from __future__ import annotations

import enum
import functools
from functools import wraps
from typing import Any

from wrapt import ObjectProxy

from coredis.exceptions import ClusterDownError, RedisClusterException
from coredis.typing import (
    Callable,
    Coroutine,
    Dict,
    Iterable,
    List,
    Mapping,
    Optional,
    P,
    R,
    ResponseType,
    Set,
    StringT,
    Tuple,
    TypeVar,
    Union,
)


class EncodingInsensitiveDict(ObjectProxy):  # type: ignore
    def __init__(
        self,
        dict: Optional[Union[Mapping[Any, Any], ResponseType]] = None,
        encoding: str = "utf-8",
    ):
        d = dict or {}
        super().__init__(d)
        self._self_encoding = encoding

    def __getitem__(self, item: StringT) -> Any:
        if isinstance(item, str) and item not in self.__wrapped__:
            return self.__wrapped__.get(
                item, self.__wrapped__.get(item.encode(self._self_encoding))
            )
        elif isinstance(item, bytes) and item not in self.__wrapped__:
            return self.__wrapped__.get(
                item, self.__wrapped__.get(item.decode(self._self_encoding))
            )
        return self.__wrapped__[item]

    def get(self, item: StringT, default: Optional[object] = None) -> Any:
        return self.__getitem__(item) or default

    def pop(self, item: StringT, default: Optional[object] = None) -> Any:
        if item in self.__wrapped__:
            return self.__wrapped__.pop(item)
        if isinstance(item, str):
            return self.__wrapped__.pop(item.encode(self._self_encoding), default)

    def clear(self) -> None:
        self.__wrapped__.clear()

    def update(self, updates: Mapping[Any, Any]) -> None:
        self.__wrapped__.update(updates)

    def __setitem__(self, item: StringT, value: object) -> None:
        if item in self.__wrapped__:
            self.__wrapped__[item] = value
        elif (
            isinstance(item, str)
            and item.encode(self._self_encoding) in self.__wrapped__
        ):
            self.__wrapped__[item.encode(self._self_encoding)] = value
        elif (
            isinstance(item, bytes)
            and item.decode(self._self_encoding) in self.__wrapped__
        ):
            self.__wrapped__[item.decode(self._self_encoding)] = value
        else:
            self.__wrapped__[item] = value

    def __contains__(self, key: StringT) -> bool:
        if isinstance(key, str):
            return (
                key in self.__wrapped__
                or key.encode(self._self_encoding) in self.__wrapped__
            )
        elif isinstance(key, bytes):
            return (
                key in self.__wrapped__
                or key.decode(self._self_encoding) in self.__wrapped__
            )
        return key in self.__wrapped__

    def __repr__(self) -> str:
        return repr(self.__wrapped__)


def b(x: ResponseType) -> bytes:
    if isinstance(x, bytes):
        return x
    if not isinstance(x, str):
        _v = str(x)
    else:
        _v = x
    return _v.encode("latin-1")


def defaultvalue(value: Optional[U], default: T) -> Union[U, T]:
    return default if value is None else value


def nativestr(x: ResponseType) -> str:
    if isinstance(x, (str, bytes)):
        return x if isinstance(x, str) else x.decode("utf-8", "replace")
    elif isinstance(x, (int, float, bool)):
        return str(x)
    raise ValueError(f"Unable to cast {x} to string")


T = TypeVar("T")
U = TypeVar("U")


def tuples_to_flat_list(nested_list: Iterable[Tuple[T, ...]]) -> List[T]:
    return [item for sublist in nested_list for item in sublist]


def dict_to_flat_list(
    mapping: Mapping[T, U], reverse: bool = False
) -> List[Union[T, U]]:
    e1: List[Union[T, U]] = list(mapping.keys())
    e2: List[Union[T, U]] = list(mapping.values())

    ret: List[Union[T, U]] = []

    if reverse:
        e1, e2 = e2, e1

    for idx, e in enumerate(e1):
        ret.append(e)
        ret.append(e2[idx])

    return ret


# ++++++++++ result callbacks helpers ++++++++++++++


def first_key(res: Dict[str, R]) -> R:
    """
    Returns the first result for the given command.

