using System.Globalization;
using OpenAC.MosswartMassacre.Backend;
using OpenAC.MosswartMassacre.Infrastructure;

namespace OpenAC.MosswartMassacre.Streams;

/// <summary>
/// The <c>telemetry</c> frame: sent right after the socket registers and then
/// every five seconds, as the original's socket loop did.
/// </summary>
/// <remarks>
/// Several fields are strings on the wire (kill rate, deaths, taper count) and
/// <c>mem_mb</c> carries bytes; the backend reads them that way.
/// </remarks>
internal sealed class TelemetryStream : IMmFeature, IBackendConnectionListener
{
    public static readonly TimeSpan Interval = TimeSpan.FromSeconds(5);

    private readonly MmContext _context;
    private readonly SessionStats _stats;
    private readonly ProcessTelemetry _process = new();
    private IDisposable? _timer;

    public TelemetryStream(MmContext context, SessionStats stats)
    {
        _context = context;
        _stats = stats;
    }

    public void OnBackendConnected()
    {
        if (!_context.IsLoggedIn)
            return;
        SendNow();
        _timer?.Dispose();
        _timer = _context.Scheduler.Every(Interval, SendNow);
    }

    public void OnLogin()
    {
    }

    public void OnLogoff()
    {
        _timer?.Dispose();
        _timer = null;
    }

    public void Dispose() => OnLogoff();

    internal void SendNow()
    {
        if (!_context.IsLoggedIn)
            return;
        _context.Send(Build());
    }

    internal object Build()
    {
        MmCoordinates coords = MmCoordinates.From(_context.Automation.Navigation.Snapshot.Position);
        var kills = _stats.Kills;
        return new
        {
            type = "telemetry",
            character_name = _context.CharacterName,
            char_tag = _context.Settings.Current.CharTag ?? "",
            session_id = _context.TelemetrySessionId,
            timestamp = Wire.Timestamp(_context.Clock),
            ew = coords.EW,
            ns = coords.NS,
            z = coords.Z,
            kills = kills.TotalKills,
            kills_per_hour = FrameworkNumberConverter.FrameworkFixed(kills.KillsPerHour, "F0", CultureInfo.CurrentCulture),
            onlinetime = (_context.Clock.Now - kills.StatsStartTime).ToString(@"dd\.hh\:mm\:ss", CultureInfo.InvariantCulture),
            deaths = kills.SessionDeaths.ToString(CultureInfo.CurrentCulture),
            total_deaths = kills.TotalDeaths.ToString(CultureInfo.CurrentCulture),
            prismatic_taper_count = _context.PrismaticTaperCount().ToString(CultureInfo.CurrentCulture),
            vt_state = _context.MetaState() ?? string.Empty,
            mem_mb = _process.MemoryBytes,
            cpu_pct = _process.SampleCpuUsage(),
            mem_handles = _process.HandleCount,
        };
    }
}