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// 
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// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
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// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
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using System;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using ICSharpCode.Decompiler.Tests.Helpers;
using Microsoft.CSharp;
using ICSharpCode.Decompiler.CSharp;
using ICSharpCode.Decompiler.CSharp.OutputVisitor;
using System.Reflection.PortableExecutable;
using ICSharpCode.Decompiler.Metadata;

namespace ICSharpCode.Decompiler.Tests
{
	public abstract class DecompilerTestBase
	{
		public static readonly string TestCasePath = Path.Combine(
			Path.GetDirectoryName(typeof(DecompilerTestBase).Assembly.Location),
			"../../../TestCases");

		protected static void ValidateFileRoundtrip(string samplesFileName)
		{
			var fullPath = Path.Combine(TestCasePath, "..", samplesFileName);
			AssertRoundtripCode(fullPath);
		}

		static string RemoveIgnorableLines(IEnumerable<string> lines)
		{
			return CodeSampleFileParser.ConcatLines(lines.Where(l => !CodeSampleFileParser.IsCommentOrBlank(l)));
		}

		protected static void AssertRoundtripCode(string fileName, bool optimize = false, bool useDebug = false, int compilerVersion = 4)
		{
			var code = RemoveIgnorableLines(File.ReadLines(fileName));
			using (var assembly = CompileLegacy(code, optimize, useDebug, compilerVersion)) {
				var module = new PEFile("temp.exe", assembly, throwOnResolveError: false, options: PEStreamOptions.PrefetchEntireImage);
				CSharpDecompiler decompiler = new CSharpDecompiler(module, new DecompilerSettings());

				decompiler.AstTransforms.Insert(0, new RemoveEmbeddedAtttributes());
				decompiler.AstTransforms.Insert(0, new RemoveCompilerAttribute());

				var syntaxTree = decompiler.DecompileWholeModuleAsSingleFile();

				var options = FormattingOptionsFactory.CreateAllman();
				options.IndentSwitchBody = false;
				CodeAssert.AreEqual(code, syntaxTree.ToString(options));
			}
		}

		protected static MemoryStream CompileLegacy(string code, bool optimize, bool useDebug, int compilerVersion)
		{
			CSharpCodeProvider provider = new CSharpCodeProvider(new Dictionary<string, string> { { "CompilerVersion", "v" + new Version(compilerVersion, 0) } });
			CompilerParameters options = new CompilerParameters();
			options.CompilerOptions = "/unsafe /o" + (optimize ? "+" : "-") + (useDebug ? " /debug" : "");
			if (compilerVersion >= 4)
				options.ReferencedAssemblies.Add("System.Core.dll");
			CompilerResults results = provider.CompileAssemblyFromSource(options, code);
			try
			{
				if (results.Errors.Cast<CompilerError>().Any((arg) => !arg.IsWarning))
				{
					StringBuilder b = new StringBuilder("Compiler error:");
					foreach (var error in results.Errors)
					{
						b.AppendLine(error.ToString());
					}
					throw new Exception(b.ToString());
				}
				using (var file = new FileStream(results.PathToAssembly, FileMode.Open, FileAccess.Read)) {
					var memory = new MemoryStream();
					file.CopyTo(memory);
					memory.Position = 0;
					return memory;
				}
			}
			finally
			{
				File.Delete(results.PathToAssembly);
				results.TempFiles.Delete();
			}
		}
	}
}