# 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.

import re


def extract_solution(solution_str, method="strict"):
    assert method in ["strict", "flexible"]

    if method == "strict":
        # this also tests the formatting of the model
        solutions = re.findall("#### (\\-?[0-9\\.\\,]+)", solution_str)
        if len(solutions) == 0:
            final_answer = None
        else:
            # take the last solution
            final_answer = solutions[-1].replace(",", "").replace("$", "")
    elif method == "flexible":
        answer = re.findall("(\\-?[0-9\\.\\,]+)", solution_str)
        final_answer = None
        if len(answer) == 0:
            # no reward is there is no answer
            pass
        else:
            invalid_str = ["", "."]
            # find the last number that is not '.'
            for final_answer in reversed(answer):
                if final_answer not in invalid_str:
                    break
    return final_answer
