using System.Text.Json;
using System.Text.Json.Serialization;
using Fleet.Core;

namespace Monitor.Protocol;

/// <summary>monitor.* 方法名。新增方法 = 在这里定义名称和 params/result，再在组装处加一行 <c>.On(...)</c>。</summary>
public static class MonitorMethods
{
    public const string TestRun = "monitor.test.run";
    public const string TestCancel = "monitor.test.cancel";
    public const string ProbeDisconnect = "monitor.probe.disconnect";
    public const string TestStatus = "monitor.test.status";
    public const string Event = "monitor.event";
    public const string Host = "monitor.host";
    public const string ProbeAgents = "monitor.probe.agents";
    public const string ProbeAgentsChanged = "monitor.probe.agents_changed";

    // Probe ↔ Agent（点对点会话）
    public const string Clock = "monitor.clock";
    public const string TestPhase = "monitor.test.phase";
    public const string TestPhaseEnd = "monitor.test.phase_end";
    public const string TestAbort = "monitor.test.abort";
}

public static class AgentEventKinds
{
    public const string ProbeConnected = "probe_connected";
    public const string ProbeDisconnected = "probe_disconnected";
    public const string EndpointChanged = "endpoint_changed";
    public const string SessionRejected = "session_rejected";
    public const string ClockStep = "clock_step";
    public const string Gap = "gap";
    public const string CpuSaturated = "cpu_saturated";

    public static readonly IReadOnlyList<string> All =
        [ProbeConnected, ProbeDisconnected, EndpointChanged, SessionRejected, ClockStep, Gap, CpuSaturated];
}

public static class TestStatuses
{
    public const string Queued = "queued";
    public const string Running = "running";
    public const string PhaseDone = "phase_done";
    public const string Succeeded = "succeeded";
    public const string Failed = "failed";
    public const string Aborted = "aborted";
}

public sealed class TestPhase
{
    [JsonPropertyName("kind")]
    public string Kind { get; set; } = "";

    [JsonPropertyName("params")]
    public Dictionary<string, JsonElement> Params { get; set; } = [];

    [JsonPropertyName("duration_s")]
    public int DurationSeconds { get; set; }
}

public sealed class TestRunParams
{
    [JsonPropertyName("test_id")]
    public TestId TestId { get; set; }

    /// <summary>在哪个 Probe 上运行：必须是当前连着这个 Agent 的 Probe。</summary>
    [JsonPropertyName("probe_id")]
    public ProbeId ProbeId { get; set; }

    [JsonPropertyName("plan")]
    public string Plan { get; set; } = "";

    [JsonPropertyName("phases")]
    public List<TestPhase> Phases { get; set; } = [];
}

public sealed class TestRunResult
{
    [JsonPropertyName("accepted")]
    public bool Accepted { get; set; }
}

public sealed class TestCancelParams
{
    [JsonPropertyName("test_id")]
    public TestId TestId { get; set; }
}

/// <summary>Backend → Agent：断开某个 Probe 的会话（Probe 会按退避重连，除非它已经被吊销）。</summary>
public sealed class ProbeDisconnectParams
{
    [JsonPropertyName("probe_id")]
    public ProbeId ProbeId { get; set; }
}

public sealed class TestStatusParams
{
    [JsonPropertyName("test_id")]
    public TestId TestId { get; set; }

    [JsonPropertyName("status")]
    public string Status { get; set; } = "";

    [JsonPropertyName("phase")]
    public int? Phase { get; set; }

    [JsonPropertyName("error_code")]
    public string? ErrorCode { get; set; }
}

public sealed class AgentEventParams
{
    /// <summary><c>probe_connected</c> 时：这个 Probe 的 id、版本、地址和连接时间（Backend 不用等下一次心跳就能显示）。</summary>
    [JsonPropertyName("probe")]
    public ConnectedProbe? Probe { get; set; }

    [JsonPropertyName("kind")]
    public string Kind { get; set; } = "";

    [JsonPropertyName("at_utc_ms")]
    public long AtUtcMs { get; set; }

    [JsonPropertyName("detail")]
    public string? Detail { get; set; }
}

public sealed class AgentEndpoint
{
    [JsonPropertyName("agent_id")]
    public NodeId AgentId { get; set; }

    [JsonPropertyName("name")]
    public string Name { get; set; } = "";

    [JsonPropertyName("host")]
    public string Host { get; set; } = "";

    [JsonPropertyName("tcp_port")]
    public int TcpPort { get; set; }

    [JsonPropertyName("udp_ports")]
    public List<int> UdpPorts { get; set; } = [];

    /// <summary>Agent 面向 Probe 的 TLS 证书指纹（SHA-256，base64）。</summary>
    [JsonPropertyName("spki")]
    public string Spki { get; set; } = "";
}

public sealed class ProbeAgentsParams
{
    /// <summary>Probe 目前持有的列表版本（用于调试；服务端总是返回当前列表）。</summary>
    [JsonPropertyName("have_version")]
    public long HaveVersion { get; set; }
}

public sealed class ProbeAgentsResult
{
    [JsonPropertyName("version")]
    public long Version { get; set; }

