using GB5Shared.DTO.Framework.Login;
using Microsoft.AspNetCore.SignalR;

namespace AutomationSL.Hubs;

// Live log-tail hub for RunDetailComponent — built once as a persona-agnostic hub (Admin/Dev/
// PowerUser all connect to the same hub and just join the run group(s) they're viewing), per the
// spec's own advice not to build three separate log viewers.
public class AutomationRunHub : Hub<IAutomationRunClient>
{
    private readonly ILogger<AutomationRunHub> _logger;

    public AutomationRunHub(ILogger<AutomationRunHub> logger) => _logger = logger;

    public override async Task OnConnectedAsync()
    {
        var login = GetLoginDTO();
        await Groups.AddToGroupAsync(Context.ConnectionId, TenantGroup(login.ClientId));
        _logger.LogInformation("AutomationRunHub connected: {ConnectionId} ClientId {ClientId}", Context.ConnectionId, login.ClientId);
        await base.OnConnectedAsync();
    }

    public override async Task OnDisconnectedAsync(Exception? exception)
    {
        if (exception is not null)
            _logger.LogWarning(exception, "AutomationRunHub disconnected with error: {ConnectionId}", Context.ConnectionId);
        // Per-run groups joined via JoinRunGroup are torn down automatically by SignalR's default
        // in-memory group manager when the connection is removed — no manual per-run bookkeeping
        // needed here (unlike the tenant group, which is fixed for the connection's lifetime).
        await base.OnDisconnectedAsync(exception);
    }

    // Client calls this once it knows which run it's watching (e.g. opening RunDetailComponent) —
    // OnConnectedAsync alone can't know the RunId, unlike a fixed per-session/OU group.
    public async Task JoinRunGroup(long runId)
        => await Groups.AddToGroupAsync(Context.ConnectionId, RunGroup(runId));

    public async Task LeaveRunGroup(long runId)
        => await Groups.RemoveFromGroupAsync(Context.ConnectionId, RunGroup(runId));

    private LoginDTO GetLoginDTO()
    {
        var http = Context.GetHttpContext()
            ?? throw new InvalidOperationException("Hub invoked outside HTTP context.");
        var raw = http.Request.Headers["Login"].FirstOrDefault()
            ?? throw new InvalidOperationException("Login header missing.");
        return System.Text.Json.JsonSerializer.Deserialize<LoginDTO>(raw)
            ?? throw new InvalidOperationException("Login header is invalid JSON.");
    }

    public static string RunGroup(long runId)      => $"automation:run:{runId}";
    public static string TenantGroup(int clientId) => $"automation:client:{clientId}";
}