"""End-to-end vertical slice against real PostgreSQL + Redis.

Run with ``make up && make migrate`` first, or let ``scripts/smoke.sh`` do it.
Skipped automatically when the infrastructure is not reachable, so ``make test``
stays fast and hermetic.

The LLM provider is faked here — ``scripts/smoke.sh`` is the one that proves the
real DeepSeek path.
"""

from __future__ import annotations

import os
import uuid
from collections.abc import AsyncIterator
from contextlib import asynccontextmanager
from decimal import Decimal
from typing import Any

import pytest


def _infra_available() -> bool:
    return bool(os.getenv("MEIDA_RUN_INTEGRATION"))


pytestmark = [
    pytest.mark.integration,
    pytest.mark.skipif(
        not _infra_available(),
        reason="set MEIDA_RUN_INTEGRATION=1 with PostgreSQL and Redis running",
    ),
]


class FakeProvider:
    """替换真实 provider：集成用例验证配额与计量链路，不该花钱也不该受网络影响。"""

    name = "deepseek"
    default_model = "deepseek-v4-flash"

    async def complete(self, request: Any) -> Any:
        from packages.llm.types import ProviderResponse, Usage

        return ProviderResponse(
            text="建议白衬衫配西裤。",
            model="deepseek-v4-flash",
            usage=Usage(tokens_in=800, tokens_out=120, tokens_cached=600),
        )

    async def aclose(self) -> None:
        return None


@asynccontextmanager
async def fake_client(app: Any) -> AsyncIterator[Any]:
    """起 app lifespan + ASGI 客户端，并把 deepseek 换成 FakeProvider。"""
    import httpx

    transport = httpx.ASGITransport(app=app)
    async with (
        httpx.AsyncClient(transport=transport, base_url="http://test") as http,
        app.router.lifespan_context(app),
    ):
        app.state.llm_gateway._providers["deepseek"] = FakeProvider()
        yield http


@pytest.fixture
async def client() -> Any:
    from apps.api.main import create_app
    from packages.shared.config import get_settings

    async with fake_client(create_app(get_settings())) as http:
        yield http


async def test_chat_slice_reserves_commits_and_records_cost(client: Any) -> None:
    token_resp = await client.post(
        "/api/v1/auth/dev-token", json={"device_key": f"it-{uuid.uuid4().hex[:8]}"}
    )
    assert token_resp.json()["code"] == 0
    headers = {"Authorization": f"Bearer {token_resp.json()['data']['access_token']}"}

    before = (await client.get("/api/v1/quota", headers=headers)).json()["data"]

    chat = await client.post("/api/v1/agent/chat", json={"message": "面试穿什么"}, headers=headers)
    body = chat.json()
    assert body["code"] == 0
    assert body["data"]["reply"]
    assert body["data"]["prompt_version"] == "v1"
    assert Decimal(body["data"]["usage"]["cost_cents"]) > 0

    after = (await client.get("/api/v1/quota", headers=headers)).json()["data"]
    assert after["used"] == before["used"] + 1

    ledger = (await client.get("/api/v1/quota/ledger", headers=headers)).json()["data"]
    assert ledger[0]["tx_type"] == "consume"
    assert ledger[0]["status"] == "committed"


async def test_alias_path_v1_matches_api_v1(client: Any) -> None:
    assert (await client.get("/healthz")).status_code == 200
    token = await client.post("/v1/auth/dev-token", json={"device_key": "alias-check"})
    assert token.json()["code"] == 0


async def test_unauthenticated_requests_get_the_unified_envelope(client: Any) -> None:
    resp = await client.post("/api/v1/agent/chat", json={"message": "hi"})
    assert resp.status_code == 401
    assert resp.json()["code"] == 40100


async def test_block_all_budget_rejects_and_refunds_the_reservation(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    """T-P1-25b：reserve 之后才触发熔断 → gateway 拒绝 → refund → 净扣减 = 0。

    这是四档降级（架构 §13.3）的验收路径：把 block_all 档的 allow 名单清空
    （连纯文本对话也拦），让 agent_chat 走 100% 档的既有 60003 语义，从而
    断言配额三段式在「先预扣、后熔断」时的补偿行为。
    """
    import json

    from apps.api.main import create_app
    from packages.llm.budget import DailyBudgetGuard, InMemoryCostCounter
    from packages.shared.config import get_settings
    from packages.shared.redis_client import get_redis

    monkeypatch.setenv("LLM_DAILY_BUDGET_CENTS", "1")  # 预算 1 分钱
    monkeypatch.setenv(
        "LLM_BUDGET_TIERS_JSON",
        json.dumps(
            [
                {"threshold": 0.6, "name": "warn", "blocked": []},
                {"threshold": 0.8, "name": "degrade_secondary", "blocked": ["hd_export"]},
                {"threshold": 0.9, "name": "degrade_generation", "blocked": ["hairstyle"]},
                # allow 清空：agent_chat 也被 block_all 拦下（演练配置）
                {"threshold": 1.0, "name": "block_all", "blocked": "*", "allow": []},
            ]
        ),
    )
    get_settings.cache_clear()
    try:
        app = create_app(get_settings())
        async with fake_client(app) as http:
            redis = get_redis()
            # 注入当日成本到预算以上（键格式照 DailyBudgetGuard.current_key()）
            key_helper = DailyBudgetGuard(InMemoryCostCounter(), daily_budget_cents=Decimal("1"))
            cost_key = key_helper.current_key()
            await redis.incrbyfloat(cost_key, 5)

            token_resp = await http.post(
                "/api/v1/auth/dev-token", json={"device_key": f"it-{uuid.uuid4().hex[:8]}"}
            )
            headers = {"Authorization": f"Bearer {token_resp.json()['data']['access_token']}"}

            resp = await http.post(
                "/api/v1/agent/chat", json={"message": "面试穿什么"}, headers=headers
            )
            assert resp.json()["code"] == 60003  # LLM_DAILY_BUDGET_EXCEEDED

            # 被拒请求的配额净扣减 = 0：consume(-1, refunded) + refund(+1, committed)
            rows = (await http.get("/api/v1/quota/ledger", headers=headers)).json()["data"]
            consume = [r for r in rows if r["tx_type"] == "consume"]
            refunds = [r for r in rows if r["tx_type"] == "refund"]
            assert len(consume) == 1 and consume[0]["status"] == "refunded"
            assert len(refunds) == 1 and refunds[0]["delta"] == 1
            assert sum(r["delta"] for r in (*consume, *refunds)) == 0

            await redis.delete(cost_key)
    finally:
        # 恢复全局 settings 缓存，避免本用例的环境覆盖渗进其它用例
        monkeypatch.undo()
        get_settings.cache_clear()