// Author Name: Matt Strapp
// Date: 25 April 2022
// x500: strap012
#ifndef UTIL_H
#define UTIL_H

// Get your libraries here
#include <arpa/inet.h>
#include <cstddef>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <poll.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/timeb.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#define NAME "SERVER"
#define ANON "ANON"
#define LINE_SIZE 5000 // overkill

#define BUF_LEN 12000000 // overkill
#define MAX_REQUEST_SIZE 10000000
#define MIN_USERNAME_LEN 4
#define MAX_USERNAME_LEN 8
#define MIN_PASSWORD_LEN 4
#define MAX_PASSWORD_LEN 8
#define MAX_COMMAND_LEN 10

enum Command {
  REGISTER = 0, // [username] [password] Register a new account
  LOGIN = 1,  // [username] [password] Log in with an existing account and enter
              // the chat room
  LOGOUT = 2, // Log out and leave the chat room
  SEND = 3,   // [msg] Send a public message
  SEND2 = 4,  // [username] [msg] Send a private message to a user
  SENDA = 5,  // [msg] Send an anonymous public message
  SENDA2 = 6, // [username] [msg] Send an anonymous private message to a user
  SENDF = 7,  // [local file] Send a file publicly
  SENDF2 = 8, // [username] [local file] Send a file to a user privately
  LIST = 9,   // List all online users
  DELAY = 10, // [N] A special command that delays for N seconds before
              // executing the next command in the script

  GETF = 11, // [filename] Server telling clinet to request a file, clinet
             // requesting a file
  PING = 12, // Check that connection is still there, doesn't do anything else
  CONNECT = 13, // [unique id] Allows the server to identify specific users when
                // they are logged in multiple times

  INVALID = 15 // Used when no valid command is found
};

enum LinkType { MESSAGE_LINK, FILE_LINK };

typedef unsigned char BYTE;
typedef unsigned int DWORD;
typedef unsigned short WORD;

Command parse_command(char *line);
bool isValidUsername(char *username);
bool isValidPassword(char *password);

void Error(const char *format, ...);
void Log(const char *format, ...);

void BigEndianToLittle(BYTE *buf, int &i);
void LittleEndianToBig(int &i, BYTE *buf);

const char *com2str(Command command);

double timeDifference(struct timeb a, struct timeb b);

int getNumEntries(const char *databse);
bool loginQuery(const char *database, char *username, char *password);
bool usernameQuery(const char *database, char *username);

void recordEntry(const char *database, char *key, char *value);

int buf2file(BYTE *buf, int nbytes, char *filename);
int file2buf(char *filename, BYTE *buf);

#define HEADER_LEN 13 // number of bytes in a message header

enum Direction { C2S, S2C };  // client to server, server to client
enum Flag { SUCCESS, FAIL };  // success, failure
enum Recipient { PUB, PRIV }; // send to all, send to one
enum Trace { SIGN, ANNON };   // send publically, send anonymously

class Header {
public:
  enum Direction m_direction;
  enum Flag m_flag;
  enum Recipient m_recipient;
  enum Trace m_trace;
  Command m_command;

  BYTE m_name[9];

  int m_size;

  Header(); // constructor

  void encode(BYTE *buf); // encode message to buffer
  void decode(BYTE *buf); // decode buffer to message

  void setFlags(enum Direction direction, enum Flag flag,
                enum Recipient recipient, enum Trace trace);

  void displayContents(bool tab); // helper to print contents of class
};

inline bool operator==(const Header &lhs, const Header &rhs) {
  bool result = true;

  result &= lhs.m_direction == rhs.m_direction;
  result &= lhs.m_flag == rhs.m_flag;
  result &= lhs.m_recipient == rhs.m_recipient;
  result &= lhs.m_trace == rhs.m_trace;
  result &= lhs.m_command == rhs.m_command;

  for (int i = 0; i < MAX_USERNAME_LEN; i++)
    result &= lhs.m_name[i] == rhs.m_name[i];

  result &= lhs.m_size == rhs.m_size;

  return result;
}

inline bool operator!=(const Header &lhs, const Header &rhs) {
  return !(lhs == rhs);
}

#endif