AutoGL/autogl/solver/classifier/node_classifier.py

"""
Auto Classfier for Node Classification
"""
import time
import json

from copy import deepcopy

import torch
import numpy as np
import yaml

from .base import BaseClassifier
from ..base import _parse_hp_space, _initialize_single_model
from ...module.feature import FEATURE_DICT
from ...module.model import MODEL_DICT, BaseModel
from ...module.train import TRAINER_DICT, NodeClassificationTrainer
from ...module.train import get_feval
from ..utils import Leaderboard, set_seed
from ...datasets import utils
from ...utils import get_logger

LOGGER = get_logger("NodeClassifier")


class AutoNodeClassifier(BaseClassifier):
    """
    Auto Multi-class Graph Node Classifier.

    Used to automatically solve the node classification problems.

    Parameters
    ----------
    feature_module: autogl.module.feature.BaseFeatureEngineer or str or None
        The (name of) auto feature engineer used to process the given dataset. Default ``deepgl``.
        Disable feature engineer by setting it to ``None``.

    graph_models: list of autogl.module.model.BaseModel or list of str
        The (name of) models to be optimized as backbone. Default ``['gat', 'gcn']``.

    hpo_module: autogl.module.hpo.BaseHPOptimizer or str or None
        The (name of) hpo module used to search for best hyper parameters. Default ``anneal``.
        Disable hpo by setting it to ``None``.

    ensemble_module: autogl.module.ensemble.BaseEnsembler or str or None
        The (name of) ensemble module used to ensemble the multi-models found. Default ``voting``.
        Disable ensemble by setting it to ``None``.

    max_evals: int (Optional)
        If given, will set the number eval times the hpo module will use.
        Only be effective when hpo_module is ``str``. Default ``None``.

    trainer_hp_space: list of dict (Optional)
        trainer hp space or list of trainer hp spaces configuration.
        If a single trainer hp is given, will specify the hp space of trainer for every model.
        If a list of trainer hp is given, will specify every model with corrsponding
        trainer hp space.
        Default ``None``.

    model_hp_spaces: list of list of dict (Optional)
        model hp space configuration.
        If given, will specify every hp space of every passed model. Default ``None``.

    size: int (Optional)
        The max models ensemble module will use. Default ``None``.

    device: torch.device or str
        The device where model will be running on. If set to ``auto``, will use gpu when available.
        You can also specify the device by directly giving ``gpu`` or ``cuda:0``, etc.
        Default ``auto``.
    """

    # pylint: disable=W0102

    def __init__(
        self,
        feature_module=None,
        graph_models=["gat", "gcn"],
        hpo_module="anneal",
        ensemble_module="voting",
        max_evals=50,
        default_trainer=None,
        trainer_hp_space=None,
        model_hp_spaces=None,
        size=4,
        device="auto",
    ):

        super().__init__(
            feature_module=feature_module,
            graph_models=graph_models,
            hpo_module=hpo_module,
            ensemble_module=ensemble_module,
            max_evals=max_evals,
            default_trainer=default_trainer or "NodeClassification",
            trainer_hp_space=trainer_hp_space,
            model_hp_spaces=model_hp_spaces,
            size=size,
            device=device,
        )

