using System.Collections.Generic;
using System.Text;

namespace TextAnalysis
{
    static class TextGeneratorTask
    {
        public static string GetSentence(string sentence, string begin, Dictionary<string, string> nextWords)
        {
            var builder = new StringBuilder();
            var array = sentence.Split();
            builder.Append(sentence);
            builder.Append(" ");
            builder.Append(nextWords[begin]);
            return builder.ToString();
        }

        public static string[] GetWrapArray(string[] last, string word)
        {
            last[0] = last[1];
            last[1] = word;
            return last;
        }

        public static string ContinuePhrase(
            Dictionary<string, string> next, string str, int count)
        {
            var last = new string[] { " ", str.Split()[str.Split().Length - 1] };
            if (str.Split().Length >= 2)
                last[0] = str.Split()[str.Split().Length - 2];
            for (int i = 0; i < count; i++)
            {
                if (next.ContainsKey(last[0] + " " + last[1]))
                {
                    str = GetSentence(str, last[0] + " " + last[1], next);
                    last[0] = last[1];
                    last[1] = next[last[0] + " " + last[1]];
                }
                else
                {
                    if (next.ContainsKey(last[1]))
                    {
                        str = GetSentence(str, last[1], next);
                        last[0] = last[1];
                        last[1] = next[last[0] + " " + last[1]];
                    }
                    else
                    {
                        return str;
                    }
                }
            }
            return str;
        }
    }
}