import time
from pathlib import Path
from astroparse_api.parse import segment_markdown, parse_pdf, _pathological_pages


# ---------------------------------------------------------------------------
# Bug A: strip_picture_text
# ---------------------------------------------------------------------------

def test_picture_text_blocks_filtered():
    from astroparse_api.parse import strip_picture_text
    lines = ["Real prose before.", "**----- Begin of picture text -----**",
             "z = 5.0 z = 4.0", "1.5", "R [kpc]",
             "**----- End of picture text -----**", "Real prose after."]
    assert strip_picture_text(lines) == ["Real prose before.", "Real prose after."]


def test_picture_text_start_end_variants():
    """Handles 'Start of picture text' / 'End of picture text' (pymupdf4llm 1.27.x)."""
    from astroparse_api.parse import strip_picture_text
    lines = [
        "Prose A.",
        "**----- Start of picture text -----**<br>",
        "axis label stuff<br>more axis<br>**----- End of picture text -----**<br>",
        "Prose B.",
    ]
    result = strip_picture_text(lines)
    assert result == ["Prose A.", "Prose B."]


def test_picture_text_multiline_block():
    """Handles multi-line blocks between start/end markers."""
    from astroparse_api.parse import strip_picture_text
    lines = [
        "Before.",
        "**----- Start of picture text -----**<br>",
        "z = 5.0 z = 4.0",
        "1.5",
        "R [kpc]",
        "**----- End of picture text -----**<br>",
        "After.",
    ]
    result = strip_picture_text(lines)
    assert result == ["Before.", "After."]


# ---------------------------------------------------------------------------
# Bug B: demarkdown
# ---------------------------------------------------------------------------

def test_demarkdown_cleans_math_debris():
    from astroparse_api.parse import demarkdown
    t = ("with a peak at _z ≈_ 4, masses between 5 _._ 7 _×_ 10[5] M _⊙_ and "
         "2 _._ 5 _×_ 10[11] M _⊙_ .")
    out = demarkdown(t)
    assert "_" not in out and "**" not in out
    assert "5.7×10⁵" in out and "2.5×10¹¹" in out and "M ⊙" in out


def test_demarkdown_bold_stripped():
    from astroparse_api.parse import demarkdown
    t = "This is **very important** and _emphasized_ text."
    out = demarkdown(t)
    assert "**" not in out and "_" not in out
    assert "very important" in out and "emphasized" in out


def test_demarkdown_backtick_stripped():
    from astroparse_api.parse import demarkdown
    t = "Use `code` here."
    out = demarkdown(t)
    assert "`" not in out
    assert "code" in out


def test_demarkdown_bracketed_exponents():
    from astroparse_api.parse import demarkdown
    assert "10⁵" in demarkdown("10[5]")
    assert "10¹¹" in demarkdown("10[11]")
    assert "10⁰" in demarkdown("10[0]")


# ---------------------------------------------------------------------------
# Bug B2: merge open-sentence continuations
# ---------------------------------------------------------------------------

def test_merge_continuation_after_open_sentence():
    # First half ends without terminal punctuation ("and"), second half starts with digit.
    # Second half is >= _MIN_PARA so len heuristic alone would NOT merge it.
    # Only the open-sentence rule (prev doesn't end with terminal punct) should merge it.
    first_half = "Alpha beta gamma delta epsilon zeta eta theta iota kappa lambda mu nu xi. " * 3
    first_half += "masses between five and"  # no terminal punctuation — ends open
    # second_half starts with "2" (digit, not lowercase) and is >= 200 chars
    second_half = ("2.5 something more here delta epsilon zeta eta theta "
                   "iota kappa lambda mu nu. " * 4)

    md = "## S\n\n" + first_half + "\n\n" + second_half
    paras, _ = segment_markdown(md)
    # Digit-starting continuation merged because prev para ended mid-sentence
    assert len(paras) == 1, (
        f"Expected 1 merged paragraph, got {len(paras)}: "
        + str([p['text'][:80] for p in paras])
    )

FIXTURE = Path(__file__).parent / "fixtures" / "mowla_iyer_2024.pdf"

MD = """# The Firefly Sparkle

## Introduction

""" + ("First intro paragraph. " * 15) + """

""" + ("Second intro paragraph. " * 15) + """

## Methods

""" + ("Methods paragraph here. " * 15) + """

