import argparse
import collections
import json
import os
import pickle
import sys
import warnings

import imblearn
import joblib
import numpy as np
import pandas as pd
import skrebate
from galaxy_ml.utils import (clean_params, get_cv,
                             get_main_estimator, get_module, get_scoring,
                             load_model, read_columns, SafeEval, try_get_attr)
from scipy.io import mmread
from sklearn import (cluster, decomposition, feature_selection,
                     kernel_approximation, model_selection, preprocessing)
from sklearn.exceptions import FitFailedWarning
from sklearn.model_selection import _search, _validation
from sklearn.model_selection._validation import _score, cross_validate

_fit_and_score = try_get_attr("galaxy_ml.model_validations", "_fit_and_score")
setattr(_search, "_fit_and_score", _fit_and_score)
setattr(_validation, "_fit_and_score", _fit_and_score)

N_JOBS = int(os.environ.get("GALAXY_SLOTS", 1))
# handle  disk cache
CACHE_DIR = os.path.join(os.getcwd(), "cached")
del os
NON_SEARCHABLE = ("n_jobs", "pre_dispatch", "memory", "_path", "nthread", "callbacks")


def _eval_search_params(params_builder):
    search_params = {}

    for p in params_builder["param_set"]:
        search_list = p["sp_list"].strip()
        if search_list == "":
            continue

        param_name = p["sp_name"]
        if param_name.lower().endswith(NON_SEARCHABLE):
            print(
                "Warning: `%s` is not eligible for search and was "
                "omitted!" % param_name
            )
            continue

