text: # Copyright The PyTorch Lightning team.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  """
  Comet
  -----
  """
  
  import os
  from argparse import Namespace
  from typing import Any, Dict, Optional, Union
  
  try:
      import comet_ml
  
  except ModuleNotFoundError:  # pragma: no-cover
      comet_ml = None
      CometExperiment = None
      CometExistingExperiment = None
      CometOfflineExperiment = None
      API = None
      generate_guid = None
  else:
      from comet_ml import ExistingExperiment as CometExistingExperiment
      from comet_ml import Experiment as CometExperiment
      from comet_ml import OfflineExperiment as CometOfflineExperiment
  
      try:
          from comet_ml.api import API
      except ImportError:  # pragma: no-cover
          # For more information, see: https://www.comet.ml/docs/python-sdk/releases/#release-300
          from comet_ml.papi import API  # pragma: no-cover
  
  import torch
  from torch import is_tensor
  
  from pytorch_lightning import _logger as log
  from pytorch_lightning.loggers.base import LightningLoggerBase, rank_zero_experiment
  from pytorch_lightning.utilities import rank_zero_only
  from pytorch_lightning.utilities.exceptions import MisconfigurationException
  
  
  class CometLogger(LightningLoggerBase):
      r"""
      Log using `Comet.ml <https://www.comet.ml>`_. Install it with pip:
  
      .. code-block:: bash
  
          pip install comet-ml
  
      Comet requires either an API Key (online mode) or a local directory path (offline mode).
  
      **ONLINE MODE**
  
      Example:
          >>> import os
          >>> from pytorch_lightning import Trainer
          >>> from pytorch_lightning.loggers import CometLogger
          >>> # arguments made to CometLogger are passed on to the comet_ml.Experiment class
          >>> comet_logger = CometLogger(
          ...     api_key=os.environ.get('COMET_API_KEY'),
          ...     workspace=os.environ.get('COMET_WORKSPACE'),  # Optional
          ...     save_dir='.',  # Optional
          ...     project_name='default_project',  # Optional
          ...     rest_api_key=os.environ.get('COMET_REST_API_KEY'),  # Optional
          ...     experiment_name='default'  # Optional
          ... )
          >>> trainer = Trainer(logger=comet_logger)
  
      **OFFLINE MODE**
  
      Example:
          >>> from pytorch_lightning.loggers import CometLogger
          >>> # arguments made to CometLogger are passed on to the comet_ml.Experiment class
          >>> comet_logger = CometLogger(
          ...     save_dir='.',
          ...     workspace=os.environ.get('COMET_WORKSPACE'),  # Optional
          ...     project_name='default_project',  # Optional
          ...     rest_api_key=os.environ.get('COMET_REST_API_KEY'),  # Optional
          ...     experiment_name='default'  # Optional
          ... )
          >>> trainer = Trainer(logger=comet_logger)
  
      Args:
          api_key: Required in online mode. API key, found on Comet.ml. If not given, this
              will be loaded from the environment variable COMET_API_KEY or ~/.comet.config
              if either exists.
          save_dir: Required in offline mode. The path for the directory to save local
              comet logs. If given, this also sets the directory for saving checkpoints.
          project_name: Optional. Send your experiment to a specific project.
              Otherwise will be sent to Uncategorized Experiments.
              If the project name does not already exist, Comet.ml will create a new project.
          rest_api_key: Optional. Rest API key found in Comet.ml settings.
              This is used to determine version number
          experiment_name: Optional. String representing the name for this particular experiment on Comet.ml.
          experiment_key: Optional. If set, restores from existing experiment.
          offline: If api_key and save_dir are both given, this determines whether
              the experiment will be in online or offline mode. This is useful if you use
              save_dir to control the checkpoints directory and have a ~/.comet.config
              file but still want to run offline experiments.
          \**kwargs: Additional arguments like `workspace`, `log_code`, etc. used by
              :class:`CometExperiment` can be passed as keyword arguments in this logger.
      """
  
      def __init__(
              self,
              api_key: Optional[str] = None,
              save_dir: Optional[str] = None,
              project_name: Optional[str] = None,
              rest_api_key: Optional[str] = None,
              experiment_name: Optional[str] = None,
              experiment_key: Optional[str] = None,
              offline: bool = False,
              **kwargs
      ):
          if comet_ml is None:
              raise ImportError(
                  "You want to use `comet_ml` logger which is not installed yet,"
                  " install it with `pip install comet-ml`."
              )
          super().__init__()
          self._experiment = None
  
          # Determine online or offline mode based on which arguments were passed to CometLogger
          api_key = api_key or comet_ml.config.get_api_key(None, comet_ml.config.get_config())
  
          if api_key is not None and save_dir is not None:
              self.mode = "offline" if offline else "online"
              self.api_key = api_key
              self._save_dir = save_dir
          elif api_key is not None:
              self.mode = "online"
              self.api_key = api_key
              self._save_dir = None
          elif save_dir is not None:
              self.mode = "offline"
              self._save_dir = save_dir
          else:
              # If neither api_key nor save_dir are passed as arguments, raise an exception
              raise MisconfigurationException("CometLogger requires either api_key or save_dir during initialization.")
  
