import xml.etree.ElementTree as ET

import pytest

from exporter.netconf_client import (
    build_transceiver_filter,
    parse_netconf_response,
    parse_port_and_channel,
)


def test_build_transceiver_filter_contains_expected_paths():
    flt = build_transceiver_filter()
    assert "<components" in flt
    assert "platform/transceiver" in flt


SAMPLE_XML = """\
<rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <data>
    <components xmlns="http://openconfig.net/yang/platform">
      <component>
        <name>323.FourHundredGigE1/0/66</name>
        <state>
          <type>TRANSCEIVER</type>
          <temperature>
            <instant>45.5</instant>
          </temperature>
        </state>
        <transceiver xmlns="http://openconfig.net/yang/platform/transceiver">
          <state>
            <present>PRESENT</present>
            <vendor>Cisco</vendor>
            <serial-no>ABC123</serial-no>
          </state>
          <physical-channels>
            <channel>
              <index>0</index>
              <state>
                <description>1/0/66:1</description>
                <output-power><instant>-2.5</instant></output-power>
              </state>
            </channel>
          </physical-channels>
        </transceiver>
      </component>
    </components>
  </data>
</rpc-reply>
"""


def test_parse_transceiver_basic():
    txs, chs = parse_netconf_response(SAMPLE_XML, "dev1")
    assert len(txs) == 1
    r = txs[0]
    assert r.device == "dev1"
    assert r.component_name == "323.FourHundredGigE1/0/66"
    assert r.temperature_c == 45.5
    assert r.vendor == "Cisco"
    assert r.serial == "ABC123"
    assert r.logical_port == "1/0/66"
    assert len(chs) == 1


def test_parse_channel_and_description():
    _, chs = parse_netconf_response(SAMPLE_XML, "dev1")
    assert len(chs) == 1
    ch = chs[0]
    assert ch.logical_port == "1/0/66"
    assert ch.logical_channel == "1/0/66:1"
    assert ch.tx_power_dbm == -2.5


def test_missing_temperature_not_fatal():
    root = ET.fromstring(SAMPLE_XML)
    # remove temperature node
    ns_platform = "{http://openconfig.net/yang/platform}"
    temp_elem = root.find(f".//{ns_platform}temperature")
    parent = root.find(f".//{ns_platform}state")
    if temp_elem is not None and parent is not None:
        parent.remove(temp_elem)
    xml_no_temp = ET.tostring(root, encoding="unicode")

    txs, _ = parse_netconf_response(xml_no_temp, "dev1")
    assert txs[0].temperature_c is None


def test_invalid_power_filtered():
    xml_invalid = SAMPLE_XML.replace("-2.5", "2147483647.00")
    _, chs = parse_netconf_response(xml_invalid, "dev1")
    assert chs[0].tx_power_dbm is None


@pytest.mark.parametrize(
    "description, component_name, index, expected_port, expected_channel",
    [
        (None, "comp1", 0, "comp1", "comp1:ch0"),
        ("", "comp1", 1, "comp1", "comp1:ch1"),
        ("1/0/1:1", "comp1", 2, "1/0/1", "1/0/1:1"),
        ("GigabitEthernet1/0/1", "comp1", 3, "GigabitEthernet1/0/1", "GigabitEthernet1/0/1:ch3"),
    ],
)
def test_parse_port_and_channel_fallbacks(
    description, component_name, index, expected_port, expected_channel
):
    lp, lc = parse_port_and_channel(description, component_name, index)
    assert lp == expected_port
    assert lc == expected_channel


def test_multiple_channels_missing_description_produce_unique_logical_channel():
    xml = """\
<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></state>
        <transceiver xmlns="http://openconfig.net/yang/platform/transceiver">
          <physical-channels>
            <channel>
              <index>0</index>
              <state></state>
            </channel>
            <channel>
              <index>1</index>
              <state></state>
            </channel>
          </physical-channels>
        </transceiver>
      </component>
    </components>
  </data>
</rpc-reply>
"""
    _, channels = parse_netconf_response(xml, "dev1")
    assert len(channels) == 2
    ch0 = next(c for c in channels if c.channel_index == 0)
    ch1 = next(c for c in channels if c.channel_index == 1)
    assert ch0.logical_port == "comp1"
    assert ch1.logical_port == "comp1"
    assert ch0.logical_channel != ch1.logical_channel


