from langchain_core.documents import Document

from langchain_classic.retrievers.document_compressors.listwise_rerank import (
    LLMListwiseRerank,
)


def test_list_rerank() -> None:
    from langchain_openai import ChatOpenAI

    documents = [
        Document("Sally is my friend from school"),
        Document("Steve is my friend from home"),
        Document("I didn't always like yogurt"),
        Document("I wonder why it's called football"),
        Document("Where's waldo"),
    ]

    reranker = LLMListwiseRerank.from_llm(
        llm=ChatOpenAI(model="gpt-4.1-mini"),
        top_n=3,
    )
    compressed_docs = reranker.compress_documents(documents, "Who is steve")
    assert len(compressed_docs) == 3
    assert "Steve" in compressed_docs[0].page_content
