from __future__ import annotations

import threading
import time
from types import SimpleNamespace

from exporter.config import DeviceConfig, GlobalConfig
from exporter.models import DeviceHealthState, DeviceMetricsSnapshot
from exporter.registry import DeviceRegistry, DeviceRuntimeState
from exporter.scraper import run_one_scrape_round, scrape_device, scraper_loop


class DummyConnectionManager:
    def __init__(self) -> None:
        self.acquired = []
        self.invalidated = []

    def acquire_session(self, cfg: DeviceConfig):
        self.acquired.append(cfg.name)
        return SimpleNamespace()  # manager 对象对测试无关紧要

    def mark_session_invalid(self, name: str) -> None:
        self.invalidated.append(name)

    def close_all(self) -> None:  # pragma: no cover - not used here
        pass


def test_scrape_device_success_updates_cache_and_health_and_registry():
    global_cfg = GlobalConfig()
    global_cfg.scrape_interval_seconds = 10
    global_cfg.failure_threshold = 3
    global_cfg.max_backoff_factor = 8

    dev_cfg = DeviceConfig(
        name="dev1",
        host="1.1.1.1",
        port=830,
        username="u",
        password="p",
    )

    registry = DeviceRegistry(global_scrape_interval=global_cfg.scrape_interval_seconds)
    registry.register_static_device(dev_cfg)
    state = registry.get_enabled_devices(time.time())[0]

    cm = DummyConnectionManager()

    # 构造一个包含简单 transceiver/channel 的 XML
    xml_reply = """
    <rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
      <data>
        <components xmlns="http://openconfig.net/yang/platform">
          <component>
            <name>comp1</name>
            <state>
              <type>TRANSCEIVER</type>
              <temperature><instant>40.0</instant></temperature>
            </state>
            <transceiver xmlns="http://openconfig.net/yang/platform/transceiver">
              <state>
                <present>PRESENT</present>
                <vendor>H3C</vendor>
                <serial-no>SN001</serial-no>
              </state>
              <physical-channels>
                <channel>
                  <index>0</index>
                  <state>
                    <description>1/0/1:1</description>
                    <output-power><instant>-2.5</instant></output-power>
                  </state>
                </channel>
              </physical-channels>
            </transceiver>
          </component>
        </components>
      </data>
    </rpc-reply>
    """.strip()

    def fake_get_rpc(_mgr, _flt: str) -> str:
        return xml_reply

    cache: dict[str, DeviceMetricsSnapshot] = {}
    health: dict[str, DeviceHealthState] = {}

    now = time.time()
    scrape_device(
        now,
        state,
        registry,
        cm,
        fake_get_rpc,
        cache,
        health,
        global_cfg,
        failure_threshold=global_cfg.failure_threshold,
        max_backoff_factor=global_cfg.max_backoff_factor,
    )

    # cache 中应有快照，且包含一个 transceiver 和一个 channel
    assert "dev1" in cache
    snapshot = cache["dev1"]
    assert len(snapshot.transceivers) == 1
    assert len(snapshot.channels) == 1

    # health 状态应标记为成功
    hs = health["dev1"]
    assert hs.last_scrape_success is True
    assert hs.last_error_type is None

    # registry 的调度状态应更新（下次采集时间向后推进）
    state_after = registry.get_enabled_devices(now + 100)[0]
    assert state_after.next_scrape_at > now


def test_scrape_device_failure_updates_health_and_invalidates_session(monkeypatch):
    global_cfg = GlobalConfig()
    global_cfg.scrape_interval_seconds = 10
    global_cfg.failure_threshold = 1
    global_cfg.max_backoff_factor = 8

    dev_cfg = DeviceConfig(
        name="dev2",
        host="1.1.1.2",
        port=830,
        username="u",
        password="p",
    )

    registry = DeviceRegistry(global_scrape_interval=global_cfg.scrape_interval_seconds)
    registry.register_static_device(dev_cfg)
    state = registry.get_enabled_devices(time.time())[0]

    cm = DummyConnectionManager()

    def failing_get_rpc(_mgr, _flt: str) -> str:
        raise RuntimeError("filter failed")

    cache: dict[str, DeviceMetricsSnapshot] = {}
    health: dict[str, DeviceHealthState] = {}

    now = time.time()
    scrape_device(
        now,
        state,
        registry,
        cm,
        failing_get_rpc,
        cache,
        health,
        global_cfg,
        failure_threshold=global_cfg.failure_threshold,
        max_backoff_factor=global_cfg.max_backoff_factor,
    )

    # cache 中不应有 dev2 的快照
    assert "dev2" not in cache

    # health 状态应为失败，且 error_type 为 FilterError
    hs = health["dev2"]
    assert hs.last_scrape_success is False
    assert hs.last_error_type == "FilterError"

