#include <iostream>
#include <fstream>
#include <string>
#include <stdlib.h>
#include <windows.h>
#include <conio.h>
using namespace std;

struct Node{
	string frame;
	Node* next;
	Node* prev;
};
typedef Node* NodePtr;


void append_frame(NodePtr &Head, NodePtr &Rear, string nframe);	//append a frame node to the doubly link list, used in load_tape() function
void load_tape(NodePtr &Head, string filename);  //load a movie text file to the memory and store in doubly link list 
void play_forward(NodePtr &ptr);	//play forward a frame
void play_backward(NodePtr &ptr);	//play backward a frame
void copy_frame(NodePtr &ptr);	//duplicate the current frame pointed to by ptr
void delete_frame(NodePtr &Head, NodePtr &ptr);	//delete the current frame pointed to by ptr
void stop(NodePtr Head, NodePtr &ptr);	//stops the player and moves ptr back to Head
void start_104player(NodePtr &Head);	//movie player control
void erase_tape(NodePtr &Head);	//free the memory
void menu();	//player menu

void main(){
	NodePtr Head = NULL;
	string filename;
	cout << "input filename: ";
	cin >> filename;
	load_tape(Head, filename);
	start_104player(Head);
	erase_tape(Head);
}

//this function is given to the students
void start_104player(NodePtr &Head){
	NodePtr ptr = Head;
	char input = 's';
	int time = 100;	//control playback speed
	do{
		if (kbhit()) 
			input = getch();
		switch(input){
		case 'f':	
			system("cls");
			play_forward(ptr);
			menu();
			Sleep(time);
			break;
		case 'b':	
			system("cls");
			play_backward(ptr);
			menu();
			Sleep(time);
			break;
		case 's':	
			system("cls");
			stop(Head, ptr);
			menu();
			input = ' ';
			break;
		case 'p':	
			input = ' ';
			break;
		case 'd':	
			system("cls");
			delete_frame(Head, ptr);
			menu();
			input = ' ';
			break;
		case 'c':	
			copy_frame(ptr);
			input = ' ';
			break;
		}
	}while(input != 'x');
}


//this function is given to the students
void menu(){
	cout << "press f for forward\n"
		 << "press b for backward\n"
		 << "press p for pause\n"
		 << "press s for stop\n"
		 << "press d for delete current frame\n"
		 << "press c for copy current frame\n"
		 << "press x to exit\n";
}

//this function is given to the students
void load_tape(NodePtr &Head, string filename){
	string nframe = "";
	char c;
	NodePtr Rear = NULL;
	ifstream fin(filename.c_str());
	while(!fin.eof()){
		nframe = "";
		for(int i=0; i<14; i++){
			do{
				c = fin.get();
				if(fin.eof())
					return;
				nframe+=c;
			}while(c != '\n');
		}
		//append a frame node to the doubly link list; you have to implement this function yourself
		append_frame(Head, Rear, nframe);
	}
	fin.close();
}