"""
.. _visualization:

Quick Visualization for Hyperparameter Optimization Analysis
============================================================

Optuna provides various visualization features in :mod:`optuna.visualization` to analyze optimization results visually.

This tutorial walks you through this module by visualizing the history of lightgbm model for breast cancer dataset.
"""

###################################################################################################
import lightgbm as lgb
import numpy as np
import sklearn.datasets
import sklearn.metrics
from sklearn.model_selection import train_test_split

import optuna
from optuna.visualization import plot_contour
from optuna.visualization import plot_edf
from optuna.visualization import plot_intermediate_values
from optuna.visualization import plot_optimization_history
from optuna.visualization import plot_parallel_coordinate
from optuna.visualization import plot_param_importances
from optuna.visualization import plot_slice

SEED = 42

np.random.seed(SEED)


###################################################################################################
# Define the objective function.
def objective(trial):
    data, target = sklearn.datasets.load_breast_cancer(return_X_y=True)
    train_x, valid_x, train_y, valid_y = train_test_split(data, target, test_size=0.25)
    dtrain = lgb.Dataset(train_x, label=train_y)
    dvalid = lgb.Dataset(valid_x, label=valid_y)

    param = {
        "objective": "binary",
        "metric": "auc",
        "verbosity": -1,
        "boosting_type": "gbdt",
        "bagging_fraction": trial.suggest_float("bagging_fraction", 0.4, 1.0),
        "bagging_freq": trial.suggest_int("bagging_freq", 1, 7),
        "min_child_samples": trial.suggest_int("min_child_samples", 5, 100),
    }

    # Add a callback for pruning.
    pruning_callback = optuna.integration.LightGBMPruningCallback(trial, "auc")
    gbm = lgb.train(
        param, dtrain, valid_sets=[dvalid], verbose_eval=False, callbacks=[pruning_callback]
    )

    preds = gbm.predict(valid_x)
    pred_labels = np.rint(preds)
    accuracy = sklearn.metrics.accuracy_score(valid_y, pred_labels)
    return accuracy


###################################################################################################
study = optuna.create_study(
    direction="maximize",
    sampler=optuna.samplers.TPESampler(seed=SEED),
    pruner=optuna.pruners.MedianPruner(n_warmup_steps=10),
)
study.optimize(objective, n_trials=100, timeout=600)

###################################################################################################
# Plot functions
# --------------
# Visualize the optimization history. See :func:`~optuna.visualization.plot_optimization_history` for the details.
plot_optimization_history(study)

###################################################################################################
# Visualize the learning curves of the trials. See :func:`~optuna.visualization.plot_intermediate_values` for the details.
plot_intermediate_values(study)

###################################################################################################
# Visualize high-dimensional parameter relationships. See :func:`~optuna.visualization.plot_parallel_coordinate` for the details.
plot_parallel_coordinate(study)

###################################################################################################
# Select parameters to visualize.
plot_parallel_coordinate(study, params=["bagging_freq", "bagging_fraction"])

###################################################################################################
# Visualize hyperparameter relationships. See :func:`~optuna.visualization.plot_contour` for the details.
plot_contour(study)

###################################################################################################
# Select parameters to visualize.
plot_contour(study, params=["bagging_freq", "bagging_fraction"])

###################################################################################################
# Visualize individual hyperparameters as slice plot. See :func:`~optuna.visualization.plot_slice` for the details.
plot_slice(study)

###################################################################################################
# Select parameters to visualize.
plot_slice(study, params=["bagging_freq", "bagging_fraction"])

###################################################################################################
# Visualize parameter importances. See :func:`~optuna.visualization.plot_param_importances` for the details.
plot_param_importances(study)

###################################################################################################
# Visualize empirical distribution function. See :func:`~optuna.visualization.plot_edf` for the details.
plot_edf(study)