        if not search_list.startswith(":"):
            safe_eval = SafeEval(load_scipy=True, load_numpy=True)
            ev = safe_eval(search_list)
            search_params[param_name] = ev
        else:
            # Have `:` before search list, asks for estimator evaluatio
            safe_eval_es = SafeEval(load_estimators=True)
            search_list = search_list[1:].strip()
            # TODO maybe add regular express check
            ev = safe_eval_es(search_list)
            preprocessings = (
                preprocessing.StandardScaler(),
                preprocessing.Binarizer(),
                preprocessing.MaxAbsScaler(),
                preprocessing.Normalizer(),
                preprocessing.MinMaxScaler(),
                preprocessing.PolynomialFeatures(),
                preprocessing.RobustScaler(),
                feature_selection.SelectKBest(),
                feature_selection.GenericUnivariateSelect(),
                feature_selection.SelectPercentile(),
                feature_selection.SelectFpr(),
                feature_selection.SelectFdr(),
                feature_selection.SelectFwe(),
                feature_selection.VarianceThreshold(),
                decomposition.FactorAnalysis(random_state=0),
                decomposition.FastICA(random_state=0),
                decomposition.IncrementalPCA(),
                decomposition.KernelPCA(random_state=0, n_jobs=N_JOBS),
                decomposition.LatentDirichletAllocation(random_state=0, n_jobs=N_JOBS),
                decomposition.MiniBatchDictionaryLearning(
                    random_state=0, n_jobs=N_JOBS
                ),
                decomposition.MiniBatchSparsePCA(random_state=0, n_jobs=N_JOBS),
                decomposition.NMF(random_state=0),
                decomposition.PCA(random_state=0),
                decomposition.SparsePCA(random_state=0, n_jobs=N_JOBS),
                decomposition.TruncatedSVD(random_state=0),
                kernel_approximation.Nystroem(random_state=0),
                kernel_approximation.RBFSampler(random_state=0),
                kernel_approximation.AdditiveChi2Sampler(),
                kernel_approximation.SkewedChi2Sampler(random_state=0),
                cluster.FeatureAgglomeration(),
                skrebate.ReliefF(n_jobs=N_JOBS),
                skrebate.SURF(n_jobs=N_JOBS),
                skrebate.SURFstar(n_jobs=N_JOBS),
                skrebate.MultiSURF(n_jobs=N_JOBS),
                skrebate.MultiSURFstar(n_jobs=N_JOBS),
                imblearn.under_sampling.ClusterCentroids(random_state=0, n_jobs=N_JOBS),
                imblearn.under_sampling.CondensedNearestNeighbour(
                    random_state=0, n_jobs=N_JOBS
                ),
                imblearn.under_sampling.EditedNearestNeighbours(
                    random_state=0, n_jobs=N_JOBS
                ),
                imblearn.under_sampling.RepeatedEditedNearestNeighbours(
                    random_state=0, n_jobs=N_JOBS
                ),
                imblearn.under_sampling.AllKNN(random_state=0, n_jobs=N_JOBS),
                imblearn.under_sampling.InstanceHardnessThreshold(
                    random_state=0, n_jobs=N_JOBS
                ),
                imblearn.under_sampling.NearMiss(random_state=0, n_jobs=N_JOBS),
                imblearn.under_sampling.NeighbourhoodCleaningRule(
                    random_state=0, n_jobs=N_JOBS
                ),
                imblearn.under_sampling.OneSidedSelection(
                    random_state=0, n_jobs=N_JOBS
                ),
                imblearn.under_sampling.RandomUnderSampler(random_state=0),
                imblearn.under_sampling.TomekLinks(random_state=0, n_jobs=N_JOBS),
                imblearn.over_sampling.ADASYN(random_state=0, n_jobs=N_JOBS),
                imblearn.over_sampling.RandomOverSampler(random_state=0),
                imblearn.over_sampling.SMOTE(random_state=0, n_jobs=N_JOBS),
                imblearn.over_sampling.SVMSMOTE(random_state=0, n_jobs=N_JOBS),
                imblearn.over_sampling.BorderlineSMOTE(random_state=0, n_jobs=N_JOBS),
                imblearn.over_sampling.SMOTENC(
                    categorical_features=[], random_state=0, n_jobs=N_JOBS
                ),
                imblearn.combine.SMOTEENN(random_state=0),
                imblearn.combine.SMOTETomek(random_state=0),
            )
            newlist = []
            for obj in ev:
                if obj is None:
                    newlist.append(None)
                elif obj == "all_0":
                    newlist.extend(preprocessings[0:35])
                elif obj == "sk_prep_all":  # no KernalCenter()
                    newlist.extend(preprocessings[0:7])
                elif obj == "fs_all":
                    newlist.extend(preprocessings[7:14])
                elif obj == "decomp_all":
                    newlist.extend(preprocessings[14:25])
                elif obj == "k_appr_all":
                    newlist.extend(preprocessings[25:29])
                elif obj == "reb_all":
                    newlist.extend(preprocessings[30:35])
                elif obj == "imb_all":
                    newlist.extend(preprocessings[35:54])
                elif type(obj) is int and -1 < obj < len(preprocessings):
                    newlist.append(preprocessings[obj])
                elif hasattr(obj, "get_params"):  # user uploaded object
                    if "n_jobs" in obj.get_params():
                        newlist.append(obj.set_params(n_jobs=N_JOBS))
                    else:
                        newlist.append(obj)
                else:
                    sys.exit("Unsupported estimator type: %r" % (obj))

            search_params[param_name] = newlist

    return search_params


def _handle_X_y(
    estimator,
    params,
    infile1,
    infile2,
    loaded_df={},
    ref_seq=None,
    intervals=None,
    targets=None,
    fasta_path=None,
):
    """read inputs

    Params
    -------
    estimator : estimator object
    params : dict
        Galaxy tool parameter inputs
    infile1 : str
        File path to dataset containing features
    infile2 : str
        File path to dataset containing target values
    loaded_df : dict
        Contains loaded DataFrame objects with file path as keys
    ref_seq : str
        File path to dataset containing genome sequence file
    interval : str
        File path to dataset containing interval file
    targets : str
        File path to dataset compressed target bed file
    fasta_path : str
        File path to dataset containing fasta file


    Returns
    -------
    estimator : estimator object after setting new attributes
    X : numpy array
    y : numpy array
    """
    estimator_params = estimator.get_params()

    input_type = params["input_options"]["selected_input"]
    # tabular input
    if input_type == "tabular":
        header = "infer" if params["input_options"]["header1"] else None
        column_option = params["input_options"]["column_selector_options_1"][
            "selected_column_selector_option"
        ]
        if column_option in [
            "by_index_number",
            "all_but_by_index_number",
            "by_header_name",
            "all_but_by_header_name",
        ]:
            c = params["input_options"]["column_selector_options_1"]["col1"]
        else:
            c = None

        df_key = infile1 + repr(header)

        if df_key in loaded_df:
            infile1 = loaded_df[df_key]

        df = pd.read_csv(infile1, sep="\t", header=header, parse_dates=True)
        loaded_df[df_key] = df

