Version 3.0.381

SharedBusinessLogic/ViewModel/Help/HelpPageViewModel.cs

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+using System;
+using System.ComponentModel;
+using System.Threading.Tasks;
+using Serilog;
+using ShareeBike.Model;
+using ShareeBike.Model.Connector;
+using ShareeBike.Model.Services.CopriApi;
+using Xamarin.Forms;
+
+namespace ShareeBike.ViewModel.Help
+{
+	public class HelpPageViewModel : INotifyPropertyChanged
+	{
+		public event PropertyChangedEventHandler PropertyChanged;
+
+		/// <summary>
+		/// Holds the current ui two letter ISO language name.
+		/// </summary>
+		private string UiIsoLanguageName { get; }
+
+		/// <summary> Holds value whether site caching is on or off.</summary>
+		bool IsSiteCachingOn { get; }
+
+		/// <summary>
+		/// Relative path to fees resources of empty if value was not yet querried from backend.
+		/// </summary>
+		private string TariffsResourcePath { get; set; }
+
+		/// <summary>
+		/// Relative path to bike info resources of empty if value was not yet querried from backend.
+		/// </summary>
+		private string ManualResourcePath { get; set; }
+
+		private bool _IsIdle = false;
+
+		/// <summary>
+		/// Is true if no action is pending, false otherwise.
+		/// </summary>
+		public bool IsIdle
+		{
+			get => _IsIdle;
+			private set
+			{
+				if (_IsIdle == value)
+				{
+					// Nothing to do.
+					return;
+				}
+
+				_IsIdle = value;
+				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(IsIdle)));
+				return;
+			}
+		}
+
+		/// <summary>
+		/// Object to query resources urls object from backend if required.
+		/// This object is used to update resources path values <see cref="TariffsResourcePath"/>, and <see cref="ManualResourcePath"/> from.
+		/// </summary>
+		private Func<IQuery> QueryProvider { get; }
+
+		/// <summary>
+		/// Action to update shared resources urls object exposed by main model. 
+		/// </summary>
+		private Action<IResourceUrls> UpdateUrlsAction { get; }
+
+		/// <summary> Constructs view model.</summary>
+		/// <param name="isSiteCachingOn">Set of user permissions</param>
+		/// <param name="resourceProvider">Delegate to get embedded html resource. Used as fallback if download from web page does not work and cache is empty.</param>
+		/// <param name="query">Object to query resources path values if required.</param>
+		public HelpPageViewModel(
+			string hostName,
+			string tariffsResourcePath,
+			string manualResourcePath,
+			bool isSiteCachingOn,
+			string uiIsoLangugageName,
+			Func<IQuery> queryProvider,
+			Action<IResourceUrls> updateUrlsAction)
+		{
+			HostName = hostName;
+			TariffsResourcePath = tariffsResourcePath;
+			ManualResourcePath = manualResourcePath;
+			IsSiteCachingOn = isSiteCachingOn;
+			QueryProvider = queryProvider;
+			UpdateUrlsAction = updateUrlsAction;
+			UiIsoLanguageName = uiIsoLangugageName;
+		}
+
+		/// <summary> Holds the name of the host.</summary>
+		private string HostName { get; }
+
+		// Get resource urls object from backend.
+		public async Task<IResourceUrls> GetUrls()
+		{
+			Result<StationsAndBikesContainer> stations;
+			try
+			{
+				stations = await QueryProvider().GetBikesAndStationsAsync();
+			}
+			catch (Exception ex)
+			{
+				Log.ForContext<HelpPageViewModel>().Error($"Getting resource urls from COPRI failed. {ex.Message}");
+				return new ResourceUrls();
+			}
+
+			return stations?.GeneralData?.ResourceUrls ?? new ResourceUrls();
+		}
+
+		/// <summary> Called when page is shown. </summary>
+		public async void OnAppearing()
+		{
+			// Set state to busy.
+			IsIdle = false;
+
+			if (string.IsNullOrEmpty(TariffsResourcePath))
+			{
+				var urls = await GetUrls();
+				TariffsResourcePath = urls.TariffsResourcePath;
+				ManualResourcePath = urls.ManualResourcePath;
+				UpdateUrlsAction(urls); // Update main model to prevent duplicate queries.
+			}
+
+			//set font size for html content (necessary for iOS)
+			string headerString = "<header><meta name='viewport' content='width=device-width, intial-scale=2.0, maximum-scale=5.0, minimum-scale=1.0, user-scalable=no'></header>";
+
+			ManualHtml = new HtmlWebViewSource
+			{
+				Html = !string.IsNullOrEmpty(ManualResourcePath)
+					? headerString + await ViewModelHelper.GetSource($"https://{HostName}/{ManualResourcePath}" /*"site/bike_info_....html"*/, IsSiteCachingOn)
+					: headerString + await Task.FromResult(ViewModelHelper.FromBody("No manual resource available. Resource path is null or empty."))
+			};
+
+			TariffsHtml = new HtmlWebViewSource
+			{
+				Html = !string.IsNullOrEmpty(TariffsResourcePath)
+					? headerString + await ViewModelHelper.GetSource($"https://{HostName}/{TariffsResourcePath}" /*"site/tarif_info_....html"*/, IsSiteCachingOn)
+					: headerString + await Task.FromResult(ViewModelHelper.FromBody("No tariffs resource available. Resource path is null or empty."))
+			};
+
+			FaqHtml = new HtmlWebViewSource
+			{
+				Html = UiIsoLanguageName == "de"
+					? await ViewModelHelper.GetSource($"https://sharee.bike/faqHtml/fahrrad-nutzung/", IsSiteCachingOn)
+					: await ViewModelHelper.GetSource($"https://sharee.bike/faqHtml/bike-usage/", IsSiteCachingOn)
+			};
+
+			// Set state to idle.
+			IsIdle = true;
+		}
+
+		private HtmlWebViewSource manualHtml;
+
+		private HtmlWebViewSource tariffsHtml;
+
+		private HtmlWebViewSource faqHtml;
+
+		public HtmlWebViewSource ManualHtml
+		{
+			get => manualHtml;
+			set
+			{
+				manualHtml = value;
+				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(ManualHtml)));
+			}
+		}
+
+		public HtmlWebViewSource TariffsHtml
+		{
+			get => tariffsHtml;
+			set
+			{
+				tariffsHtml = value;
+				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(TariffsHtml)));
+			}
+		}
+
+		public HtmlWebViewSource FaqHtml
+		{
+			get => faqHtml;
+			set
+			{
+				faqHtml = value;
+				PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(FaqHtml)));
+			}
+		}
+	}
+}