from __future__ import annotations

from datetime import UTC, datetime, timedelta
from decimal import Decimal

from sqlalchemy import create_engine
from sqlalchemy.orm import Session, sessionmaker
from sqlalchemy.pool import StaticPool

from app.db.base import Base
from app.models.budget import BudgetAllocation, BudgetTransaction
from app.models.financial_record import ExpenseClaim
from app.models.risk_observation import RiskObservation
from app.services.finance_dashboard import FinanceDashboardService


def build_session() -> Session:
    engine = create_engine(
        "sqlite+pysqlite:///:memory:",
        connect_args={"check_same_thread": False},
        poolclass=StaticPool,
    )
    Base.metadata.create_all(bind=engine)
    session_factory = sessionmaker(bind=engine, autoflush=False, autocommit=False)
    return session_factory()


def test_finance_dashboard_service_aggregates_claim_risk_and_budget_data() -> None:
    now = datetime.now(UTC)

    with build_session() as db:
        db.add_all(
            [
                ExpenseClaim(
                    claim_no="CLM-DASH-001",
                    employee_name="陈雨晴",
                    department_name="财务部",
                    expense_type="travel",
                    reason="项目差旅",
                    location="广州",
                    amount=Decimal("1200.00"),
                    invoice_count=2,
                    occurred_at=now - timedelta(hours=4),
                    submitted_at=now - timedelta(hours=3),
                    status="submitted",
                    approval_stage="finance_review",
                    risk_flags_json=[],
                    hermes_risk_flag=False,
                    created_at=now - timedelta(hours=4),
                    updated_at=now - timedelta(hours=3),
                ),
                ExpenseClaim(
                    claim_no="CLM-DASH-002",
                    employee_name="顾成宇",
                    department_name="研发中心",
                    expense_type="meal",
                    reason="客户招待",
                    location="深圳",
                    amount=Decimal("800.00"),
                    invoice_count=1,
                    occurred_at=now - timedelta(days=1, hours=2),
                    submitted_at=now - timedelta(days=1, hours=1),
                    status="paid",
                    approval_stage="payment",
                    risk_flags_json=[{"label": "招待费超标"}],
                    hermes_risk_flag=False,
                    created_at=now - timedelta(days=1, hours=2),
                    updated_at=now - timedelta(days=1),
                ),
                ExpenseClaim(
                    claim_no="CLM-DASH-003",
                    employee_name="李文静",
                    department_name="行政部",
                    expense_type="office",
                    reason="办公用品",
                    location="珠海",
                    amount=Decimal("5000.00"),
                    invoice_count=3,
                    occurred_at=now - timedelta(hours=1),
                    submitted_at=None,
                    status="draft",
                    approval_stage=None,
                    risk_flags_json=[],
                    hermes_risk_flag=False,
                    created_at=now - timedelta(hours=1),
                    updated_at=now - timedelta(hours=1),
                ),
            ]
        )
        db.add(
            RiskObservation(
                observation_key="risk-dashboard-001",
                subject_type="expense_claim",
                subject_key="CLM-DASH-002",
                subject_label="CLM-DASH-002",
                claim_no="CLM-DASH-002",
                risk_type="policy",
                risk_signal="amount_outlier",
                title="金额异常",
                risk_level="high",
                status="pending_review",
                created_at=now - timedelta(hours=2),
                updated_at=now - timedelta(hours=2),
            )
        )
        allocation = BudgetAllocation(
            budget_no="BUD-DASH-001",
            fiscal_year=now.year,
            period_type="year",
            period_key=f"{now.year}",
            department_name="财务部",
            subject_code="travel",
            subject_name="差旅费",
            original_amount=Decimal("10000.00"),
            adjusted_amount=Decimal("0.00"),
            status="active",
            warning_threshold=Decimal("80.00"),
            control_action="warn",
        )
        db.add(allocation)
        db.flush()
        db.add(
            BudgetTransaction(
                transaction_no="BTX-DASH-001",
                allocation_id=allocation.id,
                source_type="expense_claim",
                source_id="CLM-DASH-002",
                source_no="CLM-DASH-002",
                transaction_type="consume",
                amount=Decimal("4000.00"),
                before_available_amount=Decimal("10000.00"),
                after_available_amount=Decimal("6000.00"),
                operator="finance",
                reason="测试消耗",
                created_at=now - timedelta(hours=1),
            )
        )
        db.commit()

        dashboard = FinanceDashboardService(db).build_dashboard(
            range_key="近10日",
            trend_range="近7天",
            department_range="本月",
        )

        assert dashboard.has_real_data is True
        assert dashboard.totals["pendingCount"] == 1
        assert dashboard.totals["pendingAmount"] == 1200.0
        assert dashboard.totals["riskCount"] == 1
        assert dashboard.trend["applications"][-1] >= 1
        assert dashboard.spend_by_category[0]["value"] == 1200.0
        assert dashboard.department_ranking[0]["name"] == "财务部"
        assert dashboard.department_ranking[0]["amount"] == 1200.0
        assert dashboard.budget_summary["ratio"] == 40.0
        assert dashboard.budget_summary["used"] == "¥4,000"