using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace PocketGoogle
{
    public class Indexer : IIndexer
    {
        public Dictionary<int, List<string>> dictionary2 = new Dictionary<int, List<string>>();
        public Dictionary<string, Dictionary<int, List<int>>> wordsWithIndex = new Dictionary<string, Dictionary<int, List<int>>>();
        public void Add(int id, string documentText)
        {
            var splitedText = documentText.Split(new char[] { ' ', '.', ',', '!', '?', ':', '-', '\r', '\n' });
            var index = 0;
            foreach (var word in splitedText)
            {
                if (wordsWithIndex.ContainsKey(word))
                {
                    if (wordsWithIndex[word].ContainsKey(id))
                    {
                        wordsWithIndex[word][id].Add(index);
                    }
                    else
                    {
                        var listWithIndex = new List<int>() { index };
                        wordsWithIndex[word].Add(id, listWithIndex);
                    }
                }
                else
                {
                    var listWithIndex = new List<int>() { index };
                    wordsWithIndex.Add(word, new Dictionary<int, List<int>>() { { id, listWithIndex } });
                }
                index += word.Length + 1;
            }
            dictionary2.Add(id, splitedText.ToList());
        }

        public List<int> GetIds(string word)
        {
            var list = new List<int>();
            if (wordsWithIndex.ContainsKey(word))
            {
                return wordsWithIndex[word].Keys.ToList();
            }

            return new List<int>();
        }

        public List<int> GetPositions(int id, string word)
        {
            if (wordsWithIndex.ContainsKey(word))
                if (wordsWithIndex[word].ContainsKey(id))
                    return wordsWithIndex[word][id];
            return new List<int>();
        }

        public void Remove(int id)
        {
            foreach (var e in dictionary2[id])
            {
                if (wordsWithIndex.ContainsKey(e))
                {
                    wordsWithIndex[e].Remove(id);
                }
            }
            dictionary2.Remove(id);
        }
    }
}