#!/usr/bin/env python3

from itertools import islice
from typing import Any, Callable, Dict, Iterator, Tuple


def init_or_inc(
    d: Dict[Any, Any],
    key: Any,
    *,
    init_value: Any = 1,
    inc_function: Callable[..., Any] = lambda x: x + 1
) -> bool:
    if key in d.keys():
        d[key] = inc_function(d[key])
        return True
    d[key] = init_value
    return False


def shard(d: Dict[Any, Any], size: int) -> Iterator[Dict[Any, Any]]:
    items = d.items()
    for x in range(0, len(d), size):
        yield {key: value for (key, value) in islice(items, x, x + size)}


def coalesce_by_creating_list(key, v1, v2):
    from list_utils import flatten
    return flatten([v1, v2])


def coalesce_by_creating_set(key, v1, v2):
    return set(coalesce_by_creating_list(key, v1, v2))


def raise_on_duplicated_keys(key, v1, v2):
    raise Exception(f'Key {key} is duplicated in more than one input dict.')


def coalesce(
        inputs: Iterator[Dict[Any, Any]],
        *,
        aggregation_function: Callable[[Any, Any], Any] = coalesce_by_creating_list
) -> Dict[Any, Any]:
    out: Dict[Any, Any] = {}
    for d in inputs:
        for key in d:
            if key in out:
                value = aggregation_function(d[key], out[key])
            else:
                value = d[key]
            out[key] = value
    return out


def item_with_max_value(d: Dict[Any, Any]) -> Tuple[Any, Any]:
    return max(d.items(), key=lambda _: _[1])


def item_with_min_value(d: Dict[Any, Any]) -> Tuple[Any, Any]:
    return min(d.items(), key=lambda _: _[1])


def key_with_max_value(d: Dict[Any, Any]) -> Any:
    return item_with_max_value(d)[0]


def key_with_min_value(d: Dict[Any, Any]) -> Any:
    return item_with_min_value(d)[0]


def max_value(d: Dict[Any, Any]) -> Any:
    return item_with_max_value(d)[1]


def min_value(d: Dict[Any, Any]) -> Any:
    return item_with_min_value(d)[1]


def max_key(d: Dict[Any, Any]) -> Any:
    return max(d.keys())


def min_key(d: Dict[Any, Any]) -> Any:
    return min(d.keys())