sharee.bike-App/TINKLib/ViewModel/ViewModelHelper.cs

using MonkeyCache.FileStore;
using Serilog;
using System;
using System.Threading.Tasks;
using TINK.Model.Repository.Exception;
using TINK.Model.Device;
using TINK.Model.State;
using TINK.Model.Station;
using TINK.Model.User;
using Xamarin.Forms;

using TINK.Model.Bikes.Bike.BC;
using TINK.Model.Repository;
using TINK.Repository.Exception;
using System.Net;
using TINK.MultilingualResources;

namespace TINK.ViewModel
{
    public static class ViewModelHelper
    {
        /// <summary> First part of text making up a station name.</summary>
        private const string USER_FIENDLY_STATIONNUMBER_PREFIX = "Station";

        /// <summary>Holds the color which marks link to TINK- app pages, web sites, ...</summary>
        public static Color LINK_COLOR = Color.Blue;

        /// <summary>
        /// Gets station name from station object.
        /// </summary>
        /// <param name="p_oStation">Station to get id from</param>
        /// <returns></returns>
        public static string GetStationName(this IStation p_oStation)
        {
            if (p_oStation == null)
            {
                return string.Empty;
            }

            if (!string.IsNullOrEmpty(p_oStation.StationName))
            {
                return $"{p_oStation.StationName}, Nr. {p_oStation.Id}."; 
            }

            return GetStationName(p_oStation.Id);
        }

        /// <summary>
        /// Gets station name from station object.
        /// </summary>
        /// <param name="p_oStation">Station to get id from</param>
        /// <returns></returns>
        public static string GetStationName(int p_iStationId)
        {
            return string.Format("{0} {1}", USER_FIENDLY_STATIONNUMBER_PREFIX, p_iStationId);
        }

        /// <summary>
        /// Gets station id from station name.
        /// </summary>
        /// <param name="p_oStation">Station to get id from</param>
        /// <returns></returns>
        public static int GetStationId(string p_strStationName)
        {
            return int.Parse(p_strStationName.Replace(USER_FIENDLY_STATIONNUMBER_PREFIX, "").Trim());
        }

        /// <summary> Get the display name of a bike. </summary>
        /// <param name="bike">bike to get name for.</param>
        /// <returns>Display name of bike.</returns>
        public static string GetDisplayName(this IBikeInfoMutable bike)
        {
            var l_oId = bike.Id;
            var l_oIsDemo = bike.IsDemo;

            // Not known how many whells cargo bike has.
            return $"{(!string.IsNullOrEmpty(bike.Description) ? $"{bike.Description}, " : string.Empty)}Nr. {l_oId}";
        }

        /// <summary>
        /// Maps state to color.
        /// </summary>
        /// <param name="p_eState"></param>
        /// <returns></returns>
        public static Color GetColor(this InUseStateEnum p_eState)
        {
            switch (p_eState)
            {
                case InUseStateEnum.Disposable:
                    return Color.Default;

                case InUseStateEnum.Reserved:
                    return Color.Orange;

                case InUseStateEnum.Booked:
                    return Color.Green;
                default:
                    return Color.Default;
            }
        }

        /// <summary> Gets message that logged in user has not booked any bikes. </summary>
        public static string GetShortErrorInfoText(this Exception exception)
        {
            if (exception == null)
            {
                return string.Empty;
            }

            // An error occurred getting bikes information.
            switch (exception)
            {
                case WebConnectFailureException:
                    return AppResources.ActivityTextErrorWebConnectFailureException;
                case InvalidResponseException:
                    return AppResources.ActivityTextErrorInvalidResponseException;
                case WebForbiddenException:
                    return AppResources.ActivityTextErrorWebForbiddenException;
                case DeserializationException:
                    return AppResources.ActivityTextErrorDeserializationException;
                case WebException webException:
                    return string.Format(AppResources.ActivityTextErrorWebException, webException.Status);
                default:
                    return AppResources.ActivityTextErrorException;
            }

        }

        /// <summary> Gets message that logged in user has not booked any bikes. </summary>
        public static FormattedString GetErrorInfoText(this Exception p_oException)
        {
            if (p_oException == null)
            {
                return string.Empty;
            }

