using System.Globalization;
using RioJoy.Core.Profiles;

namespace RioJoy.Core.Hosting;

/// <summary>
/// The process a pod-bundled RIOJoy lives alongside (<c>--exit-with</c>):
/// either a PID or an executable name, normalized the same way auto-switch
/// triggers are (basename, no <c>.exe</c>, lower-case) so launch scripts can
/// pass whatever they have.
/// </summary>
public sealed record CompanionTarget
{
    public int? Pid { get; init; }

    /// <summary>Normalized executable name (when <see cref="Pid"/> is null).</summary>
    public string? Name { get; init; }

    public static CompanionTarget Parse(string value)
    {
        if (string.IsNullOrWhiteSpace(value))
            throw new ArgumentException("Companion target is required.", nameof(value));

        return int.TryParse(value.Trim(), NumberStyles.None, CultureInfo.InvariantCulture, out int pid)
            ? new CompanionTarget { Pid = pid }
            : new CompanionTarget { Name = AutoSwitchResolver.Normalize(value) };
    }

    public override string ToString() => Pid is int p ? $"pid {p}" : Name ?? "?";
}

/// <summary>
/// Pure decision core of <c>--exit-with</c>: RIOJoy should exit once its
/// companion game has run and then gone away. Launch order is not guaranteed
/// (the pod start script fires both), so a companion that has <i>never</i>
/// been seen only triggers exit after a startup grace — covering both "game
/// still loading" and "game failed to launch, don't linger forever". The
/// caller polls (the tray's 1 s timer) and supplies elapsed time, so this
/// stays clock-free and unit-testable.
/// </summary>
public sealed class CompanionExit
{
    public static readonly TimeSpan DefaultStartupGrace = TimeSpan.FromSeconds(60);

    private readonly TimeSpan _grace;
    private bool _seen;

    public CompanionExit(TimeSpan? startupGrace = null)
    {
        _grace = startupGrace ?? DefaultStartupGrace;
    }

    /// <summary>True once RIOJoy should tear down and exit.</summary>
    public bool ShouldExit(bool companionRunning, TimeSpan elapsed)
    {
        if (companionRunning)
        {
            _seen = true;
            return false;
        }
        return _seen || elapsed >= _grace;
    }
}