using LANCommander.Launcher.Data;
using LANCommander.Launcher.Data.Models;
using LANCommander.Launcher.Models;
using LANCommander.Launcher.Services.Extensions;
using LANCommander.SDK;
using LANCommander.SDK.Extensions;
using LANCommander.SDK.Helpers;
using LANCommander.SDK.PowerShell;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Linq;
using System.Management.Automation.Language;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace LANCommander.Launcher.Services
{
    public class LibraryService : BaseService
    {
        private readonly DownloadService DownloadService;
        private readonly GameService GameService;
        private readonly SaveService SaveService;
        private readonly PlaySessionService PlaySessionService;
        private readonly RedistributableService RedistributableService;
        private readonly ImportService ImportService;
        private readonly MessageBusService MessageBusService;

        public Dictionary<Guid, Process> RunningProcesses = new Dictionary<Guid, Process>();

        public ObservableCollection<LibraryItem> LibraryItems { get; set; } = new ObservableCollection<LibraryItem>();

        public delegate Task OnLibraryChangedHandler(IEnumerable<LibraryItem> items);
        public event OnLibraryChangedHandler OnLibraryChanged;

        public delegate Task OnPreLibraryItemsFilteredHandler(IEnumerable<LibraryItem> items);
        public event OnPreLibraryItemsFilteredHandler OnPreLibraryItemsFiltered;

        public delegate Task OnLibraryItemsFilteredHandler(IEnumerable<LibraryItem> items);
        public event OnLibraryItemsFilteredHandler OnLibraryItemsFiltered;

        public Func<LibraryItem, string[]> GroupSelector { get; set; } = _ => new string[] { };

        public LibraryService(
            SDK.Client client,
            ILogger<LibraryService> logger,
            DownloadService downloadService,
            GameService gameService,
            SaveService saveService,
            PlaySessionService playSessionService,
            RedistributableService redistributableService,
            ImportService importService,
            MessageBusService messageBusService) : base(client, logger)
        {
            DownloadService = downloadService;
            GameService = gameService;
            SaveService = saveService;
            PlaySessionService = playSessionService;
            RedistributableService = redistributableService;
            ImportService = importService;
            MessageBusService = messageBusService;

            DownloadService.OnInstallComplete += DownloadService_OnInstallComplete;
            ImportService.OnImportComplete += ImportService_OnImportComplete;
        }

        private async Task ImportService_OnImportComplete()
        {
            await RefreshLibraryItemsAsync();

            LibraryChanged();
        }

        private async Task DownloadService_OnInstallComplete(Game game)
        {
            if (OnLibraryChanged != null)
                await OnLibraryChanged.Invoke(LibraryItems);
        }

        public async Task<IEnumerable<LibraryItem>> RefreshLibraryItemsAsync()
        {
            LibraryItems = new ObservableCollection<LibraryItem>(await GetLibraryItemsAsync());

            return LibraryItems;
        }

        public IEnumerable<LibraryItem> GetLibraryItems<T>()
        {
            return LibraryItems.Where(i => i.DataItem is T).DistinctBy(i => i.Key);
        }

        public async Task<IEnumerable<LibraryItem>> GetLibraryItemsAsync()
        {
            var settings = SettingService.GetSettings();

            LibraryItems.Clear();

            using (var op = Logger.BeginOperation(LogLevel.Trace, "Loading library items from local database"))
            {
                var games = await GameService.Get(x => true).AsNoTracking().ToListAsync();

                switch (settings.Filter.GroupBy)
                {
                    case Models.Enums.GroupBy.None:
                        GroupSelector = (g) => new string[] { };
                        break;
                    case Models.Enums.GroupBy.Collection:
                        GroupSelector = (g) => (g.DataItem as Game).Collections.Select(c => c.Name).ToArray();
                        break;
                    case Models.Enums.GroupBy.Genre:
                        GroupSelector = (g) => (g.DataItem as Game).Genres.Select(ge => ge.Name).ToArray();
                        break;
                    case Models.Enums.GroupBy.Platform:
                        GroupSelector = (g) => (g.DataItem as Game).Platforms.Select(p => p.Name).ToArray();
                        break;
                }