          log.info(f"CometLogger will be initialized in {self.mode} mode")
  
          self._project_name = project_name
          self._experiment_key = experiment_key
          self._experiment_name = experiment_name
          self._kwargs = kwargs
          self._future_experiment_key = None
  
          if rest_api_key is not None:
              # Comet.ml rest API, used to determine version number
              self.rest_api_key = rest_api_key
              self.comet_api = API(self.rest_api_key)
          else:
              self.rest_api_key = None
              self.comet_api = None
  
          self._kwargs = kwargs
  
      @property
      @rank_zero_experiment
      def experiment(self):
          r"""
          Actual Comet object. To use Comet features in your
          :class:`~pytorch_lightning.core.lightning.LightningModule` do the following.
  
          Example::
  
              self.logger.experiment.some_comet_function()
  
          """
          if self._experiment is not None:
              return self._experiment
  
          if self._future_experiment_key is not None:
              os.environ["COMET_EXPERIMENT_KEY"] = self._future_experiment_key
              self._future_experiment_key = None
  
          try:
              if self.mode == "online":
                  if self._experiment_key is None:
                      self._experiment = CometExperiment(
                          api_key=self.api_key,
                          project_name=self._project_name,
                          **self._kwargs,
                      )
                      self._experiment_key = self._experiment.get_key()
                  else:
                      self._experiment = CometExistingExperiment(
                          api_key=self.api_key,
                          project_name=self._project_name,
                          previous_experiment=self._experiment_key,
                          **self._kwargs,
                      )
              else:
                  self._experiment = CometOfflineExperiment(
                      offline_directory=self.save_dir,
                      project_name=self._project_name,
                      **self._kwargs,
                  )
          finally:
              os.environ.pop("COMET_EXPERIMENT_KEY", None)
  
          if self._experiment_name:
              self._experiment.set_name(self._experiment_name)
  
          return self._experiment
  
      @rank_zero_only
      def log_hyperparams(self, params: Union[Dict[str, Any], Namespace]) -> None:
          params = self._convert_params(params)
          params = self._flatten_dict(params)
          self.experiment.log_parameters(params)
  
      @rank_zero_only
      def log_metrics(self, metrics: Dict[str, Union[torch.Tensor, float]], step: Optional[int] = None) -> None:
          assert rank_zero_only.rank == 0, "experiment tried to log from global_rank != 0"
          # Comet.ml expects metrics to be a dictionary of detached tensors on CPU
          for key, val in metrics.items():
              if is_tensor(val):
                  metrics[key] = val.cpu().detach()
  
          metrics_without_epoch = metrics.copy()
          epoch = metrics_without_epoch.pop('epoch', None)
          self.experiment.log_metrics(metrics_without_epoch, step=step, epoch=epoch)
  
      def reset_experiment(self):
          self._experiment = None
  
      @rank_zero_only
      def finalize(self, status: str) -> None:
          r"""
          When calling ``self.experiment.end()``, that experiment won't log any more data to Comet.
          That's why, if you need to log any more data, you need to create an ExistingCometExperiment.
          For example, to log data when testing your model after training, because when training is
          finalized :meth:`CometLogger.finalize` is called.
  
          This happens automatically in the :meth:`~CometLogger.experiment` property, when
          ``self._experiment`` is set to ``None``, i.e. ``self.reset_experiment()``.
          """
          self.experiment.end()
          self.reset_experiment()
  
      @property
      def save_dir(self) -> Optional[str]:
          return self._save_dir
  
      @property
      def name(self) -> str:
          # Don't create an experiment if we don't have one
          if self._experiment is not None and self._experiment.project_name is not None:
              return self._experiment.project_name
  
          if self._project_name is not None:
              return self._project_name
  
          return "comet-default"
  
      @property
      def version(self) -> str:
          # Don't create an experiment if we don't have one
          if self._experiment is not None:
              return self._experiment.id
  
          if self._experiment_key is not None:
              return self._experiment_key
  
          if self._future_experiment_key is not None:
              return self._future_experiment_key
  
          # Pre-generate an experiment key
          self._future_experiment_key = comet_ml.generate_guid()
  
          return self._future_experiment_key
  
      def __getstate__(self):
          state = self.__dict__.copy()
  
          # Save the experiment id in case an experiment object already exists,
          # this way we could create an ExistingExperiment pointing to the same
          # experiment
          state["_experiment_key"] = self._experiment.id if self._experiment is not None else None
  
          # Remove the experiment object as it contains hard to pickle objects
          # (like network connections), the experiment object will be recreated if
          # needed later
          state["_experiment"] = None
          return state
  