// Primer laboratornoi raboti ¹ 2 - klient-servernoe konsolnoe prilozenie Windows

#include <windows.h>
#include <conio.h>
#include <iostream>

#define PAGE_SIZE 10 // ispolzuetsia pri vivode
#define ADD_USER '1'
#define EDIT_USER '2'
#define DELETE_USER '3'
#define CHANGE_PWD '4'
#define VIEW_USERS '5'
#define ADD_RATING '6'
#define PURGE '7'
#define FINISH '8'
#define BUFSIZE 4096 // pipe buffer size

using namespace std;


struct User
{
	int exist;	// 0 - if deleted, 1 - otherwise
	char login[11];
	char passwd[21];
	int rating;
	User(){
		exist=0;
		login[0]=0;
		passwd[0]=0;
		rating=0;
	}
};


void print_menu(void);
void Add_User();
void Print_Users();
void Edit_User();
void Find_User(User*);
void Delete_User();
void Change_Pwd();
void Add_Rating();
void Purge();
void createServer();
void openPipe();
void initStrings();
void myExit();

wchar_t *pipename,
		*servername,
		*comandline;
PROCESS_INFORMATION pi;
HANDLE hPipe=NULL;


int main(int argc, TCHAR* argv[], TCHAR* envp[])
{
	int i='1',
		retCode;
	DWORD bytesWritten;
	
	pipename= L"\\\\.\\pipe\\oslab3";
	servername=L"lab3_server.exe";

	// Create the pipe
	openPipe();

	// Create the server
	createServer();

	// Wait until server connects to pipe
	printf("Wait server ...");
	retCode=ConnectNamedPipe(hPipe,NULL); 
    if(!retCode && GetLastError()!=ERROR_PIPE_CONNECTED){
		CloseHandle(hPipe);
		printf("Server connection waiting failed");
		exit(0);
	}
	printf(" OK\n");

	// Main cycle
	while(i!='8'){
		print_menu();	// Output menu 
		fflush(stdin);	// Clear standard input stream
		i=getc(stdin);	// read the character from standard input
		// Set command code to the server
		retCode=WriteFile(hPipe,(void*)&i,sizeof(int),&bytesWritten,NULL);
		if(!retCode || bytesWritten!=sizeof(int)){
			printf("Can't write command");
			myExit();
		}
		switch(i){
			case ADD_USER:Add_User();break;
			case VIEW_USERS:Print_Users();break;
			case EDIT_USER:Edit_User();break;
			case DELETE_USER:Delete_User();break;
			case CHANGE_PWD:Change_Pwd();break;
			case ADD_RATING:Add_Rating();break;
			case PURGE:break;
			case FINISH:FlushFileBuffers(hPipe);DisconnectNamedPipe(hPipe);CloseHandle(hPipe);break;
			default:break;
		}
	}
	return 0;
}

void createServer(){
	STARTUPINFO si;
    ZeroMemory(&si,sizeof(si));
    si.cb=sizeof(si);
	// Set window properties
	//si.dwXSize = 100;
	//si.dwYSize = 50;
    // Start the child process. 
	DWORD retCode=CreateProcess(TEXT("lab3_server.exe"),TEXT("lab3_server.exe"),NULL,NULL,FALSE,0,NULL,NULL,&si,&pi);
	DWORD err = GetLastError();
    if(!retCode){
        printf("CreateProcess failed");
		// Disconnect server from pipe
		DisconnectNamedPipe(hPipe); 
		// Close pipe
		CloseHandle(hPipe);
		exit(0);
	}
}

void openPipe(){
	// Create pipe
	hPipe = CreateNamedPipe(pipename,PIPE_ACCESS_DUPLEX,PIPE_TYPE_MESSAGE|PIPE_READMODE_MESSAGE|PIPE_WAIT,PIPE_UNLIMITED_INSTANCES,BUFSIZE,BUFSIZE,NMPWAIT_USE_DEFAULT_WAIT,NULL);
    if (hPipe == INVALID_HANDLE_VALUE){// If pipe can't be created
		printf("CreatePipe failed"); 
		exit(0);
	}
}

void myExit(){
	if(hPipe){
		int code=8;//stop server
		// send to server stop signal
		WriteFile(hPipe,(void*)&code,sizeof(int),NULL,NULL);
		// Wait until server read our message
		FlushFileBuffers(hPipe); 
		// Disconnect server from pipe
		DisconnectNamedPipe(hPipe); 
		// Close piep
		CloseHandle(hPipe);
	}
	exit(0);
}

void print_menu(void){
	int i;
	for(i=0;i<3;i++) printf("\n");
	printf("1 - Add User\n2 - Edit User\n3 - Delete User\n4 - Change Password\n5 - View Users\n6 - Add to User's Rating\n7 - Purge\n8 - Finish work\n");
}

void Add_User(){ // Add user
	User tmpUser;
	int retCode;
	DWORD bytesWritten;
	tmpUser.exist=1;  // The user is exists
	printf("Input login\n"); 
	scanf("%s",tmpUser.login); // Input login
	printf("Input password\n");  
	scanf("%s",tmpUser.passwd); // Input password
	printf("Input user's initial rating\n");
	scanf("%d",&tmpUser.rating); // Input rating
	// Send user structure ti the server
	retCode=WriteFile(hPipe,(void*)&tmpUser,sizeof(User),&bytesWritten,NULL);
	if(!retCode || bytesWritten!=sizeof(User)){
		printf("Can't write new student to pipe");
		myExit();
	}
}


