using Content.Server.DeviceLinking.Components;
using Content.Server.DeviceLinking.Events;
using Content.Shared.UserInterface;
using Content.Shared.Access.Systems;
using Content.Shared.MachineLinking;
using Content.Shared.TextScreen;
using Robust.Server.GameObjects;
using Robust.Shared.Audio.Systems;
using Robust.Shared.Timing;

namespace Content.Server.DeviceLinking.Systems;

public sealed class SignalTimerSystem : EntitySystem
{
    [Dependency] private readonly SharedAudioSystem _audio = default!;
    [Dependency] private readonly IGameTiming _gameTiming = default!;
    [Dependency] private readonly DeviceLinkSystem _signalSystem = default!;
    [Dependency] private readonly SharedAppearanceSystem _appearanceSystem = default!;
    [Dependency] private readonly UserInterfaceSystem _ui = default!;
    [Dependency] private readonly AccessReaderSystem _accessReader = default!;

    /// <summary>
    /// Per-tick timer cache.
    /// </summary>
    private List<Entity<SignalTimerComponent>> _timers = new();

    public override void Initialize()
    {
        base.Initialize();

        SubscribeLocalEvent<SignalTimerComponent, ComponentInit>(OnInit);
        SubscribeLocalEvent<SignalTimerComponent, AfterActivatableUIOpenEvent>(OnAfterActivatableUIOpen);

        SubscribeLocalEvent<SignalTimerComponent, SignalTimerTextChangedMessage>(OnTextChangedMessage);
        SubscribeLocalEvent<SignalTimerComponent, SignalTimerDelayChangedMessage>(OnDelayChangedMessage);
        SubscribeLocalEvent<SignalTimerComponent, SignalTimerStartMessage>(OnTimerStartMessage);
        SubscribeLocalEvent<SignalTimerComponent, SignalReceivedEvent>(OnSignalReceived);
    }

    private void OnInit(EntityUid uid, SignalTimerComponent component, ComponentInit args)
    {
        _appearanceSystem.SetData(uid, TextScreenVisuals.ScreenText, component.Label);
        _signalSystem.EnsureSinkPorts(uid, component.Trigger);
    }

    private void OnAfterActivatableUIOpen(EntityUid uid, SignalTimerComponent component, AfterActivatableUIOpenEvent args)
    {
        var time = TryComp<ActiveSignalTimerComponent>(uid, out var active) ? active.TriggerTime : TimeSpan.Zero;

        if (_ui.TryGetUi(uid, SignalTimerUiKey.Key, out var bui))
        {
            _ui.SetUiState(bui, new SignalTimerBoundUserInterfaceState(component.Label,
                TimeSpan.FromSeconds(component.Delay).Minutes.ToString("D2"),
                TimeSpan.FromSeconds(component.Delay).Seconds.ToString("D2"),
                component.CanEditLabel,
                time,
                active != null,
                _accessReader.IsAllowed(args.User, uid)));
        }
    }

    /// <summary>
    ///     Finishes a timer, triggering its main port, and removing its <see cref="ActiveSignalTimerComponent"/>.
    /// </summary>
    public void Trigger(EntityUid uid, SignalTimerComponent signalTimer)
    {
        RemComp<ActiveSignalTimerComponent>(uid);

        if (TryComp<AppearanceComponent>(uid, out var appearance))
        {
            _appearanceSystem.SetData(uid, TextScreenVisuals.ScreenText, signalTimer.Label, appearance);
        }

