using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Windows.Input;
using Avalonia.Controls;
using Avalonia.Media;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using ModpackUpdater.Apps.Client.Gui.LangRes;
using ModpackUpdater.Manager;
using Pilz.Extensions.Collections;

namespace ModpackUpdater.Apps.Client.Gui;

public partial class MainViewModel : ObservableObject
{
    public class EmptyRecentFilesItem;
    
    public class RecentFilesItem(string path)
    {
        public string Path => path;
        public string Display => path.Length > 50 ? $"...{path[^50..]}" : path;
    }

    private readonly UpdateCheckOptions updateOptions = new();
    private ModpackInfo modpackInfo = new();
    private ModpackConfig updateConfig = new();
    private UpdateCheckResult? lastUpdateCheckResult;
    
    [ObservableProperty] private string? minecraftProfileFolder;
    [ObservableProperty] private string? modpackConfigUrl;
    [ObservableProperty] private string? installKey;
    [ObservableProperty] private string statusText = "-";
    [ObservableProperty] private IImage? statusImage;
    [ObservableProperty] private bool hasInitialized;
    [ObservableProperty] private bool isUpdating;
    [ObservableProperty] private bool loadingData;
    [ObservableProperty] private bool canUpdate;
    [ObservableProperty] private bool canUseExtrasKey;

    public ObservableCollection<object> RecentMinecraftProfilePathItems { get; } = [];
    
    public ICommand CheckForUpdatesCommand { get; }
    public ICommand InstallCommand { get; }
    public ICommand RepairCommand { get; }

    public MainViewModel()
    {
        CheckForUpdatesCommand = new AsyncRelayCommand(async () => await CheckStatusAndUpdate(false));
        InstallCommand = new AsyncRelayCommand(async () => await ExecuteUpdate(true, false));
        RepairCommand = new AsyncRelayCommand(async () => await ExecuteUpdate(true, true));
    }

    public async Task CheckForUpdates(Window parent)
    {
        var updates = new AppUpdates("client", parent);
        updates.OnDownloadProgramUpdate += (_, _) => SetStatus(GeneralLangRes.DownloadProgramUpdate, AppGlobals.Symbols.GetImageSource(AppSymbols.software_installer));
        await updates.UpdateApp();
    }
    
    public async Task Initialize()
    {
        ClearStatus();
        LoadProfileToUi();
        LoadRecentFilesToUi();
        HasInitialized = true;
        await CheckStatusAndUpdate(true);
    }
    
    partial void OnMinecraftProfileFolderChanged(string? value)
    {
        if (!LoadingData)
            _ = CheckStatusAndUpdate(true);
    }

    partial void OnModpackConfigUrlChanged(string? value)
    {
        if (!LoadingData)
            _ = CheckStatusAndUpdate(false);
    }

    partial void OnInstallKeyChanged(string? value)
    {
        if (!LoadingData)
            _ = CheckStatusAndUpdate(false);
    }
    
    public void SetStatus(string statusText, IImage? image)
    {
        StatusText = statusText;
        StatusImage = image;
    }

    public void ClearStatus()
    {
        StatusText = "-";
        StatusImage = null;
    }

    private bool AllowExtras()
    {
        return !string.IsNullOrWhiteSpace(modpackInfo.ExtrasKey) && updateConfig.ExtrasKeys.Contains(modpackInfo.ExtrasKey);
    }

    public void LoadProfileToUi()
    {
        LoadingData = true;

        MinecraftProfileFolder = modpackInfo.LocalPath ?? AppConfig.Instance.RecentMinecraftProfilePaths.FirstOrDefault() ?? MinecraftProfileFolder;
        ModpackConfigUrl = modpackInfo.ConfigUrl ?? ModpackConfigUrl;
        InstallKey = modpackInfo.ExtrasKey ?? InstallKey;

        LoadingData = false;
    }

    private void LoadOptionsToUi()
    {
        //foreach (var set in )
        //{
        //    // ...
        //}
    }

    public void LoadRecentFilesToUi()
    {
        RecentMinecraftProfilePathItems.Clear();
        
        if (AppConfig.Instance.RecentMinecraftProfilePaths.Count == 0)
        {
            RecentMinecraftProfilePathItems.Add(new EmptyRecentFilesItem());
            return;
        }

        AppConfig.Instance.RecentMinecraftProfilePaths.ForEach(path =>
        {
            if (Directory.Exists(path))
                RecentMinecraftProfilePathItems.Add(new RecentFilesItem(path));
        });
    }

    private void StoreRecentMinecraftProfilePath(string? path)
    {
        if (string.IsNullOrWhiteSpace(path))
            return;

        AppConfig.Instance.RecentMinecraftProfilePaths.RemoveAll(n => n == path);
        AppConfig.Instance.RecentMinecraftProfilePaths.Insert(0, path);
        AppConfig.Instance.RecentMinecraftProfilePaths.Skip(10).ForEach(n => AppConfig.Instance.RecentMinecraftProfilePaths.Remove(n));
    }

    [RelayCommand]
    private void OpenRecentPath(string path)
    {
        if (!string.IsNullOrWhiteSpace(path))
            MinecraftProfileFolder = path;
    }

    public async Task CheckStatusAndUpdate(bool loadProfileToUi)
    {
        if (!CheckStatus(loadProfileToUi))
            return;
        
        await ExecuteUpdate(false, false);
        