void Print_Users(){  // List all students
	int	i,
		st=0, // number of students to print
		retCode;
	User tmpUser;
	DWORD bytesRead;
	// Read number of students
	retCode=ReadFile(hPipe,(void*)&st,sizeof(int),&bytesRead,NULL);
	if(!retCode || bytesRead!=sizeof(int)){
		printf("Can't read number of strudents for output");
		myExit();
	}
	for(i=0;i<st;i++){
		if(i>0 && i%PAGE_SIZE==0){ // Pause beetween pages
			printf("Press any key to continue\n");
			fflush(stdin);
			getc(stdin);
		}
		retCode=ReadFile(hPipe,(void*)&tmpUser,sizeof(User),&bytesRead,NULL);
		if(!retCode || bytesRead!=sizeof(User)){
			printf("Can't read strudent for output");
			myExit();
		}
		printf("User's number: %d\n",i);
		printf("Login: %s\n",tmpUser.login);
		printf("Password: %s\n",tmpUser.passwd);
		printf("Rating: %d\n\n",tmpUser.rating);
	}
}

void Edit_User(){ // Edit user data
	int retCode;
	DWORD bytesWritten;
	User tmpUser;
	printf("Search user for editing\n");
	Find_User(&tmpUser);	// Find user and get its information to tmpUser structure
	if(tmpUser.exist==-1) return; // If search fails, then exit
	// Print current information and input new information
	printf("Previous login: %s\n",tmpUser.login); // Output old login
	printf("Input new login\n");
	scanf("%s",tmpUser.login); // Input new login
	printf("Previous password: %s\n",tmpUser.passwd); //same with password
	printf("Input new password\n");
	scanf("%s",tmpUser.passwd);
	printf("Previous rating: %d\n",tmpUser.rating); // same with rating
	printf("Input user's new rating\n");
	scanf("%d",&(tmpUser.rating));
	tmpUser.exist=1;
	// Send new user data
	retCode=WriteFile(hPipe,(void*)&tmpUser,sizeof(User),&bytesWritten,NULL);
	if(!retCode || bytesWritten!=sizeof(User)){
		printf("Can't write new student data");
		myExit();
	}
}


void Find_User(User *tmpUser){ // Function for student search
	// Funkcia otsilaet login na server i polushaet infu o naidennom studente
	// esli ot servea prishel kod neudachnogo poiska, to sprashivaetsia o novom poiske
	int		i,
			retCode,
			fl1;	// otvet polzolatelia na zapros o povtornom vvode
	DWORD bytesRead,bytesWritten;
	while(1)
	{
		printf("Please input login for the user\n");
		fflush(stdin);
		tmpUser->exist=777;
		scanf("%s",tmpUser->login); // Input login for search
		// Send login to the server
		retCode=WriteFile(hPipe,(void*)tmpUser,sizeof(User),&bytesWritten,NULL);
		if(!retCode || bytesWritten!=sizeof(User)){
			printf("Can't write login for search");
			myExit();
		}
		// Recieve answer from the server. If User.exist=-1, then ask new search
		retCode=ReadFile(hPipe,(void*)tmpUser,sizeof(User),&bytesRead,NULL);
		if(!retCode || bytesRead!=sizeof(User)){
			printf("Can't read results of search");
			myExit();
		}
		if(tmpUser->exist!=-1){// search success read student info
			retCode=ReadFile(hPipe,(void*)tmpUser,sizeof(User),&bytesRead,NULL);
			if(!retCode || bytesRead!=sizeof(User)){
				printf("Can't read results of search");
				myExit();
			}
			return;
		}
		// No results
		printf("Login incorrect. Do you want to try again (y/n)?\n");
		fflush(stdin);
		fl1=getc(stdin);
		if((char)fl1=='n'){
			// send code to finish search to the server
			tmpUser->exist=-1;
			retCode=WriteFile(hPipe,(void*)tmpUser,sizeof(User),&bytesWritten,NULL);
			if(!retCode || bytesWritten!=sizeof(User)){
				printf("Can't write search decline");
				myExit();
			}
			return;
		}
	}
	return;
}

void Delete_User(){ // Delete user
	int retCode;
	User tmpUser;
	printf("Search user for deleting\n");
	Find_User(&tmpUser); // Find user to delete
	if(tmpUser.exist==-1)// no user found
		return; 
	if(tmpUser.exist==777)
		printf("Used was deleted successfully\n");
}


void Change_Pwd(){ // Password changing
	int retCode;
	DWORD bytesWritten;
	User tmpUser;
	printf("Change password for which user?\n");
	Find_User(&tmpUser);
	if(tmpUser.exist==-1)
		return;
	printf("Previous password: %s\n",tmpUser.passwd);
	printf("Input new password\n");
	scanf("%s",tmpUser.passwd);
	tmpUser.exist=1;
	// Send new password to the server
	retCode=WriteFile(hPipe,(void*)&tmpUser,sizeof(User),&bytesWritten,NULL);
	if(!retCode || bytesWritten!=sizeof(User)){
		printf("Can't write new password");
		myExit();
	}
}

void Add_Rating(){ // Add rating to user
	int retCode,
		diff; // Addition to the rating
	DWORD bytesWritten;
	User tmpUser;
	printf("Whose rating you want to change?\n");
	Find_User(&tmpUser); 
	if(tmpUser.exist==-1)
		return;
	printf("Current rating: %d\n",tmpUser.rating);
	printf("Enter the difference between old and new rating\n");
	scanf("%d",&diff);
	tmpUser.rating=diff;
	// Send rating difference to the server
	retCode=WriteFile(hPipe,(void*)&tmpUser,sizeof(User),&bytesWritten,NULL);
	if(!retCode || bytesWritten!=sizeof(User)){
		printf("Can't write rating difference");
		myExit();
	}
}