using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Console.Network;

namespace Tango.Console
{
    public class ConsoleExecutionEngine
    {
        private class ParsedCommand
        {
            public String Command { get; set; }
            public String Arguments { get; set; }

            public ParsedCommand(ConsoleCommandRequest request)
            {
                String[] s = request.Command.Split(' ');
                Command = s.First();
                Arguments = String.Join(" ", s.Skip(1));
            }
        }

        public Task<ConsoleCommandExecutionResult> Execute(ConsoleCommandRequest request)
        {
            return Task.Factory.StartNew<ConsoleCommandExecutionResult>(() =>
            {
                ParsedCommand parsedCommand = new ParsedCommand(request);

                if (parsedCommand.Command.ToLower() == "cd")
                {
                    if (parsedCommand.Arguments.Contains(":\\") && Directory.Exists(parsedCommand.Arguments))
                    {
                        return CreateResult(parsedCommand.Arguments, String.Empty);
                    }
                    else if (Directory.Exists(Path.Combine(request.WorkingFolder, parsedCommand.Arguments)))
                    {
                        return CreateResult(Path.GetFullPath(Path.Combine(request.WorkingFolder, parsedCommand.Arguments)), String.Empty);
                    }
                    else
                    {
                        return CreateResult(null, "The directory does not exists.");
                    }
                }

                String output = String.Empty;
                String error = String.Empty;

                var process = new Process();
                process.StartInfo.CreateNoWindow = true;
                process.StartInfo.UseShellExecute = false;
                process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
                process.StartInfo.RedirectStandardError = true;
                process.StartInfo.RedirectStandardOutput = true;

                if (request.RunAsAdministrator)
                {
                    process.StartInfo.Verb = "runas";
                }

                if (request.WorkingFolder != null)
                {
                    process.StartInfo.WorkingDirectory = request.WorkingFolder;
                }

                if (ConsoleDictionary.GetKnownCommands().Exists(x => x.Name.ToLower() == parsedCommand.Command.ToLower()))
                {
                    process.StartInfo.FileName = "cmd.exe";
                    process.StartInfo.Arguments = "/C " + request.Command;
                }
                else
                {
                    process.StartInfo.FileName = parsedCommand.Command;
                    process.StartInfo.Arguments = parsedCommand.Arguments;
                }

                process.Start();

                bool hasGuid = false;

                try
                {
                    process.WaitForInputIdle(5000);
                    hasGuid = true;
                }
                catch { }

                if (!hasGuid)
                {
                    output = process.StandardOutput.ReadToEnd();
                    error = process.StandardError.ReadToEnd();
                }

                return CreateResult(request.WorkingFolder, String.IsNullOrWhiteSpace(error) ? output.Replace(request.WorkingFolder + ">", "") : error);
            });
        }

        public static List<ConsoleSuggestion> GetSuggestions(String folder)
        {
            List<ConsoleSuggestion> suggestions = new List<ConsoleSuggestion>();

            foreach (var dir in Directory.GetDirectories(Path.GetFullPath(folder)))
            {
                suggestions.Add(new ConsoleSuggestion()
                {
                    Type = ConsoleSuggestionType.Folder,
                    Name = Path.GetFileName(dir)
                });
            }

            foreach (var file in Directory.GetFiles(Path.GetFullPath(folder)))
            {
                suggestions.Add(new ConsoleSuggestion()
                {
                    Type = ConsoleSuggestionType.File,
                    Name = Path.GetFileName(file),
                });
            }

            return suggestions;
        }

        private ConsoleCommandExecutionResult CreateResult(String workingFolder, String output)
        {
            ConsoleCommandExecutionResult result = new ConsoleCommandExecutionResult();
            result.WorkingFolder = workingFolder;
            result.Output = output;
            result.Suggestions.AddRange(GetSuggestions(workingFolder));

            return result;
        }
    }
}