"""PDF 下载测试 — download_pdf、路径工具、错误处理。"""

from __future__ import annotations

from unittest.mock import MagicMock, patch

import pytest

from app.services.pdf_downloader import (
    PdfDownloadError,
    download_pdf,
    paper_dir,
    tmp_dir,
)
from app.utils import PAPERS_DIR, TMP_DIR


# ═══════════════════════════════════════════════════════════════════════
# 路径工具
# ═══════════════════════════════════════════════════════════════════════


class TestPathHelpers:
    def test_paper_dir(self):
        assert paper_dir("2401.12345") == PAPERS_DIR / "2401.12345"

    def test_tmp_dir(self):
        assert tmp_dir("2401.12345") == TMP_DIR / "2401.12345"


# ═══════════════════════════════════════════════════════════════════════
# download_pdf
# ═══════════════════════════════════════════════════════════════════════


class TestDownloadPdf:
    @pytest.mark.asyncio
    async def test_success_download(self, tmp_path):
        mock_resp = MagicMock()
        mock_resp.content = b"%PDF-1.4 fake"
        mock_resp.raise_for_status = MagicMock()

        mock_session = MagicMock()
        mock_session.get.return_value = mock_resp

        with (
            patch("app.services.pdf_downloader.TMP_DIR", tmp_path),
            patch(
                "app.services.pdf_downloader._get_session", return_value=mock_session
            ),
        ):
            result = await download_pdf(
                "2401.12345", "https://arxiv.org/pdf/2401.12345.pdf"
            )

        assert result.exists()
        assert result.name == "paper.pdf"
        assert result.read_bytes() == b"%PDF-1.4 fake"

    @pytest.mark.asyncio
    async def test_empty_pdf_url_raises(self):
        with pytest.raises(PdfDownloadError, match="no pdf_url"):
            await download_pdf("2401.12345", "")

    @pytest.mark.asyncio
    async def test_http_failure_raises(self, tmp_path):
        mock_session = MagicMock()
        mock_session.get.side_effect = ConnectionError("refused")

        with (
            patch("app.services.pdf_downloader.TMP_DIR", tmp_path),
            patch(
                "app.services.pdf_downloader._get_session", return_value=mock_session
            ),
        ):
            with pytest.raises(PdfDownloadError, match="failed to download"):
                await download_pdf("2401.12345", "https://bad.url/pdf.pdf")