"""Tests for the document chunking pipeline."""

from __future__ import annotations

from openjarvis.tools.storage.chunking import ChunkConfig, chunk_text


def test_empty_string_returns_empty():
    assert chunk_text("") == []


def test_whitespace_only_returns_empty():
    assert chunk_text("   \n\n  ") == []


def test_short_text_single_chunk():
    # Need >= 50 words (default min_chunk_size)
    words = [f"word{i}" for i in range(60)]
    text = " ".join(words)
    chunks = chunk_text(text, source="test.txt")
    assert len(chunks) == 1
    assert chunks[0].source == "test.txt"
    assert chunks[0].index == 0
    assert "word0" in chunks[0].content


def test_long_text_multiple_chunks():
    # Build text that exceeds 512 tokens
    words = [f"word{i}" for i in range(600)]
    text = " ".join(words)
    chunks = chunk_text(text)
    assert len(chunks) >= 2


def test_chunk_overlap():
    cfg = ChunkConfig(chunk_size=100, chunk_overlap=20, min_chunk_size=5)
    words = [f"w{i}" for i in range(250)]
    text = " ".join(words)
    chunks = chunk_text(text, config=cfg)
    assert len(chunks) >= 2

    # The end of chunk 0 and start of chunk 1 should overlap
    first_tokens = chunks[0].content.split()
    second_tokens = chunks[1].content.split()
    tail = first_tokens[-20:]
    head = second_tokens[:20]
    assert tail == head


def test_paragraph_boundary_respected():
    cfg = ChunkConfig(chunk_size=20, chunk_overlap=0, min_chunk_size=3)
    para1 = " ".join(f"a{i}" for i in range(10))
    para2 = " ".join(f"b{i}" for i in range(10))
    text = f"{para1}\n\n{para2}"
    chunks = chunk_text(text, config=cfg)
    # Both paragraphs fit in one chunk (10 + 10 = 20 <= 20)
    assert len(chunks) == 1


def test_custom_config():
    cfg = ChunkConfig(chunk_size=50, chunk_overlap=10, min_chunk_size=5)
    words = [f"tok{i}" for i in range(200)]
    text = " ".join(words)
    chunks = chunk_text(text, config=cfg)
    # Should produce multiple chunks
    assert len(chunks) >= 3


def test_short_only_document_not_dropped():
    """A whole document below min_chunk_size must still produce a chunk.

    Regression for #502 follow-up: previously a folder of short notes indexed
    to ``chunks_indexed: 0`` (HTTP 200), silently storing nothing. ``min_chunk_size``
    should only discard tiny *trailing fragments*, never an entire short doc.
    """
    cfg = ChunkConfig(chunk_size=100, chunk_overlap=0, min_chunk_size=50)
    # 30 words is below min_chunk_size=50, but it's the entire document.
    words = [f"w{i}" for i in range(30)]
    text = " ".join(words)
    chunks = chunk_text(text, config=cfg)
    assert len(chunks) == 1
    assert chunks[0].content == text


def test_short_real_world_note_not_dropped():
    """The exact repro from the issue: a ~4-word note must not vanish."""
    chunks = chunk_text("hello world\nsome content\n", source="a.txt")
    assert len(chunks) == 1
    assert "hello world" in chunks[0].content


def test_min_chunk_size_filters_tiny_trailing_fragment():
    """A tiny fragment trailing a real chunk is still dropped by the floor."""
    cfg = ChunkConfig(chunk_size=50, chunk_overlap=0, min_chunk_size=10)
    # Two paragraphs: the first fills a real chunk, the second is a tiny tail.
    para1 = " ".join(f"a{i}" for i in range(50))
    para2 = " ".join(f"b{i}" for i in range(3))  # 3 words < min_chunk_size=10
    text = f"{para1}\n\n{para2}"
    chunks = chunk_text(text, config=cfg)
    # The 3-word trailing fragment is discarded; only the real chunk remains.
    assert len(chunks) == 1
    assert "b0" not in chunks[0].content


def test_source_propagated():
    words = [f"word{i}" for i in range(60)]
    text = " ".join(words)
    chunks = chunk_text(text, source="myfile.md")
    assert len(chunks) == 1
    assert chunks[0].source == "myfile.md"


def test_chunk_index_sequential():
    cfg = ChunkConfig(chunk_size=50, chunk_overlap=0, min_chunk_size=5)
    words = [f"w{i}" for i in range(200)]
    text = " ".join(words)
    chunks = chunk_text(text, config=cfg)
    for i, chunk in enumerate(chunks):
        assert chunk.index == i