"""Tests for native Aliyun + AliCloud Intl monthly billing via BSS.

Validates:
  * BSS host is correct per tenant region (CN vs Intl)
  * ``QueryAccountBill`` paginates via ``NextToken``
  * Service-level breakdown is summed across pages
  * Currency is reported as CNY (Aliyun's native unit)
"""
from __future__ import annotations

from datetime import date
from unittest.mock import patch

import pytest

from app.domains.cmdb.providers.alicloud_intl import AlicloudIntlProvider
from app.domains.cmdb.providers.aliyun import AliyunProvider
from app.domains.cmdb.providers.base import ProviderCredentials


def _creds(provider_type: str = "aliyun") -> ProviderCredentials:
    return ProviderCredentials(
        provider_id="test", provider_type=provider_type,
        account_alias="test", fields={
            "access_key_id": "AK", "access_key_secret": "SK",
        },
    )


@pytest.mark.asyncio
async def test_get_monthly_billing_uses_cn_bss_host_and_returns_cny():
    """国内 Aliyun: BSS endpoint must be ``business.aliyuncs.com``.
    Returned currency must be CNY (no silent USD conversion)."""
    p = AliyunProvider(_creds("aliyun"))
    captured: list[tuple[str, dict]] = []

    async def _fake_call(endpoint, params):
        captured.append((endpoint, dict(params)))
        return {
            "Data": {
                "Items": {"Item": [
                    {"ProductName": "ECS", "PretaxAmount": 100.5},
                    {"ProductName": "OSS", "PretaxAmount": 25.25},
                ]},
                "NextToken": None,
            }
        }
    with patch.object(p, "_call", new=_fake_call):
        out = await p.get_monthly_billing(date(2026, 3, 15))
    await p.close()

    assert len(captured) == 1
    endpoint, params = captured[0]
    assert endpoint == "https://business.aliyuncs.com/"
    assert params["Action"] == "QueryAccountBill"
    assert params["BillingCycle"] == "2026-03"
    assert params["Granularity"] == "MONTHLY"
    assert params["Version"] == "2017-12-14"

    assert out["month"] == date(2026, 3, 1)
    assert out["currency"] == "CNY"
    # Round-666 fix: ``total_cost_usd`` now carries the NATIVE CNY value
    # (== ``total_cost_native``) — the driver no longer pre-multiplies by
    # a stale hard-coded 0.14. The billing handler resolves CNY→USD with
    # the dynamic platform rate (Tencent/UCloud contract); on FX-fail it
    # keeps ``currency='CNY'`` so value + label agree and the overview
    # reader converts exactly once. ``cost_by_service`` keeps native units.
    assert out["total_cost_native"] == pytest.approx(125.75)
    assert out["total_cost_usd"] == pytest.approx(125.75)
    assert out["cost_by_service"]["ECS"] == pytest.approx(100.5)
    assert out["cost_by_service"]["OSS"] == pytest.approx(25.25)


@pytest.mark.asyncio
async def test_alicloud_intl_uses_sg_bss_host():
    """海外 AliCloud: BSS endpoint MUST be the Singapore variant —
    using the CN host returns ``NotApplicable``. Same fix family as
    PR #49 for daily billing."""
    p = AlicloudIntlProvider(_creds("alicloud_intl"))
    captured: list[tuple[str, dict]] = []

    async def _fake_call(endpoint, params):
        captured.append((endpoint, dict(params)))
        return {"Data": {"Items": {"Item": []}, "NextToken": None}}
    with patch.object(p, "_call", new=_fake_call):
        await p.get_monthly_billing(date(2026, 3, 1))
    await p.close()

    endpoint, _ = captured[0]
    assert endpoint == "https://business.ap-southeast-1.aliyuncs.com/"


@pytest.mark.asyncio
async def test_get_monthly_billing_follows_next_token():
    """A real busy month spans multiple BSS pages; the implementation
    must follow ``NextToken`` until the cursor disappears, otherwise
    silent under-counting happens."""
    p = AliyunProvider(_creds("aliyun"))
    pages = [
        {"Data": {"Items": {"Item": [
            {"ProductName": "ECS", "PretaxAmount": 50.0},
        ]}, "NextToken": "page2"}},
        {"Data": {"Items": {"Item": [
            {"ProductName": "ECS", "PretaxAmount": 25.0},
            {"ProductName": "RDS", "PretaxAmount": 10.0},
        ]}, "NextToken": None}},
    ]
    page_iter = iter(pages)

    async def _fake_call(endpoint, params):
        return next(page_iter)

    with patch.object(p, "_call", new=_fake_call):
        out = await p.get_monthly_billing(date(2026, 3, 1))
    await p.close()

    # ECS summed across both pages — values are CNY natively. Round-666:
    # ``total_cost_usd`` carries the native CNY value (handler resolves FX).
    assert out["cost_by_service"]["ECS"] == pytest.approx(75.0)
    assert out["cost_by_service"]["RDS"] == pytest.approx(10.0)
    assert out["total_cost_native"] == pytest.approx(85.0)
    assert out["total_cost_usd"] == pytest.approx(85.0)


@pytest.mark.asyncio
async def test_default_month_is_previous_full_month():
    """When ``month`` is omitted, the handler defaults to the
    previous full month — matches AWS impl + the cron schedule
    (runs day 2 of every month for last month's data)."""
    p = AliyunProvider(_creds("aliyun"))

    async def _fake_call(endpoint, params):
        # Echo the cycle back so we can assert on it
        return {"Data": {"Items": {"Item": []}, "NextToken": None}, "_cycle": params["BillingCycle"]}

    with patch.object(p, "_call", new=_fake_call):
        out = await p.get_monthly_billing()
    await p.close()

    today = date.today()
    expected_first = (today.replace(day=1) - __import__("datetime").timedelta(days=1)).replace(day=1)
    assert out["month"] == expected_first