# -*- coding: utf-8 -*-
import numpy as np
import os
import xgboost as xgb
import pytest
import json
from pathlib import Path
import tempfile
import testing as tm

dpath = 'demo/data/'
rng = np.random.RandomState(1994)


class TestBasic:
    def test_compat(self):
        from xgboost.compat import lazy_isinstance
        a = np.array([1, 2, 3])
        assert lazy_isinstance(a, 'numpy', 'ndarray')
        assert not lazy_isinstance(a, 'numpy', 'dataframe')

    def test_basic(self):
        dtrain = xgb.DMatrix(dpath + 'agaricus.txt.train')
        dtest = xgb.DMatrix(dpath + 'agaricus.txt.test')
        param = {'max_depth': 2, 'eta': 1,
                 'objective': 'binary:logistic'}
        # specify validations set to watch performance
        watchlist = [(dtrain, 'train')]
        num_round = 2
        bst = xgb.train(param, dtrain, num_round, watchlist, verbose_eval=True)

        preds = bst.predict(dtrain)
        labels = dtrain.get_label()
        err = sum(1 for i in range(len(preds))
                  if int(preds[i] > 0.5) != labels[i]) / float(len(preds))
        # error must be smaller than 10%
        assert err < 0.1

        preds = bst.predict(dtest)
        labels = dtest.get_label()
        err = sum(1 for i in range(len(preds))
                  if int(preds[i] > 0.5) != labels[i]) / float(len(preds))
        # error must be smaller than 10%
        assert err < 0.1

        with tempfile.TemporaryDirectory() as tmpdir:
            dtest_path = os.path.join(tmpdir, 'dtest.dmatrix')
            # save dmatrix into binary buffer
            dtest.save_binary(dtest_path)
            # save model
            model_path = os.path.join(tmpdir, 'model.booster')
            bst.save_model(model_path)
            # load model and data in
            bst2 = xgb.Booster(model_file=model_path)
            dtest2 = xgb.DMatrix(dtest_path)
            preds2 = bst2.predict(dtest2)
            # assert they are the same
            assert np.sum(np.abs(preds2 - preds)) == 0

    def test_metric_config(self):
        # Make sure that the metric configuration happens in booster so the
        # string `['error', 'auc']` doesn't get passed down to core.
        dtrain = xgb.DMatrix(dpath + 'agaricus.txt.train')
        dtest = xgb.DMatrix(dpath + 'agaricus.txt.test')
        param = {'max_depth': 2, 'eta': 1, 'verbosity': 0,
                 'objective': 'binary:logistic', 'eval_metric': ['error', 'auc']}
        watchlist = [(dtest, 'eval'), (dtrain, 'train')]
        num_round = 2
        booster = xgb.train(param, dtrain, num_round, watchlist)
        predt_0 = booster.predict(dtrain)
        with tempfile.TemporaryDirectory() as tmpdir:
            path = os.path.join(tmpdir, 'model.json')
            booster.save_model(path)

            booster = xgb.Booster(params=param, model_file=path)
            predt_1 = booster.predict(dtrain)
            np.testing.assert_allclose(predt_0, predt_1)

    def test_record_results(self):
        dtrain = xgb.DMatrix(dpath + 'agaricus.txt.train')
        dtest = xgb.DMatrix(dpath + 'agaricus.txt.test')
        param = {'max_depth': 2, 'eta': 1, 'verbosity': 0,
                 'objective': 'binary:logistic', 'eval_metric': 'error'}
        # specify validations set to watch performance
        watchlist = [(dtest, 'eval'), (dtrain, 'train')]
        num_round = 2
        result = {}
        res2 = {}
        xgb.train(param, dtrain, num_round, watchlist,
                  callbacks=[xgb.callback.record_evaluation(result)])
        xgb.train(param, dtrain, num_round, watchlist,
                  evals_result=res2)
        assert result['train']['error'][0] < 0.1
        assert res2 == result

