using System.Collections.ObjectModel;
using System.Linq;
using ytLive.Helpers;
using ytLive.Models;

namespace ytLive.ViewModels;

/// <summary>
/// The left panel's alert stack (creator design, 2026-11-05): standing state on top, transient events
/// beneath it, newest first, pushing the panel's content down. Only red rows belong here — the panel
/// is where "something needs you" lives, so it never fills with chatter.
/// <para><b>Row 1 is the Steam licence indicator</b> and nothing displaces it. It is pinned while
/// higher output tiers are unavailable, and becomes dismissible — permanently — once ownership is
/// verified. If ownership is later lost, it comes back as a pinned indicator, because that is a change
/// of state rather than a preference.</para>
/// </summary>
public partial class MainViewModel
{
    private const string SteamLicenceAlertId = "steam-licence";

    private readonly ObservableCollection<AttentionAlert> _attentionAlerts = new();
    private bool _steamLicenceDismissed;

    public ObservableCollection<AttentionAlert> AttentionAlerts => _attentionAlerts;

    public bool HasAttentionAlerts => _attentionAlerts.Count > 0;

    public RelayCommand<AttentionAlert> DismissAlertCommand => new(DismissAlert);

    public RelayCommand<AttentionAlert> ActivateAlertCommand => new(ActivateAlert);

    /// <summary>The licence indicator's text (creator wording, 2026-11-05): the limit this build runs
    /// at, plus where to find out why. Not a warning — the resolution picker explains the detail, and
    /// clicking the row opens About.</summary>
    private string SteamLicenceText()
    {
        var entitled = 30;
        if (QualityOptions.Length > 0)
        {
            entitled = QualityOptions
                .Where(option => HasProOutput || !option.RequiresPro)
                .Select(option => option.Fps)
                .DefaultIfEmpty(30)
                .Max();
        }
        return $"Steam ID Limit: {entitled}fps\nClick for More Info";
    }

    /// <summary>Recomputes row 1 in place. Called at startup and whenever ownership changes.</summary>
    private void RefreshSteamLicenceAlert()
    {
        var existing = _attentionAlerts.FirstOrDefault(alert => alert.Id == SteamLicenceAlertId);
        var hidden = IsAppOwned && _steamLicenceDismissed;

        if (hidden)
        {
            if (existing != null) _attentionAlerts.Remove(existing);
            RaiseAttentionChanged();
            return;
        }

        var alert = new AttentionAlert(
            SteamLicenceAlertId,
            SteamLicenceText(),
            IsPinned: !IsAppOwned,
            AttentionAlertAction.About);

        var index = existing == null ? -1 : _attentionAlerts.IndexOf(existing);
        if (index < 0) _attentionAlerts.Insert(0, alert);
        else _attentionAlerts[index] = alert;   // same row, updated state
        RaiseAttentionChanged();
    }

    /// <summary>Pushes an event alert. Newest sits directly under the licence indicator; older ones
    /// stack beneath, so the newest is the one nearest the eye.</summary>
    private AttentionAlert? PushAttentionAlert(string id, string text, long logFrom, long logTo)
    {
        var alert = new AttentionAlert(id, text, IsPinned: false, AttentionAlertAction.Logs, logFrom, logTo);
        var insertAt = _attentionAlerts.Count(alert => alert.Id == SteamLicenceAlertId);
        var existing = _attentionAlerts.FirstOrDefault(candidate => candidate.Id == id);
        if (existing != null)
        {
            // Same event advancing (reconnecting attempt 2 → 3): update the row, never duplicate it.
            _attentionAlerts[_attentionAlerts.IndexOf(existing)] = alert;
        }
        else
        {
            _attentionAlerts.Insert(insertAt, alert);
        }
        RaiseAttentionChanged();
        return alert;
    }

    /// <summary>Test seam: pushes an event row without a stream session behind it.</summary>
    internal AttentionAlert? PushAttentionAlertForTest(string id, string text, long logFrom, long logTo)
        => PushAttentionAlert(id, text, logFrom, logTo);

    private void RemoveAttentionAlert(string id)
    {
        var existing = _attentionAlerts.FirstOrDefault(alert => alert.Id == id);
        if (existing == null) return;
        _attentionAlerts.Remove(existing);
        RaiseAttentionChanged();
    }

    private void DismissAlert(AttentionAlert? alert)
    {
        if (alert == null || alert.IsPinned) return;

        if (alert.Id == SteamLicenceAlertId)
        {
            // Permanent for this profile: the creator said "I have seen it". Only honoured while
            // ownership holds — RefreshSteamLicenceAlert ignores it when Steam stops confirming.
            _steamLicenceDismissed = true;
            _layoutStore.SaveSteamLicenceIndicatorDismissed(true);
        }

        RemoveAttentionAlert(alert.Id);
    }

    private void ActivateAlert(AttentionAlert? alert)
    {
        if (alert == null) return;

        if (alert.Action == AttentionAlertAction.About)
        {
            ShowAbout();
            return;
        }

        // Event alert: open the log and paint this event's lines, so the alert is an entry point to
        // the detail rather than a dead end.
        HighlightLogRange(alert.LogFrom, alert.LogTo);
        SelectLogsTab(true);
    }

    private void RaiseAttentionChanged() => OnPropertyChanged(nameof(HasAttentionAlerts));
}