Delete Repository from SQLite if it has been deleted from GitHub

Author: TheCodeTraveler

GitTrends/Database/RepositoryDatabase.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using GitTrends.Mobile.Common;
 using GitTrends.Shared;
 using SQLite;
 using Xamarin.Essentials.Interfaces;
@@ -42,6 +43,29 @@ public async Task DeleteExpiredData()
 				await dailyViewsDatabaseConnection.DeleteAsync(expiredDailyView).ConfigureAwait(false);
 		}
 
+		public async Task DeleteRepository(Repository repository)
+		{
+			var (repositoryDatabaseConnection,
+					dailyClonesDatabaseConnection,
+					dailyViewsDatabaseConnection,
+					starGazerInfoDatabaseConnection) = await GetDatabaseConnections().ConfigureAwait(false);
+
+			var dailyViews = await dailyViewsDatabaseConnection.Table<DailyViewsDatabaseModel>().ToListAsync();
+			var dailyClones = await dailyClonesDatabaseConnection.Table<DailyClonesDatabaseModel>().ToListAsync();
+			var starGazerInfos = await starGazerInfoDatabaseConnection.Table<StarGazerInfoDatabaseModel>().ToListAsync();
+
+			foreach (var dailyClone in dailyClones.Where(x => x.RepositoryUrl == repository.Url))
+				await dailyClonesDatabaseConnection.DeleteAsync(dailyClone).ConfigureAwait(false);
+
+			foreach (var dailyView in dailyViews.Where(x => x.RepositoryUrl == repository.Url))
+				await dailyViewsDatabaseConnection.DeleteAsync(dailyView).ConfigureAwait(false);
+
+			foreach (var starGazerInfo in starGazerInfos.Where(x => x.RepositoryUrl == repository.Url))
+				await starGazerInfoDatabaseConnection.DeleteAsync(starGazerInfo).ConfigureAwait(false);
+
+			await repositoryDatabaseConnection.DeleteAsync(RepositoryDatabaseModel.ToRepositoryDatabase(repository)).ConfigureAwait(false);
+		}
+
 		public async Task SaveRepository(Repository repository)
 		{
 			var databaseConnection = await GetDatabaseConnection<RepositoryDatabaseModel>().ConfigureAwait(false);

GitTrends/Services/GitHubApiRepositoriesService.cs

@@ -19,6 +19,7 @@ public class GitHubApiRepositoriesService
 		readonly IAnalyticsService _analyticsService;
 		readonly GitHubUserService _gitHubUserService;
 		readonly GitHubApiV3Service _gitHubApiV3Service;
+		readonly RepositoryDatabase _repositoryDatabase;
 		readonly ReferringSitesDatabase _referringSitesDatabase;
 		readonly GitHubApiStatusService _gitHubApiStatusService;
 		readonly GitHubGraphQLApiService _gitHubGraphQLApiService;
@@ -27,6 +28,7 @@ public GitHubApiRepositoriesService(FavIconService favIconService,
 											IAnalyticsService analyticsService,
 											GitHubUserService gitHubUserService,
 											GitHubApiV3Service gitHubApiV3Service,
+											RepositoryDatabase repositoryDatabase,
 											ReferringSitesDatabase referringSitesDatabase,
 											GitHubApiStatusService gitHubApiStatusService,
 											GitHubGraphQLApiService gitHubGraphQLApiService)
@@ -35,6 +37,7 @@ public GitHubApiRepositoriesService(FavIconService favIconService,
 			_analyticsService = analyticsService;
 			_gitHubUserService = gitHubUserService;
 			_gitHubApiV3Service = gitHubApiV3Service;
+			_repositoryDatabase = repositoryDatabase;
 			_referringSitesDatabase = referringSitesDatabase;
 			_gitHubApiStatusService = gitHubApiStatusService;
 			_gitHubGraphQLApiService = gitHubGraphQLApiService;
@@ -138,9 +141,9 @@ public async IAsyncEnumerable<Repository> UpdateRepositoriesWithViewsClonesAndSt
 						await getCloneStatisticsTask.ConfigureAwait(false),
 						await getStarGazrsTask.ConfigureAwait(false));
 			}
-			catch (ApiException e) when (_gitHubApiStatusService.IsAbuseRateLimit(e.Headers, out var timespan) && timespan is TimeSpan retryTimeSpan)
+			catch (ApiException e) when (_gitHubApiStatusService.IsAbuseRateLimit(e.Headers, out var timespan))
 			{
-				OnAbuseRateLimitFound_UpdateRepositoriesWithViewsClonesAndStarsData(repository, retryTimeSpan);
+				OnAbuseRateLimitFound_UpdateRepositoriesWithViewsClonesAndStarsData(repository, timespan.Value);
 
 				return (null, null, null);
 			}
@@ -155,6 +158,17 @@ await getCloneStatisticsTask.ConfigureAwait(false),
 				reportException(e);
 
 				return (null, null, null);
+			}
+			catch (ApiException e) when (e.StatusCode is System.Net.HttpStatusCode.NotFound) // Repository deleted from GitHub but has not yet been deleted from local SQLite Database
+			{
+				reportException(e);
+
+				var repositoryFromDatabase = await _repositoryDatabase.GetRepository(repository.Url).ConfigureAwait(false);
+				if (repositoryFromDatabase is null)
+					throw;
+
+				await _repositoryDatabase.DeleteRepository(repository).ConfigureAwait(false);
+				return (null, null, null);
 			}
 
 			void reportException(in Exception e)

GitTrends/ViewModels/RepositoryViewModel.cs

@@ -254,8 +254,7 @@ async Task ExecutePullToRefreshCommand(string repositoryOwner)
 			catch (Exception e) when (_gitHubApiStatusService.IsAbuseRateLimit(e, out var retryTimeSpan)
 										|| (e is HttpRequestException && finalResponse is not null && _gitHubApiStatusService.IsAbuseRateLimit(finalResponse.Headers, out retryTimeSpan)))
 			{
-				if (repositoriesFromDatabase is null)
-					repositoriesFromDatabase = await repositoriesFromDatabaseTask.ConfigureAwait(false);
+				repositoriesFromDatabase ??= await repositoriesFromDatabaseTask.ConfigureAwait(false);
 
 				//Rate Limiting may cause some data to not return successfully from the GitHub API
 				var missingRepositories = _gitHubUserService.ShouldIncludeOrganizations switch