    def test_multiclass(self):
        dtrain = xgb.DMatrix(dpath + 'agaricus.txt.train')
        dtest = xgb.DMatrix(dpath + 'agaricus.txt.test')
        param = {'max_depth': 2, 'eta': 1, 'verbosity': 0, 'num_class': 2}
        # specify validations set to watch performance
        watchlist = [(dtest, 'eval'), (dtrain, 'train')]
        num_round = 2
        bst = xgb.train(param, dtrain, num_round, watchlist)
        # this is prediction
        preds = bst.predict(dtest)
        labels = dtest.get_label()
        err = sum(1 for i in range(len(preds))
                  if preds[i] != labels[i]) / float(len(preds))
        # error must be smaller than 10%
        assert err < 0.1

        with tempfile.TemporaryDirectory() as tmpdir:
            dtest_path = os.path.join(tmpdir, 'dtest.buffer')
            model_path = os.path.join(tmpdir, 'xgb.model')
            # save dmatrix into binary buffer
            dtest.save_binary(dtest_path)
            # save model
            bst.save_model(model_path)
            # load model and data in
            bst2 = xgb.Booster(model_file=model_path)
            dtest2 = xgb.DMatrix(dtest_path)
            preds2 = bst2.predict(dtest2)
            # assert they are the same
            assert np.sum(np.abs(preds2 - preds)) == 0

    def test_dump(self):
        data = np.random.randn(100, 2)
        target = np.array([0, 1] * 50)
        features = ['Feature1', 'Feature2']

        dm = xgb.DMatrix(data, label=target, feature_names=features)
        params = {'objective': 'binary:logistic',
                  'eval_metric': 'logloss',
                  'eta': 0.3,
                  'max_depth': 1}

        bst = xgb.train(params, dm, num_boost_round=1)

        # number of feature importances should == number of features
        dump1 = bst.get_dump()
        assert len(dump1) == 1, 'Expected only 1 tree to be dumped.'
        len(dump1[0].splitlines()) == 3, 'Expected 1 root and 2 leaves - 3 lines in dump.'

        dump2 = bst.get_dump(with_stats=True)
        assert dump2[0].count('\n') == 3, 'Expected 1 root and 2 leaves - 3 lines in dump.'
        msg = 'Expected more info when with_stats=True is given.'
        assert dump2[0].find('\n') > dump1[0].find('\n'), msg

        dump3 = bst.get_dump(dump_format="json")
        dump3j = json.loads(dump3[0])
        assert dump3j['nodeid'] == 0, 'Expected the root node on top.'

        dump4 = bst.get_dump(dump_format="json", with_stats=True)
        dump4j = json.loads(dump4[0])
        assert 'gain' in dump4j, "Expected 'gain' to be dumped in JSON."

    def test_load_file_invalid(self):
        with pytest.raises(xgb.core.XGBoostError):
            xgb.Booster(model_file='incorrect_path')

        with pytest.raises(xgb.core.XGBoostError):
            xgb.Booster(model_file=u'不正なパス')

    def test_dmatrix_numpy_init_omp(self):

        rows = [1000, 11326, 15000]
        cols = 50
        for row in rows:
            X = np.random.randn(row, cols)
            y = np.random.randn(row).astype('f')
            dm = xgb.DMatrix(X, y, nthread=0)
            np.testing.assert_array_equal(dm.get_label(), y)
            assert dm.num_row() == row
            assert dm.num_col() == cols

            dm = xgb.DMatrix(X, y, nthread=10)
            np.testing.assert_array_equal(dm.get_label(), y)
            assert dm.num_row() == row
            assert dm.num_col() == cols

    def test_cv(self):
        dm = xgb.DMatrix(dpath + 'agaricus.txt.train')
        params = {'max_depth': 2, 'eta': 1, 'verbosity': 0,
                  'objective': 'binary:logistic'}

        # return np.ndarray
        cv = xgb.cv(params, dm, num_boost_round=10, nfold=10, as_pandas=False)
        assert isinstance(cv, dict)
        assert len(cv) == (4)

    def test_cv_no_shuffle(self):
        dm = xgb.DMatrix(dpath + 'agaricus.txt.train')
        params = {'max_depth': 2, 'eta': 1, 'verbosity': 0,
                  'objective': 'binary:logistic'}