        # data to be kept when fit
        self.data = None

    def _init_graph_module(
        self, graph_models, num_classes, num_features, feval, device, loss
    ) -> "AutoNodeClassifier":
        # load graph network module
        self.graph_model_list = []
        if isinstance(graph_models, list):
            for model in graph_models:
                if isinstance(model, str):
                    if model in MODEL_DICT:
                        self.graph_model_list.append(
                            MODEL_DICT[model](
                                num_classes=num_classes,
                                num_features=num_features,
                                device=device,
                                init=False,
                            )
                        )
                    else:
                        raise KeyError("cannot find model %s" % (model))
                elif isinstance(model, type) and issubclass(model, BaseModel):
                    self.graph_model_list.append(
                        model(
                            num_classes=num_classes,
                            num_features=num_features,
                            device=device,
                            init=False,
                        )
                    )
                elif isinstance(model, BaseModel):
                    # setup the hp of num_classes and num_features
                    model.set_num_classes(num_classes)
                    model.set_num_features(num_features)
                    self.graph_model_list.append(model.to(device))
                elif isinstance(model, NodeClassificationTrainer):
                    # receive a trainer list, put trainer to list
                    assert (
                        model.get_model() is not None
                    ), "Passed trainer should contain a model"
                    model.set_feval(feval)
                    model.loss_type = loss
                    model.to(device)
                    model.model.set_num_classes(num_classes)
                    model.model.set_num_features(num_features)
                    model.num_classes = num_classes
                    model.num_features = num_features
                    self.graph_model_list.append(model)
                else:
                    raise KeyError("cannot find graph network %s." % (model))
        else:
            raise ValueError(
                "need graph network to be (list of) str or a BaseModel class/instance, get",
                graph_models,
                "instead.",
            )

        # wrap all model_cls with specified trainer
        for i, model in enumerate(self.graph_model_list):
            # set model hp space
            if self._model_hp_spaces is not None:
                if self._model_hp_spaces[i] is not None:
                    if isinstance(model, NodeClassificationTrainer):
                        model.model.hyper_parameter_space = self._model_hp_spaces[i]
                    else:
                        model.hyper_parameter_space = self._model_hp_spaces[i]
            # initialize trainer if needed
            if isinstance(model, BaseModel):
                name = (
                    self._default_trainer
                    if isinstance(self._default_trainer, str)
                    else self._default_trainer[i]
                )
                model = TRAINER_DICT[name](
                    model=model,
                    num_features=num_features,
                    num_classes=num_classes,
                    loss=loss,
                    feval=feval,
                    device=device,
                    init=False,
                )
            # set trainer hp space
            if self._trainer_hp_space is not None:
                if isinstance(self._trainer_hp_space[0], list):
                    current_hp_for_trainer = self._trainer_hp_space[i]
                else:
                    current_hp_for_trainer = self._trainer_hp_space
                model.hyper_parameter_space = current_hp_for_trainer
            self.graph_model_list[i] = model

        return self

    # pylint: disable=arguments-differ
    def fit(
        self,
        dataset,
        time_limit=-1,
        inplace=False,
        train_split=None,
        val_split=None,
        balanced=True,
        evaluation_method="infer",
        seed=None,
    ) -> "AutoNodeClassifier":
        """
        Fit current solver on given dataset.

        Parameters
        ----------
        dataset: torch_geometric.data.dataset.Dataset
            The dataset needed to fit on. This dataset must have only one graph.

        time_limit: int
            The time limit of the whole fit process (in seconds). If set below 0,
            will ignore time limit. Default ``-1``.

        inplace: bool
            Whether we process the given dataset in inplace manner. Default ``False``.
            Set it to True if you want to save memory by modifying the given dataset directly.

        train_split: float or int (Optional)
            The train ratio (in ``float``) or number (in ``int``) of dataset. If you want to
            use default train/val/test split in dataset, please set this to ``None``.
            Default ``None``.

        val_split: float or int (Optional)
            The validation ratio (in ``float``) or number (in ``int``) of dataset. If you want
            to use default train/val/test split in dataset, please set this to ``None``.
            Default ``None``.

        balanced: bool
            Wether to create the train/valid/test split in a balanced way.
            If set to ``True``, the train/valid will have the same number of different classes.
            Default ``True``.

        evaluation_method: (list of) str or autogl.module.train.evaluation
            A (list of) evaluation method for current solver. If ``infer``, will automatically
            determine. Default ``infer``.

        seed: int (Optional)
            The random seed. If set to ``None``, will run everything at random.
            Default ``None``.

