from abc import ABC, abstractmethod
from fractions import Fraction

from centvrion.errors import CentvrionError

class Val(ABC):
  @abstractmethod
  def value(self): ...

  def __repr__(self):
    return f"{self.__class__.__name__}({self.value()!r})"

  def __eq__(self, other):
    return isinstance(other, type(self)) and self.value() == other.value()

class ValInt(Val):
  def __init__(self, v: int):
    assert isinstance(v, int) and not isinstance(v, bool)
    self._v = v

  def value(self):
    return self._v

  def __bool__(self):
    return self._v != 0

  def __lt__(self, other):
    return self._v < other.value()

  def __gt__(self, other):
    return self._v > other.value()

class ValStr(Val):
  def __init__(self, v: str):
    assert isinstance(v, str)
    self._v = v

  def value(self):
    return self._v

  def __bool__(self):
    return self._v != ""

class ValBool(Val):
  def __init__(self, v: bool):
    assert isinstance(v, bool)
    self._v = v

  def value(self):
    return self._v

  def __bool__(self):
    return self._v

class ValList(Val):
  def __init__(self, v: list):
    assert isinstance(v, list)
    self._v = v

  def value(self):
    return self._v

  def __bool__(self):
    return len(self._v) > 0

  def __iter__(self):
    return iter(self._v)

class ValFrac(Val):
  def __init__(self, v: Fraction):
    assert isinstance(v, Fraction)
    self._v = v

  def value(self):
    return self._v

  def __bool__(self):
    return self._v != 0

  def __lt__(self, other):
    return self._v < other.value()

  def __gt__(self, other):
    return self._v > other.value()

class ValNul(Val):
  def value(self):
    return None

  def __bool__(self):
    raise CentvrionError("NVLLVS cannot be evaluated as a boolean")

class ValFunc(Val):
  def __init__(self, params: list, body: list):
    self._params = params
    self._body = body

  def value(self):
    return (self._params, self._body)

  @property
  def params(self):
    return self._params

  @property
  def body(self):
    return self._body