using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;

namespace Sony.Filtr.Utility
{
    public class TextUtility
    {
        public static string GenerateSlug(string phrase)
        {
            string str = RemoveAccent(phrase).ToLower();
            // invalid chars
            str = Regex.Replace(str, @"[^a-z0-9\s-]", "");
            // convert multiple spaces into one space
            str = Regex.Replace(str, @"\s+", " ").Trim();
            // cut and trim
            str = str.Substring(0, str.Length <= 45 ? str.Length : 45).Trim();
            str = Regex.Replace(str, @"\s", "-"); // hyphens
            return str;
        }

        public static string RemoveAccent(string txt)
        {
            byte[] bytes = System.Text.Encoding.GetEncoding("Cyrillic").GetBytes(txt);
            return System.Text.Encoding.ASCII.GetString(bytes);
        }

        public static IEnumerable<string> GetArtistVariations(string artistName)
        {
            List<string> nameVariations = new List<string>();

            artistName = artistName.ToLower();
            nameVariations.Add(artistName);
            nameVariations.Add("the " + artistName);
            if (artistName.Contains(" & "))
                nameVariations.Add(artistName.Replace(" & ", " and "));
            if (artistName.Contains(" and "))
                nameVariations.Add(artistName.Replace(" and ", " & "));

            var withoutAccents = RemoveAccent(artistName);
            if (string.IsNullOrWhiteSpace(withoutAccents) && withoutAccents != artistName)
                nameVariations.Add(withoutAccents);

            var withoutSpecialCharacters = RemoveSpecialCharacters(artistName);
            if (!string.IsNullOrWhiteSpace(withoutSpecialCharacters) && withoutSpecialCharacters != artistName)
                nameVariations.Add(withoutSpecialCharacters);

            return nameVariations;
        }

        public static bool LooksLikeSpecifiedArtist(string name1, string name2)
        {
            return GetArtistVariations(name1).Intersect(GetArtistVariations(name2), StringComparer.InvariantCultureIgnoreCase).Any();
        }

        public static string RemoveSpecialCharacters(string str)
        {
            StringBuilder sb = new StringBuilder();
            foreach (char c in str)
            {
                if (c == '\'' || c == '´' || c == '`')
                {
                    //
                }
                else if (c == ' ' || (c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'))
                {
                    sb.Append(c);
                }
                else
                {
                    sb.Append(' ');
                }

            }
            var stringWithExtraSpaces = Regex.Replace(sb.ToString(), @"\s+", " ");
            return stringWithExtraSpaces;
        }
    }
}