//CopyFile - Copies the content of an input file to an 
//output file.

#include <iostream>
#include <cstring>
#include <fstream>

using namespace std;

typedef char* StringPtr;

int GetFileNames(char* inputfilename, char* outputfilename, 
				 int &Start, int &Length){
	cout << "Enter name of input file. \n";
	cin.getline(inputfilename, 100);
	cout << "Enter starting position of key. ";
	cin >> Start;
	cout << "Enter length of key. ";
	cin >> Length;

	cout << "Enter name of output file. \n";
	cin.get(); //Investigate - not reading next line properly
	cin.getline(outputfilename, 100);
	return 0; //Need to return error code.
}//end GetFileNames

void DisplayData(StringPtr Items[], int TopIndex){
	for(int Posn=0; Posn<=TopIndex; Posn++){
		cout << Items[Posn] << "\n";
	}//end for
}//end DisplayData

int GetData(StringPtr Items[], char* inputfilename, ifstream &inputstream){
	//open input file and

	inputstream.open(inputfilename);

	int TopIndex = -1;
	char bufr[100];  //buffer to hold each line data
	while(! inputstream.eof()) {
	//read lines into a buffer
		inputstream.getline(bufr, 100);
		StringPtr ps = new char[strlen(bufr)+1];  //allocate space
	//put a pointer to each line in array elements
		strcpy(ps, bufr); //copy string into new memory
		Items[++TopIndex] = ps; //put pointer into array
	}//end while
	inputstream.close();
	return TopIndex;
}//end GetData

void PutData(StringPtr Items[], int TopIndex, char* outputfilename) {
	//Open output stream
	ofstream outputstream;
	outputstream.open(outputfilename); 
	//write data to output file
	for(int Posn=0; Posn<=TopIndex; Posn++){
		outputstream.write(Items[Posn], strlen(Items[Posn]));
		outputstream.write("\n",1);
	}//end for
	outputstream.close();
}//end PutData

int main() {
	//Ask user for input file name
	//Check for existence of input file
	//Ask user for starting position and length of key

	//Ask user for output file name
	//Check for existence of output file
	//If exists then ask user if want to supercede.
	int ErrCode=-1;
	char inputfilename[100]; char outputfilename[100];
	int Start; int Length;
	ifstream inputstream; //declare input stream

	ErrCode = GetFileNames(inputfilename, outputfilename, Start, Length);
	cout << "input file is " << inputfilename << "\n";
	cout << "output file is " << outputfilename << "\n";
	//cout << "Start and Length are " << Start << ", " << Length << "\n";
	//cout << "Error Code is " << ErrCode << "\n";
	//Open input file
	//Read in lines of data from input file into an array
	//close input file
	StringPtr Items[1000];
	int TopIndex = GetData(Items, inputfilename, inputstream);
	//Display data in array
	DisplayData(Items, TopIndex);

	//Sort the array's items based on starting position
	//and length of key.
	//SelSort will call FindLargest and Swap repeatedly
	//to sort the data
	//FindLargest will need to call strcmpx to compare
	//from Start to Start+Length-1
	//Display the data in array

	//Open output file
	//Write the data from the array to the output file.
	//close output file
	PutData(Items, TopIndex, outputfilename);
	return 0;
}//end main