"""Endpoint test for /spending/annual.

Mocks the actualbudget upstream HTTP API with respx so the endpoint
runs end-to-end without a live cluster connection.
"""
from __future__ import annotations

from collections.abc import AsyncIterator
from datetime import date
from decimal import Decimal
from unittest.mock import patch

import httpx
import pytest_asyncio
import respx
from httpx import ASGITransport, AsyncClient
from sqlalchemy.ext.asyncio import AsyncEngine, AsyncSession, async_sessionmaker

from fire_planner.api.dependencies import get_session
from fire_planner.app import app

API_URL = "http://budget-http-api.test"
SYNC_ID = "sync-1"


@pytest_asyncio.fixture
async def client(engine: AsyncEngine,
                 session: AsyncSession) -> AsyncIterator[AsyncClient]:
    factory = async_sessionmaker(engine, expire_on_commit=False)

    async def _override() -> AsyncIterator[AsyncSession]:
        async with factory() as s:
            yield s

    app.dependency_overrides[get_session] = _override
    transport = ASGITransport(app=app)
    async with AsyncClient(transport=transport, base_url="http://test", timeout=30) as ac:
        yield ac
    app.dependency_overrides.clear()


def _mock_two_months(rmock: respx.MockRouter) -> None:
    """Mock 2 months of spending data — Usual + Investments groups."""
    rmock.get(f"{API_URL}/v1/budgets/{SYNC_ID}/months").mock(
        return_value=httpx.Response(200, json={"data": ["2025-01", "2025-02"]}))
    for m, usual, invest in [("2025-01", -3000, -50000), ("2025-02", -4000, -10000)]:
        rmock.get(f"{API_URL}/v1/budgets/{SYNC_ID}/months/{m}").mock(
            return_value=httpx.Response(200, json={
                "data": {
                    "categoryGroups": [
                        {"name": "Usual Expenses", "is_income": False,
                         "categories": [{"spent": usual}]},
                        {"name": "Investments and Savings", "is_income": False,
                         "categories": [{"spent": invest}]},
                    ]
                }
            }))


async def test_spending_annual_excludes_investments_by_default(client: AsyncClient) -> None:
    env = {
        "ACTUALBUDGET_API_URL": API_URL,
        "ACTUALBUDGET_API_KEY": "key",
        "ACTUALBUDGET_SYNC_ID": SYNC_ID,
    }
    with patch.dict("os.environ", env, clear=False), \
            patch("fire_planner.actualbudget._today", lambda: date(2025, 3, 15)), \
            respx.mock(assert_all_called=False) as rmock:
        _mock_two_months(rmock)
        # The endpoint asks for 12 months by default but we mocked only 2;
        # the remaining 10 are silently dropped (list_months only returns 2).
        resp = await client.get("/spending/annual?months=2&inflation_pct=0")
    assert resp.status_code == 200, resp.text
    body = resp.json()
    # 0% inflation → real == nominal. Usual: 3000 + 4000 = 7000p = £70
    assert Decimal(body["total_gbp"]) == Decimal("70.00")
    assert Decimal(body["nominal_total_gbp"]) == Decimal("70.00")
    # Raw includes investments: 7000 + 60000 = 67000p = £670
    assert Decimal(body["raw_total_gbp"]) == Decimal("670.00")
    assert body["window_start"] == "2025-01"
    assert body["window_end"] == "2025-02"
    assert body["excluded_groups"] == ["Investments and Savings", "Budget Reset"]
    assert body["by_group_total_gbp"]["Usual Expenses"] == "70.00"
    assert body["by_group_total_gbp"]["Investments and Savings"] == "600.00"
    assert Decimal(body["inflation_pct"]) == Decimal("0")


async def test_spending_annual_custom_exclude(client: AsyncClient) -> None:
    env = {
        "ACTUALBUDGET_API_URL": API_URL,
        "ACTUALBUDGET_API_KEY": "key",
        "ACTUALBUDGET_SYNC_ID": SYNC_ID,
    }
    with patch.dict("os.environ", env, clear=False), \
            patch("fire_planner.actualbudget._today", lambda: date(2025, 3, 15)), \
            respx.mock(assert_all_called=False) as rmock:
        _mock_two_months(rmock)
        resp = await client.get(
            "/spending/annual?months=2&exclude=Usual%20Expenses&inflation_pct=0"
        )
    assert resp.status_code == 200
    body = resp.json()
    # Excluding "Usual Expenses" leaves only Investments: £600
    assert Decimal(body["total_gbp"]) == Decimal("600.00")
    assert body["excluded_groups"] == ["Usual Expenses"]


async def test_spending_annual_502_on_upstream_error(client: AsyncClient) -> None:
    env = {
        "ACTUALBUDGET_API_URL": API_URL,
        "ACTUALBUDGET_API_KEY": "key",
        "ACTUALBUDGET_SYNC_ID": SYNC_ID,
    }
    with patch.dict("os.environ", env, clear=False), \
            respx.mock(assert_all_called=False) as rmock:
        rmock.get(f"{API_URL}/v1/budgets/{SYNC_ID}/months").mock(
            return_value=httpx.Response(503))
        resp = await client.get("/spending/annual?months=2")
    assert resp.status_code == 502
    assert "actualbudget" in resp.json()["detail"]