using MoShiro.Protocol;

namespace MoShiro.Measurement;

/// <summary>
/// 一种采集方法（Kind）的两个角色：拨号方（Probe）和监听方（Agent），以及它能不能作为目标任务（Agent 自己探测一个地址，没有对端）运行。
/// 积木只按机制命名、只产生原始列，不知道上层的方案或协议。
/// </summary>
public sealed record BlockPair(
    string Kind,
    Func<BlockEnv, BlockSpec, IBlock> Dialer,
    Func<BlockEnv, BlockSpec, IBlock>? Listener,
    bool RunsAsTarget = false,
    bool OnDemandOnly = false,
    IReadOnlyList<string>? Directions = null)
{
    /// <summary>这个 Kind 支持 <paramref name="direction"/> 吗（没有 <c>direction</c> 参数的 Kind 传 null）。</summary>
    public bool Supports(string? direction) => Directions is null || direction is null || Directions.Contains(direction);
}

/// <summary>
/// 积木目录：新增一种采集方法 = 在 <see cref="Kinds"/> 里加一条声明，在这里加一行，实现它的两个角色。Probe 和 Agent 同时获得。
/// hello 里上报的 capabilities、本地预算检查的支持列表都从这里推出来，不再手写。
/// </summary>
public static class BlockCatalog
{
    public static readonly IReadOnlyList<BlockPair> All =
    [
        new("udp_echo", (e, s) => new UdpEchoDialer(e, s), (e, s) => new UdpEchoListener(e, s)),
        new("tcp_echo", (e, s) => new TcpEchoDialer(e, s), (e, s) => new TcpEchoListener(e, s)),
        new("udp_train", (e, s) => new TrainDialer(e, s), (e, s) => new TrainListener(e, s), OnDemandOnly: true, Directions: ["rev"]),
        new("tcp_bulk", (e, s) => new TcpBulkDialer(e, s), (e, s) => new TcpBulkListener(e, s), OnDemandOnly: true, Directions: ["fwd", "rev"]),
        new("connect", (e, s) => new ConnectDialer(e, s), (e, s) => new IdleListener(e, s), RunsAsTarget: true),
        new("hold", (e, s) => new HoldDialer(e, s), (e, s) => new TcpEchoListener(e, s, record: false)),
        new("icmp_echo", (e, s) => new IcmpEchoSolo(e, s), null, RunsAsTarget: true),
    ];

    public static BlockPair? Find(string kind) => All.FirstOrDefault(p => p.Kind == kind);

    /// <summary>这个构建的 Agent 能运行的 Kind（监听方，或目标任务）。</summary>
    public static IReadOnlyList<string> AgentKinds { get; } = [.. All.Where(p => p.Listener is not null || p.RunsAsTarget).Select(p => p.Kind)];

    /// <summary>这个构建的 Probe 能运行的 Kind（有监听方可以配对的拨号方）。</summary>
    public static IReadOnlyList<string> ProbeKinds { get; } = [.. All.Where(p => p.Listener is not null).Select(p => p.Kind)];
}