from __future__ import annotations

import json

from app.core.agent.intent_router import ConversationState, IntentRouterV2
from app.core.agent.intent_router.docs_mvp.llm_classifier import DocsMvpLlmClassifier
from app.core.agent.intent_router.intent.classifier import IntentClassifierV2
from tests.unit_tests.rag.intent_router_testkit import repo_context


class FakeLlm:
    def __init__(self, response: str, *, fail: bool = False) -> None:
        self.response = response
        self.fail = fail
        self.calls: list[tuple[str, str]] = []

    def generate(self, prompt_name: str, user_input: str, *, log_context: str | None = None) -> str:
        self.calls.append((prompt_name, user_input))
        if self.fail:
            raise RuntimeError("llm unavailable")
        return self.response


def _router(llm: FakeLlm) -> IntentRouterV2:
    return IntentRouterV2(
        classifier=IntentClassifierV2(),
        docs_llm_classifier=DocsMvpLlmClassifier(llm),
        enable_llm_disambiguation=True,
    )


def test_docs_technical_query_keeps_deterministic_routing_without_llm_call() -> None:
    llm = FakeLlm("{}")
    result = _router(llm).route("Объясни endpoint /health", ConversationState(), repo_context())

    assert result.docs_routing is not None
    assert result.docs_routing.sub_intent == "API_METHOD_EXPLAIN"
    assert result.docs_routing.routing_mode == "deterministic"
    assert result.llm_router_used is False
    assert llm.calls == []


def test_ambiguous_query_can_be_resolved_by_llm() -> None:
    llm = FakeLlm(
        json.dumps(
            {
                "intent": "DOCS_DISCOVERY",
                "sub_intent": "FIND_DOCUMENTS_BY_DOMAIN",
                "confidence": 0.83,
                "anchors": {"entity_name": "health", "doc_query": "документация по health"},
                "scope": {"level": "domain"},
                "reason_short": "health here is a docs topic",
            },
            ensure_ascii=False,
        )
    )
    result = _router(llm).route("документация по health", ConversationState(), repo_context())

    assert result.docs_routing is not None
    assert result.docs_routing.routing_mode == "llm_assisted"
    assert result.docs_routing.sub_intent == "FIND_DOCUMENTS_BY_DOMAIN"
    assert result.retrieval_plan is not None
    assert result.retrieval_plan.plan_id == "docs_find_documents_by_domain_v1"
    assert result.llm_router_used is True


def test_ambiguous_query_falls_back_to_general_docs_when_llm_fails() -> None:
    llm = FakeLlm("{}", fail=True)
    result = _router(llm).route("health документация", ConversationState(), repo_context())

    assert result.docs_routing is not None
    assert result.docs_routing.routing_mode == "llm_fallback"
    assert result.docs_routing.sub_intent == "GENERAL_DOCS_QA"
    assert result.retrieval_plan is not None
    assert result.retrieval_plan.plan_id == "docs_general_docs_qa_v1"


def test_llm_classifier_rejects_unknown_labels() -> None:
    llm = FakeLlm(json.dumps({"intent": "DOCS_QA", "sub_intent": "MADE_UP"}))
    classifier = DocsMvpLlmClassifier(llm)

    assert classifier.classify({"query": "test"}) is None