"""场景插件框架测试：注册表、场景 scan() 产出、/scenarios API（纯逻辑，无需数据库）。"""

from __future__ import annotations

from fastapi.testclient import TestClient

from app.main import app
from app.scenarios.base import ScanOutcome
from app.scenarios.churn_fraud import ChurnFraudScenario, CohortPoint
from app.scenarios.registry import SCENARIO_REGISTRY, get_scenario, scenario_meta
from app.scenarios.split_contract import ContractRecord, SplitContractScenario


def test_registry_contains_builtin_scenarios():
    # 导入 app.scenarios.* 已通过自动发现触发 @register_scenario 注册 R8/R9
    assert "R8" in SCENARIO_REGISTRY
    assert "R9" in SCENARIO_REGISTRY
    assert get_scenario("R8") is SplitContractScenario
    assert get_scenario("R9") is ChurnFraudScenario


def test_scenario_meta_fields():
    meta = {m["code"]: m for m in scenario_meta()}
    assert meta["R8"]["label"] == "政企拆单"
    assert meta["R8"]["risk_domain"] == "收入"
    assert meta["R9"]["label"] == "养卡骗补"
    assert set(meta["R8"]) == {"code", "title", "label", "risk_domain"}


def test_split_scenario_scan_hits():
    contracts = [ContractRecord(f"C{i}", f"CUST{i}", 850000) for i in range(8)]
    scenario = SplitContractScenario(
        contracts, approval_threshold=1_000_000, shared_controller=True
    )
    outcome = scenario.scan(None)
    assert isinstance(outcome, ScanOutcome)
    assert outcome.scanned_count == 8
    assert len(outcome.drafts) == 1
    draft = outcome.drafts[0]
    assert draft.score >= scenario.score_threshold
    assert draft.amount_involved > 0
    assert draft.evidence["shared_controller"] is True


def test_split_scenario_no_draft_when_clean():
    contracts = [ContractRecord("C1", "A", 100000), ContractRecord("C2", "B", 3_000_000)]
    outcome = SplitContractScenario(contracts, approval_threshold=1_000_000).scan(None)
    assert outcome.drafts == []
    assert outcome.scanned_count == 2


def test_churn_scenario_scan_produces_draft():
    curve = [CohortPoint(0, 1.0), CohortPoint(1, 0.95), CohortPoint(2, 0.1)]
    scenario = ChurnFraudScenario(
        retention_curve=curve,
        commission_paid=300000,
        active_ratio=0.05,
        zero_usage_ratio=0.9,
        channel_key="CH-001",
    )
    outcome = scenario.scan(None)
    assert outcome.scanned_count == 3
    assert len(outcome.drafts) == 1
    draft = outcome.drafts[0]
    assert draft.subjects["channel"] == "CH-001"
    assert draft.score >= scenario.score_threshold


def test_scenarios_api_endpoint():
    client = TestClient(app)
    resp = client.get("/scenarios")
    assert resp.status_code == 200
    codes = {item["code"] for item in resp.json()}
    assert {"R8", "R9"} <= codes