    If more then 1 result is returned then a `RedisClusterException` is raised.
    """

    if len(res.keys()) != 1:
        raise RedisClusterException("More then 1 result from command")

    return list(res.values())[0]


def clusterdown_wrapper(
    func: Callable[P, Coroutine[Any, Any, R]]
) -> Callable[P, Coroutine[Any, Any, R]]:
    """
    Wrapper for CLUSTERDOWN error handling.

    If the cluster reports it is down it is assumed that:
     - connection_pool was disconnected
     - connection_pool was reset
     - referesh_table_asap set to True

    It will try 3 times to rerun the command and raises ClusterDownException if it continues to
    fail.
    """

    @wraps(func)
    async def inner(*args: P.args, **kwargs: P.kwargs) -> R:
        for _ in range(0, 3):
            try:
                return await func(*args, **kwargs)
            except ClusterDownError:
                # Try again with the new cluster setup. All other errors
                # should be raised.
                pass

        # If it fails 3 times then raise exception back to caller
        raise ClusterDownError("CLUSTERDOWN error. Unable to rebuild the cluster")

    return inner


try:
    from coredis.speedups import crc16, hash_slot
except ImportError:
    x_mode_m_crc16_lookup = [
        0x0000,
        0x1021,
        0x2042,
        0x3063,
        0x4084,
        0x50A5,
        0x60C6,
        0x70E7,
        0x8108,
        0x9129,
        0xA14A,
        0xB16B,
        0xC18C,
        0xD1AD,
        0xE1CE,
        0xF1EF,
        0x1231,
        0x0210,
        0x3273,
        0x2252,
        0x52B5,
        0x4294,
        0x72F7,
        0x62D6,
        0x9339,
        0x8318,
        0xB37B,
        0xA35A,
        0xD3BD,
        0xC39C,
        0xF3FF,
        0xE3DE,
        0x2462,
        0x3443,
        0x0420,
        0x1401,
        0x64E6,
        0x74C7,
        0x44A4,
        0x5485,
        0xA56A,
        0xB54B,
        0x8528,
        0x9509,
        0xE5EE,
        0xF5CF,
        0xC5AC,
        0xD58D,
        0x3653,
        0x2672,
        0x1611,
        0x0630,
        0x76D7,
        0x66F6,
        0x5695,
        0x46B4,
        0xB75B,
        0xA77A,
        0x9719,
        0x8738,
        0xF7DF,
        0xE7FE,
        0xD79D,
        0xC7BC,
        0x48C4,
        0x58E5,
        0x6886,
        0x78A7,
        0x0840,
        0x1861,
        0x2802,
        0x3823,
        0xC9CC,
        0xD9ED,
        0xE98E,
        0xF9AF,
        0x8948,
        0x9969,
        0xA90A,
        0xB92B,
        0x5AF5,
        0x4AD4,
        0x7AB7,
        0x6A96,
        0x1A71,
        0x0A50,
        0x3A33,
        0x2A12,
        0xDBFD,
        0xCBDC,
        0xFBBF,
        0xEB9E,
        0x9B79,
        0x8B58,
        0xBB3B,
        0xAB1A,
        0x6CA6,
        0x7C87,
        0x4CE4,
        0x5CC5,
        0x2C22,
        0x3C03,
        0x0C60,
        0x1C41,
        0xEDAE,
        0xFD8F,
        0xCDEC,
        0xDDCD,
        0xAD2A,
        0xBD0B,
        0x8D68,
        0x9D49,
        0x7E97,
        0x6EB6,
        0x5ED5,
        0x4EF4,
        0x3E13,
        0x2E32,
        0x1E51,
        0x0E70,
        0xFF9F,
        0xEFBE,
        0xDFDD,
        0xCFFC,
        0xBF1B,
        0xAF3A,
        0x9F59,
        0x8F78,
        0x9188,
        0x81A9,
        0xB1CA,
        0xA1EB,
        0xD10C,
        0xC12D,
        0xF14E,
        0xE16F,
        0x1080,
        0x00A1,
        0x30C2,
        0x20E3,
        0x5004,
        0x4025,
        0x7046,
        0x6067,
        0x83B9,
        0x9398,
        0xA3FB,
        0xB3DA,
        0xC33D,
        0xD31C,
        0xE37F,
        0xF35E,
        0x02B1,
        0x1290,
        0x22F3,
        0x32D2,
        0x4235,
        0x5214,
        0x6277,
        0x7256,
        0xB5EA,
        0xA5CB,
        0x95A8,
        0x8589,
        0xF56E,
        0xE54F,
        0xD52C,
        0xC50D,
        0x34E2,
        0x24C3,
        0x14A0,
        0x0481,
        0x7466,
        0x6447,
        0x5424,
        0x4405,
        0xA7DB,
        0xB7FA,
        0x8799,
        0x97B8,
        0xE75F,
        0xF77E,
        0xC71D,
        0xD73C,
        0x26D3,
        0x36F2,
        0x0691,
        0x16B0,
        0x6657,
        0x7676,
        0x4615,
        0x5634,
        0xD94C,
        0xC96D,
        0xF90E,
        0xE92F,
        0x99C8,
        0x89E9,
        0xB98A,
        0xA9AB,
        0x5844,
        0x4865,
        0x7806,
        0x6827,
        0x18C0,
        0x08E1,
        0x3882,
        0x28A3,
        0xCB7D,
        0xDB5C,
        0xEB3F,
        0xFB1E,
        0x8BF9,
        0x9BD8,
        0xABBB,
        0xBB9A,
        0x4A75,
        0x5A54,
        0x6A37,
        0x7A16,
        0x0AF1,
        0x1AD0,
        0x2AB3,
        0x3A92,
        0xFD2E,
        0xED0F,
        0xDD6C,
        0xCD4D,
        0xBDAA,
        0xAD8B,
        0x9DE8,
        0x8DC9,
        0x7C26,
        0x6C07,
        0x5C64,
        0x4C45,
        0x3CA2,
        0x2C83,
        0x1CE0,
        0x0CC1,
        0xEF1F,
        0xFF3E,
        0xCF5D,
        0xDF7C,
        0xAF9B,
        0xBFBA,
        0x8FD9,
        0x9FF8,
        0x6E17,
        0x7E36,
        0x4E55,
        0x5E74,
        0x2E93,
        0x3EB2,
        0x0ED1,
        0x1EF0,
    ]

