"""Upload validation: size cap and PDF magic-byte check (SEC-06)."""

import asyncio
from io import BytesIO

import pytest
from fastapi import UploadFile

from app.uploads import read_pdf_upload


def make_upload(data: bytes, filename: str = "test.pdf") -> UploadFile:
    return UploadFile(file=BytesIO(data), filename=filename)


def test_valid_pdf_accepted():
    data = b"%PDF-1.7 fake content"
    out = asyncio.run(read_pdf_upload(make_upload(data)))
    assert out == data


def test_non_pdf_rejected_with_filename():
    with pytest.raises(ValueError, match=r"evil\.pdf: not a PDF"):
        asyncio.run(read_pdf_upload(make_upload(b"MZ\x90\x00binary", "evil.pdf")))


def test_oversized_rejected():
    big = b"%PDF" + b"x" * 100
    with pytest.raises(ValueError, match="exceeds the 0 MB limit"):
        asyncio.run(read_pdf_upload(make_upload(big), max_bytes=50))


def test_exact_limit_accepted():
    data = b"%PDF" + b"x" * 46  # exactly 50 bytes
    out = asyncio.run(read_pdf_upload(make_upload(data), max_bytes=50))
    assert len(out) == 50


def test_empty_file_rejected():
    with pytest.raises(ValueError, match="not a PDF"):
        asyncio.run(read_pdf_upload(make_upload(b"")))