using System;
using System.IO;
using System.Linq;
using DotnetStreams;

namespace StreamsTest
{
	class Program
	{
		
		static void Main(string[] args)
		{
			//Program p = new();

			ITextSource textSource;
			IOutputTarget textTarget = new ConsoleOutputTarget();

			if (args.Length > 0)
				textSource = new FileTextSource(args[0]);
			else
				textSource = new StdInTextSource();


			Execute(
				textSource,
				textTarget);
		}

		// Works, but needs to be more compact.
		//static void Main(string[] args)
		//{
		//	Program p = new Program();

		//	ITextSource textSource = null;

		//	if (args.Length > 0)
		//	{
		//		var filename = args[0];
		//		if (!File.Exists(filename))
		//		{
		//			Console.WriteLine($"File not found ({filename}).");
		//			Environment.Exit(1);
		//		}
		//		else
		//			textSource = new FileTextSource(filename);
		//	}
		//	else
		//		textSource = new StdInTextSource();

		//	p.Execute(
		//		textSource,
		//		new ConsoleOutputTarget());
		//}


		//public void ExecuteReadLine(string[] args)
		//{
		//	string s = Console.ReadLine();
		//	// This terminates on blank lines, no surprise
		//	//while (!string.IsNullOrEmpty(s))
		//	while (s != null)
		//	{
		//		s = s.Replace("\r", "{CR}")
		//			.Replace("\n", "{LF}")
		//			.Replace("\t", "{TAB}");
		//		if (s == string.Empty)
		//			s = "{EMPTYSTRING}";
		//		Console.WriteLine($"{s}");
		//		s = Console.ReadLine();
		//	}
		//	if (s == null)
		//		Console.WriteLine("/s/ is null");
		//}

		public static void Execute(ITextSource source, IOutputTarget target)
		{
			source.Open();
			target.Open();

			foreach (string line in source.ReadAll())
				target.Output(line);

			target.Close();
			source.Close();
		}
	}
}