"""Bounded regressions for upload-parser advisories, without hostile large allocations."""

import io
import struct
import subprocess
import sys
import zlib

import pytest
from PIL import Image


def test_truncated_pdf_xref_finishes_without_exhausting_parser_timeout():
    # GHSA-39mj-jf6j-2qj3: an incomplete xref's final short line must not spin.
    script = """
import io
from pypdf import PdfReader
from pypdf.errors import PdfReadError
body = b'%PDF-1.0\\n 1 0 obj<</Type/Catalog/Pages 2 0 R>>endobj\\n 2 0 obj<</Type/Pages/Kids[]/Count 0>>endobj\\n'
tail = b'\\n startxref\\n%d\\n%%%%EOF' % len(body)
try:
    PdfReader(io.BytesIO(body + b'xref\\n 0 3\\n 0000000000 65535 f \\n' + tail))
except PdfReadError:
    print('rejected')
else:
    raise AssertionError('Incomplete xref was accepted')
"""
    result = subprocess.run([sys.executable, "-c", script], capture_output=True, text=True, timeout=5)
    assert result.returncode == 0, result.stderr
    assert result.stdout.strip() == "rejected"


def test_apng_rejects_oversized_canvas_before_background_allocation(monkeypatch):
    # GHSA-5xm2-6676-qcp9, scaled to64 pixels so the RED case stays harmless.
    def chunk(kind, data):
        return struct.pack(">I", len(data)) + kind + data + struct.pack(">I", zlib.crc32(kind + data))

    png = (
        b"\x89PNG\r\n\x1a\n"
        + chunk(b"IHDR", struct.pack(">IIBBBBB", 8, 8, 8, 6, 0, 0, 0))
        + chunk(b"acTL", struct.pack(">II", 2, 0))
        + chunk(b"fcTL", struct.pack(">IIIIIHHBB", 0, 1, 1, 0, 0, 1, 10, 1, 0))
        + chunk(b"IDAT", zlib.compress(b"\x00\x00\x00\x00\x00"))
        + chunk(b"IEND", b"")
    )
    monkeypatch.setattr(Image, "MAX_IMAGE_PIXELS", 16)
    fills = []
    original_fill = Image.core.fill

    def record_fill(mode, size, *args):
        fills.append(size)
        return original_fill(mode, size, *args)

    monkeypatch.setattr(Image.core, "fill", record_fill)
    with pytest.raises(Image.DecompressionBombError):
        Image.open(io.BytesIO(png))
    assert (8, 8) not in fills, "An oversized canvas was allocated before bomb rejection"