from dataclasses import dataclass
from enum import Enum, auto
from typing import TypeVar, List

T = TypeVar("T", int, float, str, bool)

# classes
class NebType(Enum):
    ANY = auto()
    INT = auto()
    FLOAT = auto()
    NUMBER = auto()
    STRING = auto()
    BOOL = auto()
    EXPR = auto()
    SYMBOL = auto()

    def __str__(self):
        return ":" + self.name.lower()

@dataclass
class NebToken:
    type_: NebType

class NebLiteral(NebToken):

    def __init__(self, type_, value):
        super().__init__(type_)
        self.value = value

    def __str__(self):
        fixed = str(self.value)
        if self.type_ == NebType.BOOL:
            fixed = f"#{str(self.value).lower()}"
        elif self.type_ == NebType.STRING:
            fixed = f'"{self.value}"'
        return f"{fixed} <{self.type_}>"

class NebSeparator():
    pass

class NebOpen(NebSeparator):
    pass

class NebClose(NebSeparator):
    pass

class NebSymbol(NebToken):

    def __init__(self, name):
        super().__init__(NebType.SYMBOL)
        self.name = name

class NebExpression(NebToken):

    def __init__(self, symbol, args):
        super().__init__(NebType.EXPR)
        self.symbol = symbol
        self.args = args

    def maybe_sig(self):
        out = []
        for arg in self.args:
            if isinstance(arg, NebLiteral):
                out.append(":" + arg.type_.name.lower())
            else:
                raise Exception("expressions must have a list of literals") #TODO not true
        return " ".join(out)

class NebFunction():

    def __init__(self, name, args, returns):
        self.name = name
        self.args = args
        self.returns = returns
    
    def in_sig(self):
        return " ".join(":" + x.name.lower() for x in self.args)
    
    def out_sig(self):
        return ":" + self.returns.lower()

    def sig(self):
        return (self.in_sig() + " > " + self.out_sig()).strip()