using System;
using System.Linq;
using Sony.ChartBot.Entities.ChartApi;
using Sony.ChartBot.Entities.Storage;
using Sony.ChartBot.Repository;

namespace Sony.ChartBot.Client.InputParsers
{
    public class ArtistAndCountryInputParser : IInputParser<Tuple<Artist, SupportedCountry>>
    {
        private readonly ArtistInputParser _artistInputParser;
        private readonly CountryInputParser _countryInputParser;
        private readonly CountryRepository _countryRepository;

        public ArtistAndCountryInputParser(
            ArtistInputParser artistInputParser, 
            CountryInputParser countryInputParser,
            CountryRepository countryRepository)
        {
            _artistInputParser = artistInputParser;
            _countryInputParser = countryInputParser;
            _countryRepository = countryRepository;
        }

        public Tuple<Artist, SupportedCountry> ParseInput(string text)
        {
            text = text.Trim();

            if (text.ToLowerInvariant().EndsWith(" worldwide"))
            {
                var presumedAristName = text.Substring(0, text.ToLowerInvariant().LastIndexOf(" worldwide", StringComparison.Ordinal));

                var artist = _artistInputParser.ParseInput(presumedAristName);
                var country = _countryRepository.GetGlobalCountry();

                return Tuple.Create(artist, country);
            }

            var words = text.Split(new[] {' '}, StringSplitOptions.RemoveEmptyEntries);

            var lastOccuranceOfWordIn = words.Select(w => w.ToLowerInvariant()).ToList().LastIndexOf("in");
            var lastOccuranceOfAt = words.Select(w => w.ToLowerInvariant()).ToList().LastIndexOf("@");

            // Both artist and country
            if (lastOccuranceOfWordIn > 0 || lastOccuranceOfAt > 0)
            {
                var indexOfSeparator = lastOccuranceOfWordIn > 0 ? lastOccuranceOfWordIn : lastOccuranceOfAt;

                var wordsBeforeSeparator = words.Take(indexOfSeparator).ToList();
                var wordsAfterSeparator = words.Skip(indexOfSeparator + 1).ToList();

                if (wordsBeforeSeparator.Any() && wordsAfterSeparator.Any())
                {
                    // Ignore "the" in country names
                    if (wordsAfterSeparator.First().ToLowerInvariant() == "the")
                    {
                        wordsAfterSeparator = wordsAfterSeparator.Skip(1).ToList();
                    }

                    var presumedAristName = string.Join(" ", wordsBeforeSeparator);
                    var presumedCountryName = string.Join(" ", wordsAfterSeparator);

                    var artist = _artistInputParser.ParseInput(presumedAristName);
                    var country = _countryInputParser.ParseInput(presumedCountryName);

                    return Tuple.Create(artist, country);
                }
            }

            // Just artist
            return Tuple.Create(_artistInputParser.ParseInput(text), (SupportedCountry)null);
        }
    }
}