// -------------------------------------------------------
// Using Directives
// -------------------------------------------------------

using System.Collections.Generic;
using System.Linq;
using System.IO;
using System;

// -------------------------------------------------------
// WordSearch
// -------------------------------------------------------

public class WordSearch
{
   public static readonly int MAX_TRIES = 1000;

   public static string[] GetWordsFromFile(string fileName)
   {
      string[] lines = File.ReadAllLines(fileName);

      var linesProcessed = new List<string>();

      foreach(string line in lines)
      {
         string theLine = line.Trim().ToLower();

         if(theLine != "")
            linesProcessed.Add(theLine);
      }

      return(linesProcessed.ToArray());
   }

   public static string[] GetWords()
   {
      // -------------------------------------------------------
      // We use a hard-coded list of animals for our words
      // but you can easily swap this out for a call to
      // 'GetWordsFromFile' if you'd like to use an different
      // list of words
      // -------------------------------------------------------

      string[] animals =
      {
         "aardvark",
         "bison",
         "cat",
         "dog",
         "eagle",
         "fish",
         "gorilla",
         "horse",
         "ibex",
         "jackal",
         "kangaroo",
         "llama",
         "moose",
         "narwhal",
         "ocelot",
         "porcupine",
         "quail",
         "rooster",
         "snake",
         "tarsier",
         "urasa",
         "vole",
         "wombat",
         "yak",
         "zebra"
      };

      return(animals);
   }

   public static void MakePuzzle(string[] words, int rows, int columns)
   {
      char[,] thePuzzle = new char[rows, columns];
      Random r          = new Random();

      for(int i = 0; i < rows; i ++)
         for(int j = 0; j < rows; j ++)
            thePuzzle[i, j] = ' ';

      foreach(string s in words)
      {
         if(!s.All(Char.IsLetter))
            throw new Exception("Not a valid word: " + s);

         // Now, try to place the word

         bool placed = false;
         int tries   = 0;

         while(!placed)
         {
            int row    = r.Next(rows);
            int column = r.Next(columns);

            int rowStep    = 0;
            int columnStep = 0;

            switch(r.Next(3))
            {
               case 0: rowStep = -1; break;
               case 1: rowStep =  0; break;
               case 2: rowStep =  1; break;
            }

            switch(r.Next(3))
            {
               case 0: columnStep = -1; break;
               case 1: columnStep =  0; break;
               case 2: columnStep =  1; break;
            }

            var theCopy = (char[,])thePuzzle.Clone();

            int count = 0;

            for(int i = 0; i < s.Length; i ++)
            {
               if(row    < 0 || row    >= rows ||
                  column < 0 || column >= columns)
               {
                  break;
               }

               char current = theCopy[row, column];

               if(current == ' ')
                  theCopy[row, column] = s[i];

               else if(current != s[i])
                  break;

#if false
               Console.WriteLine(
                  "placing s[" + i + "] = " + s[i] + " at " +
                  row + "," + column
               );
#endif

               theCopy[row, column] = s[i];

               row    += rowStep;
               column += columnStep;

               count ++;
            }

            if(count == s.Length)
            {
               thePuzzle = theCopy;
               placed    = true;
            }

            if(++tries > MAX_TRIES)
               throw new Exception("Exceeded: " + MAX_TRIES + " tries");
         }
      }

      Console.WriteLine(
         "-------------------------\n" +
         "Puzzle - Before\n" +
         "-------------------------\n"
      );

      for(int i = 0; i < rows; i ++)
      {
         for(int j = 0; j < columns; j ++)
         {
            char c = thePuzzle[i, j];

            Console.Write(" " + (c == ' ' ? '.' : c) + " ");
         }

         Console.WriteLine();
      }
      
      Console.WriteLine();

      Console.WriteLine(
         "-------------------------\n" +
         "Puzzle - After\n" +
         "-------------------------\n"
      );

      string letters = "abcdefghijklmnopqrstuvwxyz";

      for(int i = 0; i < rows; i ++)
         for(int j = 0; j < columns; j ++)
            if(thePuzzle[i, j] == ' ')
               thePuzzle[i, j] = letters[r.Next(letters.Length)];

      for(int i = 0; i < rows; i ++)
      {
         for(int j = 0; j < columns; j ++)
            Console.Write(" " + thePuzzle[i, j] + " ");

         Console.WriteLine();
      }
   }

   public static void Main()
   {
      try
      {
         MakePuzzle(GetWords(), 15, 15);
      }
      catch(Exception e)
      {
         Console.WriteLine(e.Message);
      }

      Console.ReadLine();
   }
}