using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.ComponentModel;
using System.Linq;
using System.Reactive.Linq;
using System.Threading;
using CommunityToolkit.Mvvm.ComponentModel;
using FuzzySharp;
using Microsoft.Extensions.Logging;
using StabilityMatrix.Avalonia.ViewModels.Base;
using StabilityMatrix.Avalonia.Views.Dialogs;
using StabilityMatrix.Core.Attributes;
using StabilityMatrix.Core.Helper.Cache;
using StabilityMatrix.Core.Models;

namespace StabilityMatrix.Avalonia.ViewModels.Dialogs;

[View(typeof(LaunchOptionsDialog))]
[ManagedService]
[Transient]
public partial class LaunchOptionsViewModel : ContentDialogViewModelBase
{
    private readonly ILogger<LaunchOptionsViewModel> logger;
    private readonly LRUCache<string, ImmutableList<LaunchOptionCard>> cache = new(100);

    [ObservableProperty]
    private string title = "Launch Options";

    [ObservableProperty]
    private bool isSearchBoxEnabled = true;

    [ObservableProperty]
    private string searchText = string.Empty;

    [ObservableProperty]
    private IReadOnlyList<LaunchOptionCard>? filteredCards;

    public IReadOnlyList<LaunchOptionCard>? Cards { get; set; }

    /// <summary>
    /// Return cards that match the search text
    /// </summary>
    private IReadOnlyList<LaunchOptionCard>? GetFilteredCards(string? text)
    {
        if (string.IsNullOrWhiteSpace(text) || text.Length < 2)
        {
            return Cards;
        }
        // Try cache
        if (cache.Get(text, out var cachedCards))
        {
            return cachedCards!;
        }

        var searchCard = new LaunchOptionCard
        {
            Title = text.ToLowerInvariant(),
            Type = LaunchOptionType.Bool,
            Options = Array.Empty<LaunchOption>()
        };

        var extracted = Process.ExtractTop(searchCard, Cards, c => c.Title.ToLowerInvariant());
        var results = extracted.Where(r => r.Score > 40).Select(r => r.Value).ToImmutableList();
        cache.Add(text, results);
        return results;
    }

    public void UpdateFilterCards() => FilteredCards = GetFilteredCards(SearchText);

    public LaunchOptionsViewModel(ILogger<LaunchOptionsViewModel> logger)
    {
        this.logger = logger;

        Observable
            .FromEventPattern<PropertyChangedEventArgs>(this, nameof(PropertyChanged))
            .Where(x => x.EventArgs.PropertyName == nameof(SearchText))
            .Throttle(TimeSpan.FromMilliseconds(50))
            .Select(_ => SearchText)
            .ObserveOn(SynchronizationContext.Current!)
            .Subscribe(
                text => FilteredCards = GetFilteredCards(text),
                err => logger.LogError(err, "Error while filtering launch options")
            );
    }

    public override void OnLoaded()
    {
        base.OnLoaded();
        UpdateFilterCards();
    }

    /// <summary>
    /// Export the current cards options to a list of strings
    /// </summary>
    public List<LaunchOption> AsLaunchArgs()
    {
        var launchArgs = new List<LaunchOption>();
        if (Cards is null)
            return launchArgs;

        foreach (var card in Cards)
        {
            launchArgs.AddRange(card.Options);
        }
        return launchArgs;
    }
}