using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using BenchmarkDotNet.Attributes;
using DbgEngWrapper;
using MS.Dbg;

namespace DbgShell.TestHarness
{
	[Config(typeof(MyConfig))]
	public class SymbolSearchPerf
	{
		public static readonly DbgEngDebugger Debugger = DbgEngDebugger.OpenDumpFile(@"C:\Users\zhent\Source\Repos\iexplore.DMP");
		private static readonly WDbgHelpDia msDiaSession;
		private static readonly WDbgHelpDia dbghelpDiaSession;

		static SymbolSearchPerf()
		{
			var module = Debugger.GetModuleByName("mshtml").First();

			dbghelpDiaSession = Debugger.GetDiaSession2(module);

			var hr = WDbgHelpDia.CreateDiaSession(module.SymbolFileName, module.BaseAddress, out msDiaSession);

			if (hr != 0)
			{
				Marshal.ThrowExceptionForHR(hr);
			}
		}

		[Benchmark(Baseline = true)]
		public ulong FindSymbol_Enum()
		{
			return Debugger.FindSymbol_Enum("mshtml!g_hIsolatedHeap").Last().Address;
		}

		//[Benchmark]
		public ulong FindSymbol_Enum_ExplicitStar()
		{
			return Debugger.FindSymbol_Enum("mshtml!*g_hIsolatedHeap").Last().Address;
		}

		//[Benchmark]
		public ulong FindSymbol_Enum_NoType()
		{
			return Debugger.FindSymbol_Enum("mshtml!g_hIsolatedHeap", GlobalSymbolCategory.NoType).Last().Address;
		}

		//[Benchmark]
		public ulong FindSymbol_Enum_Mangled_SymOpts()
		{
			uint removeOptions = 0x00000002; //SYMOPT_UNDNAME
			return Debugger.GetOptionWrappedSymbolEnum(0, removeOptions, "mshtml!_g_hIsolatedHeap", GlobalSymbolCategory.NoType).Last().Address;
		}

		//[Benchmark]
		public ulong FindSymbol_Enum_PublicsOnly_Mangled_SymOpts()
		{
			uint addOptions = 0x00004000; //SYMOPT_PUBLICS_ONLY
			uint removeOptions = 0x00000002; //SYMOPT_UNDNAME
			return Debugger.GetOptionWrappedSymbolEnum(addOptions, removeOptions, "mshtml!_g_hIsolatedHeap", GlobalSymbolCategory.NoType).Last().Address;
		}

		
		//[Benchmark]
		public ulong FindSymbol_Search_ForcedStarGlob()
		{
			return Debugger.FindSymbol_Search("mshtml!*g_hIsolatedHeap", GlobalSymbolCategory.NoType, default, SymSearchOptions.AllItems).Last().Address;
		}

		//[Benchmark]
		public ulong FindSymbol_Search_SecretUncodumentedWildcard()
		{
			return Debugger.FindSymbol_Search("mshtml!_#g_hIsolatedHeap", GlobalSymbolCategory.NoType, default, SymSearchOptions.AllItems).Last().Address;
		}


		//[Benchmark]
		public ulong FindSymbol_Search_Mangled_SymOpts()
		{
			uint removeOptions = 0x00000002; //SYMOPT_UNDNAME
			return Debugger.GetOptionWrappedSymbolSearch(0, removeOptions, "mshtml!_g_hIsolatedHeap", GlobalSymbolCategory.NoType).Last().Address;
		}

		//[Benchmark]
		public ulong findChildren_Mangled_DiaComInterop()
		{
			var module = Debugger.GetModuleByName("mshtml").First();
			var dia = Debugger.GetDiaSession(module);

			var globalScope = dia.globalScope;
			
			globalScope.findChildren(Dia2Lib.SymTagEnum.SymTagNull, "_g_hIsolatedHeap", 0x1, out var result);//exact match, mangled name

			var length = (uint)result.count;
			var item = result.Item(length - 1);
			
			return item.relativeVirtualAddress + module.BaseAddress;
		}

		//[Benchmark]
		public ulong findChildren_Unmangled_DiaCppCli()
		{
			ulong result = 0;
			var module = Debugger.GetModuleByName("mshtml").First();
			var dia = Debugger.GetDiaSession2(module);
			var searchFlags = DiaSearchOptions.CaseSensitive | DiaSearchOptions.UndecoratedName;
			dia.SearchSymbols("_g_hIsolatedHeap", Microsoft.Diagnostics.Runtime.Interop.SymTag.Null, searchFlags,
				(name, addr) => { result = addr; });
			return result;
		}

		//[Benchmark]
		public ulong findChildren_Mangled_DiaCppCli()
		{
			ulong result = 0;
			var module = Debugger.GetModuleByName("mshtml").First();
			var dia = Debugger.GetDiaSession2(module);
			var searchFlags = DiaSearchOptions.CaseSensitive;
			dia.SearchSymbols("_g_hIsolatedHeap", Microsoft.Diagnostics.Runtime.Interop.SymTag.PublicSymbol, searchFlags,
				(name, addr) => { result = addr; });
			return result;
		}

