//------------------------------------------------------------------
// Purpose:     This program reads an ascii file and calculates the
//              number of words that begin with each letter of the 
//              alphabet.  All punctuation and digits are ignored.
// Author:      John Gauch
//------------------------------------------------------------------

#include <iostream>
#include <fstream>
#include <string>
#include <climits>
#include "list/list.h"
using namespace std;

//------------------------------------------------------------------
// Read a single word from din
//------------------------------------------------------------------
bool read_word(string & word, ifstream & din)
{
   word = "";
   bool done = false;
   while (!din.fail() && !din.eof() && !done)
   {
      char ch;
      din.get(ch);
      if (ch >= 'a' && ch <= 'z')
	 word = word + ch;
      else if (ch >= 'A' && ch <= 'Z')
	 word = word + char(ch - 'A' + 'a');
      else if (word.length() > 0)
	 done = true;
   }
   return done;
}

//------------------------------------------------------------------
// Read input file and put words into 26 linked lists
//------------------------------------------------------------------
void read_file(string filename, List list[])
{
   // Open input file
   ifstream din;
   din.open(filename.c_str());

   // Read words from input file
   string word;
   while (read_word(word, din))
   {
      // cout << word << " ";
      int count = 0;
      int index = int(word[0] - 'a');
      list[index].Search(word, count);
      list[index].Insert(word, count + 1);
   }

   // Close input file
   din.close();
}

//---------------------------------------------------------------------
// Process lists to get word counts
//---------------------------------------------------------------------
void process_lists(List list[])
{
   // Print number of words in each list
   // and find lists with min/max words
   int min_list = 0;
   int max_list = 0;
   int min_count = INT_MAX;
   int max_count = INT_MIN;
   for (int i = 0; i < 26; i++)
   {
      int count = list[i].Count();
      cout << char('a' + i) << " word count: " << count << endl;
      if (min_count > count)
      {
	 min_list = i;
	 min_count = count;
      }
      if (max_count < count)
      {
	 max_list = i;
	 max_count = count;
      }
   }

   // Print min/max word lists
   cout << "List with minimum number of words: "
      << char('a' + min_list) << " = " << min_count << endl;
   cout << "List with maximum number of words: "
      << char('a' + max_list) << " = " << max_count << endl;

   // Print selected word list
   string letter;
   cout << "Enter letter [a..z] to see list: ";
   cin >> letter;
   int index = int(letter[0] - 'a');
   if ((index >= 0) && (index < 26))
      list[index].Print();
}

//---------------------------------------------------------------------
// Main program 
//---------------------------------------------------------------------
int main(int argc, char *argv[])
{
   // Get input file name
   string filename;
   if (argc == 2)
      filename = argv[1];
   else
   {
      cout << "Enter name of input file: ";
      cin >> filename;
   }

   // Process input file to get word counts
   List list[26];
   read_file(filename, list);
   process_lists(list);
}