from app.rag.chunking import TARGET_CHUNK_CHARS, chunk_markdown


def test_heading_paths_follow_hierarchy() -> None:
    md = (
        "Intro before any heading.\n\n"
        "## Wartung\n\nWöchentlich schmieren.\n\n"
        "### Schmierstoffe\n\nNur GX-220 verwenden.\n\n"
        "## Sicherheit\n\nLichtvorhang nie überbrücken.\n"
    )
    chunks = chunk_markdown(md, "Maschinenhandbuch")
    paths = [chunk.heading_path for chunk in chunks]
    assert paths == [
        "Maschinenhandbuch",
        "Maschinenhandbuch › Wartung",
        "Maschinenhandbuch › Wartung › Schmierstoffe",
        "Maschinenhandbuch › Sicherheit",
    ]
    assert "GX-220" in chunks[2].content


def test_leading_h1_equal_to_title_is_not_duplicated() -> None:
    md = "# Handbuch\n\nText direkt unter dem Titel.\n\n## Details\n\nMehr.\n"
    chunks = chunk_markdown(md, "Handbuch")
    assert chunks[0].heading_path == "Handbuch"
    assert chunks[1].heading_path == "Handbuch › Details"


def test_oversized_section_is_split_at_paragraphs() -> None:
    paragraph = "Absatz mit ausreichend vielen Wörtern für den Test. " * 20
    md = "## Lang\n\n" + "\n\n".join([paragraph] * 5)
    chunks = chunk_markdown(md, "Doc")
    assert len(chunks) > 1
    assert all(len(chunk.content) <= TARGET_CHUNK_CHARS + 100 for chunk in chunks)
    assert all(chunk.heading_path == "Doc › Lang" for chunk in chunks)


def test_code_fences_are_never_split() -> None:
    fence = "```\n" + "\n\n".join(["zeile eins", "zeile zwei", "zeile drei"]) + "\n```"
    filler = "Wort " * 500
    md = f"## Code\n\n{filler}\n\n{fence}\n\n{filler}"
    chunks = chunk_markdown(md, "Doc")
    fenced = [chunk for chunk in chunks if "```" in chunk.content]
    for chunk in fenced:
        assert chunk.content.count("```") % 2 == 0, "chunk split inside a fence"


def test_heading_inside_fence_is_not_a_section() -> None:
    md = "## Skript\n\n```\n# kein heading, nur ein Kommentar\necho hi\n```\n"
    chunks = chunk_markdown(md, "Doc")
    assert len(chunks) == 1
    assert chunks[0].heading_path == "Doc › Skript"


def test_empty_document_yields_no_chunks() -> None:
    assert chunk_markdown("", "Leer") == []
    assert chunk_markdown("\n\n   \n", "Leer") == []