#!/usr/bin/env python3

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


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


def item_with_min_value(d: Dict[Any, 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())


def merge(a: Dict[Any, Any], b: Dict[Any, Any], path=None) -> Dict[Any, Any]:
    if path is None:
        path = []
    for key in b:
        if key in a:
            if isinstance(a[key], dict) and isinstance(b[key], dict):
                merge(a[key], b[key], path + [str(key)])
            elif a[key] == b[key]:
                pass
            else:
                raise Exception("Conflict at %s" % ".".join(path + [str(key)]))
        else:
            a[key] = b[key]
    return a