import gzip
import io
import zipfile
from email.message import EmailMessage
from pathlib import Path

import pytest

from app.attachment_extractor import AttachmentExtractionError, extract_dmarc_attachments, extract_payload


def _xml() -> bytes:
    return Path("tests/fixtures/sample_dmarc.xml").read_bytes()


def test_gzip_attachment_extraction():
    gz = gzip.compress(_xml())
    reports = extract_payload("report.xml.gz", "application/octet-stream", gz, 20)

    assert len(reports) == 1
    assert reports[0].payload.startswith(b"<?xml")
    assert len(reports[0].sha256) == 64


def test_zip_attachment_extraction_rejects_traversal():
    buf = io.BytesIO()
    with zipfile.ZipFile(buf, "w") as archive:
        archive.writestr("report.xml", _xml())
        archive.writestr("../evil.xml", _xml())

    with pytest.raises(AttachmentExtractionError, match="unsafe zip path"):
        extract_payload("reports.zip", "application/zip", buf.getvalue(), 20)


def test_zip_attachment_extraction_rejects_nested_archives():
    buf = io.BytesIO()
    with zipfile.ZipFile(buf, "w") as archive:
        archive.writestr("nested.zip", b"not allowed")

    with pytest.raises(AttachmentExtractionError, match="nested archive"):
        extract_payload("reports.zip", "application/zip", buf.getvalue(), 20)


def test_zip_attachment_extraction_caps_reports_per_archive():
    buf = io.BytesIO()
    with zipfile.ZipFile(buf, "w") as archive:
        archive.writestr("one.xml", _xml())
        archive.writestr("two.xml", _xml())

    with pytest.raises(AttachmentExtractionError, match="archive XML report limit"):
        extract_payload("reports.zip", "application/zip", buf.getvalue(), 20, max_reports_per_archive=1)


def test_message_attachment_detection_with_octet_stream_valid_filename():
    msg = EmailMessage()
    msg["Subject"] = "Report domain tukutoi.com"
    msg.set_content("attached")
    msg.add_attachment(gzip.compress(_xml()), maintype="application", subtype="octet-stream", filename="report.gz")

    reports = extract_dmarc_attachments(msg, 20)

    assert len(reports) == 1