# tests/test_synthesizer.py
"""Tests for Synthesizer — mocked LLM, citation assembly."""
from __future__ import annotations

from unittest.mock import MagicMock

from app.services.retriever import RetrievedChunk
from app.services.synthesizer import Synthesizer, SynthesisResult


def _chunk(doc_id: str = "book-a", page: int = 5, text: str = "Fireball rules") -> RetrievedChunk:
    return RetrievedChunk(
        chunk_id="c1", doc_id=doc_id, page_number=page, text=text,
        bm25_score=1.0, vector_score=None,
    )


def test_synthesizer_returns_answer_and_citations():
    mock_llm = MagicMock()
    mock_llm.complete.return_value = "Fireball deals 8d6 damage [p.5]."

    synth = Synthesizer(mock_llm)
    result = synth.synthesize(
        message="How does Fireball work?",
        history=[],
        chunks=[_chunk()],
    )

    assert isinstance(result, SynthesisResult)
    assert "Fireball" in result.answer
    assert len(result.citations) == 1
    assert result.citations[0].page_number == 5
    assert result.citations[0].doc_id == "book-a"


def test_synthesizer_builds_context_from_chunks():
    mock_llm = MagicMock()
    mock_llm.complete.return_value = "Answer."

    synth = Synthesizer(mock_llm)
    synth.synthesize("Q?", [], [_chunk(text="Detailed rule text here.")])

    assert "Detailed rule text here." in mock_llm.complete.call_args.args[0]


def test_synthesizer_uses_system_prompt():
    mock_llm = MagicMock()
    mock_llm.complete.return_value = "Answer."
    synth = Synthesizer(mock_llm)
    synth.synthesize("Q?", [], [_chunk()])

    call_kwargs = mock_llm.complete.call_args
    assert call_kwargs.kwargs.get("system") or call_kwargs[1].get("system")