using System.Collections.Generic;
using System.Globalization;

namespace TextAnalysis
{
    static class FrequencyAnalysisTask
    {
        public static Dictionary<string, string> GetMostFrequentNextWords(List<List<string>> text)
        {
            var result = new Dictionary<string, string>();
            var bigramms = new Dictionary<string, int>();
            var trigramms = new Dictionary<string, int>();
            bool findBigramm = true;
            bool findTrigramm = true;
            for (var currentSentenceCounter = 0; currentSentenceCounter < text.Capacity; currentSentenceCounter++)
            {
                for (var currentWordCounter = 0; currentWordCounter < text.Capacity - 1; currentWordCounter++)
                {
                    findBigramm = true;
                    findTrigramm = true;
                    var bigramm = text[currentSentenceCounter][currentWordCounter] + ' ' + text[currentSentenceCounter][currentWordCounter + 1];
                    string trigramm = null;
                    if (currentWordCounter < text.Capacity - 2)
                    {
                        trigramm = text[currentSentenceCounter][currentWordCounter] + ' ' +
                                   text[currentSentenceCounter][currentWordCounter + 1] + ' ' +
                                   text[currentSentenceCounter][currentWordCounter + 2];
                    }
                    if (bigramms.ContainsKey(bigramm))
                    {
                        findBigramm = false;
                    }
                    if (trigramms.ContainsKey(trigramm))
                    {
                        findTrigramm = false;
                    }
                    if (findBigramm || findTrigramm)
                    {
                        var tempWordCounter = currentWordCounter;
                        for (var sentenceCounter = currentSentenceCounter;
                            sentenceCounter < text.Capacity;
                            sentenceCounter++)
                        {
                            for (var wordCounter = tempWordCounter; wordCounter < text.Capacity - 1; wordCounter++)
                            {
                                if ((text[sentenceCounter][wordCounter] + ' ' + text[sentenceCounter][wordCounter + 1])
                                    .Equals(bigramm))
                                {
                                    if (!bigramms.ContainsKey(bigramm)) bigramms[bigramm] = 0;
                                    bigramms[bigramm]++;
                                }

                                if ((text[currentSentenceCounter][currentWordCounter] + ' ' +
                                     text[currentSentenceCounter][currentWordCounter + 1] + ' ' +
                                     text[currentSentenceCounter][currentWordCounter + 2]).Equals(trigramm))
                                {
                                    if (!trigramms.ContainsKey(trigramm)) trigramms[trigramm] = 0;
                                    trigramms[trigramm]++;
                                }
                            }
                            tempWordCounter = 0;
                        }
                    }
                }
            }
            return result;
        }
   }
}