# Copyright 2019 Huawei Technologies Co., Ltd
#
# 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.
# ==============================================================================
import numpy as np

import mindspore.dataset as ds
from mindspore import log as logger


def test_batch_corner_cases():
    def gen(num):
        for i in range(num):
            yield (np.array([i]),)

    def test_repeat_batch(gen_num, repeats, batch_size, drop, res):
        data1 = ds.GeneratorDataset((lambda: gen(gen_num)), ["num"]).repeat(repeats).batch(batch_size, drop)
        for item in data1.create_dict_iterator(num_epochs=1):
            res.append(item["num"])

    def test_batch_repeat(gen_num, repeats, batch_size, drop, res):
        data1 = ds.GeneratorDataset((lambda: gen(gen_num)), ["num"]).batch(batch_size, drop).repeat(repeats)
        for item in data1.create_dict_iterator(num_epochs=1):
            res.append(item["num"])

    tst1, tst2, tst3, tst4 = [], [], [], []
    # case 1 & 2, where batch_size is greater than the entire epoch, with drop equals to both val
    test_repeat_batch(gen_num=2, repeats=4, batch_size=7, drop=False, res=tst1)
    np.testing.assert_array_equal(np.array([[0], [1], [0], [1], [0], [1], [0]]), tst1[0], "\nATTENTION BATCH FAILED\n")
    np.testing.assert_array_equal(np.array([[1]]), tst1[1], "\nATTENTION TEST BATCH FAILED\n")
    assert len(tst1) == 2, "\nATTENTION TEST BATCH FAILED\n"
    test_repeat_batch(gen_num=2, repeats=4, batch_size=5, drop=True, res=tst2)
    np.testing.assert_array_equal(np.array([[0], [1], [0], [1], [0]]), tst2[0], "\nATTENTION BATCH FAILED\n")
    assert len(tst2) == 1, "\nATTENTION TEST BATCH FAILED\n"
    # case 3 & 4, batch before repeat with different drop
    test_batch_repeat(gen_num=5, repeats=2, batch_size=4, drop=True, res=tst3)
    np.testing.assert_array_equal(np.array([[0], [1], [2], [3]]), tst3[0], "\nATTENTION BATCH FAILED\n")
    np.testing.assert_array_equal(tst3[0], tst3[1], "\nATTENTION BATCH FAILED\n")
    assert len(tst3) == 2, "\nATTENTION BATCH FAILED\n"
    test_batch_repeat(gen_num=5, repeats=2, batch_size=4, drop=False, res=tst4)
    np.testing.assert_array_equal(np.array([[0], [1], [2], [3]]), tst4[0], "\nATTENTION BATCH FAILED\n")
    np.testing.assert_array_equal(tst4[0], tst4[2], "\nATTENTION BATCH FAILED\n")
    np.testing.assert_array_equal(tst4[1], np.array([[4]]), "\nATTENTION BATCH FAILED\n")
    np.testing.assert_array_equal(tst4[1], tst4[3], "\nATTENTION BATCH FAILED\n")
    assert len(tst4) == 4, "\nATTENTION BATCH FAILED\n"


# each sub-test in this function is tested twice with exact parameter except that the second test passes each row
# to a pyfunc which makes a deep copy of the row
def test_variable_size_batch():
    def check_res(arr1, arr2):
        for ind, _ in enumerate(arr1):
            if not np.array_equal(arr1[ind], np.array(arr2[ind])):
                return False
        return len(arr1) == len(arr2)

    def gen(num):
        for i in range(num):
            yield (np.array([i]),)

    def add_one_by_batch_num(batchInfo):
        return batchInfo.get_batch_num() + 1

    def add_one_by_epoch(batchInfo):
        return batchInfo.get_epoch_num() + 1

    def simple_copy(colList, batchInfo):
        _ = batchInfo
        return ([np.copy(arr) for arr in colList],)

    def test_repeat_batch(gen_num, r, drop, func, res):
        data1 = ds.GeneratorDataset((lambda: gen(gen_num)), ["num"]).repeat(r).batch(batch_size=func,
                                                                                     drop_remainder=drop)
        for item in data1.create_dict_iterator(num_epochs=1):
            res.append(item["num"])

    # same as test_repeat_batch except each row is passed through via a map which makes a copy of each element
    def test_repeat_batch_with_copy_map(gen_num, r, drop, func):
        res = []
        data1 = ds.GeneratorDataset((lambda: gen(gen_num)), ["num"]).repeat(r) \
            .batch(batch_size=func, drop_remainder=drop, input_columns=["num"], per_batch_map=simple_copy)
        for item in data1.create_dict_iterator(num_epochs=1):
            res.append(item["num"])
        return res

    def test_batch_repeat(gen_num, r, drop, func, res):
        data1 = ds.GeneratorDataset((lambda: gen(gen_num)), ["num"]).batch(batch_size=func, drop_remainder=drop).repeat(
            r)
        for item in data1.create_dict_iterator(num_epochs=1):
            res.append(item["num"])

