using Quadarax.Foundation.Core.QConsole.Argument;
using Quadarax.Foundation.Core.QConsole.Command.Base;
using System;
using System.Collections.Generic;
using System.IO.Abstractions;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace qdr.app.tools.qfu.Commands.Aspects
{
    internal class ListAspect
    {
        #region *** Constants ***
        private const string ARG_LIST_NAME = "list";
        private const string ARG_LIST_HINT = "list";
        private const string ARG_LIST_DESCR = "Flag if defined, then first argument of target file represents text file with new line defined full file paths";
        #endregion

        #region *** Public Operations ***
        public static IEnumerable<AbstractArgument> SetupArguments()
        {
            return
            [
                new FlagArgument(ARG_LIST_NAME, ARG_LIST_DESCR, ARG_LIST_HINT, false)
            ];
        }

        public static string[] GetFiles(AbstractCommand context, IFileSystem fs,IEnumerable<string> defaultResult, bool checkValidity = false)
        {
            if (context == null)
                throw new ArgumentNullException(nameof(context), "Command context cannot be null.");
            var filesArgument = context.Arguments.First(x => string.Equals(x.Code, ARG_LIST_NAME));
            if (filesArgument.Value.Get() == null)
                throw new ArgumentException($"Argument '{ARG_LIST_NAME}' is not set.", ARG_LIST_NAME);
            if (!(bool)filesArgument.Value.Get()!)
                return defaultResult.ToArray();

            var listFileName = defaultResult.First();
            if (!fs.File.Exists(listFileName))
                throw new FileNotFoundException($"List file '{listFileName}' does not exist.");
            var files = fs.File.ReadAllLines(listFileName).Where(x => !string.IsNullOrWhiteSpace(x)).ToArray();
            if (checkValidity)
            {
                var sb = new StringBuilder();
                foreach (var file in files)
                {
                    if (string.IsNullOrEmpty(file))
                        continue;
                    if (!fs.File.Exists(file) && !fs.Directory.Exists(file))
                        sb.AppendLine(file);
                }
                if (sb.Length > 0)
                    throw new FileNotFoundException($"The following files do not exist:\n{sb.ToString()}");
            }
            return files;
        }
        #endregion
    }
}