import re

from enum import Enum, IntFlag  # Python 3.11 >= StrEnum
from enum import auto as auto_enum
from uuid import UUID as RowId

from sqlalchemy import TypeDecorator, Integer, VARCHAR
from sqlmodel import SQLModel
from sqlalchemy.orm import declared_attr

__all__ = [
    "RowId",
    "DocumentedStrEnum",
    "DocumentedIntFlag",
    "auto_enum",
    "ApiTags",
    "BaseSQLModel",
    "Message",
]

# region SQLModel base class ###################################################


class BaseSQLModel(SQLModel):
    # Generate __tablename__ automatically with snake_case
    # noinspection PyMethodParameters
    @declared_attr  # type: ignore
    def __tablename__(cls) -> str:
        rx = re.compile(r"(?<=.)(((?<![A-Z])[A-Z])|([A-Z](?=[a-z])))")
        return rx.sub("_\\1", cls.__name__).lower()

# endregion


# region enum # Fields #########################################################


class DocumentedStrEnum(str, Enum):
    pass


class DocumentedIntFlag(IntFlag):
    @property
    def names(self) -> str:
        """
        Returns a comma-separated string of all active flag names.
        """
        # Exclude 0-value flags
        return ",".join([flag.name for flag in type(self) if flag in self and flag.value != 0])

    def __str__(self) -> str:
        # Default string conversion uses the names
        return self.names

    # Optional: for Pydantic compatibility
    def __get_pydantic_json__(self) -> str:
        return self.names



class DocumentedIntFlagType(TypeDecorator):
    impl = Integer
    cache_ok = True

    def __init__(self, enum_class: type[IntFlag], *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.enum_class = enum_class

    def process_bind_param(self, value, dialect):
        """
        Convert IntFlag to integer before storing
        """
        if value is None:
            return None
        if isinstance(value, self.enum_class):
            return int(value)
        if isinstance(value, int):
            return value
        raise ValueError(f"Invalid value for {self.enum_class.__name__}: {value!r}")

    def process_result_value(self, value, dialect):
        """
        Convert integer from DB back to IntFlag
        """
        if value is None:
            return None
        return self.enum_class(value)


class DocumentedStrFlagType(TypeDecorator):
    impl = VARCHAR
    cache_ok = True

    def __init__(self, enum_class: type[IntFlag], *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.enum_class = enum_class

    def process_bind_param(self, value, dialect):
        """
        Convert IntFlag to comma-separated string of names for storing in DB.
        """
        if value is None:
            return None
        if isinstance(value, self.enum_class):
            return str(value)
        raise ValueError(f"Invalid value for {self.enum_class.__name__}: {value!r}")

    def process_result_value(self, value, dialect):
        """
        Convert comma-separated string of names from DB back to IntFlag.
        """
        if value is None or value == "":
            return self.enum_class(0)
        names = value.split(",")
        result = self.enum_class(0)
        for name in names:
            try:
                result |= self.enum_class[name]
            except KeyError:
                raise ValueError(f"Invalid flag name '{name}' for {self.enum_class.__name__}")
        return result


# #############################################################################


class ApiTags(DocumentedStrEnum):
    LOGIN = "Login"
    USERS = "Users"
    UTILS = "Utils"
    PRIVATE = "Private"

    APIKEY = "APIKey"

    EVENTS = "Events"
    TEAMS = "Teams"
    ASSOCIATIONS = "Associations"
    DIVISIONS = "Divisions"
    MEMBERS = "Members"

    HIKES = "Hikes"


# endregion


# region Generic message #######################################################


class Message(SQLModel):
    message: str


# #############################################################################

# endregion