        Returns
        -------
        self: autogl.solver.AutoNodeClassifier
            A reference of current solver.
        """
        set_seed(seed)

        if time_limit < 0:
            time_limit = 3600 * 24
        time_begin = time.time()

        # initialize leaderboard
        if evaluation_method == "infer":
            if hasattr(dataset, "metric"):
                evaluation_method = [dataset.metric]
            else:
                num_of_label = dataset.num_classes
                if num_of_label == 2:
                    evaluation_method = ["auc"]
                else:
                    evaluation_method = ["acc"]
        assert isinstance(evaluation_method, list)
        evaluator_list = get_feval(evaluation_method)

        self.leaderboard = Leaderboard(
            [e.get_eval_name() for e in evaluator_list],
            {e.get_eval_name(): e.is_higher_better() for e in evaluator_list},
        )

        # set up the dataset
        if train_split is not None and val_split is not None:
            size = dataset.data.x.shape[0]
            if balanced:
                train_split = (
                    train_split if train_split > 1 else int(train_split * size)
                )
                val_split = val_split if val_split > 1 else int(val_split * size)
                utils.random_splits_mask_class(
                    dataset,
                    num_train_per_class=train_split // dataset.num_classes,
                    num_val_per_class=val_split // dataset.num_classes,
                    seed=seed,
                )
            else:
                train_split = train_split if train_split < 1 else train_split / size
                val_split = val_split if val_split < 1 else val_split / size
                utils.random_splits_mask(
                    dataset, train_ratio=train_split, val_ratio=val_split
                )
        else:
            assert hasattr(dataset.data, "train_mask") and hasattr(
                dataset.data, "val_mask"
            ), (
                "The dataset has no default train/val split! Please manually pass "
                "train and val ratio."
            )
            LOGGER.info("Use the default train/val/test ratio in given dataset")

        # feature engineering
        if self.feature_module is not None:
            dataset = self.feature_module.fit_transform(dataset, inplace=inplace)

        self.dataset = dataset
        assert self.dataset[0].x is not None, (
            "Does not support fit on non node-feature dataset!"
            " Please add node features to dataset or specify feature engineers that generate"
            " node features."
        )

        # initialize graph networks
        self._init_graph_module(
            self.gml,
            num_features=self.dataset[0].x.shape[1],
            num_classes=dataset.num_classes,
            feval=evaluator_list,
            device=self.runtime_device,
            loss="cross_entropy" if not hasattr(dataset, "loss") else dataset.loss,
        )

        # train the models and tune hpo
        result_valid = []
        names = []
        for idx, model in enumerate(self.graph_model_list):
            time_for_each_model = (time_limit - time.time() + time_begin) / (
                len(self.graph_model_list) - idx
            )
            if self.hpo_module is None:
                model.initialize()
                model.train(self.dataset, True)
                optimized = model
            else:
                optimized, _ = self.hpo_module.optimize(
                    trainer=model, dataset=self.dataset, time_limit=time_for_each_model
                )
            # to save memory, all the trainer derived will be mapped to cpu
            optimized.to(torch.device("cpu"))
            name = optimized.get_name_with_hp() + "_idx%d" % (idx)
            names.append(name)
            performance_on_valid, _ = optimized.get_valid_score(return_major=False)
            result_valid.append(optimized.get_valid_predict_proba().cpu().numpy())
            self.leaderboard.insert_model_performance(
                name,
                dict(
                    zip(
                        [e.get_eval_name() for e in evaluator_list],
                        performance_on_valid,
                    )
                ),
            )
            self.trained_models[name] = optimized

        # fit the ensemble model
        if self.ensemble_module is not None:
            performance = self.ensemble_module.fit(
                result_valid,
                self.dataset[0].y[self.dataset[0].val_mask].cpu().numpy(),
                names,
                evaluator_list,
                n_classes=dataset.num_classes,
            )
            self.leaderboard.insert_model_performance(
                "ensemble",
                dict(zip([e.get_eval_name() for e in evaluator_list], performance)),
            )

        return self

    def fit_predict(
        self,
        dataset,
        time_limit=-1,
        inplace=False,
        train_split=None,
        val_split=None,
        balanced=True,
        evaluation_method="infer",
        use_ensemble=True,
        use_best=True,
        name=None,
    ) -> np.ndarray:
        """
        Fit current solver on given dataset and return the predicted value.

