from dataclasses import dataclass
from enum import Enum, auto
from typing import ClassVar, DefaultDict

from .location import Range
from .tokenize import BaseToken


class ContextType(Enum):
    Use = auto()
    Assign = auto()
    Declare = auto()
    Unbind = auto()


@dataclass(frozen=True)
class Context:
    lookup: ClassVar[dict[ContextType, list["Context"]]] = {}

    typ: ContextType
    token: list[BaseToken]

    def __post_init__(self):
        type(self).lookup.setdefault(self.typ, [])
        type(self).lookup[self.typ].append(self)

    @property
    def range(self) -> Range:
        new_range = self.token[0].range
        for token in self.token[1:]:
            new_range += token.range
        return new_range