
+        logger=None,
+        colors=False,
+        levels_taints_dict=None,
+        force_colors=False,
+        backend_data=None,
+    ):
+        if fmt is None:
+            fmt = C.LOG_OPT_FORMAT[1]
+        if output is None:
+            output = C.LOG_OPT_OUTPUT[1]
+        super(ConfigureStandard, self).__init__(
+            level,
+            fmt,
+            output,
+            logger,
+            colors,
+            levels_taints_dict,
+            force_colors,
+            backend_data,
+        )
+
+    def pre_treatment(self):
+        """We use logging methods directly, instead of using Logger"""
+        import logging
+
+        log.getLogger = logging.getLogger
+        log.debug = logging.debug
+        log.info = logging.info
+        log.warning = logging.warning
+        log.error = logging.error
+        log.critical = logging.critical
+
+    def configure_level(self, level):
+        if level is None:
+            level = C.LOG_LVL_DEBUG
+        self.level = level
+
+    def configure_format(self, fmt):
+        super(ConfigureStandard, self).configure_format(fmt)
+        import logging
+
+        class SatFormatter(logging.Formatter):
+            """Formatter which manage SàT specificities"""
+            _format = fmt
+            _with_profile = "%(profile)s" in fmt
+
+            def __init__(self, can_colors=False):
+                super(SatFormatter, self).__init__(self._format)
+                self.can_colors = can_colors
+
+            def format(self, record):
+                if self._with_profile:
+                    record.profile = ConfigureStandard.get_profile()
+                do_color = self.with_colors and (self.can_colors or self.force_colors)
+                if ConfigureStandard._color_location:
+                    # we copy raw formatting strings for color_*
+                    # as formatting is handled in ansi_colors in this case
+                    if do_color:
+                        record.color_start = log.COLOR_START
+                        record.color_end = log.COLOR_END
+                    else:
+                        record.color_start = record.color_end = ""
+                s = super(SatFormatter, self).format(record)
+                if do_color:
+                    s = ConfigureStandard.ansi_colors(record.levelname, s)
+                return s
+
+        self.formatterClass = SatFormatter
+
+    def configure_output(self, output):
+        self.manage_outputs(output)
+
+    def configure_logger(self, logger):
+        self.name_filter = log.FilterName(logger) if logger else None
+
+    def configure_colors(self, colors, force_colors, levels_taints_dict):
+        super(ConfigureStandard, self).configure_colors(
+            colors, force_colors, levels_taints_dict
+        )
+        self.formatterClass.with_colors = colors
+        self.formatterClass.force_colors = force_colors
+        if not colors and force_colors:
+            raise ValueError("force_colors can't be used if colors is False")
+
+    def _add_handler(self, root_logger, hdlr, can_colors=False):
+        hdlr.setFormatter(self.formatterClass(can_colors))
+        root_logger.addHandler(hdlr)
+        root_logger.setLevel(self.level)
+        if self.name_filter is not None:
+            hdlr.addFilter(self.name_filter)
+
+    def post_treatment(self):
+        import logging
+
+        root_logger = logging.getLogger()
+        if len(root_logger.handlers) == 0:
+            for handler, options in list(log.handlers.items()):
+                if handler == C.LOG_OPT_OUTPUT_DEFAULT:
+                    hdlr = logging.StreamHandler()
+                    try:
+                        can_colors = hdlr.stream.isatty()
+                    except AttributeError:
+                        can_colors = False
+                    self._add_handler(root_logger, hdlr, can_colors=can_colors)
+                elif handler == C.LOG_OPT_OUTPUT_MEMORY:
+                    from logging.handlers import BufferingHandler
+
+                    class SatMemoryHandler(BufferingHandler):
+                        def emit(self, record):
+                            super(SatMemoryHandler, self).emit(self.format(record))
+
+                    hdlr = SatMemoryHandler(options)
+                    log.handlers[
+                        handler
+                    ] = (
+                        hdlr
+                    )  # we keep a reference to the handler to read the buffer later
+                    self._add_handler(root_logger, hdlr, can_colors=False)
+                elif handler == C.LOG_OPT_OUTPUT_FILE:
+                    import os.path
+
+                    for path in options:
+                        hdlr = logging.FileHandler(os.path.expanduser(path))
+                        self._add_handler(root_logger, hdlr, can_colors=False)
+                else:
+                    raise ValueError("Unknown handler type")
+        else:
+            root_logger.warning("Handlers already set on root logger")
+
+    @staticmethod
+    def memory_get(size=None):
+        """Return buffered logs
+
+        @param size: number of logs to return
+        """
+        mem_handler = log.handlers[C.LOG_OPT_OUTPUT_MEMORY]
+        return (
+            log_msg for log_msg in mem_handler.buffer[size if size is None else -size :]
+        )
+
+
+log.configure_cls[C.LOG_BACKEND_BASIC] = ConfigureBasic
+log.configure_cls[C.LOG_BACKEND_TWISTED] = ConfigureTwisted
+log.configure_cls[C.LOG_BACKEND_STANDARD] = ConfigureStandard
+
+
+def configure(backend, **options):
+    """Configure logging behaviour
+    @param backend: can be:
+        C.LOG_BACKEND_STANDARD: use standard logging module
+        C.LOG_BACKEND_TWISTED: use twisted logging module (with standard logging observer)
+        C.LOG_BACKEND_BASIC: use a basic print based logging
+        C.LOG_BACKEND_CUSTOM: use a given Logger subclass
+    """
+    return log.configure(backend, **options)
+
+
+def _parse_options(options):
+    """Parse string options as given in conf or environment variable, and return expected python value
+
+    @param options (dict): options with (key: name, value: string value)
+    """
+    COLORS = C.LOG_OPT_COLORS[0]
+    LEVEL = C.LOG_OPT_LEVEL[0]
+
+    if COLORS in options:
+        if options[COLORS].lower() in ("1", "true"):
+            options[COLORS] = True
+        elif options[COLORS] == "force":
+            options[COLORS] = True
+            options["force_colors"] = True
+        else:
+            options[COLORS] = False
+    if LEVEL in options:
+        level = options[LEVEL].upper()
+        if level not in C.LOG_LEVELS:
+            level = C.LOG_LVL_INFO
+        options[LEVEL] = level
+
+
+def sat_configure(backend=C.LOG_BACKEND_STANDARD, const=None, backend_data=None):
+    """Configure logging system for SàT, can be used by frontends
+
+    logs conf is read in SàT conf, then in environment variables. It must be done before Memory init
+    @param backend: backend to use, it can be:
+        - C.LOG_BACKEND_BASIC: print based backend
+        - C.LOG_BACKEND_TWISTED: Twisted logging backend
+        - C.LOG_BACKEND_STANDARD: standard logging backend
+    @param const: Const class to use instead of sat.core.constants.Const (mainly used to change default values)
+    """
+    if const is not None:
+        global C
+        C = const
+        log.C = const
+    from libervia.backend.tools import config
+    import os
+
+    log_conf = {}
+    sat_conf = config.parse_main_conf()
+    for opt_name, opt_default in C.LOG_OPTIONS():
+        try:
+            log_conf[opt_name] = os.environ[
+                "".join((C.ENV_PREFIX, C.LOG_OPT_PREFIX.upper(), opt_name.upper()))
+            ]
+        except KeyError:
+            log_conf[opt_name] = config.config_get(
+                sat_conf, C.LOG_OPT_SECTION, C.LOG_OPT_PREFIX + opt_name, opt_default
+            )
+
+    _parse_options(log_conf)
+    configure(backend, backend_data=backend_data, **log_conf)