            FormattedString l_oError;
            // An error occurred getting bikes information.
            if (p_oException is WebConnectFailureException)
            {

                l_oError = new FormattedString();
                l_oError.Spans.Add(new Span { Text = "Information!\r\n", FontAttributes = FontAttributes.Bold });
                l_oError.Spans.Add(new Span { Text = $"{p_oException.Message}\r\n{WebConnectFailureException.GetHintToPossibleExceptionsReasons}" });
                return l_oError;

            }
            else if (p_oException is InvalidResponseException)
            {
                l_oError = new FormattedString();
                l_oError.Spans.Add(new Span { Text = "Fehler, ungültige Serverantwort!\r\n", FontAttributes = FontAttributes.Bold });
                l_oError.Spans.Add(new Span { Text = $"{p_oException.Message}" });
                return l_oError;
            }
            else if (p_oException is WebForbiddenException)
            {
                l_oError = new FormattedString();
                l_oError.Spans.Add(new Span { Text = "Beschäftigt... Einen Moment bitte!" });
                return l_oError;
            }

            l_oError = new FormattedString();
            l_oError.Spans.Add(new Span { Text = "Allgemeiner Fehler!\r\n", FontAttributes = FontAttributes.Bold });
            l_oError.Spans.Add(new Span { Text = $"{p_oException}" });
            return l_oError;
        }


        /// <summary> User tabbed a URI. </summary>
        /// <param name="p_oSender">Sender of the event.</param>
        /// <param name="p_eEventArgs">Event arguments</param>
        public static void OnNavigating(object p_oSender, WebNavigatingEventArgs p_eEventArgs)
        {

            if (!p_eEventArgs.Url.ToUpper().StartsWith("HTTP"))
            {
                // An internal link was detected.
                // Stay inside WebView
                p_eEventArgs.Cancel = false;
                return;
            }

            // Do not navigate outside the document.
            p_eEventArgs.Cancel = true;

            DependencyService.Get<IExternalBrowserService>().OpenUrl(p_eEventArgs.Url);
        }

        /// <summary> Gets the user group if a user friendly name.</summary>
        /// <param name="p_oUser"></param>
        /// <returns></returns>
        public static string GetUserGroupDisplayName(this User p_oUser)
        {
            return string.Join(" & ", p_oUser.Group);
        }


        /// <summary> Called when page is shown. </summary>
        /// <param name="resourceUrl">Url to load data from.</param>
        /// <param name="isSiteCachingOn">Holds value wether site caching is on or off.</param>
        /// <param name="resourceProvider"> Provides resource from embedded ressources.</param>
        public static async Task<string> GetSource(
            string resourceUrl,
            bool isSiteCachingOn,
            Func<string> resourceProvider = null)
        {
            if (!Barrel.Current.IsExpired(resourceUrl) && isSiteCachingOn)
            {
                // Cached html is still valid and caching is on.
                return Barrel.Current.Get<string>(resourceUrl);
            }

            string htmlContent = string.Empty;

            try
            {
                // Get info from web server.
                htmlContent = await CopriCallsHttps.Get(resourceUrl);
            }
            catch (Exception l_oException)
            {
                // Getting html failed.
                Log.Error($"Requesting {resourceUrl} failed. {l_oException.Message}");
            }

            switch (string.IsNullOrEmpty(htmlContent))
            {
                case true:
                    // An error occurred getting resource from web
                    htmlContent = Barrel.Current.Exists(resourceUrl)
                        ? Barrel.Current.Get<string>(key: resourceUrl) // Get from MonkeyCache
                        : resourceProvider != null ? resourceProvider() : $"<DOCTYPE html>Error loading {resourceUrl}.";  // Get build in ressource.
                    break;

                default:
                    // Add resource to cache.
                    Barrel.Current.Add(key: resourceUrl, data: htmlContent, expireIn: isSiteCachingOn ? TimeSpan.FromDays(1) : TimeSpan.FromMilliseconds(1) );
                    break;
            }

            return htmlContent ?? string.Format("<!DOCTYPE html><html lang=\"de\"><body>An error occurred loading html- ressource.</body>");
        }

    }
}