**Figure 1.** A caption that should be dropped.

## References

[1] Someone et al. 2020
"""

def test_segment_basic():
    paras, _ = segment_markdown(MD)
    sections = [p["section"] for p in paras]
    assert sections == ["Introduction", "Introduction", "Methods"]
    assert paras[0]["firstOfSection"] and not paras[1]["firstOfSection"]
    assert paras[2]["firstOfSection"]
    assert paras[0]["id"] == "p1"
    assert all(len(p["text"]) >= 200 for p in paras)

def test_segment_drops_captions_and_references():
    paras, raw_refs = segment_markdown(MD)
    joined = " ".join(p["text"] for p in paras)
    assert "Figure 1" not in joined
    assert "Someone et al" not in joined      # not in paras
    assert "Someone et al" in raw_refs        # but captured in raw_refs

def test_parse_pdf_fixture():
    paper, _ = parse_pdf(FIXTURE.read_bytes(), "mowla_iyer_2024.pdf")
    assert 10 <= len(paper.paragraphs) <= 80
    assert paper.pages >= 10
    assert "firefly" in paper.title.lower() or len(paper.title) > 10


def test_segment_drops_author_affiliation_block():
    md = """# A Great Paper

F.RENAUD[1] _[,]_[ 2] , K. KRALJIC[1] , J. FREUNDLICH[1] , B. MAGNELLI[3] , M. BÉTHERMIN[1] , C. ACCARD[1] , D. ISMAIL[1] , E. DADDI[3] , D. ELBAZ[3] , L. CIESLA[4] , G. MARTIN[5] , Y. DUBOIS[6] , S. PEIRANI[7]
> 1 _Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS UMR 7550, 11 rue de l'Université, F-67000 Strasbourg, France_
> 2 _University of Strasbourg Institute for Advanced Study, 5 allée du Général Rouvillois, F-67083 Strasbourg, France_

## ABSTRACT

""" + ("Star-forming galaxies spend most of their lifetimes on the main sequence of star formation. " * 4)
    paras, _ = segment_markdown(md)
    joined = " ".join(p["text"] for p in paras)
    assert "KRALJIC" not in joined and "Observatoire" not in joined
    assert any("Star-forming galaxies" in p["text"] for p in paras)


def test_clean_authors_three_plus_et_al():
    from astroparse_api.parse import _clean_authors
    raw = "F.RENAUD[1] _[,]_[ 2] , K. KRALJIC[1] , J. FREUNDLICH[1] , B. MAGNELLI[3] , M. BÉTHERMIN[1]"
    assert _clean_authors(raw) == "F.RENAUD, K. KRALJIC, J. FREUNDLICH et al."


def test_clean_authors_short_list_unchanged():
    from astroparse_api.parse import _clean_authors
    assert _clean_authors("A. One, B. Two") == "A. One, B. Two"


# ---------------------------------------------------------------------------
# Pathological-page detection unit tests
# ---------------------------------------------------------------------------

def test_pathological_pages_detects_large_stream():
    """_pathological_pages returns the index of a page whose content stream
    exceeds _MAX_PAGE_STREAM_BYTES (8 MB).  We duck-type a minimal fake doc."""
    from astroparse_api.parse import _MAX_PAGE_STREAM_BYTES

    class _FakePage:
        def __init__(self, size: int):
            self._size = size
        def read_contents(self) -> bytes:
            return b"x" * self._size

    class _FakeDoc:
        def __init__(self, sizes):
            self._pages = [_FakePage(s) for s in sizes]
        def __iter__(self):
            return iter(self._pages)

    # One small page, one huge page, one small page
    sizes = [100, _MAX_PAGE_STREAM_BYTES + 1, 200]
    doc = _FakeDoc(sizes)
    bad = _pathological_pages(doc)
    assert bad == {1}, f"Expected {{1}}, got {bad}"


def test_pathological_pages_empty_when_all_small():
    """_pathological_pages returns empty set when all pages are below threshold."""
    from astroparse_api.parse import _MAX_PAGE_STREAM_BYTES

    class _FakePage:
        def __init__(self, size: int):
            self._size = size
        def read_contents(self) -> bytes:
            return b"x" * self._size

    class _FakeDoc:
        def __init__(self, sizes):
            self._pages = [_FakePage(s) for s in sizes]
        def __iter__(self):
            return iter(self._pages)

    sizes = [100, _MAX_PAGE_STREAM_BYTES - 1, 200]
    doc = _FakeDoc(sizes)
    bad = _pathological_pages(doc)
    assert bad == set(), f"Expected empty set, got {bad}"


# ---------------------------------------------------------------------------
# Feature: parse_text — plaintext/markdown input
# ---------------------------------------------------------------------------

_MD_DOC = """# Galactic Winds in Starburst Galaxies

## Introduction

""" + ("Galaxy-scale winds driven by stellar feedback are a key mechanism for regulating " * 15) + """