    # same as test_batch_repeat except each row is passed through via a map which makes a copy of each element
    def test_batch_repeat_with_copy_map(gen_num, r, drop, func):
        res = []
        data1 = ds.GeneratorDataset((lambda: gen(gen_num)), ["num"]) \
            .batch(batch_size=func, drop_remainder=drop, input_columns=["num"], per_batch_map=simple_copy).repeat(r)
        for item in data1.create_dict_iterator(num_epochs=1):
            res.append(item["num"])
        return res

    tst1, tst2, tst3, tst4, tst5, tst6, tst7 = [], [], [], [], [], [], []

    # no repeat, simple var size, based on batch_num
    test_repeat_batch(7, 1, True, add_one_by_batch_num, tst1)
    assert check_res(tst1, [[[0]], [[1], [2]], [[3], [4], [5]]]), "\nATTENTION VAR BATCH FAILED\n"
    assert check_res(tst1, test_repeat_batch_with_copy_map(7, 1, True, add_one_by_batch_num)), "\nMAP FAILED\n"
    test_repeat_batch(9, 1, False, add_one_by_batch_num, tst2)
    assert check_res(tst2, [[[0]], [[1], [2]], [[3], [4], [5]], [[6], [7], [8]]]), "\nATTENTION VAR BATCH FAILED\n"
    assert check_res(tst2, test_repeat_batch_with_copy_map(9, 1, False, add_one_by_batch_num)), "\nMAP FAILED\n"
    # batch after repeat, cross epoch batch
    test_repeat_batch(7, 2, False, add_one_by_batch_num, tst3)
    assert check_res(tst3, [[[0]], [[1], [2]], [[3], [4], [5]], [[6], [0], [1], [2]],
                            [[3], [4], [5], [6]]]), "\nATTENTION VAR BATCH FAILED\n"
    assert check_res(tst3, test_repeat_batch_with_copy_map(7, 2, False, add_one_by_batch_num)), "\nMAP FAILED\n"
    # repeat after batch, no cross epoch batch, remainder dropped
    test_batch_repeat(9, 7, True, add_one_by_batch_num, tst4)
    assert check_res(tst4, [[[0]], [[1], [2]], [[3], [4], [5]]] * 7), "\nATTENTION VAR BATCH FAILED\n"
    assert check_res(tst4, test_batch_repeat_with_copy_map(9, 7, True, add_one_by_batch_num)), "\nAMAP FAILED\n"
    # repeat after batch, no cross epoch batch, remainder kept
    test_batch_repeat(9, 3, False, add_one_by_batch_num, tst5)
    assert check_res(tst5, [[[0]], [[1], [2]], [[3], [4], [5]], [[6], [7], [8]]] * 3), "\nATTENTION VAR BATCH FAILED\n"
    assert check_res(tst5, test_batch_repeat_with_copy_map(9, 3, False, add_one_by_batch_num)), "\nMAP FAILED\n"
    # batch_size based on epoch number, drop
    test_batch_repeat(4, 4, True, add_one_by_epoch, tst6)
    assert check_res(tst6, [[[0]], [[1]], [[2]], [[3]], [[0], [1]], [[2], [3]], [[0], [1], [2]],
                            [[0], [1], [2], [3]]]), "\nATTENTION VAR BATCH FAILED\n"
    assert check_res(tst6, test_batch_repeat_with_copy_map(4, 4, True, add_one_by_epoch)), "\nMAP FAILED\n"
    # batch_size based on epoch number, no drop
    test_batch_repeat(4, 4, False, add_one_by_epoch, tst7)
    assert check_res(tst7, [[[0]], [[1]], [[2]], [[3]], [[0], [1]], [[2], [3]], [[0], [1], [2]], [[3]],
                            [[0], [1], [2], [3]]]), "\nATTENTION VAR BATCH FAILED\n" + str(tst7)
    assert check_res(tst7, test_batch_repeat_with_copy_map(4, 4, False, add_one_by_epoch)), "\nMAP FAILED\n"


def test_basic_batch_map():
    def check_res(arr1, arr2):
        for ind, _ in enumerate(arr1):
            if not np.array_equal(arr1[ind], np.array(arr2[ind])):
                return False
        return len(arr1) == len(arr2)

    def gen(num):
        for i in range(num):
            yield (np.array([i]),)