		//[Benchmark]
		public ulong findChildren_Mangled_DiaCppCli_SearchGlob()
		{
			ulong result = 0;
			var module = Debugger.GetModuleByName("mshtml").First();
			var dia = Debugger.GetDiaSession2(module);
			var searchFlags = DiaSearchOptions.CaseSensitive | DiaSearchOptions.RegularExpression;
			var searchGlob = DotNet.Globbing.Glob.Parse("*g_hIsolatedHeap");
			dia.SearchSymbols(searchGlob, Microsoft.Diagnostics.Runtime.Interop.SymTag.PublicSymbol, searchFlags, (name, addr) => { result = addr; });
			return result;
		}

		//[Benchmark]
		public ulong findChildren_Mangled_DiaCppCli_BuiltinSearchGlob()
		{
			ulong result = 0;
			var module = Debugger.GetModuleByName("mshtml").First();
			var dia = Debugger.GetDiaSession2(module);
			var searchFlags = DiaSearchOptions.CaseSensitive | DiaSearchOptions.RegularExpression;
			dia.SearchSymbols("*g_hIsolatedHeap", Microsoft.Diagnostics.Runtime.Interop.SymTag.PublicSymbol, searchFlags, (name, addr) => { result = addr; });
			return result;
		}


		[Benchmark]
		public ulong findChildren_Mangled_DiaCppCli_CachedSession()
		{
			ulong result = 0;
			var searchFlags = DiaSearchOptions.CaseSensitive;
			dbghelpDiaSession.SearchSymbols("_g_hIsolatedHeap", Microsoft.Diagnostics.Runtime.Interop.SymTag.PublicSymbol, searchFlags,
				(name, addr) => { result = addr; });
			return result;
		}

		[Benchmark]
		public ulong findChildren_Unmangled_msdia140CppCli()
		{
			ulong result = 0;
			var searchFlags = DiaSearchOptions.CaseSensitive | DiaSearchOptions.UndecoratedName;
			msDiaSession.SearchSymbols("_g_hIsolatedHeap", Microsoft.Diagnostics.Runtime.Interop.SymTag.Null, searchFlags,
				(name, addr) => { result = addr; });
			return result;
		}

		[Benchmark]
		public ulong findChildren_Mangled_msdia140CppCli()
		{
			ulong result = 0;
			var searchFlags = DiaSearchOptions.CaseSensitive;
			msDiaSession.SearchSymbols("_g_hIsolatedHeap", Microsoft.Diagnostics.Runtime.Interop.SymTag.PublicSymbol, searchFlags,
				(name, addr) => { result = addr; });
			return result;
		}

		[Benchmark]
		public ulong findChildren_Mangled_msdia140CppCli_SearchGlob()
		{
			ulong result = 0;
			var searchFlags = DiaSearchOptions.CaseSensitive | DiaSearchOptions.RegularExpression;
			var searchGlob = DotNet.Globbing.Glob.Parse("*g_hIsolatedHeap");
			msDiaSession.SearchSymbols(searchGlob, Microsoft.Diagnostics.Runtime.Interop.SymTag.PublicSymbol, searchFlags, (name, addr) => { result = addr; });
			return result;
		}

		[Benchmark]
		public ulong findChildren_Mangled_msdia140CppCli_BuiltinSearchGlob()
		{
			ulong result = 0;
			var searchFlags = DiaSearchOptions.CaseSensitive | DiaSearchOptions.RegularExpression;
			msDiaSession.SearchSymbols("*g_hIsolatedHeap", Microsoft.Diagnostics.Runtime.Interop.SymTag.PublicSymbol, searchFlags, (name, addr) => { result = addr; });
			return result;
		}

	}


	public static class DbgHelpHelpers
	{
		[DllImport("dbghelp.dll", SetLastError = true, CharSet = CharSet.Unicode)]
		private static extern uint SymGetOptions();

		[DllImport("dbghelp.dll", SetLastError = true, CharSet = CharSet.Unicode)]
		private static extern uint SymSetOptions(uint SymOptions);


		public static IEnumerable<DbgSymbol> GetOptionWrappedSymbolEnum(this DbgEngDebugger @this, uint addOptions, uint removeOptions, string search, GlobalSymbolCategory category)
		{
			var origOpts = SymGetOptions();

			var newOpts = (origOpts | addOptions) & ~removeOptions;
			SymSetOptions(newOpts);

			var results = @this.FindSymbol_Enum(search, category).ToList();

			SymSetOptions(origOpts);
			return results;
		}

		public static IEnumerable<DbgSymbol> GetOptionWrappedSymbolSearch(this DbgEngDebugger @this, uint addOptions, uint removeOptions, string search, GlobalSymbolCategory category)
		{
			var origOpts = SymGetOptions();

			var newOpts = (origOpts | addOptions) & ~removeOptions;
			SymSetOptions(newOpts);

			var results = @this.FindSymbol_Search(search, category, default, SymSearchOptions.AllItems).ToList();

			SymSetOptions(origOpts);
			return results;
		}


		[DllImport("dbghelp.dll", SetLastError = true, CharSet = CharSet.Unicode)]
		private static extern unsafe uint UnDecorateSymbolName([MarshalAs(UnmanagedType.LPWStr)] string name, char* output, uint outputLen, uint flags);


		private static unsafe string Demangle(string demanglePlz)
		{
			var buffer = stackalloc char[1024];
			var outputLen = UnDecorateSymbolName(demanglePlz, buffer, 1024, 0);
			if (outputLen < 1024)
			{
				return new string(buffer, 0, (int)outputLen);
			}

			return string.Empty;
		}
	}
}