# Copyright (c) 2025 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import annotations

from typing import Generic, TypeVar

_T = TypeVar("_T", "int", "float", "bool")


class SymbolicValue(Generic[_T]):
    example_value: _T | None

    def __init__(self, example_value=None):
        self.example_value = example_value

    def __repr__(self) -> str:
        if self.is_backed():
            return f"{self.__class__.__name__}({self.example_value})"
        return f"{self.__class__.__name__}()"

    def get_static_type(self) -> type[_T]:
        raise NotImplementedError("get_py_type is not implemented.")

    def is_backed(self):
        return self.example_value is not None

    def get_example_value(self) -> _T:
        if self.example_value is None:
            raise ValueError(f"{self} is not backed by a value.")
        return self.example_value


class SymbolicBool(SymbolicValue):
    def get_static_type(self) -> type[bool]:
        return bool


class SymbolicInt(SymbolicValue):
    def get_static_type(self) -> type[int]:
        return int


class SymbolicFloat(SymbolicValue):
    def get_static_type(self) -> type[float]:
        return float