using ytLive.Helpers;
using ytLive.Services;

namespace ytLive.ViewModels;

public partial class MainViewModel
{
    // TASK 10 — Polar license validation
    private string _licenseKey = string.Empty;
    private string _licenseMessage = string.Empty;
    private bool _isLicenseValidating;
    private bool _isLicenseEntryOpen;
    private static readonly TimeSpan OfflineGracePeriod = TimeSpan.FromDays(14);

    /// <summary>True when the user holds a valid LlamaCasty license (Polar). When
    /// false, the branding flash runs on every live stream.</summary>
    private bool _isPremium;
    public bool IsPremium
    {
        get => _isPremium;
        private set
        {
            if (!SetProperty(ref _isPremium, value)) return;
            // Flip the branding flash when premium state changes.
            BrandFlashEnabled = !value;
        }
    }

    // TASK 10 — license key entry
    public string LicenseKey
    {
        get => _licenseKey;
        set => SetProperty(ref _licenseKey, value);
    }

    public string LicenseMessage
    {
        get => _licenseMessage;
        private set => SetProperty(ref _licenseMessage, value);
    }

    public bool IsLicenseValidating
    {
        get => _isLicenseValidating;
        private set => SetProperty(ref _isLicenseValidating, value);
    }

    public bool IsLicenseEntryOpen
    {
        get => _isLicenseEntryOpen;
        set
        {
            if (SetProperty(ref _isLicenseEntryOpen, value))
                OnPropertyChanged(nameof(IsHubVisible));
        }
    }

    /// <summary>The About hub is visible only when neither the licenses panel
    /// nor the license entry panel is open.</summary>
    public bool IsHubVisible => !IsLicensesOpen && !IsLicenseEntryOpen;

    // ─── TASK 10 — Polar license validation ───

    /// <summary>At startup, load the cached license state and re-validate online
    /// if a key exists. If offline and within the 14-day grace period, the cached
    /// premium state is trusted. If the grace period is exceeded, premium lapses.</summary>
    private async Task ValidateLicenseAtStartupAsync()
    {
        var savedKey = _layoutStore.LoadLicenseKey();
        if (string.IsNullOrWhiteSpace(savedKey))
        {
            IsPremium = false;
            return;
        }

        LicenseKey = savedKey;
        var validatedAt = _layoutStore.LoadLicenseValidatedAt();
        var cachedPremium = _layoutStore.LoadIsPremium();

        // If the last validation was within the grace period, trust the cache
        // while we attempt an online re-validation in the background.
        if (validatedAt.HasValue && DateTime.UtcNow - validatedAt.Value < OfflineGracePeriod)
        {
            IsPremium = cachedPremium;
        }

        // Try an online check — if it succeeds, it overrides the cache.
        try
        {
            var service = new PolarLicenseService();
            var result = await service.ValidateAsync(savedKey);
            if (result.IsValid)
            {
                IsPremium = true;
                _layoutStore.SaveIsPremium(true);
                _layoutStore.SaveLicenseValidatedAt(DateTime.UtcNow);
            }
            else
            {
                // Key revoked or expired — clear premium.
                IsPremium = false;
                _layoutStore.SaveIsPremium(false);
                _layoutStore.SaveLicenseValidatedAt(DateTime.UtcNow);
                AppLog.Write($"License validation failed: {result.Error}");
                _notifications.Warning("Premium is no longer active",
                    $"{result.Error} — watermark branding returns until the license is renewed.");
            }
        }
        catch (Exception ex)
        {
            // Offline or network error — keep the cached state, log it.
            AppLog.Write($"License re-validation skipped (offline?): {ex.Message}");
            if (!validatedAt.HasValue || DateTime.UtcNow - validatedAt.Value >= OfflineGracePeriod)
            {
                IsPremium = false;
                _layoutStore.SaveIsPremium(false);
            }
        }
    }

    /// <summary>Called from the Activate button in the About overlay. Validates
    /// the entered key, persists it, and flips premium state.</summary>
    private async Task ActivateLicenseAsync()
    {
        if (string.IsNullOrWhiteSpace(LicenseKey)) return;

        IsLicenseValidating = true;
        LicenseMessage = "Validating\u2026";

        try
        {
            var service = new PolarLicenseService();
            var result = await service.ValidateAsync(LicenseKey);
            if (result.IsValid)
            {
                IsPremium = true;
                _layoutStore.SaveLicenseKey(LicenseKey.Trim());
                _layoutStore.SaveIsPremium(true);
                _layoutStore.SaveLicenseValidatedAt(DateTime.UtcNow);
                LicenseMessage = "Premium activated! The watermark has been removed.";
                AppLog.Write("License activated successfully");
            }
            else
            {
                IsPremium = false;
                _layoutStore.SaveLicenseKey(null);
                _layoutStore.SaveIsPremium(false);
                LicenseMessage = result.Error ?? "Invalid license key.";
                AppLog.Write($"License activation failed: {result.Error}");
            }
        }
        catch (Exception ex)
        {
            LicenseMessage = $"Activation error: {ex.Message}";
            AppLog.Write($"License activation error: {ex}");
        }
        finally
        {
            IsLicenseValidating = false;
        }
    }
}