    # 连接应被标记为无效
    assert "dev2" in cm.invalidated


def test_run_one_scrape_round_invokes_scrape_for_enabled_devices(monkeypatch):
    global_cfg = GlobalConfig()
    global_cfg.scrape_interval_seconds = 5
    global_cfg.failure_threshold = 3
    global_cfg.max_backoff_factor = 8

    dev_cfg = DeviceConfig(
        name="dev3",
        host="1.1.1.3",
        port=830,
        username="u",
        password="p",
    )

    registry = DeviceRegistry(global_scrape_interval=global_cfg.scrape_interval_seconds)
    registry.register_static_device(dev_cfg)
    state = registry.get_enabled_devices(time.time())[0]

    cm = DummyConnectionManager()

    def fake_get_rpc(_mgr, _flt: str) -> str:
        # 返回最小合法 XML
        return """
        <rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
          <data>
            <components xmlns="http://openconfig.net/yang/platform">
              <component>
                <name>compX</name>
                <state><type>TRANSCEIVER</type></state>
                <transceiver xmlns="http://openconfig.net/yang/platform/transceiver">
                  <physical-channels>
                    <channel>
                      <index>0</index>
                      <state></state>
                    </channel>
                  </physical-channels>
                </transceiver>
              </component>
            </components>
          </data>
        </rpc-reply>
        """.strip()

    cache: dict[str, DeviceMetricsSnapshot] = {}
    health: dict[str, DeviceHealthState] = {}

    now = time.time()
    # 调用 run_one_scrape_round，确保会调用到 scrape_device
    run_one_scrape_round(
        now,
        registry,
        cm,
        fake_get_rpc,
        cache,
        health,
        global_cfg,
        failure_threshold=global_cfg.failure_threshold,
        max_backoff_factor=global_cfg.max_backoff_factor,
    )

    # dev3 应该被采集一次，并产生快照
    assert "dev3" in cache
    assert "dev3" in health


def test_scraper_loop_covers_wait_true_and_false(monkeypatch):
    """
    覆盖 scraper_loop 中 stop_event.wait 的 True/False 两个分支，
    以及 while 条件的退出分支。
    """
    global_cfg = GlobalConfig()
    global_cfg.scrape_interval_seconds = 0  # 立即触发多轮调度

    registry = DeviceRegistry(global_scrape_interval=global_cfg.scrape_interval_seconds)
    cm = DummyConnectionManager()

    # 使用计数器控制 run_one_scrape_round 调用次数
    call_count = {"n": 0}

    def fake_get_rpc(_mgr, _flt: str) -> str:
        # 返回最小合法 XML
        return """
        <rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
          <data>
            <components xmlns="http://openconfig.net/yang/platform">
              <component>
                <name>compY</name>
                <state><type>TRANSCEIVER</type></state>
              </component>
            </components>
          </data>
        </rpc-reply>
        """.strip()

    cache: dict[str, DeviceMetricsSnapshot] = {}
    health: dict[str, DeviceHealthState] = {}

    # monkeypatch run_one_scrape_round，使其在第二次调用时设置 stop_event
    from exporter import scraper as scraper_mod

    real_run_one = scraper_mod.run_one_scrape_round

    def counting_run_one(
        now: float,
        registry_: DeviceRegistry,
        connection_manager_,
        netconf_get_rpc_,
        cache_,
        health_,
        global_cfg_,
        failure_threshold: int,
        max_backoff_factor: int,
    ):
        call_count["n"] += 1
        if call_count["n"] >= 2:
            # 第二次调用后设置 stop_event，确保有一次 wait 返回 False，一次返回 True
            stop_event.set()
        return real_run_one(
            now,
            registry_,
            connection_manager_,
            netconf_get_rpc_,
            cache_,
            health_,
            global_cfg_,
            failure_threshold,
            max_backoff_factor,
        )

    monkeypatch.setattr(scraper_mod, "run_one_scrape_round", counting_run_one)

    stop_event = threading.Event()
    t = threading.Thread(
        target=scraper_loop,
        args=(stop_event, registry, cm, fake_get_rpc, cache, health, global_cfg),
        daemon=True,
    )
    t.start()
    t.join(timeout=5.0)

    # 至少调用了两次 run_one_scrape_round（一次 wait=False，一次 wait=True）
    assert call_count["n"] >= 2


def test_scrape_device_preserves_existing_health_entry():
    """
    第二次采集同一设备时，health 字典中已存在条目，应走 device in health 分支。
    """
    global_cfg = GlobalConfig()
    dev_cfg = DeviceConfig(
        name="dev4",
        host="1.1.1.4",
        port=830,
        username="u",
        password="p",
    )

    registry = DeviceRegistry(global_scrape_interval=global_cfg.scrape_interval_seconds)
    registry.register_static_device(dev_cfg)
    state = registry.get_enabled_devices(time.time())[0]

    cm = DummyConnectionManager()

    xml_reply = """
    <rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
      <data>
        <components xmlns="http://openconfig.net/yang/platform">
          <component>
            <name>compZ</name>
            <state><type>TRANSCEIVER</type></state>
            <transceiver xmlns="http://openconfig.net/yang/platform/transceiver">
              <physical-channels>
                <channel>
                  <index>0</index>
                  <state></state>
                </channel>
              </physical-channels>
            </transceiver>
          </component>
        </components>
      </data>
    </rpc-reply>
    """.strip()

    def fake_get_rpc(_mgr, _flt: str) -> str:
        return xml_reply

    cache: dict[str, DeviceMetricsSnapshot] = {}
    health: dict[str, DeviceHealthState] = {}

    now = time.time()
    # 第一次采集，health 中还没有 dev4
    scrape_device(
        now,
        state,
        registry,
        cm,
        fake_get_rpc,
        cache,
        health,
        global_cfg,
        failure_threshold=global_cfg.failure_threshold,
        max_backoff_factor=global_cfg.max_backoff_factor,
    )
    assert "dev4" in health

    # 第二次采集，应走 device 已存在分支
    scrape_device(
        now + 1,
        state,
        registry,
        cm,
        fake_get_rpc,
        cache,
        health,
        global_cfg,
        failure_threshold=global_cfg.failure_threshold,
        max_backoff_factor=global_cfg.max_backoff_factor,
    )
    # health 条目仍然存在且状态为成功
    assert health["dev4"].last_scrape_success is True