java-tutorials/libraries-llms/src/test/java/com/baeldung/langchain/ChainWithDocumentLiveTest.java

package com.baeldung.langchain;

import static dev.langchain4j.data.document.FileSystemDocumentLoader.loadDocument;
import static dev.langchain4j.model.openai.OpenAiModelName.GPT_3_5_TURBO;
import static java.time.Duration.ofSeconds;
import static java.util.stream.Collectors.joining;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Logger;

import org.junit.Assert;
import org.junit.Test;

import dev.langchain4j.data.document.Document;
import dev.langchain4j.data.document.DocumentSplitter;
import dev.langchain4j.data.document.splitter.DocumentSplitters;
import dev.langchain4j.data.embedding.Embedding;
import dev.langchain4j.data.message.AiMessage;
import dev.langchain4j.data.segment.TextSegment;
import dev.langchain4j.model.chat.ChatLanguageModel;
import dev.langchain4j.model.embedding.AllMiniLmL6V2EmbeddingModel;
import dev.langchain4j.model.embedding.EmbeddingModel;
import dev.langchain4j.model.input.Prompt;
import dev.langchain4j.model.input.PromptTemplate;
import dev.langchain4j.model.openai.OpenAiChatModel;
import dev.langchain4j.model.openai.OpenAiTokenizer;
import dev.langchain4j.store.embedding.EmbeddingMatch;
import dev.langchain4j.store.embedding.EmbeddingStore;
import dev.langchain4j.store.embedding.inmemory.InMemoryEmbeddingStore;

public class ChainWithDocumentLiveTest {

    @Test
    public void givenChainWithDocument_whenPrompted_thenValidResponse() {

        Document document = loadDocument(toPath("src/test/resources/example-files/simpson's_adventures.txt"));
        DocumentSplitter splitter = DocumentSplitters.recursive(100, 0, new OpenAiTokenizer(GPT_3_5_TURBO));
        List<TextSegment> segments = splitter.split(document);

        EmbeddingModel embeddingModel = new AllMiniLmL6V2EmbeddingModel();
        List<Embedding> embeddings = embeddingModel.embedAll(segments)
            .content();
        EmbeddingStore<TextSegment> embeddingStore = new InMemoryEmbeddingStore<>();
        embeddingStore.addAll(embeddings, segments);

        String question = "Who is Simpson?";
        Embedding questionEmbedding = embeddingModel.embed(question)
            .content();
        int maxResults = 3;
        double minScore = 0.7;
        List<EmbeddingMatch<TextSegment>> relevantEmbeddings = embeddingStore.findRelevant(questionEmbedding, maxResults, minScore);

        PromptTemplate promptTemplate = PromptTemplate.from("Answer the following question to the best of your ability:\n" + "\n" + "Question:\n" + "{{question}}\n" + "\n" + "Base your answer on the following information:\n" + "{{information}}");

        String information = relevantEmbeddings.stream()
            .map(match -> match.embedded()
                .text())
            .collect(joining("\n\n"));

        Map<String, Object> variables = new HashMap<>();
        variables.put("question", question);
        variables.put("information", information);

        Prompt prompt = promptTemplate.apply(variables);
        ChatLanguageModel chatModel = OpenAiChatModel.builder()
            .apiKey(Constants.OPEN_API_KEY)
            .timeout(ofSeconds(60))
            .build();
        AiMessage aiMessage = chatModel.generate(prompt.toUserMessage())
            .content();

        Logger.getGlobal()
            .info(aiMessage.text());
        Assert.assertNotNull(aiMessage.text());

    }

    private static Path toPath(String fileName) {
        try {
            URL fileUrl = new File(fileName).toURI()
                .toURL();
            System.out.println(new File(fileName).toURI()
                .toURL());
            return Paths.get(fileUrl.toURI());
        } catch (URISyntaxException | MalformedURLException e) {
            throw new RuntimeException(e);
        }
    }

}