        _audio.PlayPvs(signalTimer.DoneSound, uid);
        _signalSystem.InvokePort(uid, signalTimer.TriggerPort);

        if (_ui.TryGetUi(uid, SignalTimerUiKey.Key, out var bui))
        {
            _ui.SetUiState(bui, new SignalTimerBoundUserInterfaceState(signalTimer.Label,
                TimeSpan.FromSeconds(signalTimer.Delay).Minutes.ToString("D2"),
                TimeSpan.FromSeconds(signalTimer.Delay).Seconds.ToString("D2"),
                signalTimer.CanEditLabel,
                TimeSpan.Zero,
                false,
                true));
        }
    }

    public override void Update(float frameTime)
    {
        base.Update(frameTime);
        UpdateTimer();
    }

    private void UpdateTimer()
    {
        _timers.Clear();

        var query = EntityQueryEnumerator<ActiveSignalTimerComponent, SignalTimerComponent>();
        while (query.MoveNext(out var uid, out var active, out var timer))
        {
            if (active.TriggerTime > _gameTiming.CurTime)
                continue;

            _timers.Add((uid, timer));
        }

        foreach (var timer in _timers)
        {
            // Exploded or the likes.
            if (!Exists(timer.Owner))
                continue;

            Trigger(timer.Owner, timer.Comp);
        }
    }

    /// <summary>
    ///     Checks if a UI <paramref name="message"/> is allowed to be sent by the user.
    /// </summary>
    /// <param name="uid">The entity that is interacted with.</param>
    private bool IsMessageValid(EntityUid uid, BoundUserInterfaceMessage message)
    {
        if (message.Session.AttachedEntity is not { Valid: true } mob)
            return false;

        if (!_accessReader.IsAllowed(mob, uid))
            return false;

        return true;
    }

    /// <summary>
    ///     Called by <see cref="SignalTimerTextChangedMessage"/> to both
    ///     change the default component label, and propagate that change to the TextScreen.
    /// </summary>
    private void OnTextChangedMessage(EntityUid uid, SignalTimerComponent component, SignalTimerTextChangedMessage args)
    {
        if (!IsMessageValid(uid, args))
            return;

        component.Label = args.Text[..Math.Min(5, args.Text.Length)];

        if (!HasComp<ActiveSignalTimerComponent>(uid))
            _appearanceSystem.SetData(uid, TextScreenVisuals.ScreenText, component.Label);
    }

    /// <summary>
    ///     Called by <see cref="SignalTimerDelayChangedMessage"/> to change the <see cref="SignalTimerComponent"/>
    ///     delay, and propagate that change to a textscreen.
    /// </summary>
    private void OnDelayChangedMessage(EntityUid uid, SignalTimerComponent component, SignalTimerDelayChangedMessage args)
    {
        if (!IsMessageValid(uid, args))
            return;

        component.Delay = args.Delay.TotalSeconds;
        _appearanceSystem.SetData(uid, TextScreenVisuals.TargetTime, component.Delay);
    }

    /// <summary>
    ///     Called by <see cref="SignalTimerStartMessage"/> to instantiate an <see cref="ActiveSignalTimerComponent"/>,
    ///     clear <see cref="TextScreenVisuals.ScreenText"/>, propagate those changes, and invoke the start port.
    /// </summary>
    private void OnTimerStartMessage(EntityUid uid, SignalTimerComponent component, SignalTimerStartMessage args)
    {
        if (!IsMessageValid(uid, args))
            return;
        OnStartTimer(uid, component);
    }

    private void OnSignalReceived(EntityUid uid, SignalTimerComponent component, ref SignalReceivedEvent args)
    {
        if (args.Port == component.Trigger)
        {
            OnStartTimer(uid, component);
        }
    }

    public void OnStartTimer(EntityUid uid, SignalTimerComponent component)
    {
        TryComp<AppearanceComponent>(uid, out var appearance);
        var timer = EnsureComp<ActiveSignalTimerComponent>(uid);
        timer.TriggerTime = _gameTiming.CurTime + TimeSpan.FromSeconds(component.Delay);

        if (appearance != null)
        {
            _appearanceSystem.SetData(uid, TextScreenVisuals.TargetTime, timer.TriggerTime, appearance);
            _appearanceSystem.SetData(uid, TextScreenVisuals.ScreenText, string.Empty, appearance);
        }

        _signalSystem.InvokePort(uid, component.StartPort);
    }
}