using System;
using System.IO;
using System.Management.Automation;

namespace PowerShellScriptRunner
{
    class Program
    {
        static Exception _lastException;

        static void Main(string[] args)
        {
            if (args.Length == 0)
            {
                Console.Error.WriteLine("The first argument should the path to the script to run.");
                System.Environment.Exit(-1);
            }
            else if (!File.Exists(args[0]))
            {
                Console.Error.WriteLine($"Script {args[0]} can not be found.");
                System.Environment.Exit(-2);
            }

            var executingScript = File.ReadAllText(args[0]);
            Console.WriteLine("Executing script:");
            Console.WriteLine(executingScript);
            var ps = PowerShell.Create();
            SetupStreamHandlers(ps);

            ps.AddScript(executingScript);

            var output = new PSDataCollection<PSObject>();
            var asyncResult = ps.BeginInvoke<PSObject, PSObject>(null, output);

            while (!asyncResult.IsCompleted)
            {
                asyncResult.AsyncWaitHandle.WaitOne(500);
            }
        }

        private static void SetupStreamHandlers(PowerShell ps)
        {

            Func<string, EventHandler<DataAddingEventArgs>> _loggerFactory = (prefix) =>
            {
                EventHandler<DataAddingEventArgs> handler = (sender, e) =>
                {
                    var message = e?.ItemAdded?.ToString();

                    LogMessage(prefix, message);

                    var errorRecord = e?.ItemAdded as ErrorRecord;
                    if (errorRecord?.Exception != null)
                    {
                        _lastException = errorRecord.Exception;
                    }
                };
                return handler;
            };

            ps.Streams.Verbose.DataAdding += _loggerFactory("Verbose");
            ps.Streams.Information.DataAdding += _loggerFactory("Information");
            ps.Streams.Warning.DataAdding += _loggerFactory("Warning");
            ps.Streams.Error.DataAdding += _loggerFactory("Error");
        }

        private static void LogMessage(string prefix, string message)
        {
            if (string.IsNullOrEmpty(message))
            {
                return;
            }

            if (!string.IsNullOrEmpty(prefix))
            {
                message = $"[{prefix}] - {message}";
            }

            Console.WriteLine(message);
        }
    }
}