        # return np.ndarray
        cv = xgb.cv(params, dm, num_boost_round=10, shuffle=False, nfold=10,
                    as_pandas=False)
        assert isinstance(cv, dict)
        assert len(cv) == (4)

    def test_cv_explicit_fold_indices(self):
        dm = xgb.DMatrix(dpath + 'agaricus.txt.train')
        params = {'max_depth': 2, 'eta': 1, 'verbosity': 0, 'objective':
                  'binary:logistic'}
        folds = [
            # Train        Test
            ([1, 3], [5, 8]),
            ([7, 9], [23, 43]),
        ]

        # return np.ndarray
        cv = xgb.cv(params, dm, num_boost_round=10, folds=folds,
                    as_pandas=False)
        assert isinstance(cv, dict)
        assert len(cv) == (4)

    def test_cv_explicit_fold_indices_labels(self):
        params = {'max_depth': 2, 'eta': 1, 'verbosity': 0, 'objective':
                  'reg:squarederror'}
        N = 100
        F = 3
        dm = xgb.DMatrix(data=np.random.randn(N, F), label=np.arange(N))
        folds = [
            # Train        Test
            ([1, 3], [5, 8]),
            ([7, 9], [23, 43, 11]),
        ]

        # Use callback to log the test labels in each fold
        def cb(cbackenv):
            print([fold.dtest.get_label() for fold in cbackenv.cvfolds])

        # Run cross validation and capture standard out to test callback result
        with tm.captured_output() as (out, err):
            xgb.cv(
                params, dm, num_boost_round=1, folds=folds, callbacks=[cb],
                as_pandas=False
            )
            output = out.getvalue().strip()
        solution = ('[array([5., 8.], dtype=float32), array([23., 43., 11.],' +
                    ' dtype=float32)]')
        assert output == solution


class TestBasicPathLike:
    """Unit tests using pathlib.Path for file interaction."""

    def test_DMatrix_init_from_path(self):
        """Initialization from the data path."""
        dpath = Path('demo/data')
        dtrain = xgb.DMatrix(dpath / 'agaricus.txt.train')
        assert dtrain.num_row() == 6513
        assert dtrain.num_col() == 127

    def test_DMatrix_save_to_path(self):
        """Saving to a binary file using pathlib from a DMatrix."""
        data = np.random.randn(100, 2)
        target = np.array([0, 1] * 50)
        features = ['Feature1', 'Feature2']

        dm = xgb.DMatrix(data, label=target, feature_names=features)

        # save, assert exists, remove file
        binary_path = Path("dtrain.bin")
        dm.save_binary(binary_path)
        assert binary_path.exists()
        Path.unlink(binary_path)

    def test_Booster_init_invalid_path(self):
        """An invalid model_file path should raise XGBoostError."""
        with pytest.raises(xgb.core.XGBoostError):
            xgb.Booster(model_file=Path("invalidpath"))

    def test_Booster_save_and_load(self):
        """Saving and loading model files from paths."""
        save_path = Path("saveload.model")

        data = np.random.randn(100, 2)
        target = np.array([0, 1] * 50)
        features = ['Feature1', 'Feature2']

        dm = xgb.DMatrix(data, label=target, feature_names=features)
        params = {'objective': 'binary:logistic',
                  'eval_metric': 'logloss',
                  'eta': 0.3,
                  'max_depth': 1}

        bst = xgb.train(params, dm, num_boost_round=1)

        # save, assert exists
        bst.save_model(save_path)
        assert save_path.exists()

        def dump_assertions(dump):
            """Assertions for the expected dump from Booster"""
            assert len(dump) == 1, 'Exepcted only 1 tree to be dumped.'
            assert len(dump[0].splitlines()) == 3, 'Expected 1 root and 2 leaves - 3 lines.'

        # load the model again using Path
        bst2 = xgb.Booster(model_file=save_path)
        dump2 = bst2.get_dump()
        dump_assertions(dump2)

        # load again using load_model
        bst3 = xgb.Booster()
        bst3.load_model(save_path)
        dump3 = bst3.get_dump()
        dump_assertions(dump3)

        # remove file
        Path.unlink(save_path)
