// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// 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.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// 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
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
using System;
using System.Collections.Generic;
using System.Linq;

namespace LocalFunctions
{
	internal class LocalFunctions
	{
		private int field;

		private static void Test(int x)
		{
		}

		private static int GetInt(string a)
		{
			return a.Length;
		}

		private static string GetString(int a)
		{
			return a.ToString();
		}

		public static void StaticContextNoCapture(int length)
		{
			for (int i = 0; i < length; i++) {
				LocalWrite("Hello " + i);
			}

			void LocalWrite(string s)
			{
				Console.WriteLine(s);
			}
		}

		public static void StaticContextSimpleCapture(int length)
		{
			for (int i = 0; i < length; i++) {
				LocalWrite();
			}

			void LocalWrite()
			{
				Console.WriteLine("Hello " + length);
			}
		}

		public static void StaticContextCaptureForLoopVariable(int length)
		{
			int i;
			for (i = 0; i < length; i++) {
				LocalWrite();
			}
			void LocalWrite()
			{
				Console.WriteLine("Hello " + i + "/" + length);
			}
		}

		public void ContextNoCapture()
		{
			for (int i = 0; i < field; i++) {
				LocalWrite("Hello " + i);
			}

			void LocalWrite(string s)
			{
				Console.WriteLine(s);
			}
		}

		public void ContextSimpleCapture()
		{
			for (int i = 0; i < field; i++) {
				LocalWrite();
			}

			void LocalWrite()
			{
				Console.WriteLine("Hello " + field);
			}
		}

		public void ContextCaptureForLoopVariable()
		{
			int i;
			for (i = 0; i < field; i++) {
				LocalWrite();
			}
			void LocalWrite()
			{
				Console.WriteLine("Hello " + i + "/" + field);
			}
		}

		public void CapturedOutsideLoop()
		{
			int i = 0;
			while (i < field) {
				i = GetInt("asdf");
				LocalWrite();
			}

			void LocalWrite()
			{
				Console.WriteLine("Hello " + i + "/" + field);
			}
		}

		public void CapturedInForeachLoop(IEnumerable<string> args)
		{
			foreach (string arg2 in args) {
				string arg = arg2;
				LocalWrite();
				void LocalWrite()
				{
					Console.WriteLine("Hello " + arg);
				}
			}
		}

		public void Overloading()
		{
			Test(5);
			LocalFunctions.Test(2);

			void Test(int x)
			{
				Console.WriteLine("x: {0}", x);
			}
		}

		private void Name()
		{

		}

		private void LocalFunctionHidingMethod()
		{
			Action action = this.Name;
			Name();
			action();

			void Name()
			{

			}
		}

		public void NamedArgument()
		{
			Use(Get(1), Get(2), Get(3));
			Use(Get(1), c: Get(2), b: Get(3));

			int Get(int i)
			{
				return i;
			}

			void Use(int a, int b, int c)
			{
				Console.WriteLine(a + b + c);
			}
		}

		public static Func<int> LambdaInLocalFunction()
		{
			int x = (int)Math.Pow(2.0, 10.0);
			return Create();

			Func<int> Create()
			{
				return () => x;
			}
		}

		public static Func<int> MethodRef()
		{
			int x = (int)Math.Pow(2.0, 10.0);
			Enumerable.Range(1, 100).Select(LocalFunction);
			return null;

			int LocalFunction(int y)
			{
				return x * y;
			}
		}

		public static int Fib(int i)
		{
			return FibHelper(i);

			int FibHelper(int n)
			{
				if (n <= 0) {
					return 0;
				}

				return FibHelper(n - 1) + FibHelper(n - 2);
			}
		}
		public int MutuallyRecursiveLocalFunctions()
		{
			return B(4) + C(3);

			int A(int i)
			{
				if (i > 0) {
					return A(i - 1) + 2 * B(i - 1) + 3 * C(i - 1);
				}
				return 1;
			}

			int B(int i)
			{
				if (i > 0) {
					return 3 * A(i - 1) + B(i - 1);
				}
				return 1;
			}

			int C(int i)
			{
				if (i > 0) {
					return 2 * A(i - 1) + C(i - 1);
				}
				return 1;
			}
		}

		public static int NestedLocalFunctions(int i)
		{
			return A();

			int A()
			{
				double x = Math.Pow(10.0, 2.0);
				return B();

				int B()
				{
					return i + (int)x;
				}
			}
		}

		public static int LocalFunctionInLambda(IEnumerable<int> xs)
		{
			return xs.First(delegate(int x) {
				return Do();

				bool Do()
				{
					return x == 3;
				}
			});
		}
		//public static void LocalFunctionInUsing()
		//{
		//	using (MemoryStream memoryStream = new MemoryStream()) {
		//		Do();

		//		void Do()
		//		{
		//			memoryStream.WriteByte(42);
		//		}
		//	}
		//}
	}
}