    def invert_sign_per_epoch(colList, batchInfo):
        return ([np.copy(((-1) ** batchInfo.get_epoch_num()) * arr) for arr in colList],)

    def invert_sign_per_batch(colList, batchInfo):
        return ([np.copy(((-1) ** batchInfo.get_batch_num()) * arr) for arr in colList],)

    def batch_map_config(num, r, batch_size, func, res):
        data1 = ds.GeneratorDataset((lambda: gen(num)), ["num"]) \
            .batch(batch_size=batch_size, input_columns=["num"], per_batch_map=func).repeat(r)
        for item in data1.create_dict_iterator(num_epochs=1):
            res.append(item["num"])

    tst1, tst2, = [], []
    batch_map_config(4, 2, 2, invert_sign_per_epoch, tst1)
    assert check_res(tst1, [[[0], [1]], [[2], [3]], [[0], [-1]], [[-2], [-3]]]), "\nATTENTION MAP BATCH FAILED\n" + str(
        tst1)
    # each batch, the sign of a row is changed, test map is corrected performed according to its batch_num
    batch_map_config(4, 2, 2, invert_sign_per_batch, tst2)
    assert check_res(tst2,
                     [[[0], [1]], [[-2], [-3]], [[0], [1]], [[-2], [-3]]]), "\nATTENTION MAP BATCH FAILED\n" + str(tst2)


def test_batch_multi_col_map():
    def check_res(arr1, arr2):
        for ind, _ in enumerate(arr1):
            if not np.array_equal(arr1[ind], np.array(arr2[ind])):
                return False
        return len(arr1) == len(arr2)

    def gen(num):
        for i in range(num):
            yield (np.array([i]), np.array([i ** 2]))

    def col1_col2_add_num(col1, col2, batchInfo):
        _ = batchInfo
        return ([[np.copy(arr + 100) for arr in col1],
                 [np.copy(arr + 300) for arr in col2]])

    def invert_sign_per_batch(colList, batchInfo):
        return ([np.copy(((-1) ** batchInfo.get_batch_num()) * arr) for arr in colList],)

    def invert_sign_per_batch_multi_col(col1, col2, batchInfo):
        return ([np.copy(((-1) ** batchInfo.get_batch_num()) * arr) for arr in col1],
                [np.copy(((-1) ** batchInfo.get_batch_num()) * arr) for arr in col2])

    def batch_map_config(num, r, batch_size, func, col_names, res):
        data1 = ds.GeneratorDataset((lambda: gen(num)), ["num", "num_square"]) \
            .batch(batch_size=batch_size, input_columns=col_names, per_batch_map=func).repeat(r)
        for item in data1.create_dict_iterator(num_epochs=1):
            res.append(np.array([item["num"], item["num_square"]]))

    tst1, tst2, tst3, tst4 = [], [], [], []
    batch_map_config(4, 2, 2, invert_sign_per_batch, ["num_square"], tst1)
    assert check_res(tst1, [[[[0], [1]], [[0], [1]]], [[[2], [3]], [[-4], [-9]]], [[[0], [1]], [[0], [1]]],
                            [[[2], [3]], [[-4], [-9]]]]), "\nATTENTION MAP BATCH FAILED\n" + str(tst1)

    batch_map_config(4, 2, 2, invert_sign_per_batch_multi_col, ["num", "num_square"], tst2)
    assert check_res(tst2, [[[[0], [1]], [[0], [1]]], [[[-2], [-3]], [[-4], [-9]]], [[[0], [1]], [[0], [1]]],
                            [[[-2], [-3]], [[-4], [-9]]]]), "\nATTENTION MAP BATCH FAILED\n" + str(tst2)

    # the two tests below verify the order of the map.
    # num_square column adds 100, num column adds 300.
    batch_map_config(4, 3, 2, col1_col2_add_num, ["num_square", "num"], tst3)
    assert check_res(tst3, [[[[300], [301]], [[100], [101]]],
                            [[[302], [303]], [[104], [109]]]] * 3), "\nATTENTION MAP BATCH FAILED\n" + str(tst3)
    # num column adds 100, num_square column adds 300.
    batch_map_config(4, 3, 2, col1_col2_add_num, ["num", "num_square"], tst4)
    assert check_res(tst4, [[[[100], [101]], [[300], [301]]],
                            [[[102], [103]], [[304], [309]]]] * 3), "\nATTENTION MAP BATCH FAILED\n" + str(tst4)


def test_var_batch_multi_col_map():
    def check_res(arr1, arr2):
        for ind, _ in enumerate(arr1):
            if not np.array_equal(arr1[ind], np.array(arr2[ind])):
                return False
        return len(arr1) == len(arr2)