""" + ("The outflow rates in starburst systems can exceed the star formation rate by factors " * 15) + """

## References

[1] Veilleux et al. 2005
[2] Rupke & Veilleux 2011
"""

def test_parse_text_title_from_heading():
    from astroparse_api.parse import parse_text
    result, _ = parse_text(_MD_DOC.encode(), "notes.md")
    assert result.title == "Galactic Winds in Starburst Galaxies"


def test_parse_text_two_paragraphs():
    from astroparse_api.parse import parse_text
    result, _ = parse_text(_MD_DOC.encode(), "notes.md")
    assert len(result.paragraphs) == 2


def test_parse_text_sections_correct():
    from astroparse_api.parse import parse_text
    result, _ = parse_text(_MD_DOC.encode(), "notes.md")
    assert all(p.section == "Introduction" for p in result.paragraphs)


def test_parse_text_references_dropped():
    from astroparse_api.parse import parse_text
    result, _ = parse_text(_MD_DOC.encode(), "notes.md")
    joined = " ".join(p.text for p in result.paragraphs)
    assert "Veilleux" not in joined


def test_parse_text_pages_zero_authors_empty():
    from astroparse_api.parse import parse_text
    result, _ = parse_text(_MD_DOC.encode(), "notes.md")
    assert result.pages == 0
    assert result.authors == ""


def test_parse_text_title_fallback_to_stem():
    from astroparse_api.parse import parse_text
    # No heading — falls back to stem of filename
    plain = ("A " + "paragraph without any heading content describing galaxies " * 20)
    result, _ = parse_text(plain.encode(), "my_draft.txt")
    assert result.title == "my_draft"


def test_parse_text_arxiv_from_filename():
    from astroparse_api.parse import parse_text
    result, _ = parse_text(_MD_DOC.encode(), "2402.08696.md")
    assert result.arxivId == "2402.08696"


def test_parse_text_utf8_replace_on_bad_bytes():
    from astroparse_api.parse import parse_text
    # Inject a Latin-1 byte that isn't valid UTF-8, surrounded by valid UTF-8
    bad = b"# My Title\n\n" + b"Good text here. " * 20 + b"\xff" + b" more text. " * 10
    result, _ = parse_text(bad, "test.md")
    assert result.title == "My Title"


def test_pathological_pages_handles_read_contents_exception():
    """_pathological_pages silently skips pages where read_contents raises."""
    class _FaultyPage:
        def read_contents(self):
            raise RuntimeError("PDF error")

    class _FakeDoc:
        def __iter__(self):
            return iter([_FaultyPage()])

    bad = _pathological_pages(_FakeDoc())
    assert bad == set()


# ---------------------------------------------------------------------------
# Integration test: real pathological PDF
# ---------------------------------------------------------------------------

def test_parse_pdf_handles_vector_heavy_pages():
    """parse_pdf completes within 60s on the JWST paper (page 3 has 65 MB
    vector drawings that previously caused pymupdf4llm to run for 400+s)."""
    pdf = Path(__file__).parent.parent.parent / "test_papers" / "s41586-024-08293-0.pdf"
    if not pdf.exists():
        import pytest
        pytest.skip("test paper not present")
    t0 = time.time()
    paper, _ = parse_pdf(pdf.read_bytes(), pdf.name)
    elapsed = time.time() - t0
    assert elapsed < 60, f"parse_pdf took {elapsed:.1f}s — expected < 60s"
    assert len(paper.paragraphs) >= 30, (
        f"Expected >= 30 paragraphs, got {len(paper.paragraphs)}"
    )
    joined = " ".join(p.text for p in paper.paragraphs)
    assert (
        "Firefly" in paper.title
        or "Firefly" in joined
        or len(joined) > 10000
    ), "Expected Firefly Sparkle content or substantial text"


# --- Fix 0.1: pending-head buffer saves section openers ---
def test_pending_buffer_saves_section_opener():
    """A short block at a section boundary should be kept, not dropped."""
    short_opener = "We begin with a key observation here."  # < 200 chars
    long_body = "The stellar mass function at high redshift is uncertain. " * 6
    md = f"## Section A\n\n{short_opener}\n\n{long_body}"
    paras, _ = segment_markdown(md)
    joined = " ".join(p["text"] for p in paras)
    assert "key observation" in joined, "short section opener was dropped (pending buffer failed)"

