using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Azure.Management.AppService.Fluent;
using Microsoft.Azure.Management.Fluent;

namespace Tango.AzureUtils.Logging
{
    public class LogStreamManager : AzureUtilsComponentBase
    {
        private Stream _currentStream;
        private StreamReader _reader;
        private Thread _pullThread;

        public event EventHandler<String> LogAvailable;

        public LogStreamManager(IAzure azure) : base(azure)
        {

        }

        public void StopLogStreaming()
        {
            _reader.Dispose();
            _currentStream.Dispose();

            _reader = null;
            _currentStream = null;
            _pullThread = null;
        }

        public async Task StartLogStreamingAsync(IWebAppBase webApp)
        {
            _currentStream = await webApp.StreamApplicationLogsAsync();
            _reader = new StreamReader(_currentStream);

            if (_pullThread == null)
            {
                _pullThread = new Thread(PullThreadMethod);
                _pullThread.IsBackground = true;
                _pullThread.Start();
            }
        }

        private void PullThreadMethod()
        {
            while (_currentStream != null)
            {
                String line = null;

                do
                {
                    try
                    {
                        line = _reader.ReadLine();
                        if (line != null)
                        {
                            LogAvailable?.Invoke(this, line);
                        }
                    }
                    catch
                    {
                        line = null;
                    }
                } while (line != null);

                Thread.Sleep(2000);
            }
        }
    }
}