                foreach (var item in games.Select(g => new LibraryItem(g, GroupSelector)).OrderByTitle(g => !String.IsNullOrWhiteSpace(g.SortName) ? g.SortName : g.Name))
                {
                    LibraryItems.Add(item);
                }

                op.Complete();
            }

            return await FilterLibraryItems(LibraryItems);
        }

        async Task<IEnumerable<LibraryItem>> FilterLibraryItems(IEnumerable<LibraryItem> items)
        {
            var settings = SettingService.GetSettings();

            using (var op = Logger.BeginOperation(LogLevel.Trace, "Filtering library items"))
            {
                if (OnPreLibraryItemsFiltered != null)
                    await OnPreLibraryItemsFiltered.Invoke(items);

                if (!String.IsNullOrWhiteSpace(settings.Filter.Title))
                    items = items.Where(i => i.Name?.IndexOf(settings.Filter.Title, StringComparison.OrdinalIgnoreCase) >= 0 || i.SortName?.IndexOf(settings.Filter.Title, StringComparison.OrdinalIgnoreCase) >= 0);

                if (settings.Filter.Engines != null && settings.Filter.Engines.Any())
                    items = items.Where(i => settings.Filter.Engines.Any(e => e == (i.DataItem as Game)?.Engine?.Name));

                if (settings.Filter.Genres != null && settings.Filter.Genres.Any())
                    items = items.Where(i => settings.Filter.Genres.Any(fg => (i.DataItem as Game).Genres.Any(g => fg == g.Name)));

                if (settings.Filter.Tags != null && settings.Filter.Tags.Any())
                    items = items.Where(i => settings.Filter.Tags.Any(ft => (i.DataItem as Game).Tags.Any(t => ft == t.Name)));

                if (settings.Filter.Developers != null && settings.Filter.Developers.Any())
                    items = items.Where(i => settings.Filter.Developers.Any(fc => (i.DataItem as Game).Developers.Any(c => fc == c.Name)));

                if (settings.Filter.Publishers != null && settings.Filter.Publishers.Any())
                    items = items.Where(i => settings.Filter.Publishers.Any(fc => (i.DataItem as Game).Publishers.Any(c => fc == c.Name)));

                if (settings.Filter.MinPlayers != null)
                    items = items.Where(i => (i.DataItem as Game).MultiplayerModes.Any(mm => mm.MinPlayers <= settings.Filter.MinPlayers && mm.MaxPlayers >= settings.Filter.MinPlayers));

                if (settings.Filter.MaxPlayers != null)
                    items = items.Where(i => (i.DataItem as Game).MultiplayerModes.Any(mm => mm.MaxPlayers <= settings.Filter.MaxPlayers));

                if (settings.Filter.Installed)
                    items = items.Where(i => (i.DataItem as Game).Installed);

                if (OnLibraryItemsFiltered != null)
                    await OnLibraryItemsFiltered.Invoke(items);

                op.Complete();
            }

            return items;
        }

        public LibraryItem GetLibraryItem(Guid key)
        {
            var item = LibraryItems.FirstOrDefault(i => i.Key == key);

            if (item == null)
                item = LibraryItems.FirstOrDefault(i => i.Key == key);

            return item;
        }

        public async Task<LibraryItem> GetLibraryItemAsync(LibraryItem libraryItem)
        {
            return await GetLibraryItemAsync(libraryItem.Key);
        }

        public async Task<LibraryItem> GetLibraryItemAsync(Guid key)
        {
            var game = await GameService.Get(key);

            return new LibraryItem(game, GroupSelector);
        }

        public async Task Install(LibraryItem libraryItem, string installDirectory = "")
        {
            var game = libraryItem.DataItem as Game;

            await DownloadService.Add(game, installDirectory);
        }

        public async Task LibraryChanged()
        {
            if (OnLibraryChanged != null)
                await OnLibraryChanged.Invoke(LibraryItems);
        }

        public async Task FilterChanged()
        {
            LibraryItems = new ObservableCollection<LibraryItem>(await GetLibraryItemsAsync());
        }
    }
}