// Generates frequency table with regard to words in text files

#include <stdio.h>
#include <stdlib.h>
#include <iostream.h>
#include "ezstring.cpp"

struct Word
{
	EZString word;
	unsigned frequency;

	Word()
	{
		frequency=0;
	}

	Word(const Word& right)
	{
		word=right.word;
		frequency=right.frequency;
	}

	Word& operator=(const EZString& right)
	{
		if (word==right)
		{
			frequency++;
		}
		else
		{
			word=right;
			frequency=1;
		}

		return *this;
	}

	Word& operator=(const Word& right)
	{
		if (word==right.word)
		{
			frequency++;
		}
		else
		{
			word=right.word;
			frequency=right.frequency;
		}

		return *this;
	}

	friend int operator==(const Word& left, const Word& right);
	friend int operator > (const Word& left, const Word& right);
	friend int operator < (const Word& left, const Word& right);
};

int operator==(const Word& left, const Word& right)
{
	return left.word == right.word;
}

int operator > (const Word& left, const Word& right)
{
	return left.word > right.word;
}

int operator < (const Word& left, const Word& right)
{
	return left.word < right.word;
}

#include "binary_search_tree.cpp"
#include "queue.h"

#define MAXSTRINGLENGTH 200
#define MAXDIGITLENGTH 200

// Function prototypes
void QueueStrings(FILE* input, Queue<EZString>* stringQueue);
bool isLetter(char c);

void main(int argc, char* argv[])
{
	FILE *input, *output;
	Binary_Search_Tree<Word> wordList;
	char string[MAXSTRINGLENGTH], number[MAXDIGITLENGTH];
	Word *wordOutputList, word;
	Queue<EZString> stringQueue;
	int numberOfWords, counter;

	if (argc != 3)
	{
		puts("Usage: cfile1 input_file output_file");
		return;
	}

	if ((input=fopen(argv[1], "r")) == NULL)
	{
		puts ("Unable to open input file");
		return;
	}
	
	if ((output=fopen(argv[2], "w")) == NULL)
	{
		puts ("Unable to open output file");
		return;
	}

	QueueStrings(input, &stringQueue);

	while (stringQueue.size())
	{
		word=stringQueue.pop();

		wordList.add(word);
	}

	numberOfWords=wordList.size();
	wordOutputList = new Word [numberOfWords];

	wordList.display_inorder(wordOutputList);

	counter=0;
	while (counter < numberOfWords)
	{
		strcpy(string, wordOutputList[counter].word.str);
		strcat(string, " : ");
		itoa(wordOutputList[counter].frequency, number, 10);
		strcat(string, number);
		strcat(string, "\n");
		fputs(string, output);
		
		counter++;
	}

	delete [] wordOutputList;
	
	fclose(input);
	fclose(output);
}

bool isLetter(char c)
{
	return ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'));
}

//------------------------------------------------------------
// Put all words from the file into a queue
//------------------------------------------------------------
void QueueStrings(FILE* input, Queue<EZString>* stringQueue)
{
	char *string, *index1, *index2;
	bool endOfLine;

	string = new char[MAXSTRINGLENGTH];

	while (fgets(string, MAXSTRINGLENGTH, input))
	{
		index1=string;
		endOfLine=false;

		while (*index1 != 0)
		{
			// Go to the first letter
			while (!isLetter(*index1))
			{
				index1++;
				if (*index1==0)
					break;
			}

			// read another line if this is the end of the string
			if (*index1==0)
					break;

			// Go to the end of the current word
			index2=index1+1;
			while (isLetter(*index2))
				index2++;

			if (index2==0)
				endOfLine=true;
			else
				*index2=0;

			strcpy(string, index1);

			// put the word on the queue
			stringQueue->push(EZString(string));

			if (endOfLine)
				break;

			// Continue to next word
			index1=index2+1;
		}
	}

	delete [] string;
}