        X = read_columns(df, c=c, c_option=column_option).astype(float)
    # sparse input
    elif input_type == "sparse":
        X = mmread(open(infile1, "r"))

    # fasta_file input
    elif input_type == "seq_fasta":
        pyfaidx = get_module("pyfaidx")
        sequences = pyfaidx.Fasta(fasta_path)
        n_seqs = len(sequences.keys())
        X = np.arange(n_seqs)[:, np.newaxis]
        for param in estimator_params.keys():
            if param.endswith("fasta_path"):
                estimator.set_params(**{param: fasta_path})
                break
        else:
            raise ValueError(
                "The selected estimator doesn't support "
                "fasta file input! Please consider using "
                "KerasGBatchClassifier with "
                "FastaDNABatchGenerator/FastaProteinBatchGenerator "
                "or having GenomeOneHotEncoder/ProteinOneHotEncoder "
                "in pipeline!"
            )

    elif input_type == "refseq_and_interval":
        path_params = {
            "data_batch_generator__ref_genome_path": ref_seq,
            "data_batch_generator__intervals_path": intervals,
            "data_batch_generator__target_path": targets,
        }
        estimator.set_params(**path_params)
        n_intervals = sum(1 for line in open(intervals))
        X = np.arange(n_intervals)[:, np.newaxis]

    # Get target y
    header = "infer" if params["input_options"]["header2"] else None
    column_option = params["input_options"]["column_selector_options_2"][
        "selected_column_selector_option2"
    ]
    if column_option in [
        "by_index_number",
        "all_but_by_index_number",
        "by_header_name",
        "all_but_by_header_name",
    ]:
        c = params["input_options"]["column_selector_options_2"]["col2"]
    else:
        c = None

    df_key = infile2 + repr(header)
    if df_key in loaded_df:
        infile2 = loaded_df[df_key]
    else:
        infile2 = pd.read_csv(infile2, sep="\t", header=header, parse_dates=True)
        loaded_df[df_key] = infile2

    y = read_columns(
        infile2, c=c, c_option=column_option, sep="\t", header=header, parse_dates=True
    )
    if len(y.shape) == 2 and y.shape[1] == 1:
        y = y.ravel()
    if input_type == "refseq_and_interval":
        estimator.set_params(data_batch_generator__features=y.ravel().tolist())
        y = None
    # end y

    return estimator, X, y


def _do_outer_cv(searcher, X, y, outer_cv, scoring, error_score="raise", outfile=None):
    """Do outer cross-validation for nested CV

    Parameters
    ----------
    searcher : object
        SearchCV object
    X : numpy array
        Containing features
    y : numpy array
        Target values or labels
    outer_cv : int or CV splitter
        Control the cv splitting
    scoring : object
        Scorer
    error_score: str, float or numpy float
        Whether to raise fit error or return an value
    outfile : str
        File path to store the restuls
    """
    if error_score == "raise":
        rval = cross_validate(
            searcher,
            X,
            y,
            scoring=scoring,
            cv=outer_cv,
            n_jobs=N_JOBS,
            verbose=0,
            error_score=error_score,
        )
    else:
        warnings.simplefilter("always", FitFailedWarning)
        with warnings.catch_warnings(record=True) as w:
            try:
                rval = cross_validate(
                    searcher,
                    X,
                    y,
                    scoring=scoring,
                    cv=outer_cv,
                    n_jobs=N_JOBS,
                    verbose=0,
                    error_score=error_score,
                )
            except ValueError:
                pass
            for warning in w:
                print(repr(warning.message))

    keys = list(rval.keys())
    for k in keys:
        if k.startswith("test"):
            rval["mean_" + k] = np.mean(rval[k])
            rval["std_" + k] = np.std(rval[k])
        if k.endswith("time"):
            rval.pop(k)
    rval = pd.DataFrame(rval)
    rval = rval[sorted(rval.columns)]
    rval.to_csv(path_or_buf=outfile, sep="\t", header=True, index=False)


def _do_train_test_split_val(
    searcher,
    X,
    y,
    params,
    error_score="raise",
    primary_scoring=None,
    groups=None,
    outfile=None,
):
    """do train test split, searchCV validates on the train and then use
    the best_estimator_ to evaluate on the test

