import re

"""
general info:
https://en.wikipedia.org/wiki/Naming_convention_(programming)#Python_and_Ruby

pascal case [ an upper Camel Case ]: https://en.wikipedia.org/wiki/Camel_case

camel case: https://en.wikipedia.org/wiki/Camel_case

kebab case [ can be found in general info ]:
https://en.wikipedia.org/wiki/Naming_convention_(programming)#Python_and_Ruby

snake case: https://en.wikipedia.org/wiki/Snake_case
"""


# assistant functions
def split_input(str_: str) -> list:
 """
 >>> split_input("one two 31235three4four")
 [['one', 'two', '31235three4four']]
 """
 return [char.split() for char in re.split(r"[^ a-z A-Z 0-9 \s]", str_)]


def to_simple_case(str_: str) -> str:
 """
 >>> to_simple_case("one two 31235three4four")
 'OneTwo31235three4four'
 >>> to_simple_case("This should be combined")
 'ThisShouldBeCombined'
 >>> to_simple_case("The first letters are capitalized, then string is merged")
 'TheFirstLettersAreCapitalizedThenStringIsMerged'
 >>> to_simple_case("special characters :, ', %, ^, ,ドル are ignored")
 'SpecialCharactersAreIgnored'
 """
 string_split = split_input(str_)
 return "".join(
 ["".join([char.capitalize() for char in sub_str]) for sub_str in string_split]
 )


def to_complex_case(text: str, upper: bool, separator: str) -> str:
 """
 Returns the string concatenated with the delimiter we provide.

 Parameters:
 @text: The string on which we want to perform operation
 @upper: Boolean value to determine whether we want capitalized result or not
 @separator: The delimiter with which we want to concatenate words

 Examples:
 >>> to_complex_case("one two 31235three4four", True, "_")
 'ONE_TWO_31235THREE4FOUR'
 >>> to_complex_case("one two 31235three4four", False, "-")
 'one-two-31235three4four'
 """
 try:
 string_split = split_input(text)
 if upper:
 res_str = "".join(
 [
 separator.join([char.upper() for char in sub_str])
 for sub_str in string_split
 ]
 )
 else:
 res_str = "".join(
 [
 separator.join([char.lower() for char in sub_str])
 for sub_str in string_split
 ]
 )
 return res_str
 except IndexError:
 return "not valid string"


# main content
def to_pascal_case(text: str) -> str:
 """
 >>> to_pascal_case("one two 31235three4four")
 'OneTwo31235three4four'
 """
 return to_simple_case(text)


def to_camel_case(text: str) -> str:
 """
 >>> to_camel_case("one two 31235three4four")
 'oneTwo31235three4four'
 """
 try:
 res_str = to_simple_case(text)
 return res_str[0].lower() + res_str[1:]
 except IndexError:
 return "not valid string"


def to_snake_case(text: str, upper: bool) -> str:
 """
 >>> to_snake_case("one two 31235three4four", True)
 'ONE_TWO_31235THREE4FOUR'
 >>> to_snake_case("one two 31235three4four", False)
 'one_two_31235three4four'
 """
 return to_complex_case(text, upper, "_")


def to_kebab_case(text: str, upper: bool) -> str:
 """
 >>> to_kebab_case("one two 31235three4four", True)
 'ONE-TWO-31235THREE4FOUR'
 >>> to_kebab_case("one two 31235three4four", False)
 'one-two-31235three4four'
 """
 return to_complex_case(text, upper, "-")


if __name__ == "__main__":
 __import__("doctest").testmod()