update scan time

OneMore/Commands/Tagging/HashtagProvider.cs

@@ -269,6 +269,54 @@ private Hashtags ReadTags(string sql, SQLiteParameter[] parameters)
 		}
 
 
+		/// <summary>
+		/// Records the given tags.
+		/// </summary>
+		/// <param name="tags">A collection of Hashtags</param>
+		public void UpdateContext(Hashtags tags)
+		{
+			using var cmd = con.CreateCommand();
+			cmd.CommandText = "UPDATE hashtags " +
+				"SET context = @c, lastScan = @s " +
+				"WHERE tag = @t AND moreID = @m";
+
+			cmd.CommandType = CommandType.Text;
+			cmd.Parameters.Add("@c", DbType.String);
+			cmd.Parameters.Add("@s", DbType.String);
+			cmd.Parameters.Add("@t", DbType.String);
+			cmd.Parameters.Add("@m", DbType.String);
+
+			using var transaction = con.BeginTransaction();
+			foreach (var tag in tags)
+			{
+				logger.Verbose($"updating tag {tag.Tag}");
+
+				cmd.Parameters["@c"].Value = tag.Context;
+				cmd.Parameters["@s"].Value = tag.LastScan;
+				cmd.Parameters["@t"].Value = tag.Tag;
+				cmd.Parameters["@m"].Value = tag.MoreID;
+
+				try
+				{
+					cmd.ExecuteNonQuery();
+				}
+				catch (Exception exc)
+				{
+					logger.WriteLine($"error updating tag {tag.Tag} on {tag.PageID}", exc);
+				}
+			}
+
+			try
+			{
+				transaction.Commit();
+			}
+			catch (Exception exc)
+			{
+				logger.WriteLine("error committing transaction", exc);
+			}
+		}
+
+
 		/// <summary>
 		/// Records the timestamp value that was initialized at construction of this class
 		/// instance

OneMore/Commands/Tagging/HashtagScanner.cs

@@ -91,7 +91,7 @@ public async Task<int> Scan()
 
 		private async Task<int> Scan(XElement parent, string path)
 		{
-			//logger.WriteLine($"scanning parent {path}");
+			//logger.Verbose($"scanning parent {path}");
 
 			int totalPages = 0;
 
@@ -114,7 +114,7 @@ private async Task<int> Scan(XElement parent, string path)
 					totalPages += pages.Count();
 
 					var sectionPath = $"{path}/{section.Attribute("name").Value}";
-					//logger.WriteLine($"scanning section {sectionPath} ({pages.Count()} pages)");
+					//logger.Verbose($"scanning section {sectionPath} ({pages.Count()} pages)");
 
 					foreach (var page in pages)
 					{
@@ -166,6 +166,7 @@ private async Task ScanPage(string pageID, string path)
 
 			var saved = provider.ReadPageTags(pageID);
 			var discovered = new Hashtags();
+			var updated = new Hashtags();
 
 			foreach (var candidate in candidates)
 			{
@@ -176,36 +177,47 @@ private async Task ScanPage(string pageID, string path)
 				}
 				else
 				{
-					//logger.WriteLine($"found tag {found.Tag}");
+					if (candidate.LastScan.CompareTo(lastTime) > 0)
+					{
+						updated.Add(candidate);
+					}
+
 					saved.Remove(found);
 				}
 			}
 
-			var updated = false;
+			var updatedAny = false;
 
 			if (saved.Any())
 			{
 				// remaining saved entries were not matched with candidates
 				// on page so should be deleted
 				provider.DeleteTags(saved);
-				updated = true;
+				updatedAny = true;
+			}
+
+			if (updated.Any())
+			{
+				// tag context updated since last scan
+				provider.UpdateContext(updated);
+				updatedAny = true;
 			}
 
 			if (discovered.Any())
 			{
 				// discovered entries are new on the page and not found in saved
 				provider.WriteTags(discovered);
-				updated = true;
+				updatedAny = true;
 			}
 
 			// if first time hashtags were discovered on this page then set omPageID
-			if (scanner.UpdateMeta && updated)
+			if (scanner.UpdateMeta && updatedAny)
 			{
 				page.SetMeta(MetaNames.PageID, scanner.MoreID);
 				await one.Update(page);
 			}
 
-			if (updated)
+			if (updatedAny)
 			{
 				// will likely rewrite same data but needed in case old page is moved
 				// TODO: could track moreID+pageID to determine if REPLACE is needed; but then