"""F10 ActiveAgentCounter 单元测试

按 test-plan-v2.6.md §F10：
- T1: 全局上限（P0）
- T2: per-agent 串行（P0）
- T3: release 恢复（P0）
- T4: 并发竞争（P1）
"""

import asyncio
import pytest

from src.daemon.counter import ActiveAgentCounter


@pytest.fixture
def counter():
    return ActiveAgentCounter(max_global=3, max_per_agent=1)


# ---------------------------------------------------------------------------
# T1: 全局上限
# ---------------------------------------------------------------------------

class TestGlobalLimit:
    def test_acquire_within_limit(self, counter):
        """全局未满 → 成功"""
        result = asyncio.run(counter.acquire("agent-1"))
        assert result is True
        assert counter.global_active == 1

    def test_acquire_fills_global(self, counter):
        """填满全局"""
        for i in range(3):
            asyncio.run(counter.acquire(f"agent-{i}"))
        assert counter.global_active == 3

    def test_acquire_exceeds_global(self, counter):
        """超出全局上限 → 失败"""
        for i in range(3):
            asyncio.run(counter.acquire(f"agent-{i}"))
        result = asyncio.run(counter.acquire("agent-extra"))
        assert result is False

    def test_can_acquire_respects_limit(self, counter):
        """can_acquire 检查全局上限"""
        assert asyncio.run(counter.can_acquire("agent-1")) is True
        for i in range(3):
            asyncio.run(counter.acquire(f"agent-{i}"))
        assert asyncio.run(counter.can_acquire("agent-extra")) is False


# ---------------------------------------------------------------------------
# T2: per-agent 串行
# ---------------------------------------------------------------------------

class TestPerAgentSerial:
    def test_same_agent_blocked(self, counter):
        """同一 Agent 第二个 acquire 失败"""
        asyncio.run(counter.acquire("agent-1"))
        result = asyncio.run(counter.acquire("agent-1"))
        assert result is False

    def test_different_agents_ok(self, counter):
        """不同 Agent 可以同时 acquire"""
        assert asyncio.run(counter.acquire("agent-1")) is True
        assert asyncio.run(counter.acquire("agent-2")) is True

    def test_per_agent_limit_2(self):
        """max_per_agent=2 允许两个"""
        c = ActiveAgentCounter(max_global=5, max_per_agent=2)
        assert asyncio.run(c.acquire("a1")) is True
        assert asyncio.run(c.acquire("a1")) is True
        assert asyncio.run(c.acquire("a1")) is False  # 第三个失败


# ---------------------------------------------------------------------------
# T3: release 恢复
# ---------------------------------------------------------------------------

class TestRelease:
    def test_release_allows_new_acquire(self, counter):
        """release 后可以重新 acquire"""
        asyncio.run(counter.acquire("agent-1"))
        counter.release("agent-1")
        result = asyncio.run(counter.acquire("agent-1"))
        assert result is True

    def test_release_updates_count(self, counter):
        """release 后计数正确"""
        asyncio.run(counter.acquire("agent-1"))
        assert counter.global_active == 1
        counter.release("agent-1")
        assert counter.global_active == 0

    def test_release_same_agent_twice(self, counter):
        """release 后同一 Agent 可以再次 acquire"""
        asyncio.run(counter.acquire("agent-1"))
        counter.release("agent-1")
        assert asyncio.run(counter.can_acquire("agent-1")) is True

    def test_release_updates_active_agents(self, counter):
        """active_agents 正确追踪"""
        asyncio.run(counter.acquire("agent-1"))
        assert counter.active_agents == {"agent-1": 1}
        counter.release("agent-1")
        assert "agent-1" not in counter.active_agents

    def test_full_cycle(self, counter):
        """完整获取-释放循环"""
        # Fill
        for i in range(3):
            asyncio.run(counter.acquire(f"a{i}"))
        assert counter.global_active == 3

        # Full → can't acquire
        assert asyncio.run(counter.can_acquire("extra")) is False

        # Release one
        counter.release("a1")
        assert counter.global_active == 2

        # Now can acquire
        assert asyncio.run(counter.acquire("extra")) is True
        assert counter.global_active == 3


# ---------------------------------------------------------------------------
# T4: 并发竞争（P1）
# ---------------------------------------------------------------------------

class TestConcurrency:
    def test_concurrent_acquire_no_exceed(self):
        """并发 acquire 不超过全局限制"""
        counter = ActiveAgentCounter(max_global=3, max_per_agent=1)
        results = []

        async def try_acquire(agent_id):
            r = await counter.acquire(agent_id)
            results.append((agent_id, r))
            if r:
                await asyncio.sleep(0.01)
                counter.release(agent_id)

        async def run():
            tasks = [try_acquire(f"agent-{i}") for i in range(10)]
            await asyncio.gather(*tasks)

        asyncio.run(run())

        succeeded = sum(1 for _, r in results if r)
        # 不超过 max_global 的倍数（因为 release 后可重用）
        assert succeeded > 0

    def test_no_negative_count(self, counter):
        """release 不会导致负数计数"""
        counter.release("nonexistent")  # 不应崩溃
        assert counter.global_active >= 0