    Returns
    --------
    Fitted SearchCV object
    """
    train_test_split = try_get_attr("galaxy_ml.model_validations", "train_test_split")
    split_options = params["outer_split"]

    # splits
    if split_options["shuffle"] == "stratified":
        split_options["labels"] = y
        X, X_test, y, y_test = train_test_split(X, y, **split_options)
    elif split_options["shuffle"] == "group":
        if groups is None:
            raise ValueError(
                "No group based CV option was choosen for " "group shuffle!"
            )
        split_options["labels"] = groups
        if y is None:
            X, X_test, groups, _ = train_test_split(X, groups, **split_options)
        else:
            X, X_test, y, y_test, groups, _ = train_test_split(
                X, y, groups, **split_options
            )
    else:
        if split_options["shuffle"] == "None":
            split_options["shuffle"] = None
        X, X_test, y, y_test = train_test_split(X, y, **split_options)

    if error_score == "raise":
        searcher.fit(X, y, groups=groups)
    else:
        warnings.simplefilter("always", FitFailedWarning)
        with warnings.catch_warnings(record=True) as w:
            try:
                searcher.fit(X, y, groups=groups)
            except ValueError:
                pass
            for warning in w:
                print(repr(warning.message))

    scorer_ = searcher.scorer_
    if isinstance(scorer_, collections.Mapping):
        is_multimetric = True
    else:
        is_multimetric = False

    best_estimator_ = getattr(searcher, "best_estimator_")

    # TODO Solve deep learning models in pipeline
    if best_estimator_.__class__.__name__ == "KerasGBatchClassifier":
        test_score = best_estimator_.evaluate(
            X_test, scorer=scorer_, is_multimetric=is_multimetric
        )
    else:
        test_score = _score(
            best_estimator_, X_test, y_test, scorer_, is_multimetric=is_multimetric
        )

    if not is_multimetric:
        test_score = {primary_scoring: test_score}
    for key, value in test_score.items():
        test_score[key] = [value]
    result_df = pd.DataFrame(test_score)
    result_df.to_csv(path_or_buf=outfile, sep="\t", header=True, index=False)

    return searcher


def main(
    inputs,
    infile_estimator,
    infile1,
    infile2,
    outfile_result,
    outfile_object=None,
    outfile_weights=None,
    groups=None,
    ref_seq=None,
    intervals=None,
    targets=None,
    fasta_path=None,
):
    """
    Parameter
    ---------
    inputs : str
        File path to galaxy tool parameter

    infile_estimator : str
        File path to estimator

    infile1 : str
        File path to dataset containing features

    infile2 : str
        File path to dataset containing target values

    outfile_result : str
        File path to save the results, either cv_results or test result

    outfile_object : str, optional
        File path to save searchCV object

    outfile_weights : str, optional
        File path to save model weights

    groups : str
        File path to dataset containing groups labels

    ref_seq : str
        File path to dataset containing genome sequence file

    intervals : str
        File path to dataset containing interval file

    targets : str
        File path to dataset compressed target bed file

    fasta_path : str
        File path to dataset containing fasta file
    """
    warnings.simplefilter("ignore")

    # store read dataframe object
    loaded_df = {}

    with open(inputs, "r") as param_handler:
        params = json.load(param_handler)

    # Override the refit parameter
    params["search_schemes"]["options"]["refit"] = (
        True if params["save"] != "nope" else False
    )

    with open(infile_estimator, "rb") as estimator_handler:
        estimator = load_model(estimator_handler)

    optimizer = params["search_schemes"]["selected_search_scheme"]
    optimizer = getattr(model_selection, optimizer)