        Parameters
        ----------
        dataset: torch_geometric.data.dataset.Dataset
            The dataset needed to fit on. This dataset must have only one graph.

        time_limit: int
            The time limit of the whole fit process (in seconds).
            If set below 0, will ignore time limit. Default ``-1``.

        inplace: bool
            Whether we process the given dataset in inplace manner. Default ``False``.
            Set it to True if you want to save memory by modifying the given dataset directly.

        train_split: float or int (Optional)
            The train ratio (in ``float``) or number (in ``int``) of dataset. If you want to
            use default train/val/test split in dataset, please set this to ``None``.
            Default ``None``.

        val_split: float or int (Optional)
            The validation ratio (in ``float``) or number (in ``int``) of dataset. If you want
            to use default train/val/test split in dataset, please set this to ``None``.
            Default ``None``.

        balanced: bool
            Wether to create the train/valid/test split in a balanced way.
            If set to ``True``, the train/valid will have the same number of different classes.
            Default ``False``.

        evaluation_method: (list of) str or autogl.module.train.evaluation
            A (list of) evaluation method for current solver. If ``infer``, will automatically
            determine. Default ``infer``.

        use_ensemble: bool
            Whether to use ensemble to do the predict. Default ``True``.

        use_best: bool
            Whether to use the best single model to do the predict. Will only be effective when
            ``use_ensemble`` is ``False``.
            Default ``True``.

        name: str or None
            The name of model used to predict. Will only be effective when ``use_ensemble`` and
            ``use_best`` both are ``False``.
            Default ``None``.

        Returns
        -------
        result: np.ndarray
            An array of shape ``(N,)``, where ``N`` is the number of test nodes. The prediction
            on given dataset.
        """
        self.fit(
            dataset=dataset,
            time_limit=time_limit,
            inplace=inplace,
            train_split=train_split,
            val_split=val_split,
            balanced=balanced,
            evaluation_method=evaluation_method,
        )
        return self.predict(
            dataset=dataset,
            inplaced=inplace,
            inplace=inplace,
            use_ensemble=use_ensemble,
            use_best=use_best,
            name=name,
        )

    def predict_proba(
        self,
        dataset=None,
        inplaced=False,
        inplace=False,
        use_ensemble=True,
        use_best=True,
        name=None,
        mask="test",
    ) -> np.ndarray:
        """
        Predict the node probability.

        Parameters
        ----------
        dataset: torch_geometric.data.dataset.Dataset or None
            The dataset needed to predict. If ``None``, will use the processed dataset passed
            to ``fit()`` instead. Default ``None``.

        inplaced: bool
            Whether the given dataset is processed. Only be effective when ``dataset``
            is not ``None``. If you pass the dataset to ``fit()`` with ``inplace=True``, and
            you pass the dataset again to this method, you should set this argument to ``True``.
            Otherwise ``False``. Default ``False``.

        inplace: bool
            Whether we process the given dataset in inplace manner. Default ``False``. Set it to
            True if you want to save memory by modifying the given dataset directly.

        use_ensemble: bool
            Whether to use ensemble to do the predict. Default ``True``.

        use_best: bool
            Whether to use the best single model to do the predict. Will only be effective when
            ``use_ensemble`` is ``False``. Default ``True``.

        name: str or None
            The name of model used to predict. Will only be effective when ``use_ensemble`` and
            ``use_best`` both are ``False``. Default ``None``.

        mask: str
            The data split to give prediction on. Default ``test``.

