using cwebplusApp.Shared.Models;
using cwebplusApp.Shared.ResourceFiles;
using Microsoft.Extensions.Localization;
using Microsoft.JSInterop;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace cwebplusApp.Shared.Services {
    public class MasterDataService {

        private readonly IBicycleRestService _bicycleRestService;
        private readonly IJSRuntime _jsRuntime;
        private readonly IStringLocalizer<Resources> _i18n;
        private readonly OnlineStatusProvider _onlineStatusProvider;
        private const string KeyNameColors = "colors";
        private const string KeyNameBcTypes = "bicycleTypes";
        private const string KeyNameBrands = "brands";

        private bool _initializedColors;
        private bool _initializedBcTypes;
        private bool _initializedBrands;
        private bool _firstActivation;
        public bool FirstActivation { get => _firstActivation; }
        private ColorItem[] _colors;
        private BicycleType[] _bicycleTypes;
        private Brand[] _brands;

        public ColorItem[] Colors {
            get => _colors;
        }

        public BicycleType[] BicycleTypes {
            get => _bicycleTypes;
        }

        public Brand[] Brands {
            get => _brands;
        }

        public event EventHandler Changed;

        public MasterDataService(IJSRuntime jsRuntime, IBicycleRestService bicycleRestService, IStringLocalizer<Resources> i18n, OnlineStatusProvider onlineStatusProvider) {
            _jsRuntime = jsRuntime;
            _bicycleRestService = bicycleRestService;
            _i18n = i18n;
            _onlineStatusProvider = onlineStatusProvider;
            _firstActivation = true;
            _brands = Defaults.GetBrandDefaults(_i18n).ToArray();
            _colors = Defaults.GetColorDefaults(_i18n).ToArray();
            _bicycleTypes = Defaults.GetBicycleTypeDefaults(_i18n).ToArray();
        }

        public async Task SynchronizeMasterdata() {
            if (_onlineStatusProvider.Online) {
                try {
                    await SynchronizeColors();
                    await SynchronizeBcTypes();
                    await SynchronizeBrands();
                } finally {
                    _firstActivation = false;
                }
            } else {
                throw new Exception("No internet connection available!");
            }
        }

        public async Task SynchronizeColors() {
            ColorItem[] colors = (await _bicycleRestService.GetColors()).ToArray();
            if (colors != null && colors.Length > 0) {
                _colors = colors;
                await SaveColorsToStorage(colors);
            };
        }

        public async Task SynchronizeBcTypes() {
            BicycleType[] bicycleTypes = (await _bicycleRestService.GetBicycleTypes()).ToArray();
            if (bicycleTypes != null && bicycleTypes.Length > 0) {
                _bicycleTypes = bicycleTypes;
                await SaveBcTypesToStorage(bicycleTypes);
            }
        }

        public async Task SynchronizeBrands() {
            Brand[] brands = (await _bicycleRestService.GetBrands()).ToArray();
            if (brands != null && brands.Length > 0) {
                _brands = brands;
                await SaveBrandsToStorage(brands);
            }
        }

        public async Task<ColorItem[]> GetColors() {
            ColorItem[] colors = await GetColorsFromStorage();
            if (colors != null && colors.Length > 0) {
                _colors = colors;
            }
            _colors = SortColors(new List<ColorItem>(_colors)).ToArray();
            return Colors;
        }

        public async Task<BicycleType[]> GetBicycleTypes() {
            BicycleType[] bicycleTypes = await GetBicycleTypesFromStorage();
            if (bicycleTypes != null && bicycleTypes.Length > 0) {
                _bicycleTypes = bicycleTypes;
            }
            _bicycleTypes = SortBicycleTypes(new List<BicycleType>(_bicycleTypes)).ToArray();
            return BicycleTypes;
        }

        public async Task<Brand[]> GetBrands() {
            Brand[] brands = await GetBrandsFromStorage();
            if (brands != null && brands.Length > 0) {
                _brands = brands;
            }
            _brands = SortBrands(new List<Brand>(_brands)).ToArray();
            return Brands;
        }

        // This method is called from BlazorRegisterStorageEvent when the storage changed
        [JSInvokable]
        public void OnStorageUpdated(string key) {
            // Reset the settings. The next call to Get will reload the data
            if (key == KeyNameColors) {
                _colors = null;
                Changed?.Invoke(this, EventArgs.Empty);
            } else if (key == KeyNameBcTypes) {
                _bicycleTypes = null;
                Changed?.Invoke(this, EventArgs.Empty);
            } else if (key == KeyNameBrands) {
                _brands = null;
                Changed?.Invoke(this, EventArgs.Empty);
            }
        }

        private async ValueTask<ColorItem[]> GetColorsFromStorage() {

            // Register the Storage event handler. This handler calls OnStorageUpdated when the storage changed.
            // This way, you can reload the settings when another instance of the application (tab / window) save the settings
            if (!_initializedColors) {
                // Create a reference to the current object, so the JS function can call the public method "OnStorageUpdated"
                var reference = DotNetObjectReference.Create(this);
                await _jsRuntime.InvokeVoidAsync("BlazorRegisterStorageEvent", reference);
                _initializedColors = true;
            }