def test_h3c_multi_component_same_serial():
    xml_multi = """\
<rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <data>
    <components xmlns="http://openconfig.net/yang/platform">
      <component>
        <name>63.TwoHundredGigE1/0/1:1</name>
        <state><type>TRANSCEIVER</type></state>
        <transceiver xmlns="http://openconfig.net/yang/platform/transceiver">
          <state><serial-no>SN001</serial-no></state>
        </transceiver>
      </component>
      <component>
        <name>64.TwoHundredGigE1/0/1:2</name>
        <state><type>TRANSCEIVER</type></state>
        <transceiver xmlns="http://openconfig.net/yang/platform/transceiver">
          <state><serial-no>SN001</serial-no></state>
        </transceiver>
      </component>
    </components>
  </data>
</rpc-reply>
"""
    txs, _ = parse_netconf_response(xml_multi, "h3c")
    assert len(txs) == 2
    assert txs[0].serial == "SN001"
    assert txs[1].serial == "SN001"
    assert txs[0].component_name != txs[1].component_name


def test_prefer_config_description_over_state():
    """
    测试当 config 和 state 的 description 不一致时，优先使用 config。
    这是为了解决 H3C 设备 state/description 有时错误的问题。
    """
    xml = """\
<rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <data>
    <components xmlns="http://openconfig.net/yang/platform">
      <component>
        <name>67.TwoHundredGigE1/0/2:1</name>
        <state><type>TRANSCEIVER</type></state>
        <transceiver xmlns="http://openconfig.net/yang/platform/transceiver">
          <physical-channels>
            <channel>
              <index>1</index>
              <config>
                <description>1/0/2:1</description>
              </config>
              <state>
                <description>1/0/2:1</description>
                <output-power><instant>1.53</instant></output-power>
              </state>
            </channel>
            <channel>
              <index>2</index>
              <config>
                <description>1/0/2:2</description>
              </config>
              <state>
                <description>1/0/1:2</description>
                <input-power><instant>1.07</instant></input-power>
              </state>
            </channel>
          </physical-channels>
        </transceiver>
      </component>
    </components>
  </data>
</rpc-reply>
"""
    _, channels = parse_netconf_response(xml, "h3c-device")
    assert len(channels) == 2

    ch1 = next(c for c in channels if c.channel_index == 1)
    ch2 = next(c for c in channels if c.channel_index == 2)

    # 验证 channel 1: config 和 state 一致，结果应该是 1/0/2:1
    assert ch1.logical_port == "1/0/2"
    assert ch1.logical_channel == "1/0/2:1"
    assert ch1.tx_power_dbm == 1.53

    # 验证 channel 2: config 是 1/0/2:2，state 是错误的 1/0/1:2
    # 应该优先使用 config 的值
    assert ch2.logical_port == "1/0/2"  # 从 config 的 1/0/2:2 解析
    assert ch2.logical_channel == "1/0/2:2"  # 使用 config 的值
    assert ch2.rx_power_dbm == 1.07

    # 验证两个 channel 的 port 一致（都是 1/0/2）
    assert ch1.logical_port == ch2.logical_port


def test_fallback_to_state_when_config_missing():
    """
    测试当 config/description 不存在时，fallback 到 state/description。
    """
    xml = """\
<rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
  <data>
    <components xmlns="http://openconfig.net/yang/platform">
      <component>
        <name>test-component</name>
        <state><type>TRANSCEIVER</type></state>
        <transceiver xmlns="http://openconfig.net/yang/platform/transceiver">
          <physical-channels>
            <channel>
              <index>1</index>
              <state>
                <description>1/0/5:1</description>
              </state>
            </channel>
          </physical-channels>
        </transceiver>
      </component>
    </components>
  </data>
</rpc-reply>
"""
    _, channels = parse_netconf_response(xml, "device")
    assert len(channels) == 1

    ch = channels[0]
    # 没有 config，应该 fallback 到 state
    assert ch.logical_port == "1/0/5"
    assert ch.logical_channel == "1/0/5:1"