using System;
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Linq;
using System.Text;
using System.IO;
using System.Text.RegularExpressions;
using System.Threading.Tasks;


namespace Pithos.Interfaces
{
    public static class FileInfoExtensions
    {
        public static  string AsRelativeTo(this FileInfo fileInfo,string path )
        {
            if (String.IsNullOrWhiteSpace(path))
                throw new ArgumentNullException("path");            
            Contract.EndContractBlock();
            

            if (!path.EndsWith("\\"))
                path=path.ToLower() + "\\";
            int pathLength = path.Length;            
            
            var filePath = fileInfo.FullName;

            if (!filePath.StartsWith(path,StringComparison.InvariantCultureIgnoreCase))
                throw new ArgumentException(String.Format("The path {0} doesn't contain the file {1}",path,filePath));
            
            var relativePath = filePath.Substring(pathLength, filePath.Length - pathLength);

            return relativePath;
        }

        public static string AsRelativeUrlTo(this FileInfo fileInfo,string path )
        {
            if (String.IsNullOrWhiteSpace(path))
                throw new ArgumentNullException("path");
            Contract.EndContractBlock();

            var relativePath = fileInfo.AsRelativeTo(path);
            var replacedSlashes = relativePath.Replace("\\","/");
            var escaped = Uri.EscapeUriString(replacedSlashes);
            return escaped;
        }

        public static string RelativeUriToFilePath(this Uri uri)
        {
            var unescaped = Uri.UnescapeDataString(uri.ToString());
            var path = unescaped.Replace("/", "\\");
            return path;
        }



    }
}