"""契约测试共享 fixture: 后端参数化(M1 仅 memory,M2 增 redis 零改测试)。

FakeClock 仅对支持时钟注入的后端有效(memory);M2 接入 Redis 后端时,
依赖时钟推进的用例按后端能力跳过或改用真实等待。
"""

import pytest

from polygateway.backends.memory.breaker import InMemoryGate
from polygateway.backends.memory.limiter import InMemoryLimiter
from polygateway.types import BreakerConfig, GlobalLimits, SourceConfig


class FakeClock:
    """确定性单调时钟;契约测试推进时间验证租约/冷却语义。"""

    def __init__(self, start: float = 1000.0) -> None:
        self.t = start

    def __call__(self) -> float:
        return self.t

    def advance(self, seconds: float) -> None:
        self.t += seconds


def make_source(name: str = "s1", **overrides) -> SourceConfig:
    base = dict(
        name=name, provider="openai", base_url="https://gw.example/v1",
        api_key="sk-test", model="m", timeout_s=10.0,
    )
    base.update(overrides)
    return SourceConfig(**base)


@pytest.fixture
def clock() -> FakeClock:
    return FakeClock()


@pytest.fixture(params=["memory"])
def limiter_factory(request, clock):
    """返回 (sources, global_limits, lease_ttl_s) -> RateLimiter 的工厂。"""

    def make(sources: list[SourceConfig], global_limits: GlobalLimits, lease_ttl_s: float = 100.0):
        return InMemoryLimiter(
            scope="llm", sources={s.name: s for s in sources},
            global_limits=global_limits, lease_ttl_s=lease_ttl_s, now=clock,
        )

    return make


@pytest.fixture(params=["memory"])
def gate_factory(request, clock):
    """返回 (BreakerConfig) -> ProviderGate 的工厂。"""

    def make(config: BreakerConfig):
        return InMemoryGate(config=config, now=clock)

    return make