        Returns
        -------
        result: np.ndarray
            An array of shape ``(N,C,)``, where ``N`` is the number of test nodes and ``C`` is
            the number of classes. The prediction on given dataset.
        """
        if dataset is None:
            dataset = self.dataset
            assert dataset is not None, (
                "Please execute fit() first before" " predicting on remembered dataset"
            )
        elif not inplaced and self.feature_module is not None:
            dataset = self.feature_module.transform(dataset, inplace=inplace)

        if use_ensemble:
            LOGGER.info("Ensemble argument on, will try using ensemble model.")

        if not use_ensemble and use_best:
            LOGGER.info(
                "Ensemble argument off and best argument on, will try using best model."
            )

        if (use_ensemble and self.ensemble_module is not None) or (
            not use_best and name == "ensemble"
        ):
            # we need to get all the prediction of every model trained
            predict_result = []
            names = []
            for model_name in self.trained_models:
                predict_result.append(
                    self._predict_proba_by_name(dataset, model_name, mask)
                )
                names.append(model_name)
            return self.ensemble_module.ensemble(predict_result, names)

        if use_ensemble and self.ensemble_module is None:
            LOGGER.warning(
                "Cannot use ensemble because no ensebmle module is given."
                "Will use best model instead."
            )

        if use_best or (use_ensemble and self.ensemble_module is None):
            # just return the best model we have found
            name = self.leaderboard.get_best_model()
            return self._predict_proba_by_name(dataset, name, mask)

        if name is not None:
            # return model performance by name
            return self._predict_proba_by_name(dataset, name, mask)

        LOGGER.error(
            "No model name is given while ensemble and best arguments are off."
        )
        raise ValueError(
            "You need to specify a model name if you do not want use ensemble and best model."
        )

    def _predict_proba_by_name(self, dataset, name, mask="test"):
        self.trained_models[name].to(self.runtime_device)
        predicted = (
            self.trained_models[name].predict_proba(dataset, mask=mask).cpu().numpy()
        )
        self.trained_models[name].to(torch.device("cpu"))
        return predicted

    def predict(
        self,
        dataset=None,
        inplaced=False,
        inplace=False,
        use_ensemble=True,
        use_best=True,
        name=None,
        mask="test",
    ) -> np.ndarray:
        """
        Predict the node class number.

        Parameters
        ----------
        dataset: torch_geometric.data.dataset.Dataset or None
            The dataset needed to predict. If ``None``, will use the processed dataset passed
            to ``fit()`` instead. Default ``None``.

        inplaced: bool
            Whether the given dataset is processed. Only be effective when ``dataset``
            is not ``None``. If you pass the dataset to ``fit()`` with ``inplace=True``,
            and you pass the dataset again to this method, you should set this argument
            to ``True``. Otherwise ``False``. Default ``False``.

        inplace: bool
            Whether we process the given dataset in inplace manner. Default ``False``.
            Set it to True if you want to save memory by modifying the given dataset directly.

        use_ensemble: bool
            Whether to use ensemble to do the predict. Default ``True``.

        use_best: bool
            Whether to use the best single model to do the predict. Will only be effective
            when ``use_ensemble`` is ``False``. Default ``True``.

        name: str or None
            The name of model used to predict. Will only be effective when ``use_ensemble``
            and ``use_best`` both are ``False``. Default ``None``.

        mask: str
            The data split to give prediction on. Default ``test``.

        Returns
        -------
        result: np.ndarray
            An array of shape ``(N,)``, where ``N`` is the number of test nodes.
            The prediction on given dataset.
        """
        proba = self.predict_proba(
            dataset, inplaced, inplace, use_ensemble, use_best, name, mask
        )
        return np.argmax(proba, axis=1)

    @classmethod
    def from_config(cls, path_or_dict, filetype="auto") -> "AutoNodeClassifier":
        """
        Load solver from config file.

        You can use this function to directly load a solver from predefined config dict
        or config file path. Currently, only support file type of ``json`` or ``yaml``,
        if you pass a path.

