using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using FileLiberator;

namespace LibationWinForms.BookLiberation
{
	// decouple serilog and form. include convenience factory method
	public class LogMe
	{
		public event EventHandler<string> LogInfo;
		public event EventHandler<string> LogErrorString;
		public event EventHandler<(Exception, string)> LogError;

		private LogMe()
		{
			LogInfo += (_, text) => Serilog.Log.Logger.Information($"Automated backup: {text}");
			LogErrorString += (_, text) => Serilog.Log.Logger.Error(text);
			LogError += (_, tuple) => Serilog.Log.Logger.Error(tuple.Item1, tuple.Item2 ?? "Automated backup: error");
		}

		public static LogMe RegisterForm<T>(T form) where T : ILogForm
		{
			var logMe = new LogMe();

			if (form is null)
				return logMe;

			logMe.LogInfo += (_, text) => form?.WriteLine(text);

			logMe.LogErrorString += (_, text) => form?.WriteLine(text);

			logMe.LogError += (_, tuple) =>
			{
				form?.WriteLine(tuple.Item2 ?? "Automated backup: error");
				form?.WriteLine("ERROR: " + tuple.Item1.Message);
			};

			return logMe;
		}

		public void Info(string text) => LogInfo?.Invoke(this, text);
		public void Error(string text) => LogErrorString?.Invoke(this, text);
		public void Error(Exception ex, string text = null) => LogError?.Invoke(this, (ex, text));
	}

	public static class ProcessorAutomationController
	{
		public static void DownloadFile(string url, string destination, bool showDownloadCompletedDialog = false)
		{
			Serilog.Log.Logger.Information($"Begin {nameof(DownloadFile)} for {url}");

			void onDownloadFileStreamingCompleted(object sender, string savedFile)
			{
				Serilog.Log.Logger.Information($"Completed {nameof(DownloadFile)} for {url}. Saved to {savedFile}");

				if (showDownloadCompletedDialog)
					MessageBox.Show($"File downloaded to:{Environment.NewLine}{Environment.NewLine}{savedFile}");
			}

			var downloadFile = new DownloadFile();
			var downloadForm = new DownloadForm();
			downloadForm.RegisterFileLiberator(downloadFile);
			downloadFile.StreamingCompleted += onDownloadFileStreamingCompleted;

			async void runDownload() => await downloadFile.PerformDownloadFileAsync(url, destination);
			new Task(runDownload).Start();
		}
	}
}