from __future__ import annotations


def test_document_upload_extracts_and_chunks_text_file(client) -> None:
    response = client.post(
        "/documents/upload",
        data={
            "title": "Upload smoke test",
            "subject": "Biology",
            "chapter": "Photosynthesis",
        },
        files={
            "file": (
                "photosynthesis.txt",
                b"Photosynthesis uses light to make glucose and oxygen.",
                "text/plain",
            ),
        },
    )

    assert response.status_code == 201
    payload = response.json()
    assert payload["status"] == "ready"
    assert payload["chunk_count"] >= 1
    # extracted_text was removed from API response (security hardening)
    assert "extracted_text" not in payload


def test_document_upload_returns_failed_document_when_indexing_fails(client, monkeypatch) -> None:
    from app.routes import documents

    def fail_indexing(*_args, **_kwargs) -> None:
        raise RuntimeError("embedding backend unavailable")

    monkeypatch.setattr(documents, "replace_document_chunks", fail_indexing)

    response = client.post(
        "/documents/upload",
        data={"title": "Indexing failure"},
        files={
            "file": (
                "notes.txt",
                b"This text extracts but indexing fails.",
                "text/plain",
            ),
        },
    )

    assert response.status_code == 201
    payload = response.json()
    assert payload["status"] == "failed"
    assert payload["chunk_count"] == 0
    # extraction_error is stored server-side but must NOT be in the API response
    assert "extraction_error" not in payload


def test_document_upload_strips_lone_surrogates_before_database_write(client, monkeypatch) -> None:
    from app.routes import documents

    monkeypatch.setattr(
        documents,
        "extract_text_from_file",
        lambda *_args, **_kwargs: "Clean biology text \ud835 with invalid surrogate.",
    )

    response = client.post(
        "/documents/upload",
        data={"title": "Unicode repair", "subject": "Biology"},
        files={
            "file": (
                "unicode.txt",
                b"placeholder",
                "text/plain",
            ),
        },
    )

    assert response.status_code == 201
    payload = response.json()
    assert payload["status"] == "ready"
    # extracted_text was removed from API response (security hardening);
    # verify it is NOT leaked to the client and the upload still succeeds
    assert "extracted_text" not in payload


def test_upload_rejects_unsupported_mime_type(client) -> None:
    response = client.post(
        "/documents/upload",
        data={"title": "Bad type"},
        files={"file": ("notes.exe", b"MZ\x90\x00", "application/x-msdownload")},
    )
    assert response.status_code == 415


def test_upload_rejects_images_before_creating_a_failed_document(client) -> None:
    response = client.post(
        "/documents/upload",
        data={"title": "Scanned notes"},
        files={"file": ("notes.png", b"\x89PNG\r\n\x1a\n", "image/png")},
    )

    assert response.status_code == 415
    detail = response.json()["detail"]
    assert "Image OCR" in detail
    assert client.get("/documents").json() == []


def test_upload_rejects_file_over_the_size_limit(client) -> None:
    # 20 MB + 1 byte of allowed-type content must be rejected as 413, not stored.
    oversized = b"a" * (20 * 1024 * 1024 + 1)
    response = client.post(
        "/documents/upload",
        data={"title": "Too big"},
        files={"file": ("huge.txt", oversized, "text/plain")},
    )
    assert response.status_code == 413


def test_upload_accepts_a_malayalam_filename_and_sanitises_it(client) -> None:
    response = client.post(
        "/documents/upload",
        data={"title": "Malayalam name"},
        files={
            "file": (
                "ശബ്ദം physics notes.txt",
                b"Sound travels as a longitudinal wave.",
                "text/plain",
            ),
        },
    )
    assert response.status_code == 201
    assert response.json()["status"] == "ready"


def test_upload_requires_authentication(auth_client) -> None:
    # No Authorization header -> the upload endpoint must refuse.
    response = auth_client.post(
        "/documents/upload",
        data={"title": "Anon"},
        files={"file": ("x.txt", b"hello", "text/plain")},
    )
    assert response.status_code in (401, 403)