/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

package com.hw.langchain.chains.prompt.selector;

import com.hw.langchain.base.language.BaseLanguageModel;
import com.hw.langchain.prompts.base.BasePromptTemplate;

import org.apache.commons.lang3.tuple.Pair;

import java.util.List;
import java.util.function.Predicate;

/**
 * Prompt collection that goes through conditionals.
 *
 * @author HamaWhite
 */
public class ConditionalPromptSelector extends BasePromptSelector {

    private final BasePromptTemplate defaultPrompt;

    private final List<Pair<Predicate<BaseLanguageModel>, BasePromptTemplate>> conditionals;

    public ConditionalPromptSelector(BasePromptTemplate defaultPrompt,
            List<Pair<Predicate<BaseLanguageModel>, BasePromptTemplate>> conditionals) {
        this.defaultPrompt = defaultPrompt;
        this.conditionals = conditionals;
    }

    @Override
    public BasePromptTemplate getPrompt(BaseLanguageModel llm) {
        for (var condition : conditionals) {
            if (condition.getLeft().test(llm)) {
                return condition.getRight();
            }
        }
        return defaultPrompt;
    }
}
