import pytest

from splitter_mr.splitter import ParagraphSplitter


@pytest.fixture
def reader_output():
    # 5 paragraphs, mixed line breaks
    return {
        "text": (
            "Para1 first sentence. Para1 second sentence.\n"
            "Para2 here.\n"
            "Para3 is this line.\n"
            "Para4 once more.\n"
            "Para5 and last."
        ),
        "document_name": "sample.txt",
        "document_path": "/tmp/sample.txt",
        "document_id": "123",
        "conversion_method": "text",
        "ocr_method": None,
    }


def test_basic_split(reader_output):
    splitter = ParagraphSplitter(chunk_size=2, chunk_overlap=0)
    result = splitter.split(reader_output)
    assert "chunks" in result
    assert (
        result["chunks"][0]
        == "Para1 first sentence. Para1 second sentence.\nPara2 here."
    )
    assert result["chunks"][1] == "Para3 is this line.\nPara4 once more."
    assert result["chunks"][2] == "Para5 and last."
    assert result["split_method"] == "paragraph_splitter"
    assert result["split_params"]["chunk_size"] == 2
    assert result["split_params"]["chunk_overlap"] == 0


def test_split_with_overlap_int(reader_output):
    splitter = ParagraphSplitter(chunk_size=2, chunk_overlap=3)
    result = splitter.split(reader_output)
    # Each chunk after the first should start with the last 3 words of the previous chunk
    first_chunk = result["chunks"][0]
    second_chunk = result["chunks"][1]
    first_words = first_chunk.split()[-3:]
    assert " ".join(first_words) in second_chunk


def test_split_with_overlap_float(reader_output):
    splitter = ParagraphSplitter(chunk_size=2, chunk_overlap=0.5)
    result = splitter.split(reader_output)
    # overlap = int(max_para_words * 0.5)
    # Let's check that overlap words of the previous chunk are present in the next chunk
    if len(result["chunks"]) > 1:
        prev_words = result["chunks"][0].split()
        overlap = set(prev_words) & set(result["chunks"][1].split())
        assert len(overlap) >= 1


def test_custom_linebreak():
    text = "P1||P2||P3"
    reader_output = {"text": text, "document_path": "/tmp/sample.txt"}
    splitter = ParagraphSplitter(chunk_size=2, chunk_overlap=0, line_break="||")
    result = splitter.split(reader_output)
    assert result["chunks"][0] == "P1||P2"
    assert result["chunks"][1] == "P3"


def test_output_contains_metadata(reader_output):
    splitter = ParagraphSplitter(chunk_size=2, chunk_overlap=0)
    result = splitter.split(reader_output)
    for field in [
        "chunks",
        "chunk_id",
        "document_name",
        "document_path",
        "document_id",
        "conversion_method",
        "ocr_method",
        "split_method",
        "split_params",
        "metadata",
    ]:
        assert field in result


def test_empty_text():
    splitter = ParagraphSplitter(chunk_size=2, chunk_overlap=0)
    reader_output = {"text": ""}
    result = splitter.split(reader_output)
    assert result["chunks"] == []