    # gen 3 columns
    # first column: 0, 3, 6, 9 ... ...
    # second column:1, 4, 7, 10 ... ...
    # third column: 2, 5, 8, 11 ... ...
    def gen_3_cols(num):
        for i in range(num):
            yield (np.array([i * 3]), np.array([i * 3 + 1]), np.array([i * 3 + 2]))

    # first epoch batch_size per batch: 1, 2 ,3 ... ...
    # second epoch batch_size per batch: 2, 4, 6 ... ...
    # third epoch batch_size per batch: 3, 6 ,9 ... ...
    def batch_func(batchInfo):
        return (batchInfo.get_batch_num() + 1) * (batchInfo.get_epoch_num() + 1)

    # multiply first col by batch_num, multiply second col by -batch_num
    def map_func(col1, col2, batchInfo):
        return ([np.copy((1 + batchInfo.get_batch_num()) * arr) for arr in col1],
                [np.copy(-(1 + batchInfo.get_batch_num()) * arr) for arr in col2])

    def batch_map_config(num, r, fbatch, fmap, col_names, res):
        data1 = ds.GeneratorDataset((lambda: gen_3_cols(num)), ["col1", "col2", "col3"]) \
            .batch(batch_size=fbatch, input_columns=col_names, per_batch_map=fmap).repeat(r)
        for item in data1.create_dict_iterator(num_epochs=1):
            res.append(np.array([item["col1"], item["col2"], item["col3"]]))

    tst1 = []
    tst1_res = [[[[0]], [[-1]], [[2]]], [[[6], [12]], [[-8], [-14]], [[5], [8]]],
                [[[27], [36], [45]], [[-30], [-39], [-48]], [[11], [14], [17]]],
                [[[72], [84], [96], [108]], [[-76], [-88], [-100], [-112]], [[20], [23], [26], [29]]]]
    batch_map_config(10, 1, batch_func, map_func, ["col1", "col2"], tst1)
    assert check_res(tst1, tst1_res), "test_var_batch_multi_col_map FAILED"


def test_var_batch_var_resize():
    # fake resize image according to its batch number, if it's 5-th batch, resize to (5^2, 5^2) = (25, 25)
    def np_psedo_resize(col, batchInfo):
        s = (batchInfo.get_batch_num() + 1) ** 2
        return ([np.copy(c[0:s, 0:s, :]) for c in col],)

    def add_one(batchInfo):
        return batchInfo.get_batch_num() + 1

    data1 = ds.ImageFolderDataset("../data/dataset/testPK/data/", num_parallel_workers=4, decode=True)
    data1 = data1.batch(batch_size=add_one, drop_remainder=True, input_columns=["image"], per_batch_map=np_psedo_resize)
    # i-th batch has shape [i, i^2, i^2, 3]
    i = 1
    for item in data1.create_dict_iterator(num_epochs=1):
        assert item["image"].shape == (i, i ** 2, i ** 2, 3), "\ntest_var_batch_var_resize FAILED\n"
        i += 1


def test_exception():
    def gen(num):
        for i in range(num):
            yield (np.array([i]),)

    def bad_batch_size(batchInfo):
        raise StopIteration
        #return batchInfo.get_batch_num()

    def bad_map_func(col, batchInfo):
        raise StopIteration
        #return (col,)

    data1 = ds.GeneratorDataset((lambda: gen(100)), ["num"]).batch(bad_batch_size)
    try:
        for _ in data1.create_dict_iterator(num_epochs=1):
            pass
        assert False
    except RuntimeError:
        pass

    data2 = ds.GeneratorDataset((lambda: gen(100)), ["num"]).batch(4, input_columns=["num"], per_batch_map=bad_map_func)
    try:
        for _ in data2.create_dict_iterator(num_epochs=1):
            pass
        assert False
    except RuntimeError:
        pass


if __name__ == '__main__':
    logger.info("Running test_var_batch_map.py test_batch_corner_cases() function")
    test_batch_corner_cases()

    logger.info("Running test_var_batch_map.py test_variable_size_batch() function")
    test_variable_size_batch()

    logger.info("Running test_var_batch_map.py test_basic_batch_map() function")
    test_basic_batch_map()

    logger.info("Running test_var_batch_map.py test_batch_multi_col_map() function")
    test_batch_multi_col_map()

    logger.info("Running test_var_batch_map.py tesgit t_var_batch_multi_col_map() function")
    test_var_batch_multi_col_map()

    logger.info("Running test_var_batch_map.py test_var_batch_var_resize() function")
    test_var_batch_var_resize()

    logger.info("Running test_var_batch_map.py test_exception() function")
    test_exception()