life-echo/api/tests/test_image_prompt_policy.py

"""MemoirImagePromptService 与 image_prompt_fallback_disabled（story 主图 / 章节封面）。"""

import json

import pytest

from app.features.memoir.memoir_images.prompting import MemoirImagePromptService
from app.features.memoir.memoir_images.settings import MemoirImageSettings


def _svc(llm=None) -> MemoirImagePromptService:
    return MemoirImagePromptService(llm=llm, settings=MemoirImageSettings())


def test_story_primary_fallback_uses_placeholder_when_llm_disabled():
    from app.features.memoir.memoir_images.image_placeholder_template import (
        IMAGE_PLACEHOLDER_TEMPLATE,
    )

    out = _svc(llm=None).build_story_primary_prompt(
        "My Story", "career", "rainy street", None
    )
    assert IMAGE_PLACEHOLDER_TEMPLATE in out["prompt"]
    assert "rainy street" in out["prompt"]


def test_story_primary_fallback_disabled_requires_brief(monkeypatch):
    monkeypatch.setattr(
        "app.features.memoir.memoir_images.prompting.settings.image_prompt_fallback_disabled",
        True,
    )
    with pytest.raises(RuntimeError, match="prompt_brief"):
        _svc(llm=None).build_story_primary_prompt("T", "career", "", None)


def test_story_primary_style_from_chapter_category_when_no_intent_style():
    """Story.stage 存章节 category 时，未指定 style_profile 应走 CATEGORY_STYLE_MAP。"""
    out = _svc(llm=None).build_story_primary_prompt("T", "career_early", "brief", None)
    assert out["style"] == "realistic"


def test_story_primary_style_from_chat_stage_when_no_intent_style():
    out = _svc(llm=None).build_story_primary_prompt("T", "career", "brief", None)
    assert out["style"] == "realistic"


def test_story_primary_fallback_disabled_requires_llm(monkeypatch):
    monkeypatch.setattr(
        "app.features.memoir.memoir_images.prompting.settings.image_prompt_fallback_disabled",
        True,
    )
    with pytest.raises(RuntimeError, match="requires LLM"):
        _svc(llm=None).build_story_primary_prompt("T", "career", "brief", None)


def test_story_primary_llm_path(monkeypatch):
    class _FakeLlm:
        def invoke(self, *_a, **_kw):  # noqa: ANN001
            raise AssertionError("invoke should not be used")

    captured: dict[str, str] = {}

    def fake_invoke_json(llm, prompt_text, **_kw):  # noqa: ANN001
        captured["prompt_text"] = prompt_text
        return json.dumps(
            {
                "prompt": "A hero scene at dawn",
                "style": "watercolor",
                "size": "1280x720",
            }
        )

    monkeypatch.setattr(
        "app.features.memoir.memoir_images.prompting.invoke_json_object",
        fake_invoke_json,
    )
    out = _svc(llm=_FakeLlm()).build_story_primary_prompt(
        "Title", "childhood", "memo", "realistic"
    )
    assert out["prompt"].lower().startswith("watercolor")
    assert "dawn" in out["prompt"].lower()
    assert out["style"] == "watercolor"
    raw = captured.get("prompt_text", "")
    assert "Title" in raw and "memo" in raw


def test_cover_fallback_uses_service_template_when_llm_disabled():
    out = _svc(llm=None).build_cover_prompt(
        chapter_title="Ch1",
        chapter_category="family",
        context_excerpt="mountain lake",
    )
    assert "mountain lake" in out["prompt"].lower()
    assert (
        "chapter cover" in out["prompt"].lower()
        or "illustration" in out["prompt"].lower()
    )


def test_cover_fallback_when_excerpt_empty(monkeypatch):
    monkeypatch.setattr(
        "app.features.memoir.memoir_images.prompting.settings.image_prompt_fallback_disabled",
        False,
    )
    out = _svc(llm=None).build_cover_prompt(
        chapter_title="",
        chapter_category="family",
        context_excerpt="",
    )
    assert len(out["prompt"]) > 20


def test_cover_fallback_disabled_requires_excerpt(monkeypatch):
    monkeypatch.setattr(
        "app.features.memoir.memoir_images.prompting.settings.image_prompt_fallback_disabled",
        True,
    )
    with pytest.raises(RuntimeError, match="context_excerpt"):
        _svc(llm=None).build_cover_prompt(
            chapter_title="T",
            chapter_category="family",
            context_excerpt="",
        )


def test_image_prompt_orchestrator_provider_failure_uses_fallback(monkeypatch):
    from app.agents.image_prompt.orchestrator import get_image_prompt_orchestrator

    class BoomGateway:
        def langchain_llm_for(self, *_a, **_kw):  # noqa: ANN001
            raise RuntimeError("provider missing")

    monkeypatch.setattr(
        "app.agents.image_prompt.orchestrator.settings.image_prompt_fallback_disabled",
        False,
    )
    monkeypatch.setattr("app.core.llm_gateway.LlmGateway", lambda: BoomGateway())

    orch = get_image_prompt_orchestrator()
    out = orch.build_cover_prompt(
        chapter_title="T",
        chapter_category="family",
        context_excerpt="mountain lake",
    )
    assert "mountain lake" in out["prompt"].lower()


def test_image_prompt_orchestrator_provider_failure_raises_when_disabled(
    monkeypatch,
):
    from app.agents.image_prompt.orchestrator import get_image_prompt_orchestrator

    class BoomGateway:
        def langchain_llm_for(self, *_a, **_kw):  # noqa: ANN001
            raise RuntimeError("provider missing")

    monkeypatch.setattr(
        "app.agents.image_prompt.orchestrator.settings.image_prompt_fallback_disabled",
        True,
    )
    monkeypatch.setattr("app.core.llm_gateway.LlmGateway", lambda: BoomGateway())

    with pytest.raises(RuntimeError, match="provider missing"):
        get_image_prompt_orchestrator()