from pathlib import Path

from app.config import Settings
from app.decision_engine import DemoDecisionEngine
from app.schemas import Evidence, QualityGrade, QueryRequest, RouteName
from app.service import AgenticRAGService
from app.sql_store import initialize_database


class FakeVectorStore:
    def __init__(self, return_evidence: bool = True) -> None:
        self.return_evidence = return_evidence
        self.calls = 0

    def search(
        self,
        query: str,
        top_k: int = 5,
        policy_type: str = "",
    ) -> list[Evidence]:
        self.calls += 1
        if not self.return_evidence:
            return []
        return [
            Evidence(
                source_type="milvus",
                source="shipping_policy.md",
                content="单笔有效订单实付满 99 元免基础运费。",
                score=0.91,
                metadata={"policy_type": policy_type},
            )
        ]


class FakeWebSearchProvider:
    def __init__(self) -> None:
        self.calls = 0

    def search(self, query: str, max_results: int = 5) -> list[Evidence]:
        self.calls += 1
        return [
            Evidence(
                source_type="web",
                source="https://brand.example/xphone-15-pro-notice",
                content="品牌官网发布了 XPhone 15 Pro 最新服务公告。",
                score=0.88,
                metadata={"title": "XPhone 15 Pro 最新公告"},
            )
        ]


class AlwaysRewriteDecisionEngine(DemoDecisionEngine):
    """模拟模型忽略检索预算、每轮都要求继续改写。"""

    def grade(self, *args, **kwargs) -> QualityGrade:
        return QualityGrade(
            relevant=False,
            sufficient=False,
            missing_aspects=["网页证据"],
            recommended_action="rewrite_query",
            reason="模拟模型持续要求 Rewrite",
        )


def create_settings(sqlite_path: Path, max_rounds: int = 2) -> Settings:
    return Settings(
        llm_provider="demo",
        sqlite_path=sqlite_path,
        max_retrieval_rounds=max_rounds,
        min_evidence_score=0.35,
    )


def test_multi_source_graph(tmp_path) -> None:
    database = tmp_path / "shop.db"
    initialize_database(database, reset=True)
    service = AgenticRAGService(create_settings(database), FakeVectorStore())

    response = service.invoke(
        QueryRequest(
            query="统计 U1001 最近 30 天订单，并结合内部运费规则说明是否包邮",
            debug=True,
        )
    )

    assert response.route.routes == [RouteName.MILVUS_SEARCH, RouteName.SQL_QUERY]
    assert response.termination_reason == "evidence_accepted"
    assert {item.source_type for item in response.citations} == {"milvus", "sql"}
    assert {item["tool"] for item in response.executed_queries} == {
        "milvus_search",
        "sql_query",
    }
    assert all(item["query"] for item in response.executed_queries)
    assert [event["node"] for event in response.trace] == [
        "normalize_query",
        "route_query",
        "plan_query",
        "execute_plan",
        "grade_evidence",
        "generate_answer",
    ]


def test_empty_retrieval_stops_after_budget(tmp_path) -> None:
    database = tmp_path / "shop.db"
    initialize_database(database, reset=True)
    vector_store = FakeVectorStore(return_evidence=False)
    service = AgenticRAGService(
        create_settings(database, max_rounds=1), vector_store
    )

    response = service.invoke(
        QueryRequest(query="耳机拆封后还能七日无理由退货吗？", debug=True)
    )

    assert vector_store.calls == 2
    assert response.termination_reason == "retrieval_budget_exhausted"
    assert "未获得" in response.answer
    assert [event["node"] for event in response.trace].count("rewrite_query") == 1


def test_graph_forces_stop_when_model_ignores_rewrite_budget(
    tmp_path, monkeypatch
) -> None:
    database = tmp_path / "shop.db"
    initialize_database(database, reset=True)
    vector_store = FakeVectorStore(return_evidence=False)
    monkeypatch.setattr(
        "app.service.create_decision_engine",
        lambda settings: AlwaysRewriteDecisionEngine(),
    )
    service = AgenticRAGService(
        create_settings(database, max_rounds=1),
        vector_store,
    )

    response = service.invoke(
        QueryRequest(query="耳机退货政策", debug=True)
    )

    assert vector_store.calls == 2
    assert response.termination_reason == "retrieval_budget_exhausted"
    assert response.trace[-2]["node"] == "grade_evidence"
    assert response.trace[-2]["detail"]["recommended_action"] == "stop"


def test_three_source_graph(tmp_path) -> None:
    database = tmp_path / "shop.db"
    initialize_database(database, reset=True)
    web_provider = FakeWebSearchProvider()
    service = AgenticRAGService(
        create_settings(database),
        FakeVectorStore(),
        web_provider,
    )

    response = service.invoke(
        QueryRequest(
            query=(
                "统计 U1001 最近 30 天购买 XPhone 15 Pro 的订单金额，"
                "结合内部退货政策和品牌官网最新公告给出售后建议"
            ),
            debug=True,
        )
    )

    assert response.route.routes == [
        RouteName.MILVUS_SEARCH,
        RouteName.SQL_QUERY,
        RouteName.WEB_SEARCH,
    ]
    assert web_provider.calls == 1
    assert {item.source_type for item in response.citations} == {
        "milvus",
        "sql",
        "web",
    }
    assert response.termination_reason == "evidence_accepted"
    assert len(response.executed_queries) == 3
    sql_call = next(
        item for item in response.executed_queries if item["tool"] == "sql_query"
    )
    assert sql_call["arguments"]["user_id"] == "U1001"
    assert sql_call["arguments"]["product_keyword"] == "XPhone 15 Pro"


def test_clarification_does_not_call_vector_store(tmp_path) -> None:
    database = tmp_path / "shop.db"
    initialize_database(database, reset=True)
    vector_store = FakeVectorStore()
    service = AgenticRAGService(create_settings(database), vector_store)

    response = service.invoke(QueryRequest(query="我最近 30 天买了几单？"))

    assert response.termination_reason == "clarification_required"
    assert vector_store.calls == 0