    [JsonPropertyName("agents")]
    public List<AgentEndpoint> Agents { get; set; } = [];
}

/// <summary>注册元数据（Monitor 定义，经 Fleet 的 <c>meta</c> 字段带上来）。</summary>
public sealed class AgentEnrollMeta
{
    [JsonPropertyName("probe_tcp_port")]
    public int ProbeTcpPort { get; set; } = 7443;

    [JsonPropertyName("probe_udp_ports")]
    public List<int> ProbeUdpPorts { get; set; } = [7443];

    [JsonPropertyName("public_host")]
    public string? PublicHost { get; set; }

    [JsonPropertyName("kinds")]
    public List<string> Kinds { get; set; } = [];
}

public sealed class LocalLimits
{
    [JsonPropertyName("max_total_mbps")]
    public double MaxTotalMbps { get; set; }

    [JsonPropertyName("max_total_pps")]
    public long MaxTotalPps { get; set; }

    [JsonPropertyName("allowed_target_cidrs")]
    public List<string> AllowedTargetCidrs { get; set; } = [];

    [JsonPropertyName("max_concurrent_tests")]
    public int MaxConcurrentTests { get; set; } = 1;
}

/// <summary><c>fleet.hello</c> 的附加字段。</summary>
public sealed class AgentHelloMeta
{
    [JsonPropertyName("tls_spki")]
    public string? TlsSpki { get; set; }

    [JsonPropertyName("probe_tcp_port")]
    public int? ProbeTcpPort { get; set; }

    [JsonPropertyName("probe_udp_ports")]
    public List<int>? ProbeUdpPorts { get; set; }

    [JsonPropertyName("local_limits")]
    public LocalLimits? LocalLimits { get; set; }
}

/// <summary>
/// 主机资源占用的只读快照（Agent → Backend，每隔几秒一次）。只有汇总的数字：<b>没有 CPU 型号、主机名、网卡名，也没有任何 IP 地址</b>。
/// 读不到的项是 null。
/// </summary>
public sealed class HostSnapshot
{
    [JsonPropertyName("cpu_percent")]
    public double? CpuPercent { get; set; }

    [JsonPropertyName("mem_used")]
    public long? MemUsed { get; set; }

    [JsonPropertyName("mem_total")]
    public long? MemTotal { get; set; }

    [JsonPropertyName("disk_used")]
    public long? DiskUsed { get; set; }

    [JsonPropertyName("disk_total")]
    public long? DiskTotal { get; set; }

    /// <summary>所有物理网卡的累计收发字节（自开机以来）。</summary>
    [JsonPropertyName("net_rx_total")]
    public long? NetRxTotal { get; set; }

    [JsonPropertyName("net_tx_total")]
    public long? NetTxTotal { get; set; }

    [JsonPropertyName("net_rx_bps")]
    public long? NetRxBps { get; set; }

    [JsonPropertyName("net_tx_bps")]
    public long? NetTxBps { get; set; }

    [JsonPropertyName("uptime_s")]
    public long? UptimeSeconds { get; set; }

    [JsonPropertyName("at_utc_ms")]
    public long AtUtcMs { get; set; }
}

/// <summary>Agent 眼中的一个已连接 Probe。</summary>
public sealed class ConnectedProbe
{
    [JsonPropertyName("id")]
    public ProbeId Id { get; set; }

    [JsonPropertyName("version")]
    public string? Version { get; set; }

    /// <summary>Probe 的远端地址（经过 NAT 之后的公网 IP:端口）。</summary>
    [JsonPropertyName("remote")]
    public string? Remote { get; set; }

    [JsonPropertyName("since_utc_ms")]
    public long SinceUtcMs { get; set; }
}

/// <summary><c>fleet.heartbeat</c> 的附加字段：只有进程内的计数，没有主机信息。</summary>
public sealed class AgentHeartbeatExtra
{
    /// <summary>当前连着的 Probe 会话数（等于 <see cref="Probes"/> 的个数）。</summary>
    [JsonPropertyName("sessions")]
    public int Sessions { get; set; }

    /// <summary>当前连着的 Probe：每次心跳都是完整的快照，Backend 靠它纠正错过的 probe_connected / probe_disconnected 事件。</summary>
    [JsonPropertyName("probes")]
    public List<ConnectedProbe> Probes { get; set; } = [];

    [JsonPropertyName("pps_in")]
    public long PpsIn { get; set; }

    [JsonPropertyName("pps_out")]
    public long PpsOut { get; set; }

    [JsonPropertyName("dropped_invalid")]
    public long DroppedInvalid { get; set; }

    [JsonPropertyName("dropped_rate_limited")]
    public long DroppedRateLimited { get; set; }

    [JsonPropertyName("queue_bytes")]
    public long QueueBytes { get; set; }
}

/// <summary>Agent 下发给 Probe 的一条线路任务（期望状态类型 <c>line_task_set</c> 里的一项）。</summary>
public sealed class LineTask
{
    [JsonPropertyName("id")]
    public TaskId Id { get; set; }

    [JsonPropertyName("kind")]
    public string Kind { get; set; } = "";

