"""Custom JSON encoding functionality."""
import re
from datetime import date, datetime
from flask.json.provider import DefaultJSONProvider
from typing import Any


class CustomJSONProvider(DefaultJSONProvider):
    def default(self, o):
        if isinstance(o, (date, datetime)):
            return o.isoformat()
        return super().default(o)


def str_to_date(value: Any) -> Any:
    """Recursive str to date.

    Args:
        value (Any): Any value.

    Returns:
        Any: date or original value.

    """
    if isinstance(value, list):
        return [str_to_date(i) for i in value]
    if isinstance(value, str) and re.match(r"^\d{4}-\d{2}-\d{2}[T ]\d{2}:\d{2}:\d{2}\.*\d*$", value):
        return datetime.fromisoformat(value)
    if isinstance(value, str) and re.match(r"^\d{4}-\d{2}-\d{2}$", value):
        return datetime.strptime(value, "%Y-%m-%d").date()
    return value


def date_hook(json_dict: dict) -> dict:
    """Deserialize dates for json loads.

    Args:
        json_dict (dict): Json keys and values.

    Returns:
        dict: Formatter json.

    """
    for key, value in json_dict.items():
        json_dict[key] = str_to_date(value)
    return json_dict


def serialize_value(v, datefmt=None):
    """Convert arbitrary value to a JSON-serializable value.

    Conversion rules are:
        * Objects of types int, float, bool, str and None object returned unmodified.
        * Date and datetime objects are converted to strings according to format string passed with datefmt argument,
          by default ISO format is used.
        * If a list is passed the function is recursively called for each of its elements and a new list is returned.
        * If a dictionary is passed the function is recursively called for each of its keys and values, and a new
          dictionary is returned. Keys of the resulting dictionary converted to strings.
        * Objects of other types converted to their string representation.

    Args:
        v: Value of an arbitrary data type.
        datefmt (str): Optional format string for date and datetime objects. By default ISO 8601 is used.

    Returns:
        A JSON-serializable value.

    """
    if isinstance(v, (int, float, bool, str, type(None))):
        return v

    if isinstance(v, (date, datetime)):
        if not datefmt:
            return v.isoformat()
        return v.strftime(datefmt)

    if isinstance(v, list):
        return [serialize_value(i, datefmt) for i in v]

    if isinstance(v, dict):
        return {str(serialize_value(key, datefmt)): serialize_value(value, datefmt) for key, value in v.items()}

    return str(v)