using System.IO;

namespace AntiAntiSwearingBot;
public class SearchDictionary
{
    public SearchDictionary(Config cfg)
    {
        var s = cfg.SearchDictionary;
        path = s.DictionaryPath;
        tmppath = path + ".tmp";

        words = File.ReadAllLines(path).ToList();
    }

    public int Count => words.Count;

    public void Save()
    {
        if (File.Exists(tmppath))
            File.Delete(tmppath);
        File.WriteAllLines(tmppath, words);
        if (File.Exists(path))
            File.Delete(path);
        File.Move(tmppath, path);
    }

    public struct WordMatch
    {
        public string Word;
        public int Distance;
        public int Rating;
    }

    public WordMatch Match(string pattern)
        => AllMatches(pattern).First();

    public IEnumerable<WordMatch> AllMatches(string pattern)
    {
        lock (SyncRoot)
        {
            pattern = pattern.ToLowerInvariant();
            return words
                .Select((w, i) => new WordMatch { Word = w, Distance = Language.LevenshteinDistance(pattern, w), Rating = i })
                .OrderBy(m => m.Distance)
                .ThenBy(m => m.Rating);
        }
    }

    public bool Learn(string word)
    {
        lock (SyncRoot)
        {
            int index = words.IndexOf(word);
            if (index > 0)
            {
                words.Move(index, 0);
                return false;
            }
            else
            {
                words.Insert(0, word);
                return true;
            }
        }
    }

    public bool Unlearn(string word)
    {
        lock (SyncRoot)
            return words.Remove(word);
    }

    #region service

    readonly string path, tmppath;

    object SyncRoot = new object();
    List<string> words;

    #endregion
}