using System;
using System.Windows;
using System.Text.RegularExpressions;

using Prism.Commands;
using Prism.Events;
using Prism.Ioc;
using Prism.Mvvm;
using Prism.Services.Dialogs;
using XamlService.Events;
using XamlService.Payloads;
using XamlUtil.Common;
using XamlUtil.Net;
using XamlTheme.Controls;
using XamlViewer.Models;
using XamlViewer.Utils;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace XamlViewer.ViewModels
{
    public class DataViewModel : BindableBase
    {
        private AppData _appData = null;
        private IEventAggregator _eventAggregator = null;
        private IDialogService _dialogService = null;

        private TextEditorEx _textEditor = null;

        public DelegateCommand<TextEditorEx> LoadedCommand { get; private set; }
        public DelegateCommand DelayArrivedCommand { get; private set; }

        public DelegateCommand ClearCommand { get; private set; }
        public DelegateCommand FormatCommand { get; private set; }
        public DelegateCommand RequestCommand { get; private set; }

        public DataViewModel(IContainerExtension container, IEventAggregator eventAggregator)
        {
            _appData = container.Resolve<AppData>();

            _eventAggregator = eventAggregator;
            _dialogService = container.Resolve<IDialogService>();

            InitEvent();
            InitCommand();
        }

        #region Init

        private void InitEvent()
        {
            _eventAggregator.GetEvent<SettingChangedEvent>().Subscribe(OnSettingChanged, ThreadOption.PublisherThread, false);
        }

        private void InitCommand()
        {
            LoadedCommand = new DelegateCommand<TextEditorEx>(Loaded);
            DelayArrivedCommand = new DelegateCommand(DelayArrived);

            ClearCommand = new DelegateCommand(Clear);
            FormatCommand = new DelegateCommand(Format);
            RequestCommand = new DelegateCommand(RequestAsync);
        }

        #endregion

        #region Event

        private void OnSettingChanged(ValueWithGuid<EditorSetting> valueWithGuid)
        {
            FontFamily = valueWithGuid.Value.FontFamily;
            FontSize = valueWithGuid.Value.FontSize;
            WordWrap = valueWithGuid.Value.WordWrap;
        }

        #endregion

        #region Command
        
        private void Loaded(TextEditorEx textEditor)
        {
            _textEditor = textEditor;
            
            if(_textEditor != null)
            {
                _textEditor.LoadSyntaxHighlighting(AppDomain.CurrentDomain.BaseDirectory + "Assets\\Json.xshd");
                _textEditor.Text =     JsonString;
            }

            UpdateByJsonString();
            
            if (IsSyncDataSource)
                UpdateDataSource(true);
        }

        private void DelayArrived()
        {
            JsonString = _textEditor?.Text;
        }
        
        private void Clear()
        {
            _textEditor.Text = JsonString = string.Empty;
        }

        private void Format()
        {
            var text = _textEditor.Text;
            if(string.IsNullOrWhiteSpace(text))
                return;
            
            JsonString = JToken.Parse(text).ToString(Formatting.Indented);
            _textEditor.Text = JsonString;
        }

        private async void RequestAsync()
        {
            try
            {
                if (string.IsNullOrWhiteSpace(RestApi) || !Regex.IsMatch(RestApi, @"^https?://[-A-Za-z0-9+&@#/%?=~_|!:,.;]+[-A-Za-z0-9+&@#/%=~_|]$"))
                {
                    _dialogService.ShowMessage("Please check the rest api and try again.", MessageButton.OK, MessageType.Error);
                    return;
                }

                CanFetch = false;

                var json = await HttpUtil.GetString(RestApi);
                if(!string.IsNullOrWhiteSpace(json))
                    json = JToken.Parse(json).ToString(Formatting.Indented);

                JsonString = json;
                _textEditor.Text = JsonString;

                CanFetch = true;
            }
            catch(Exception ex)
            {
                System.Diagnostics.Trace.TraceError("[ Http GetString ] " + XamlUtil.Common.Common.GetExceptionStringFormat(ex));
                _dialogService.ShowMessage(ex.Message, MessageButton.OK, MessageType.Error);
            }
            finally
            {
                CanFetch = true;
            }
        }

        #endregion

        private string _fontFamily = "Calibri";
        public string FontFamily
        {
            get { return _fontFamily; }
            set { SetProperty(ref _fontFamily, value); }
        }

        private double _fontSize = 12d;
        public double FontSize
        {
            get { return _fontSize; }
            set { SetProperty(ref _fontSize, value); }
        }

        private bool _wordWrap = false;
        public bool WordWrap
        {
            get { return _wordWrap; }
            set { SetProperty(ref _wordWrap, value); }
        }

        public bool IsSyncDataSource
        {
            get { return _appData.Config.IsSyncDataSource; }
            set
            {
                if(_appData.Config.IsSyncDataSource == value)
                    return;

                _appData.Config.IsSyncDataSource = value;

                RaisePropertyChanged();
                UpdateDataSource(value);
            }
        }

        private bool _canClear = true;
        public bool CanClear
        {
            get { return _canClear; }
            set { SetProperty(ref _canClear, value); }
        }

        private bool _canFetch;
        public bool CanFetch
        {
            get { return _canFetch; }
            set { SetProperty(ref _canFetch, value); }
        }

        private string _restApi;
        public string RestApi
        {
            get { return _restApi; }
            set
            {
                SetProperty(ref _restApi, value); 
                CanFetch = !string.IsNullOrWhiteSpace(_restApi);
            }
        }

        public string JsonString
        {
            get { return _appData.Config.DataSourceJsonString; }
            set
            {
                if (_appData.Config.DataSourceJsonString == value)
                    return;

                _appData.Config.DataSourceJsonString = value;

                UpdateByJsonString();
                UpdateDataSource(IsSyncDataSource);
            }
        }

        private Visibility _jsonTipVisibility = Visibility.Visible;
        public Visibility JsonTipVisibility
        {
            get { return _jsonTipVisibility; }
            set { SetProperty(ref _jsonTipVisibility, value); }
        }

        private void UpdateDataSource(bool isSync)
        {
            _eventAggregator.GetEvent<SyncDataSourceEvent>().Publish(isSync ? JsonString?.Trim() : null);
        }

        private void UpdateByJsonString()
        {
            CanClear = !string.IsNullOrEmpty(JsonString);
            JsonTipVisibility =  CanClear ? Visibility.Collapsed : Visibility.Visible;
        }
    }
}