"""Vendor 360 (cross-channel) + CFO leadership dashboard composition."""
from __future__ import annotations

from decimal import Decimal

import pytest

from app.domains.finance import read_service
from app.domains.finance.models import FinanceSpendFact

PERIOD = "2026-05"


def _fact(vendor, cost_type, usd, *, dept="研发", basis="consumption", period=PERIOD):
    return FinanceSpendFact(
        fact_key=f"k|{vendor}|{cost_type}|{usd}|{dept}|{period}",
        period=period, cost_type=cost_type, basis=basis,
        amount_native=Decimal(str(usd)), currency_native="USD",
        amount_usd=Decimal(str(usd)), fx_basis="native_usd",
        allocation_source="rule", vendor=vendor, department=dept,
        source_domain=cost_type, rollup_fingerprint="t", is_provisional=False,
    )


@pytest.mark.asyncio
async def test_vendor_360_unifies_consumption_excluding_other_bases(db_session):
    db = db_session
    # AWS spans multiple consumption cost types; a procurement-basis PO for
    # the SAME vendor must NOT be summed in — procurement and consumption are
    # two lenses on one spend, and summing them double-counts the money.
    db.add(_fact("AWS", "cloud", 3000))
    db.add(_fact("AWS", "procurement", 2000, basis="procurement"))  # excluded
    db.add(_fact("AWS", "cloud", 500, dept="销售"))
    db.add(_fact("Microsoft", "software", 1000))  # other vendor
    await db.flush()

    res = await read_service.vendor_360(db, PERIOD, "AWS")
    assert res["total_usd"] == "3500.00"  # 3000 + 500 (procurement leg excluded)
    by_ct = {r["cost_type"]: r["amount_usd"] for r in res["by_cost_type"]}
    assert by_ct["cloud"] == "3500.00" and "procurement" not in by_ct
    by_dep = {r["department"]: r["amount_usd"] for r in res["by_department"]}
    assert by_dep["研发"] == "3000.00" and by_dep["销售"] == "500.00"
    # Concentration = AWS consumption / company consumption (3500 + 1000).
    assert res["concentration_pct"] == round(3500 / 4500 * 100, 2)
    assert len(res["trend"]) == 12 and res["trend"][-1]["period"] == PERIOD


@pytest.mark.asyncio
async def test_top_vendors_ranked(db_session):
    db = db_session
    db.add(_fact("AWS", "cloud", 3000))
    db.add(_fact("Microsoft", "software", 5000))
    db.add(_fact(None, "cloud", 9999))  # null vendor → excluded
    # A large procurement PO for AWS must NOT inflate its consumption rank.
    db.add(_fact("AWS", "procurement", 9000, basis="procurement"))
    await db.flush()
    res = await read_service.top_vendors(db, PERIOD, limit=5)
    vendors = [v["vendor"] for v in res["vendors"]]
    assert vendors[0] == "Microsoft" and "AWS" in vendors  # 5000 > 3000
    assert all(v["vendor"] is not None for v in res["vendors"])
    aws = next(v for v in res["vendors"] if v["vendor"] == "AWS")
    assert aws["amount_usd"] == "3000.00"  # procurement leg excluded


@pytest.mark.asyncio
async def test_leadership_dashboard_composes(db_session):
    db = db_session
    db.add(_fact("AWS", "cloud", 3000))
    db.add(_fact("Microsoft", "software", 1000))
    await db.flush()
    res = await read_service.leadership_dashboard(db, PERIOD)
    # Bundled, consistent snapshot — all sections present without error.
    assert res["period"] == PERIOD
    assert set(res) >= {
        "summary", "headcount", "cost_per_headcount_usd", "dept_movers",
        "top_vendors", "bu_costs", "budget_health",
    }
    assert res["summary"]["consumption_total_usd"] == "4000.00"
    assert any(v["vendor"] == "AWS" for v in res["top_vendors"])