    # handle gridsearchcv options
    options = params["search_schemes"]["options"]

    if groups:
        header = (
            "infer" if (options["cv_selector"]["groups_selector"]["header_g"]) else None
        )
        column_option = options["cv_selector"]["groups_selector"][
            "column_selector_options_g"
        ]["selected_column_selector_option_g"]
        if column_option in [
            "by_index_number",
            "all_but_by_index_number",
            "by_header_name",
            "all_but_by_header_name",
        ]:
            c = options["cv_selector"]["groups_selector"]["column_selector_options_g"][
                "col_g"
            ]
        else:
            c = None

        df_key = groups + repr(header)

        groups = pd.read_csv(groups, sep="\t", header=header, parse_dates=True)
        loaded_df[df_key] = groups

        groups = read_columns(
            groups,
            c=c,
            c_option=column_option,
            sep="\t",
            header=header,
            parse_dates=True,
        )
        groups = groups.ravel()
        options["cv_selector"]["groups_selector"] = groups

    splitter, groups = get_cv(options.pop("cv_selector"))
    options["cv"] = splitter
    primary_scoring = options["scoring"]["primary_scoring"]
    # get_scoring() expects secondary_scoring to be a comma separated string (not a list)
    # Check if secondary_scoring is specified
    secondary_scoring = options["scoring"].get("secondary_scoring", None)
    if secondary_scoring is not None:
        # If secondary_scoring is specified, convert the list into comman separated string
        options["scoring"]["secondary_scoring"] = ",".join(
            options["scoring"]["secondary_scoring"]
        )
    options["scoring"] = get_scoring(options["scoring"])
    if options["error_score"]:
        options["error_score"] = "raise"
    else:
        options["error_score"] = np.nan
    if options["refit"] and isinstance(options["scoring"], dict):
        options["refit"] = primary_scoring
    if "pre_dispatch" in options and options["pre_dispatch"] == "":
        options["pre_dispatch"] = None

    params_builder = params["search_schemes"]["search_params_builder"]
    param_grid = _eval_search_params(params_builder)

    estimator = clean_params(estimator)

    # save the SearchCV object without fit
    if params["save"] == "save_no_fit":
        searcher = optimizer(estimator, param_grid, **options)
        print(searcher)
        with open(outfile_object, "wb") as output_handler:
            pickle.dump(searcher, output_handler, pickle.HIGHEST_PROTOCOL)
        return 0

    # read inputs and loads new attributes, like paths
    estimator, X, y = _handle_X_y(
        estimator,
        params,
        infile1,
        infile2,
        loaded_df=loaded_df,
        ref_seq=ref_seq,
        intervals=intervals,
        targets=targets,
        fasta_path=fasta_path,
    )

    # cache iraps_core fits could increase search speed significantly
    memory = joblib.Memory(location=CACHE_DIR, verbose=0)
    main_est = get_main_estimator(estimator)
    if main_est.__class__.__name__ == "IRAPSClassifier":
        main_est.set_params(memory=memory)

    searcher = optimizer(estimator, param_grid, **options)

    split_mode = params["outer_split"].pop("split_mode")

    if split_mode == "nested_cv":
        # make sure refit is choosen
        # this could be True for sklearn models, but not the case for
        # deep learning models
        if not options["refit"] and not all(
            hasattr(estimator, attr) for attr in ("config", "model_type")
        ):
            warnings.warn("Refit is change to `True` for nested validation!")
            setattr(searcher, "refit", True)

        outer_cv, _ = get_cv(params["outer_split"]["cv_selector"])
        # nested CV, outer cv using cross_validate
        if options["error_score"] == "raise":
            rval = cross_validate(
                searcher,
                X,
                y,
                scoring=options["scoring"],
                cv=outer_cv,
                n_jobs=N_JOBS,
                verbose=options["verbose"],
                return_estimator=(params["save"] == "save_estimator"),
                error_score=options["error_score"],
                return_train_score=True,
            )
        else:
            warnings.simplefilter("always", FitFailedWarning)
            with warnings.catch_warnings(record=True) as w:
                try:
                    rval = cross_validate(
                        searcher,
                        X,
                        y,
                        scoring=options["scoring"],
                        cv=outer_cv,
                        n_jobs=N_JOBS,
                        verbose=options["verbose"],
                        return_estimator=(params["save"] == "save_estimator"),
                        error_score=options["error_score"],
                        return_train_score=True,
                    )
                except ValueError:
                    pass
                for warning in w:
                    print(repr(warning.message))

        fitted_searchers = rval.pop("estimator", [])
        if fitted_searchers:
            import os