    [JsonPropertyName("params")]
    public Dictionary<string, JsonElement> Params { get; set; } = [];

    /// <summary>数据面用它区分任务；Agent 在本进程生命周期内分配。</summary>
    [JsonPropertyName("stream_id")]
    public uint StreamId { get; set; }

    [JsonPropertyName("port")]
    public int Port { get; set; }
}

/// <summary>这条线路的期望状态（Agent → Probe）：Probe 按它调和自己一侧的角色。</summary>
public sealed class LineTaskSet
{
    public const string StateType = "line_task_set";

    [JsonPropertyName("version")]
    public long Version { get; set; }

    [JsonPropertyName("tasks")]
    public List<LineTask> Tasks { get; set; } = [];

    /// <summary>Agent 的数据面端口（Probe 把包发到这里）。</summary>
    [JsonPropertyName("udp_ports")]
    public List<int> UdpPorts { get; set; } = [];

    [JsonPropertyName("tcp_ports")]
    public List<int> TcpPorts { get; set; } = [];
}

/// <summary><c>monitor.clock</c>：Probe 用它估计与 Agent 单调时钟的偏移（对称往返假设）。</summary>
public sealed class ClockParams
{
    [JsonPropertyName("probe_mono_us")]
    public long ProbeMonoUs { get; set; }
}

public sealed class ClockResult
{
    [JsonPropertyName("agent_mono_us")]
    public long AgentMonoUs { get; set; }
}

/// <summary>按需测试的一个阶段（Agent → Probe）：Agent 编排时间，Probe 准备好自己一侧的角色之后应答。</summary>
public sealed class TestPhaseStartParams
{
    [JsonPropertyName("test_id")]
    public TestId TestId { get; set; }

    [JsonPropertyName("phase")]
    public int Phase { get; set; }

    [JsonPropertyName("kind")]
    public string Kind { get; set; } = "";

    [JsonPropertyName("params")]
    public Dictionary<string, JsonElement> Params { get; set; } = [];

    [JsonPropertyName("stream_id")]
    public uint StreamId { get; set; }

    [JsonPropertyName("duration_s")]
    public int DurationSeconds { get; set; }

    [JsonPropertyName("port")]
    public int Port { get; set; }
}

public sealed class TestPhaseStartResult
{
    [JsonPropertyName("accepted")]
    public bool Accepted { get; set; }
}

/// <summary>阶段结束（Agent → Probe）：Probe 收尾并把自己一侧的列块交给 Agent。<c>sent_count</c> 是 Agent 一侧发出的包数（单向数据流用）。</summary>
public sealed class TestPhaseEndParams
{
    [JsonPropertyName("test_id")]
    public TestId TestId { get; set; }

    [JsonPropertyName("phase")]
    public int Phase { get; set; }

    [JsonPropertyName("stream_id")]
    public uint StreamId { get; set; }

    [JsonPropertyName("sent_count")]
    public long SentCount { get; set; }
}

/// <summary>Probe 收尾之后回复：它交给 Agent 的列块个数（Agent 据此等待全部列块到齐再进入下一阶段）。</summary>
public sealed class TestPhaseEndResult
{
    [JsonPropertyName("fragments")]
    public int Fragments { get; set; }
}

public sealed class TestAbortParams
{
    [JsonPropertyName("test_id")]
    public TestId TestId { get; set; }
}

/// <summary>Probe 一侧的列块放在 RawChunk 头部 params 里的保留键：本块覆盖的序号范围 [from, to)（单向数据流由 Agent 一侧按它取行）。</summary>
public static class FragmentKeys
{
    public const string SeqFrom = "_seq_from";
    public const string SeqTo = "_seq_to";
}

[JsonSourceGenerationOptions(DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull)]
[JsonSerializable(typeof(LineTaskSet))]
[JsonSerializable(typeof(ClockParams))]
[JsonSerializable(typeof(ClockResult))]
[JsonSerializable(typeof(TestPhaseStartParams))]
[JsonSerializable(typeof(TestPhaseStartResult))]
[JsonSerializable(typeof(TestPhaseEndParams))]
[JsonSerializable(typeof(TestPhaseEndResult))]
[JsonSerializable(typeof(TestAbortParams))]
[JsonSerializable(typeof(TaskSet))]
[JsonSerializable(typeof(TestRunParams))]
[JsonSerializable(typeof(TestRunResult))]
[JsonSerializable(typeof(TestCancelParams))]
[JsonSerializable(typeof(ProbeDisconnectParams))]
[JsonSerializable(typeof(HostSnapshot))]
[JsonSerializable(typeof(TestStatusParams))]
[JsonSerializable(typeof(AgentEventParams))]
[JsonSerializable(typeof(ProbeAgentsParams))]
[JsonSerializable(typeof(ProbeAgentsResult))]
[JsonSerializable(typeof(AgentEnrollMeta))]
[JsonSerializable(typeof(AgentHelloMeta))]
[JsonSerializable(typeof(AgentHeartbeatExtra))]
[JsonSerializable(typeof(RawChunkHeader))]
public sealed partial class MonitorJsonContext : JsonSerializerContext;