from datetime import datetime
from decimal import Decimal

import pytest

from app.core.contracts import RequestContext
from app.model.audit import InteractionAudit
from app.model.fund import FundCustomerProfile, FundRiskAlert
from app.service.risk_action_service import RiskActionError, RiskActionService


class FakeSession:
    def __init__(self, alerts=None, profiles=None):
        self.values = list(alerts or [])
        self.profiles = list(profiles or [])
        self.added = []
        self.committed = False

    async def scalar(self, _statement):
        if self.values:
            return self.values.pop(0)
        if self.profiles:
            return self.profiles.pop(0)
        return None

    def add(self, value):
        self.added.append(value)

    async def commit(self):
        self.committed = True

    async def refresh(self, _value):
        return None


def context() -> RequestContext:
    return RequestContext(
        user_id="990000002",
        trace_id="action-trace",
        permissions=("risk:alert:write",),
        data_scope="all",
    )


def alert(
    *,
    status: str = "待处理",
    ack_at: datetime | None = None,
    level: str = "高",
) -> FundRiskAlert:
    return FundRiskAlert(
        id=1,
        alert_no="ALERT-001",
        customer_id=9,
        alert_type="适当性错配",
        alert_level=level,
        trigger_rule_codes=["RW-007"],
        evidence_summary="证据",
        evidence_snapshot={},
        priority_score=90,
        event_status="正在发生",
        status=status,
        ack_status="已确认" if ack_at else "未确认",
        ack_at=ack_at,
        is_escalated=0,
        created_at=datetime(2026, 9, 10),
        updated_at=datetime(2026, 9, 10),
    )


def profile(score: int = 20) -> FundCustomerProfile:
    return FundCustomerProfile(
        customer_id=9,
        trade_account="ACC-009",
        real_name="张三",
        investor_type="C2",
        total_asset=Decimal("100000.00"),
        behavior_score=score,
        updated_at=datetime(2026, 9, 10),
    )


@pytest.mark.asyncio
async def test_acknowledge_updates_status_and_audit() -> None:
    session = FakeSession(alerts=[alert()])

    result = await RiskActionService(session).acknowledge("ALERT-001", context())

    assert result["ack_status"] == "已确认"
    assert session.committed is True
    assert session.added[0].action_type == "risk_alert_acknowledged"


@pytest.mark.asyncio
async def test_investigate_requires_acknowledgement() -> None:
    session = FakeSession(alerts=[alert()])

    with pytest.raises(RiskActionError, match="确认接收"):
        await RiskActionService(session).investigate("ALERT-001", context())


@pytest.mark.asyncio
async def test_exclude_requires_reason_and_closes_false_positive() -> None:
    session = FakeSession(alerts=[alert(ack_at=datetime(2026, 9, 10))])

    result = await RiskActionService(session).exclude("ALERT-001", "客户本人确认", context())

    assert result["status"] == "已排除"
    assert result["handle_result"] == "客户本人确认"


@pytest.mark.parametrize(
    ("level", "before", "deduction", "after"),
    [("低", 20, 3, 17), ("中", 20, 5, 15), ("高", 20, 20, 0), ("高", 4, 20, 0)],
)
@pytest.mark.asyncio
async def test_resolve_applies_behavior_score_deduction(
    level: str,
    before: int,
    deduction: int,
    after: int,
) -> None:
    session = FakeSession(
        alerts=[alert(status="调查中", ack_at=datetime(2026, 9, 10), level=level)],
        profiles=[profile(before)],
    )

    result = await RiskActionService(session).resolve("ALERT-001", "已核实", context())

    assert result["status"] == "已结案"
    assert result["behavior_score_deduction"] == deduction
    assert result["behavior_score_after"] == after
    assert any(isinstance(item, InteractionAudit) for item in session.added)


@pytest.mark.asyncio
async def test_escalate_is_not_terminal_and_rejects_duplicate() -> None:
    session = FakeSession(alerts=[alert(status="调查中", ack_at=datetime(2026, 9, 10))])

    result = await RiskActionService(session).escalate("ALERT-001", "需要高级复核", context())

    assert result["is_escalated"] is True
    assert result["status"] == "调查中"
    assert result["escalation_reason"] == "需要高级复核"

    session = FakeSession(alerts=[alert(status="调查中", ack_at=datetime(2026, 9, 10))])
    session.values[0].is_escalated = 1
    with pytest.raises(RiskActionError, match="已经升级"):
        await RiskActionService(session).escalate("ALERT-001", "重复", context())