using System;
using System.Xml;
using System.Xml.Linq;
using CommandLine;
using Sprache;
using XNeedle.Parser;
using XNeedle.Parser.Elements;
using XNeedle.Transformation;

namespace XNeedle
{
    class Program
    {
        public class Options
        {
            [Value(0, MetaName = "xn", Required = true, HelpText = "XN transformation definition")]
            public string XnDefinition { get; set; }

            [Option('i', "input", HelpText = "Input XML file", Required = true)]
            public string Input { get; set; }

            [Option('o', "output", HelpText = "Output XML file", Required = true)]
            public string Output { get; set; }

            [Option('v', "verbose", Required = false, HelpText = "Set output to verbose messages.")]
            public bool Verbose { get; set; }
        }
        static void Main(string[] args)
        {
              CommandLine.Parser.Default.ParseArguments<Options>(args)
                .WithParsed(RunOptions)
                .WithNotParsed(HandleParseError);
        }

        static void RunOptions(Options opts)
        {
            var masterRule = (Rule)XnParser.RuleObject.Parse(File.ReadAllText(opts.XnDefinition));
            var doc = XDocument.Load(opts.Input, LoadOptions.PreserveWhitespace);
            masterRule.Transform(doc);
            doc.Save(opts.Output, SaveOptions.DisableFormatting);
            
            Console.WriteLine($"Applied \"{opts.XnDefinition}\" to \"{opts.Input}\" and saved result to \"{opts.Output}\"");
        }

        static void HandleParseError(IEnumerable<Error> errs) {}
    }

    public static class DocumentExtensions
    {
        public static XmlDocument ToXmlDocument(this XDocument xDocument)
        {
            var xmlDocument = new XmlDocument();
            using(var xmlReader = xDocument.CreateReader())
            {
                xmlDocument.Load(xmlReader);
            }
            return xmlDocument;
        }

        public static XDocument ToXDocument(this XmlDocument xmlDocument)
        {
            using (var nodeReader = new XmlNodeReader(xmlDocument))
            {
                nodeReader.MoveToContent();
                return XDocument.Load(nodeReader);
            }
        }
    }
}