        StoreRecentMinecraftProfilePath(modpackInfo.LocalPath);
        LoadRecentFilesToUi();
    }
    
    private bool CheckStatus(bool loadProfileToUi)
    {
        ClearStatus();
        
        try
        {
            modpackInfo = ModpackInfo.TryLoad(MinecraftProfileFolder?.Trim());
        }
        catch
        {
            // Ignore
        }

        if (loadProfileToUi)
            LoadProfileToUi();

        try
        {
            updateConfig = ModpackConfig.LoadFromUrl(ModpackConfigUrl);
        }
        catch
        {
            // Ignore
        }

        modpackInfo.ExtrasKey = InstallKey?.Trim();
        if (!string.IsNullOrWhiteSpace(modpackInfo.ExtrasKey) && !AllowExtras())
        {
            SetStatus(GeneralLangRes.InstallationKeyNotValid, AppGlobals.Symbols.GetImageSource(AppSymbols.general_warning_sign));
            return false;
        }

        CanUseExtrasKey = updateConfig.ExtrasKeys.Count > 0;

        if (string.IsNullOrWhiteSpace(MinecraftProfileFolder) /*|| modpackInfo.Valid*/)
        {
            SetStatus(GeneralLangRes.MinecraftProfileFolderSeemsInvalid, AppGlobals.Symbols.GetImageSource(AppSymbols.general_warning_sign));
            CanUpdate = false;
            return false;
        }
        else if (string.IsNullOrWhiteSpace(ModpackConfigUrl))
        {
            SetStatus(GeneralLangRes.ConfigIncompleteOrNotLoaded, AppGlobals.Symbols.GetImageSource(AppSymbols.general_warning_sign));
            CanUpdate = false;
            return false;
        }
        else if (updateConfig.Maintenance && !updateOptions.IgnoreMaintenance)
        {
            SetStatus(GeneralLangRes.UpdateServerInMaintenance, AppGlobals.Symbols.GetImageSource(AppSymbols.services));
            CanUpdate = false;
            return false;
        }
        LoadOptionsToUi();
        CanUpdate = true;
        return true;
    }

    private async Task ExecuteUpdate(bool doInstall, bool repair)
    {
        ClearStatus();
        
        // Ensure set extras key
        modpackInfo.ExtrasKey = InstallKey?.Trim();

        var updater = new ModpackInstaller(updateConfig, modpackInfo);
        updater.InstallProgessUpdated += Updater_InstallProgressUpdated;
        updater.CheckingProgressUpdated += Updater_CheckingProgressUpdated;

        void error()
        {
            SetStatus(GeneralLangRes.ErrorOnUpdateCheckOrUpdating, AppGlobals.Symbols.GetImageSource(AppSymbols.close));
            IsUpdating = false;
        }
        void installing()
        {
            SetStatus(GeneralLangRes.Installing, AppGlobals.Symbols.GetImageSource(AppSymbols.software_installer));
            IsUpdating = true;
        }
        void updatesAvailable()
        {
            SetStatus(GeneralLangRes.AnUpdateIsAvailable, AppGlobals.Symbols.GetImageSource(AppSymbols.software_installer));
            IsUpdating = false;
        }
        void everythingOk()
        {
            SetStatus(GeneralLangRes.EverythingIsRightAndUpToDate, AppGlobals.Symbols.GetImageSource(AppSymbols.done));
            IsUpdating = false;
        }

        // Check only if not pressed "install", not really needed otherwise.
        if (lastUpdateCheckResult is null || !doInstall || repair)
        {
            SetStatus(GeneralLangRes.CheckingForUpdates, AppGlobals.Symbols.GetImageSource(AppSymbols.update_done));

            // Check for extras once again
            updateOptions.IncludeExtras = AllowExtras();

            // Force re-install on repair
            updateOptions.IgnoreInstalledVersion = repair;

            try
            {
                lastUpdateCheckResult = await updater.Check(updateOptions);
            }
            catch
            {
                error();
                if (Debugger.IsAttached)
                    throw;
            }
        }

        // Error while update check
        if (lastUpdateCheckResult is null || lastUpdateCheckResult.HasError)
        {
            error();
            return;
        }

        // Load options
        // lastUpdateCheckResult.OptionsAvailable...
        // lastUpdateCheckResult.OptionsEnabled...

        // No updates available
        if (!lastUpdateCheckResult.HasUpdates)
        {
            everythingOk();
            return;
        }

        // Updates available (but don't install)
        if (!doInstall)
        {
            updatesAvailable();
            return;
        }

        // Install updates
        installing();
        IsUpdating = true;
        try
        {
            // Install
            if (await updater.Install(lastUpdateCheckResult) == false)
            {
                error();
                return;
            }

            // Success
            lastUpdateCheckResult = null; // Reset last update check, a new one would be needed now.
            everythingOk();
        }
        catch
        {
            // Error
            error();
            if (Debugger.IsAttached)
                throw;
        }
    }

    private void Updater_CheckingProgressUpdated(int toCheck, int processed)
    {
        SetStatus(Math.Round(processed / (double)toCheck * 100d, 1) + "%", AppGlobals.Symbols.GetImageSource(AppSymbols.update_done));
    }

    private void Updater_InstallProgressUpdated(UpdateCheckResult result, int processedSyncs)
    {
        var actionCount = result.Actions.Count;
        SetStatus(Math.Round(processedSyncs / (double)actionCount * 100d, 1) + "%", AppGlobals.Symbols.GetImageSource(AppSymbols.software_installer));
    }
}