"""Tests for codex.sources.semanticscholar."""

from __future__ import annotations

import httpx
import pytest

from codex.models import Citation
from codex.sources import semanticscholar

# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

_SAMPLE_REFS_RESPONSE = {
    "data": [
        {
            "citedPaper": {
                "paperId": "abc123",
                "externalIds": {"DOI": "10.1000/xyz1"},
            },
            "contexts": ["This approach was first described in [1]."],
        },
        {
            "citedPaper": {
                "paperId": "def456",
                "externalIds": {"ArXiv": "2301.07041"},
            },
            "contexts": [],
        },
    ]
}

_SAMPLE_RECS_RESPONSE = {
    "recommendedPapers": [
        {"paperId": "rec_id_1"},
        {"paperId": "rec_id_2"},
        {"paperId": "rec_id_3"},
    ]
}


# ---------------------------------------------------------------------------
# fetch_references
# ---------------------------------------------------------------------------


def test_fetch_references_returns_citations(monkeypatch: pytest.MonkeyPatch) -> None:
    """fetch_references maps API response to Citation objects correctly."""

    def mock_get(url: str, params: dict[str, object] | None = None) -> httpx.Response:
        return httpx.Response(200, json=_SAMPLE_REFS_RESPONSE)

    monkeypatch.setattr(semanticscholar, "_get", mock_get)

    citations = semanticscholar.fetch_references("abc123")

    assert len(citations) == 2
    assert all(isinstance(c, Citation) for c in citations)

    # First citation uses DOI and has context
    assert citations[0].citing_id == "abc123"
    assert citations[0].cited_id == "10.1000/xyz1"
    assert citations[0].context == "This approach was first described in [1]."

    # Second citation falls back to ArXiv ID, no context
    assert citations[1].citing_id == "abc123"
    assert citations[1].cited_id == "2301.07041"
    assert citations[1].context is None


def test_fetch_references_404_returns_empty(monkeypatch: pytest.MonkeyPatch) -> None:
    """A 404 response should return an empty list."""

    def mock_get(url: str, params: dict[str, object] | None = None) -> httpx.Response:
        raise httpx.HTTPStatusError(
            "Not Found",
            request=httpx.Request("GET", url),
            response=httpx.Response(404, request=httpx.Request("GET", url)),
        )

    monkeypatch.setattr(semanticscholar, "_get", mock_get)

    result = semanticscholar.fetch_references("nonexistent")
    assert result == []


# ---------------------------------------------------------------------------
# fetch_recommendations
# ---------------------------------------------------------------------------


def test_fetch_recommendations_returns_list_of_str(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    """fetch_recommendations returns a flat list of paperId strings."""

    def mock_get(url: str, params: dict[str, object] | None = None) -> httpx.Response:
        return httpx.Response(200, json=_SAMPLE_RECS_RESPONSE)

    monkeypatch.setattr(semanticscholar, "_get", mock_get)

    result = semanticscholar.fetch_recommendations("abc123", limit=3)

    assert isinstance(result, list)
    assert len(result) == 3
    assert all(isinstance(r, str) for r in result)
    assert result == ["rec_id_1", "rec_id_2", "rec_id_3"]


def test_fetch_recommendations_404_returns_empty(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    """A 404 response should return an empty list."""

    def mock_get(url: str, params: dict[str, object] | None = None) -> httpx.Response:
        raise httpx.HTTPStatusError(
            "Not Found",
            request=httpx.Request("GET", url),
            response=httpx.Response(404, request=httpx.Request("GET", url)),
        )

    monkeypatch.setattr(semanticscholar, "_get", mock_get)

    result = semanticscholar.fetch_recommendations("nonexistent")
    assert result == []


# ---------------------------------------------------------------------------
# fetch_references — {"data": null} guard (DQ-1 regression)
# ---------------------------------------------------------------------------


def test_fetch_references_null_data_returns_empty(monkeypatch: pytest.MonkeyPatch) -> None:
    """S2 returns HTTP 200 with ``{"data": null}`` for a known paper that has no
    parsed references; this must yield [] rather than raising TypeError."""

    def mock_get(url: str, params: dict[str, object] | None = None) -> httpx.Response:
        return httpx.Response(200, json={"data": None, "citingPaperInfo": {}})

    monkeypatch.setattr(semanticscholar, "_get", mock_get)
    assert semanticscholar.fetch_references("DOI:10.14279/depositonce-5415") == []


# ---------------------------------------------------------------------------
# fetch_abstract (DQ-2)
# ---------------------------------------------------------------------------


def test_fetch_abstract_returns_text(monkeypatch: pytest.MonkeyPatch) -> None:
    """fetch_abstract returns the abstract string when present."""

    def mock_get(url: str, params: dict[str, object] | None = None) -> httpx.Response:
        return httpx.Response(200, json={"abstract": "We study ideal hyperbolic polyhedra."})

    monkeypatch.setattr(semanticscholar, "_get", mock_get)
    assert semanticscholar.fetch_abstract("DOI:10.1007/s00454-019-00132-8") == (
        "We study ideal hyperbolic polyhedra."
    )


def test_fetch_abstract_null_returns_none(monkeypatch: pytest.MonkeyPatch) -> None:
    """A null/absent abstract yields None."""

    def mock_get(url: str, params: dict[str, object] | None = None) -> httpx.Response:
        return httpx.Response(200, json={"abstract": None})

    monkeypatch.setattr(semanticscholar, "_get", mock_get)
    assert semanticscholar.fetch_abstract("arXiv:1234.5678") is None