Restore SEBPatch

SafeExamBrowser.Browser/Filters/RequestFilter.cs

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+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using System.Collections.Generic;
+using SafeExamBrowser.Browser.Contracts.Filters;
+using SafeExamBrowser.Settings.Browser.Filter;
+
+namespace SafeExamBrowser.Browser.Filters
+{
+	internal class RequestFilter : IRequestFilter
+	{
+		private IList<IRule> allowRules;
+		private IList<IRule> blockRules;
+
+		public FilterResult Default { get; set; }
+
+		internal RequestFilter()
+		{
+			allowRules = new List<IRule>();
+			blockRules = new List<IRule>();
+			Default = FilterResult.Block;
+		}
+
+		public void Load(IRule rule)
+		{
+			switch (rule.Result)
+			{
+				case FilterResult.Allow:
+					allowRules.Add(rule);
+					break;
+				case FilterResult.Block:
+					blockRules.Add(rule);
+					break;
+				default:
+					throw new NotImplementedException($"Filter processing for result '{rule.Result}' is not yet implemented!");
+			}
+		}
+
+		public FilterResult Process(Request request)
+		{
+			foreach (var rule in blockRules)
+			{
+				if (rule.IsMatch(request))
+				{
+					return FilterResult.Block;
+				}
+			}
+
+			foreach (var rule in allowRules)
+			{
+				if (rule.IsMatch(request))
+				{
+					return FilterResult.Allow;
+				}
+			}
+
+			return Default;
+		}
+	}
+}