using System;
using System.Diagnostics;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Reflection;
namespace ln.logging
{
	public class Logger
	{
        public static ConsoleLogger ConsoleLogger { get; } = new ConsoleLogger();
        public static Logger Default { get; set; } = new Logger(ConsoleLogger);

        public static TextWriter SysOut = Console.Out;
        public static TextWriter SysError = Console.Error;

        public static void CaptureConsole(Logger logger)
        {
            LoggingWriter outWriter = new LoggingWriter(logger);
            Console.SetOut(outWriter);
            LoggingWriter errorWriter = new LoggingWriter(logger, LogLevel.ERROR);
            Console.SetError(errorWriter);
        }


        public HashSet<ILoggingBackend> Backends { get; } = new HashSet<ILoggingBackend>();

        public Logger(ILoggingBackend backend)
		{
            Backends.Add(backend);
		}
        public Logger(Stream logStream)
		{
            Backends.Add(new FileLogger(logStream));
		}

		public void Log(LogLevel level,string message, params object[] args)
		{
            Log(level,String.Format(message, args));
		}

		public void Log(string message,params object[] args){
			Log(LogLevel.INFO,String.Format(message, args));
		}

		public void Log(string message)
		{
			Log(LogLevel.INFO, message);
		}
		public void Log(LogLevel level,string message)
		{
			string[] lines = message.Split('\n');

			lines[0] = String.Format("{0} [{1}] [ {3,-10} ] {2}", 
			                         DateTime.Now.ToLocalTime(), 
			                         Process.GetCurrentProcess().Id, 
			                         lines[0],
			                         level.ToString()
			                        );
			
			for (int n = 1; n < lines.Length; n++){
				lines[n] = "    " + lines[n];
			}

            Send(level,lines);
		}

        private void Send(LogLevel logLevel,String[] lines)
        {
            foreach (ILoggingBackend backend in Backends)
                backend.Message(logLevel,lines);
        }





        public void Log(Exception exception)
        {
            StringBuilder stringBuilder = new StringBuilder();
            stringBuilder.AppendFormat("Exception {0} [{1}]\n", exception.GetType().Name,exception.Message);

            StackTrace stackTrace = new StackTrace(exception, true);

            foreach (StackFrame stackFrame in stackTrace.GetFrames())
            {
                MethodBase methodBase = stackFrame.GetMethod();
                MethodBody methodBody = methodBase.GetMethodBody();

                stringBuilder.AppendFormat("    {0} in {1}:{2}\n",
                                           methodBase.Name,
                                           stackFrame.GetFileName(),
                                           stackFrame.GetFileLineNumber()
                                          );
                //if (methodBody != null)
                //{
                //    foreach (LocalVariableInfo lvi in methodBody.LocalVariables)
                //    {
                //        stringBuilder.AppendFormat("        {0}\n", lvi);
                //    }
                //}
            }

            Log(LogLevel.ERROR, stringBuilder.ToString());
        }




	}
}