#include <iostream>
#include <fstream>
using namespace std;

char riff[4], id[5], fmt1[5];
long s, datasize, bitrate;
short compressioncode, chan;
char* filename = "sample2.wav";


void insert (char* fname, int si, char* data, int datasize, string text) {
//this method inserts the message into the file header
ifstream file (fname, ios::in|ios::binary);
if (file.is_open())
{
file.seekg (0, ios::beg);
char beg[16];
file.read(beg,16);
long size;
file.read((char*)&size,4);
char rest[si-28];
file.read(rest,si-28);
char dat[8];
file.read(dat,8);
int str = text.length();
size+=str;	//adding length of message to header size
ofstream fileo;
fileo.open("output2.wav", ios::out | ios::binary);
if (fileo.is_open()) { 
	fileo.write(beg,16);
	fileo.write((char*)&size,4);
	fileo.write(rest,si-28);
	char tex[str];
	for(int i=0; i<str; i++){
	tex[i] = text[i];}
	//message written here at end of header
	fileo.write(tex,str);
	fileo.write(dat,8);
	fileo.write(data,datasize);
	}
cout << "message written to output2.wav\n";
fileo.close();
}
file.close();
}


void insert2 (char* fname, int si, char* data, int datasize, string text) {
//this method inserts each byte of the message into the least significant bytes of the data chunks
ifstream file2 (fname, ios::in|ios::binary);
if (file2.is_open())
{
file2.seekg (0, ios::beg);
char beg[16];
file2.read(beg,16);
long size;
file2.read((char*)&size,4);
char rest[si-28];
file2.read(rest,si-28);
char datbs[4];
file2.read(datbs,4);
long datlen;
file2.read((char*)&datlen,4);
int str = text.length();
size+=4; //just 4 extra bytes added to file size for length of string
if(datlen==datasize){cout << "datsize confirmed\n";}
char d[datasize];
file2.read((char*)&d,datasize);
ofstream fileo;
fileo.open("output3.wav", ios::out | ios::binary);
if (fileo.is_open()) { 
	fileo.write((char*)&beg,16);
	fileo.write((char*)&size,4);
	fileo.write((char*)&rest,si-28);
	char tex[str];
	for(int i=0; i<str; i++){
	tex[i] = text[i];}
	fileo.write((char*)&str,4);	//stores length of message within file header
	fileo.write((char*)&datbs,4);
	fileo.write((char*)&datlen,4);	
	char temp[4];
	int now=0;

	//message inserted one character at a time into file along with data[]
	for(int k=0; k<str; k++){
		for(int j=0; j<4; j++){
		temp[j] = data[now];
		if(j==0){
		temp[0]=tex[k];}
		fileo.write((char*)&temp[j],1);
		now++;
		}	
		
	}
	int textsize=4*str;
	datlen = datasize-textsize;
	cout << "datlen" << datlen << "\n";
	//inserts rest of data after message has been inserted	
	for(int g=textsize; g<datasize; g++){
	fileo.write((char*)&data[g],1);	
	}
	
	}
cout << "message written to output3.wav\n";
fileo.close();
}
file2.close();
}

void extract (char* fname) {
//this extraction method corresponds to the first insertion method/algorithm (aka file header insertion)
ifstream file (fname, ios::in|ios::binary);
if (file.is_open())
{
file.seekg (0, ios::beg);
char beg[16];
file.read(beg,16);
long size;
file.read((char*)&size,4);
size-=16;
char junk[16];
file.read(junk,16);
char te[size];
file.read(te,size);
cout << "Message extracted:\n";
//message simply found in last few bytes of file header
for(int k=0; k<size; k++)
{
	cout << te[k];
}
cout << "\n";
}
file.close();
}