            // Read the JSON string that contains the data from the local storage
            ColorItem[] result;
            var str = await _jsRuntime.InvokeAsync<string>("BlazorGetLocalStorage", KeyNameColors);
            if (String.IsNullOrEmpty(str)) {
                result = Array.Empty<ColorItem>();
            } else {
                result = JsonConvert.DeserializeObject<ColorItem[]>(str) ?? Array.Empty<ColorItem>();
            }
            return result;
        }

        private async ValueTask<BicycleType[]> GetBicycleTypesFromStorage() {

            // Register the Storage event handler. This handler calls OnStorageUpdated when the storage changed.
            // This way, you can reload the settings when another instance of the application (tab / window) save the settings
            if (!_initializedBcTypes) {
                // Create a reference to the current object, so the JS function can call the public method "OnStorageUpdated"
                var reference = DotNetObjectReference.Create(this);
                await _jsRuntime.InvokeVoidAsync("BlazorRegisterStorageEvent", reference);
                _initializedBcTypes = true;
            }

            // Read the JSON string that contains the data from the local storage
            BicycleType[] result;
            var str = await _jsRuntime.InvokeAsync<string>("BlazorGetLocalStorage", KeyNameBcTypes);
            if (String.IsNullOrEmpty(str)) {
                result = Array.Empty<BicycleType>();
            } else {
                result = JsonConvert.DeserializeObject<BicycleType[]>(str) ?? Array.Empty<BicycleType>();
            }
            return result;
        }

        private async ValueTask<Brand[]> GetBrandsFromStorage() {

            // Register the Storage event handler. This handler calls OnStorageUpdated when the storage changed.
            // This way, you can reload the settings when another instance of the application (tab / window) save the settings
            if (!_initializedBrands) {
                // Create a reference to the current object, so the JS function can call the public method "OnStorageUpdated"
                var reference = DotNetObjectReference.Create(this);
                await _jsRuntime.InvokeVoidAsync("BlazorRegisterStorageEvent", reference);
                _initializedBrands = true;
            }

            // Read the JSON string that contains the data from the local storage
            Brand[] result;
            var str = await _jsRuntime.InvokeAsync<string>("BlazorGetLocalStorage", KeyNameBrands);
            if (String.IsNullOrEmpty(str)) {
                result = Array.Empty<Brand>();
            } else {
                result = JsonConvert.DeserializeObject<Brand[]>(str) ?? Array.Empty<Brand>();
            }
            return result;
        }


        private async Task SaveColorsToStorage(ColorItem[] colors) {
            var json = JsonConvert.SerializeObject(colors);
            await _jsRuntime.InvokeVoidAsync("BlazorSetLocalStorage", KeyNameColors, json);
        }

        private async Task SaveBcTypesToStorage(BicycleType[] bicycleTypes) {
            var json = JsonConvert.SerializeObject(bicycleTypes);
            await _jsRuntime.InvokeVoidAsync("BlazorSetLocalStorage", KeyNameBcTypes, json);
        }

        private async Task SaveBrandsToStorage(Brand[] brands) {
            var json = JsonConvert.SerializeObject(brands);
            await _jsRuntime.InvokeVoidAsync("BlazorSetLocalStorage", KeyNameBrands, json);
        }

        private static List<ColorItem> SortColors(List<ColorItem> cols) {
            cols.Sort(delegate (ColorItem c1, ColorItem c2) { return c1.Id == 0 ? -1 : c2.Id == 0 ? 1 : c1.Bezeichnung.CompareTo(c2.Bezeichnung); });
            return cols;
        }

        private static List<BicycleType> SortBicycleTypes(List<BicycleType> bcTypes) {
            bcTypes.Sort(delegate (BicycleType bct1, BicycleType bct2) { return bct1.Id == 0 ? -1 : bct2.Id == 0 ? 1 : bct1.Bezeichnung.CompareTo(bct2.Bezeichnung); });
            return bcTypes;
        }

        private static List<Brand> SortBrands(List<Brand> brands) {
            brands.Sort(delegate (Brand b1, Brand b2) { return b1.Id == 0 ? -1 : b2.Id == 0 ? 1 : b1.Bezeichnung.CompareTo(b2.Bezeichnung); });
            return brands;
        }
    }
}