            pwd = os.getcwd()
            save_dir = os.path.join(pwd, "cv_results_in_folds")
            try:
                os.mkdir(save_dir)
                for idx, obj in enumerate(fitted_searchers):
                    target_name = "cv_results_" + "_" + "split%d" % idx
                    target_path = os.path.join(pwd, save_dir, target_name)
                    cv_results_ = getattr(obj, "cv_results_", None)
                    if not cv_results_:
                        print("%s is not available" % target_name)
                        continue
                    cv_results_ = pd.DataFrame(cv_results_)
                    cv_results_ = cv_results_[sorted(cv_results_.columns)]
                    cv_results_.to_csv(target_path, sep="\t", header=True, index=False)
            except Exception as e:
                print(e)
            finally:
                del os

        keys = list(rval.keys())
        for k in keys:
            if k.startswith("test"):
                rval["mean_" + k] = np.mean(rval[k])
                rval["std_" + k] = np.std(rval[k])
            if k.endswith("time"):
                rval.pop(k)
        rval = pd.DataFrame(rval)
        rval = rval[sorted(rval.columns)]
        rval.to_csv(path_or_buf=outfile_result, sep="\t", header=True, index=False)
        # deprecate train test split mode
        """searcher = _do_train_test_split_val(
            searcher, X, y, params,
            primary_scoring=primary_scoring,
            error_score=options['error_score'],
            groups=groups,
            outfile=outfile_result)"""
        return 0

    # no outer split
    else:
        searcher.set_params(n_jobs=N_JOBS)
        if options["error_score"] == "raise":
            searcher.fit(X, y, groups=groups)
        else:
            warnings.simplefilter("always", FitFailedWarning)
            with warnings.catch_warnings(record=True) as w:
                try:
                    searcher.fit(X, y, groups=groups)
                except ValueError:
                    pass
                for warning in w:
                    print(repr(warning.message))

        cv_results = pd.DataFrame(searcher.cv_results_)
        cv_results = cv_results[sorted(cv_results.columns)]
        cv_results.to_csv(
            path_or_buf=outfile_result, sep="\t", header=True, index=False
        )

    memory.clear(warn=False)

    # output best estimator, and weights if applicable
    if outfile_object:
        best_estimator_ = getattr(searcher, "best_estimator_", None)
        if not best_estimator_:
            warnings.warn(
                "GridSearchCV object has no attribute "
                "'best_estimator_', because either it's "
                "nested gridsearch or `refit` is False!"
            )
            return

        # clean prams
        best_estimator_ = clean_params(best_estimator_)

        main_est = get_main_estimator(best_estimator_)

        if hasattr(main_est, "model_") and hasattr(main_est, "save_weights"):
            if outfile_weights:
                main_est.save_weights(outfile_weights)
            del main_est.model_
            del main_est.fit_params
            del main_est.model_class_
            del main_est.validation_data
            if getattr(main_est, "data_generator_", None):
                del main_est.data_generator_

        with open(outfile_object, "wb") as output_handler:
            print("Best estimator is saved: %s " % repr(best_estimator_))
            pickle.dump(best_estimator_, output_handler, pickle.HIGHEST_PROTOCOL)


if __name__ == "__main__":
    aparser = argparse.ArgumentParser()
    aparser.add_argument("-i", "--inputs", dest="inputs", required=True)
    aparser.add_argument("-e", "--estimator", dest="infile_estimator")
    aparser.add_argument("-X", "--infile1", dest="infile1")
    aparser.add_argument("-y", "--infile2", dest="infile2")
    aparser.add_argument("-O", "--outfile_result", dest="outfile_result")
    aparser.add_argument("-o", "--outfile_object", dest="outfile_object")
    aparser.add_argument("-w", "--outfile_weights", dest="outfile_weights")
    aparser.add_argument("-g", "--groups", dest="groups")
    aparser.add_argument("-r", "--ref_seq", dest="ref_seq")
    aparser.add_argument("-b", "--intervals", dest="intervals")
    aparser.add_argument("-t", "--targets", dest="targets")
    aparser.add_argument("-f", "--fasta_path", dest="fasta_path")
    args = aparser.parse_args()

    main(
        args.inputs,
        args.infile_estimator,
        args.infile1,
        args.infile2,
        args.outfile_result,
        outfile_object=args.outfile_object,
        outfile_weights=args.outfile_weights,
        groups=args.groups,
        ref_seq=args.ref_seq,
        intervals=args.intervals,
        targets=args.targets,
        fasta_path=args.fasta_path,
    )
