"""" Command Line Interface for `openml` to configure its settings. """

import argparse
import os
import pathlib
import string
from typing import Union, Callable
from urllib.parse import urlparse


from openml import config


def is_hex(string_: str) -> bool:
    return all(c in string.hexdigits for c in string_)


def looks_like_url(url: str) -> bool:
    # There's no thorough url parser, but we only seem to use netloc.
    try:
        return bool(urlparse(url).netloc)
    except Exception:
        return False


def wait_until_valid_input(
    prompt: str, check: Callable[[str], str], sanitize: Union[Callable[[str], str], None]
) -> str:
    """  Asks `prompt` until an input is received which returns True for `check`.

    Parameters
    ----------
    prompt: str
        message to display
    check: Callable[[str], str]
        function to call with the given input, that provides an error message if the input is not
        valid otherwise, and False-like otherwise.
    sanitize: Callable[[str], str], optional
        A function which attempts to sanitize the user input (e.g. auto-complete).

    Returns
    -------
    valid input

    """

    while True:
        response = input(prompt)
        if sanitize:
            response = sanitize(response)
        error_message = check(response)
        if error_message:
            print(error_message, end="\n\n")
        else:
            return response


def print_configuration():
    file = config.determine_config_file_path()
    header = f"File '{file}' contains (or defaults to):"
    print(header)

    max_key_length = max(map(len, config.get_config_as_dict()))
    for field, value in config.get_config_as_dict().items():
        print(f"{field.ljust(max_key_length)}: {value}")


def verbose_set(field, value):
    config.set_field_in_config_file(field, value)
    print(f"{field} set to '{value}'.")


def configure_apikey(value: str) -> None:
    def check_apikey(apikey: str) -> str:
        if len(apikey) != 32:
            return f"The key should contain 32 characters but contains {len(apikey)}."
        if not is_hex(apikey):
            return "Some characters are not hexadecimal."
        return ""

    instructions = (
        f"Your current API key is set to: '{config.apikey}'. "
        "You can get an API key at https://new.openml.org. "
        "You must create an account if you don't have one yet:\n"
        "  1. Log in with the account.\n"
        "  2. Navigate to the profile page (top right circle > Your Profile). \n"
        "  3. Click the API Key button to reach the page with your API key.\n"
        "If you have any difficulty following these instructions, let us know on Github."
    )

    configure_field(
        field="apikey",
        value=value,
        check_with_message=check_apikey,
        intro_message=instructions,
        input_message="Please enter your API key:",
    )


def configure_server(value: str) -> None:
    def check_server(server: str) -> str:
        is_shorthand = server in ["test", "production"]
        if is_shorthand or looks_like_url(server):
            return ""
        return "Must be 'test', 'production' or a url."

    def replace_shorthand(server: str) -> str:
        if server == "test":
            return "https://test.openml.org/api/v1/xml"
        if server == "production":
            return "https://www.openml.org/api/v1/xml"
        return server

    configure_field(
        field="server",
        value=value,
        check_with_message=check_server,
        intro_message="Specify which server you wish to connect to.",
        input_message="Specify a url or use 'test' or 'production' as a shorthand: ",
        sanitize=replace_shorthand,
    )


def configure_cachedir(value: str) -> None:
    def check_cache_dir(path: str) -> str:
        p = pathlib.Path(path)
        if p.is_file():
            return f"'{path}' is a file, not a directory."
        expanded = p.expanduser()
        if not expanded.is_absolute():
            return f"'{path}' is not absolute (even after expanding '~')."
        if not expanded.exists():
            try:
                os.mkdir(expanded)
            except PermissionError:
                return f"'{path}' does not exist and there are not enough permissions to create it."
        return ""

    configure_field(
        field="cachedir",
        value=value,
        check_with_message=check_cache_dir,
        intro_message="Configuring the cache directory. It can not be a relative path.",
        input_message="Specify the directory to use (or create) as cache directory: ",
    )
    print("NOTE: Data from your old cache directory is not moved over.")


def configure_connection_n_retries(value: str) -> None:
    def valid_connection_retries(n: str) -> str:
        if not n.isdigit():
            return f"'{n}' is not a valid positive integer."
        if int(n) <= 0:
            return "connection_n_retries must be positive."
        return ""

    configure_field(
        field="connection_n_retries",
        value=value,
        check_with_message=valid_connection_retries,
        intro_message="Configuring the number of times to attempt to connect to the OpenML Server",
        input_message="Enter a positive integer: ",
    )


def configure_avoid_duplicate_runs(value: str) -> None:
    def is_python_bool(bool_: str) -> str:
        if bool_ in ["True", "False"]:
            return ""
        return "Must be 'True' or 'False' (mind the capital)."

    def autocomplete_bool(bool_: str) -> str:
        if bool_.lower() in ["n", "no", "f", "false", "0"]:
            return "False"
        if bool_.lower() in ["y", "yes", "t", "true", "1"]:
            return "True"
        return bool_

    intro_message = (
        "If set to True, when `run_flow_on_task` or similar methods are called a lookup is "
        "performed to see if there already exists such a run on the server. "
        "If so, download those results instead. "
        "If set to False, runs will always be executed."
    )

    configure_field(
        field="avoid_duplicate_runs",
        value=value,
        check_with_message=is_python_bool,
        intro_message=intro_message,
        input_message="Enter 'True' or 'False': ",
        sanitize=autocomplete_bool,
    )


def configure_verbosity(value: str) -> None:
    def is_zero_through_two(verbosity: str) -> str:
        if verbosity in ["0", "1", "2"]:
            return ""
        return "Must be '0', '1' or '2'."