        Parameters
        ----------
        path_or_dict: str or dict
            The path to the config file or the config dictionary object

        filetype: str
            The filetype the given file if the path is specified. Currently only support
            ``json`` or ``yaml``. You can set to ``auto`` to automatically detect the file
            type (from file name). Default ``auto``.

        Returns
        -------
        solver: autogl.solver.AutoGraphClassifier
            The solver that is created from given file or dictionary.
        """
        assert filetype in ["auto", "yaml", "json"], (
            "currently only support yaml file or json file type, but get type "
            + filetype
        )
        if isinstance(path_or_dict, str):
            if filetype == "auto":
                if path_or_dict.endswith(".yaml"):
                    filetype = "yaml"
                elif path_or_dict.endswith(".json"):
                    filetype = "json"
                else:
                    LOGGER.error(
                        "cannot parse the type of the given file name, "
                        "please manually set the file type"
                    )
                    raise ValueError(
                        "cannot parse the type of the given file name, "
                        "please manually set the file type"
                    )
            if filetype == "yaml":
                path_or_dict = yaml.load(
                    open(path_or_dict, "r").read(), Loader=yaml.FullLoader
                )
            else:
                path_or_dict = json.load(open(path_or_dict, "r"))

        path_or_dict = deepcopy(path_or_dict)
        solver = cls(None, [], None, None)
        fe_list = path_or_dict.pop("feature", None)
        if fe_list is not None:
            fe_list_ele = []
            for feature_engineer in fe_list:
                name = feature_engineer.pop("name")
                if name is not None:
                    fe_list_ele.append(FEATURE_DICT[name](**feature_engineer))
            if fe_list_ele != []:
                solver.set_feature_module(fe_list_ele)

        models = path_or_dict.pop("models", [{"name": "gcn"}, {"name": "gat"}])
        model_hp_space = [
            _parse_hp_space(model.pop("hp_space", None)) for model in models
        ]
        model_list = [
            _initialize_single_model(model.pop("name"), model) for model in models
        ]

        trainer = path_or_dict.pop("trainer", None)
        default_trainer = "NodeClassification"
        trainer_space = None
        if isinstance(trainer, dict):
            # global default
            default_trainer = trainer.pop("name", "NodeClassification")
            trainer_space = _parse_hp_space(trainer.pop("hp_space", None))
            default_kwargs = {"num_features": None, "num_classes": None}
            default_kwargs.update(trainer)
            default_kwargs["init"] = False
            for i in range(len(model_list)):
                model = model_list[i]
                trainer_wrap = TRAINER_DICT[default_trainer](
                    model=model, **default_kwargs
                )
                model_list[i] = trainer_wrap
        elif isinstance(trainer, list):
            # sequential trainer definition
            assert len(trainer) == len(
                model_list
            ), "The number of trainer and model does not match"
            trainer_space = []
            for i in range(len(model_list)):
                train, model = trainer[i], model_list[i]
                default_trainer = train.pop("name", "NodeClassification")
                trainer_space.append(_parse_hp_space(train.pop("hp_space", None)))
                default_kwargs = {"num_features": None, "num_classes": None}
                default_kwargs.update(train)
                default_kwargs["init"] = False
                trainer_wrap = TRAINER_DICT[default_trainer](
                    model=model, **default_kwargs
                )
                model_list[i] = trainer_wrap

        solver.set_graph_models(
            model_list, default_trainer, trainer_space, model_hp_space
        )

        hpo_dict = path_or_dict.pop("hpo", {"name": "anneal"})
        if hpo_dict is not None:
            name = hpo_dict.pop("name")
            solver.set_hpo_module(name, **hpo_dict)

        ensemble_dict = path_or_dict.pop("ensemble", {"name": "voting"})
        if ensemble_dict is not None:
            name = ensemble_dict.pop("name")
            solver.set_ensemble_module(name, **ensemble_dict)

        return solver