code-test-drone/utils/tests/pod_bridge/ground_link_test.py

"""ground_link_test.py —— 地面站链路单元测试。

覆盖：parse_payload 解析（合法/缺字段/非法 JSON/非对象/类型错误）、
parse_message 双通道（坐标 + {"cmd"} 命令）、命令队列 drain、
is_valid 新鲜度判定（未注入/新鲜/超龄边界）、run() 真 UDP 回环。
"""

import pytest

from pod_bridge.ground_link import (GroundCommand, GroundInjectConfig,
                                    GroundLink, GroundTarget)


# --- parse_payload ----------------------------------------------------------
def test_parse_valid_payload():
    t = GroundLink.parse_payload(
        b'{"lat": 39.9042, "lon": 116.4074, "alt": 50.0}')
    assert t is not None
    assert t.latitude_deg == pytest.approx(39.9042)
    assert t.longitude_deg == pytest.approx(116.4074)
    assert t.abs_alt_m == pytest.approx(50.0)
    assert t.time_ms == 0  # 打戳由接收方（run）负责


def test_parse_default_alt_is_zero():
    t = GroundLink.parse_payload(b'{"lat": 1.0, "lon": 2.0}')
    assert t is not None
    assert t.abs_alt_m == 0.0


def test_parse_missing_lat_returns_none():
    assert GroundLink.parse_payload(b'{"lon": 2.0}') is None


def test_parse_missing_lon_returns_none():
    assert GroundLink.parse_payload(b'{"lat": 1.0}') is None


def test_parse_invalid_json_returns_none():
    assert GroundLink.parse_payload(b'not json') is None


def test_parse_non_object_returns_none():
    assert GroundLink.parse_payload(b'[1, 2, 3]') is None


def test_parse_string_coords_returns_none():
    assert GroundLink.parse_payload(b'{"lat": "x", "lon": 2.0}') is None


def test_parse_bool_coords_returns_none():
    # True 是 bool 不是数值 → 拒绝
    assert GroundLink.parse_payload(b'{"lat": true, "lon": 2.0}') is None


def test_parse_ignores_ts_field():
    """ts 字段仅诊断，不参与解析（新鲜度用本地接收时刻）。"""
    t = GroundLink.parse_payload(b'{"lat": 1.0, "lon": 2.0, "ts": 999}')
    assert t is not None
    assert t.latitude_deg == pytest.approx(1.0)


# --- is_valid ---------------------------------------------------------------
def _link(timeout_ms=5000):
    return GroundLink(GroundInjectConfig(timeout_ms=timeout_ms),
                      now_ms_fn=lambda: 0)


def _inject(link, time_ms):
    link._target = GroundTarget(latitude_deg=1.0, longitude_deg=2.0,
                                time_ms=time_ms)


def test_is_valid_false_when_never_injected():
    assert _link().is_valid(1000) is False


def test_is_valid_true_when_fresh():
    link = _link(timeout_ms=5000)
    _inject(link, 1000)
    assert link.is_valid(1000) is True
    assert link.is_valid(4000) is True


def test_is_valid_timeout_boundary():
    link = _link(timeout_ms=5000)
    _inject(link, 1000)
    assert link.is_valid(6000) is True   # 恰好 5000ms，未超龄
    assert link.is_valid(6001) is False  # 5001ms，超龄


def test_latest_returns_injected_target():
    link = _link()
    _inject(link, 1000)
    assert link.latest().latitude_deg == pytest.approx(1.0)
    assert link.latest().time_ms == 1000


# --- parse_message（坐标 + 命令双通道）---------------------------------------
def test_parse_message_command():
    m = GroundLink.parse_message(b'{"cmd": "rtl"}')
    assert isinstance(m, GroundCommand)
    assert m.name == "rtl"


def test_parse_message_command_normalized():
    m = GroundLink.parse_message(b'{"cmd": " RTL "}')
    assert isinstance(m, GroundCommand)
    assert m.name == "rtl"


def test_parse_message_cmd_takes_precedence_over_coords():
    m = GroundLink.parse_message(b'{"cmd": "emergency", "lat": 1.0, "lon": 2.0}')
    assert isinstance(m, GroundCommand)
    assert m.name == "emergency"


def test_parse_message_coords_still_work():
    m = GroundLink.parse_message(b'{"lat": 1.0, "lon": 2.0}')
    assert isinstance(m, GroundTarget)
    assert m.latitude_deg == pytest.approx(1.0)


def test_parse_message_empty_cmd_falls_back_to_coords():
    m = GroundLink.parse_message(b'{"cmd": "", "lat": 1.0, "lon": 2.0}')
    assert isinstance(m, GroundTarget)


def test_parse_message_non_string_cmd_falls_back_to_coords():
    m = GroundLink.parse_message(b'{"cmd": 5, "lat": 1.0, "lon": 2.0}')
    assert isinstance(m, GroundTarget)


def test_parse_message_invalid_returns_none():
    assert GroundLink.parse_message(b"not json") is None


# --- drain_commands ---------------------------------------------------------
def test_drain_commands_empty():
    assert _link().drain_commands() == []


def test_drain_commands_fifo_and_clear():
    link = _link()
    link._commands.append("rtl")
    link._commands.append("pod_center")
    assert link.drain_commands() == ["rtl", "pod_center"]
    assert link.drain_commands() == []      # 取后清空


def test_commands_queue_drops_oldest_when_full():
    link = _link()
    for i in range(20):
        link._commands.append(f"c{i}")
    cmds = link.drain_commands()
    assert len(cmds) == 16                  # maxlen=16
    assert cmds[0] == "c4" and cmds[-1] == "c19"


# --- run() 真 UDP 回环（坐标 + 命令）-----------------------------------------
def test_run_receives_coords_and_commands():
    import asyncio
    import socket as socket_mod

    probe = socket_mod.socket(socket_mod.AF_INET, socket_mod.SOCK_DGRAM)
    probe.bind(("127.0.0.1", 0))
    port = probe.getsockname()[1]
    probe.close()

    link = GroundLink(GroundInjectConfig(host="127.0.0.1", port=port),
                      now_ms_fn=lambda: 1234)
    addr = ("127.0.0.1", port)

    async def scenario():
        stop = asyncio.Event()
        task = asyncio.ensure_future(link.run(stop))
        udp = socket_mod.socket(socket_mod.AF_INET, socket_mod.SOCK_DGRAM)
        try:
            for _ in range(200):            # 重发防 bind 竞态
                udp.sendto(b'{"lat": 1.5, "lon": 2.5}', addr)
                await asyncio.sleep(0.01)
                if link.latest().time_ms == 1234:
                    break
            udp.sendto(b'{"cmd": "rtl"}', addr)
            for _ in range(100):
                if link._commands:
                    break
                await asyncio.sleep(0.01)
        finally:
            udp.close()
            stop.set()
            task.cancel()  # 收包循环阻塞在 sock_recvfrom，须 cancel 唤醒（同 SITL 入口）
            try:
                await task
            except asyncio.CancelledError:
                pass

    asyncio.run(scenario())
    assert link.latest().latitude_deg == pytest.approx(1.5)
    assert link.latest().time_ms == 1234
    assert link.drain_commands() == ["rtl"]