void extract2 (char* fname) {
//this extraction method corresponds to the second insertion method/algorithm (aka least significant byte substitution)
ifstream file (fname, ios::in|ios::binary);
if (file.is_open())
{
file.seekg (0, ios::beg);
char beg[16];
file.read(beg,16);
long size;
file.read((char*)&size,4);
char junk[size-4];
file.read(junk,size-4);
int str;
file.read((char*)&str,4);
char datchunk[8];
file.read(datchunk,8);
string message;
char tem[1];
cout << "Message found:\n";
//message found in first byte of every 4 bytes of the sound data
for(int k=0; k<str; k++){
	for(int j=0; j<4; j++){
		file.read(tem,1);
		if(j==0){
			cout << tem[0];
			}
	}	
}
cout << "\n";
}
file.close();
}

int main (int argc, char *argv[]) {
    char* filename = "test.wav";
    string text;
    char* fromfile;
	//argc is the # of parameters used when running the file
    if(argc==2){
    filename = argv[1];}
    if(argc==3){	//3 parameters means extraction method will be run
    filename = argv[1];
    if(strcmp(argv[2],"-x")==0){
	extract(filename);	//runs first extraction method
	exit(0);
	}
    else if(strcmp(argv[2],"-x2")==0){
	extract2(filename);	//runs advanced extraction method
	exit(0);}
	}
    if(argc==4){	//4 parameters means insertion method will be run
    filename = argv[1];
    text = argv[3];
	}
    if(argc==5&&strcmp(argv[3],"-f")==0){	//5 parameters means insertion method from file
	filename=argv[1];
	fromfile=argv[4];
	string line;
 	ifstream myfile;
	myfile.open(fromfile, ios::in);
  	if (myfile.is_open())
  	{
    		while (! myfile.eof() )
    		{
      		getline (myfile,line);		//file's contents stored in "text" string
      		text+=line;
    		}
    	myfile.close();
  	}
    }
    cout << filename << " " << text << "\n";
    ifstream file1;
    file1.open(filename, ios::in|ios::binary);
    if (file1.is_open())
    {
    file1.seekg(0, ios::beg);
    file1.read(riff, 4);
    file1.read((char*)&s, 4);
    file1.read(id, 4);
    cout << riff << " " << s << " " << id << "\n";
    if(strcmp(riff,"RIFFWAVE")==0) //correct file type
	{ 
	if (strcmp(id,"WAVE")==0) //is a wav file
		{ 
		
		file1.read(fmt1, 4);
		if(strcmp(fmt1, "fmt ")==0){
		long si;
		file1.read((char*)&si, 4);
		file1.read((char*)&compressioncode, 2);
		file1.read((char*)&chan, 2);
		if(chan==1){
		cout << "mono" << "\n";}
		else if(chan==2){cout << "stereo" << "\n";}
		else cout << "other" << "\n";
		file1.read((char*)&bitrate, 4);		
		cout << "sample bit rate " << bitrate << "\n";
		char details[si-8];
		file1.read(details,si-8);
		char datatag[4];
		file1.read(datatag,4); 
		int newsize;
		while(datatag[0]!='d'){
		file1.read((char*)&newsize,4);
		char temp[newsize];
		file1.read(temp,newsize);
		file1.read((char*)&datatag,4);
		}
		cout << "data chunk reached" << "\n"; 
		// if datatag = "data", we have reached data chunk
		file1.read((char*)&datasize,4);
		cout << "datasize: " << datasize << "\n";
		char data[datasize];
		file1.read(data,datasize);
		file1.close();
		int siz = si+28;
		cout << "data read successfully\n";
		if(argc==2){
		file1.close();
		return0;}
		else if(argc==4&&strcmp(argv[2],"-i")==0){
		//this insert method is for insertion with the -i method
		insert(filename, siz, (char*)&data, datasize, text);}
		else if(argc==4&&strcmp(argv[2],"-i2")==0){
		//next 2 insert2 statements are for insertion with -i2 method
		insert2(filename, siz, (char*)&data, datasize, text);}
		else if(argc==5&&strcmp(argv[2],"-i2")==0){

		insert2(filename, siz, (char*)&data, datasize, text);}
		}
		}
		}
		

	

    else{file1.close();}

  }
  else cout << "Unable to open file";
  return 0;
}