    intro_message = (
        "Set the verbosity of log messages which should be shown by openml-python."
        " 0: normal output (warnings and errors)"
        " 1: info output (some high-level progress output)"
        " 2: debug output (detailed information (for developers))"
    )

    configure_field(
        field="verbosity",
        value=value,
        check_with_message=is_zero_through_two,
        intro_message=intro_message,
        input_message="Enter '0', '1' or '2': ",
    )


def configure_retry_policy(value: str) -> None:
    def is_known_policy(policy: str) -> str:
        if policy in ["human", "robot"]:
            return ""
        return "Must be 'human' or 'robot'."

    def autocomplete_policy(policy: str) -> str:
        for option in ["human", "robot"]:
            if option.startswith(policy.lower()):
                return option
        return policy

    intro_message = (
        "Set the retry policy which determines how to react if the server is unresponsive."
        "We recommend 'human' for interactive usage and 'robot' for scripts."
        "'human': try a few times in quick succession, less reliable but quicker response."
        "'robot': try many times with increasing intervals, more reliable but slower response."
    )

    configure_field(
        field="retry_policy",
        value=value,
        check_with_message=is_known_policy,
        intro_message=intro_message,
        input_message="Enter 'human' or 'robot': ",
        sanitize=autocomplete_policy,
    )


def configure_field(
    field: str,
    value: Union[None, str],
    check_with_message: Callable[[str], str],
    intro_message: str,
    input_message: str,
    sanitize: Union[Callable[[str], str], None] = None,
) -> None:
    """ Configure `field` with `value`. If `value` is None ask the user for input.

    `value` and user input are first corrected/auto-completed with `convert_value` if provided,
    then validated with `check_with_message` function.
    If the user input a wrong value in interactive mode, the user gets to input a new value.
    The new valid value is saved in the openml configuration file.
    In case an invalid `value` is supplied directly (non-interactive), no changes are made.

    Parameters
    ----------
    field: str
        Field to set.
    value: str, None
        Value to field to. If `None` will ask user for input.
    check_with_message: Callable[[str], str]
        Function which validates `value` or user input, and returns either an error message if it
        is invalid, or a False-like value if `value` is valid.
    intro_message: str
        Message that is printed once if user input is requested (e.g. instructions).
    input_message: str
        Message that comes with the input prompt.
    sanitize: Union[Callable[[str], str], None]
        A function to convert user input to 'more acceptable' input, e.g. for auto-complete.
        If no correction of user input is possible, return the original value.
        If no function is provided, don't attempt to correct/auto-complete input.
    """
    if value is not None:
        if sanitize:
            value = sanitize(value)
        malformed_input = check_with_message(value)
        if malformed_input:
            print(malformed_input)
            quit()
    else:
        print(intro_message)
        value = wait_until_valid_input(
            prompt=input_message, check=check_with_message, sanitize=sanitize,
        )
    verbose_set(field, value)


def configure(args: argparse.Namespace):
    """ Calls the right submenu(s) to edit `args.field` in the configuration file. """
    set_functions = {
        "apikey": configure_apikey,
        "server": configure_server,
        "cachedir": configure_cachedir,
        "retry_policy": configure_retry_policy,
        "connection_n_retries": configure_connection_n_retries,
        "avoid_duplicate_runs": configure_avoid_duplicate_runs,
        "verbosity": configure_verbosity,
    }

    def not_supported_yet(_):
        print(f"Setting '{args.field}' is not supported yet.")

    if args.field not in ["all", "none"]:
        set_functions.get(args.field, not_supported_yet)(args.value)
    else:
        if args.value is not None:
            print(f"Can not set value ('{args.value}') when field is specified as '{args.field}'.")
            quit()
        print_configuration()

    if args.field == "all":
        for set_field_function in set_functions.values():
            print()  # Visually separating the output by field.
            set_field_function(args.value)


def main() -> None:
    subroutines = {"configure": configure}

    parser = argparse.ArgumentParser()
    subparsers = parser.add_subparsers(dest="subroutine")

    parser_configure = subparsers.add_parser(
        "configure",
        description="Set or read variables in your configuration file. For more help also see "
        "'https://openml.github.io/openml-python/main/usage.html#configuration'.",
    )

    configurable_fields = [f for f in config._defaults if f not in ["max_retries"]]

    parser_configure.add_argument(
        "field",
        type=str,
        choices=[*configurable_fields, "all", "none"],
        default="all",
        nargs="?",
        help="The field you wish to edit. "
        "Choosing 'all' lets you configure all fields one by one. "
        "Choosing 'none' will print out the current configuration.",
    )

    parser_configure.add_argument(
        "value", type=str, default=None, nargs="?", help="The value to set the FIELD to.",
    )

    args = parser.parse_args()
    subroutines.get(args.subroutine, lambda _: parser.print_help())(args)


if __name__ == "__main__":
    main()