# --- Fix 0.2: skip-and-resume keeps appendix content ---
def test_references_captured_and_appendix_preserved():
    """Content after the References heading, in an Appendix, should appear in paras."""
    body = "Star-forming galaxies remain on the main sequence for extended periods. " * 5
    ref_body = "[1] Smith et al. 2020 ApJ 900 1"
    appendix_body = "This appendix derives the mass-to-light ratio correction. " * 5
    md = (
        f"## Introduction\n\n{body}\n\n"
        f"## References\n\n{ref_body}\n\n"
        f"## Appendix A\n\n{appendix_body}"
    )
    paras, raw_refs = segment_markdown(md)
    joined = " ".join(p["text"] for p in paras)
    assert "mass-to-light ratio" in joined, "appendix content was discarded after References"
    assert "Smith et al." in raw_refs, "raw_refs should contain references section text"

# --- Fix 0.3: headings chain attached to paragraphs ---
def test_headings_chain_on_paragraph():
    """First paragraph under a heading should carry the heading in its headings list."""
    body = "Galaxy evolution proceeds through mergers and secular processes. " * 5
    md = f"## Methods\n\n{body}"
    paras, _ = segment_markdown(md)
    assert len(paras) == 1
    assert "Methods" in paras[0]["headings"]

def test_headings_chain_consecutive_headings():
    """Two consecutive headings both appear in the next paragraph's headings list."""
    body = "The SFR surface density is measured from UV continuum emission. " * 5
    md = f"## Results\n\n### 3.1 Star Formation\n\n{body}"
    paras, _ = segment_markdown(md)
    assert len(paras) == 1
    assert paras[0]["headings"] == ["Results", "3.1 Star Formation"]

# --- Fix 0.4: heading hygiene ---
def test_heading_hygiene_filters_page_numbers():
    """A heading shaped like '456 K. G. Iyer et al.' should be discarded."""
    body = "Outflow rates exceed the star formation rate in starburst systems. " * 5
    md = (
        "## Introduction\n\n" + body +
        "\n\n## 456 K. G. Iyer et al.\n\n" +
        "## Results\n\n" + body
    )
    paras, _ = segment_markdown(md)
    sections = [p["section"] for p in paras]
    assert "456 K. G. Iyer et al." not in sections

# --- Fix 0.5: caption gate allows figure-referencing prose ---
def test_caption_gate_allows_figure_prose():
    """'Figure 4 shows that the fraction...' is prose and must not be dropped."""
    prose = ("Figure 4 shows that the fraction of star-forming galaxies decreases "
             "sharply above a stellar mass of 10^10.5 solar masses, consistent with "
             "quenching operating preferentially at the high-mass end of the distribution "
             "and in dense environments where AGN feedback is more effective.")
    md = "## Results\n\n" + prose
    paras, _ = segment_markdown(md)
    assert any("fraction of star-forming galaxies" in p["text"] for p in paras), \
        "caption gate dropped figure-referencing prose"

def test_caption_gate_still_drops_real_captions():
    """'Figure 4. The fraction...' is a caption and should be dropped."""
    caption = "Figure 4. The fraction of star-forming galaxies as a function of stellar mass."
    body = "Galaxy stellar mass functions have been measured across cosmic time. " * 5
    md = f"## Results\n\n{body}\n\n{caption}"
    paras, _ = segment_markdown(md)
    joined = " ".join(p["text"] for p in paras)
    assert "The fraction of star-forming galaxies as a function" not in joined

def test_heading_not_leaked_from_empty_section():
    """Headings from a section with no prose don't appear in the next section's paragraph."""
    body = "The stellar mass function evolves significantly from z=2 to the present day. " * 5
    # Ghost section has no content (heading immediately followed by another heading)
    md = "## Ghost Section\n\n## Real Section\n\n" + body
    paras, _ = segment_markdown(md)
    assert len(paras) == 1
    # "Ghost Section" must NOT appear in the paragraph's headings
    assert "Ghost Section" not in paras[0]["headings"], \
        f"Ghost Section leaked into headings: {paras[0]['headings']}"
    assert "Real Section" in paras[0]["headings"]


# --- Fix 0.6: length measured post-demarkdown ---
def test_length_measured_post_demarkdown():
    """A paragraph with heavy markdown markup that is still >= 200 chars after demarkdown must survive."""
    # Raw text has lots of emphasis markers; after demarkdown the content is still >= 200 chars.
    core = ("_z_ ≈ 3 sources show Lyman-alpha emission tracing the neutral hydrogen distribution "
            "in high-redshift galaxies at cosmic noon. "
            "The _flux_ calibration introduces _systematic_ uncertainties of order 10 per cent, "
            "which must be accounted for in the _stellar mass_ estimates.")
    md = "## Discussion\n\n" + core
    paras, _ = segment_markdown(md)
    assert len(paras) == 1, "post-demarkdown paragraph was dropped by length gate"