    def crc16(data: bytes) -> int:
        crc = 0

        for byte in data:
            crc = ((crc << 8) & 0xFF00) ^ x_mode_m_crc16_lookup[
                ((crc >> 8) & 0xFF) ^ byte
            ]

        return crc & 0xFFFF

    def hash_slot(key: bytes) -> int:
        start = key.find(b"{")

        if start > -1:
            end = key.find(b"}", start + 1)

            if end > -1 and end != start + 1:
                key = key[start + 1 : end]

        return crc16(key) % 16384


@enum.unique
class CaseAndEncodingInsensitiveEnum(bytes, enum.Enum):
    @functools.cached_property
    def variants(self) -> Set[StringT]:
        decoded = str(self)
        return {self.value.lower(), self.value, decoded.lower(), decoded.upper()}

    def __eq__(self, other: object) -> bool:
        """
        Since redis tokens are case insensitive allow mixed case
        Additionally allow strings to be passed in instead of
        bytes.
        """

        if other:
            if isinstance(other, self.__class__):
                return bool(self.value == other.value)
            else:
                return other in self.variants
        return False

    def __str__(self) -> str:
        return self.decode("latin-1")

    def __hash__(self) -> int:
        return hash(self.value)


__all__ = [
    "hash_slot",
    "EncodingInsensitiveDict",
    "CaseAndEncodingInsensitiveEnum",
]
