#include <iostream>
#include <string>
#include <queue>
#include <sys/types.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <string.h>
#include <algorithm>

using namespace std;

void printWall(const queue<string> messages, int clientSocket)
{
	string printclient;
	printclient = "Wall Contents\n-------------\n";
	send(clientSocket, printclient.c_str(), printclient.size(), 0);
	if (messages.empty())
	{
		printclient = "[NO MESSAGES - WALL EMPTY]\n";
		send(clientSocket, printclient.c_str(), printclient.size(), 0);
	}
	else
	{
		queue<string> temp = messages;
		while (!temp.empty())
		{
			printclient = temp.front() + "\n";
			send(clientSocket, printclient.c_str(), printclient.size(), 0);
			temp.pop();
		}
	}
	printclient = "\n";
	send(clientSocket, printclient.c_str(), printclient.size(), 0);
}

void post(int size, queue<string>& messages, int clientSocket)
{
	string name;
	string message;
	string printclient;
	printclient = "Enter name: ";
	send(clientSocket, printclient.c_str(), printclient.size(), 0);
	char buff[4096];
	memset(buff, 0, 4096);
	int bytesReceived = recv(clientSocket, buff, 4096, 0);
	name = string(buff, bytesReceived);
	name.erase(remove(name.begin(), name.end(), '\n'), name.end());
	if (name.length() >= 77)
	{
		printclient = "Error: message is too long!\n";
		send(clientSocket, printclient.c_str(), printclient.size() + 1, 0);
	}
	else
	{
		printclient = "Post [Max length " + to_string(80 - name.length() - 2) + "]:";
		send(clientSocket, printclient.c_str(), printclient.size(), 0);
		char buff2[4096];
		memset(buff2, 0, 4096);
		int bytesReceived2 = recv(clientSocket, buff2, 4096, 0);
		message = string(buff2, bytesReceived2);
		message.erase(remove(message.begin(), message.end(), '\n'), message.end());
		name = name + ": " + message;
		if (name.length() > 80)
		{
			printclient = "Error: message is too long!\n";
			send(clientSocket, printclient.c_str(), printclient.size(), 0);
		}
		else
		{
			if (messages.size() < size)
				messages.push(name);
			else
			{
				messages.pop();
				messages.push(name);
			}
			printclient = "Successfully tagged the wall.\n";
			send(clientSocket, printclient.c_str(), printclient.size(), 0);
		}
		printclient = "\n";
		send(clientSocket, printclient.c_str(), printclient.size(), 0);
	}
}

int main(int argc, char *argv[])
{
	int size = 20;
	int port = 5514;
	queue<string> messages;
	string initmsg;
	if (argv[1])
	{
		size = strtol(argv[1], nullptr, 0);
		if (argv[2])
			port = strtol(argv[2], nullptr, 0);
	}
	initmsg = "Wall server running on port " + to_string(port) + " with queue size " + to_string(size) + ".\n";
	cout << initmsg << "\n";
	start:
	int listening = socket(AF_INET, SOCK_STREAM, 0);
	if (listening == -1)
	{
		cerr << "Cannot create the socket.\n";
		return -1;
	}
	sockaddr_in hint;
	hint.sin_family = AF_INET;
	hint.sin_port = htons(port);
	inet_pton(AF_INET, "0.0.0.0", &hint.sin_addr);
	if (bind(listening, (sockaddr*)&hint, sizeof(hint)) == -1)
	{
		cerr << "Cannot bind to IP or port.\n";
		return -1;
	}
	if (listen(listening, SOMAXCONN) == -1)
	{
		cerr << "Cannot listen via listener.\n";
		return -1;
	}
	sockaddr_in client;
	socklen_t clientSize = sizeof(client);
	char host[NI_MAXHOST];
	char svc[NI_MAXSERV];
	int clientSocket = accept(listening, (sockaddr*)&client, &clientSize);
	if (clientSocket == -1)
	{
		cerr << "Client cannot connect.\n";
		return -1;
	}
	close(listening);
	memset(host, 0, NI_MAXHOST);
	memset(svc, 0, NI_MAXSERV);
	int result = getnameinfo((sockaddr*)&client, sizeof(client), host, NI_MAXHOST, svc, NI_MAXSERV, 0);
	printWall(messages, clientSocket);
	string command;
	char buff[4096];
	while (command != "kill")
	{	memset(buff, 0, 4096);
		initmsg = "Enter command: ";
		send(clientSocket, initmsg.c_str(), initmsg.size(), 0);
		if (command != "quit") {
			int bytesRecv = recv(clientSocket, buff, 4096, 0);
			command = string(buff, bytesRecv);
			command.erase(remove(command.begin(), command.end(), '\n'), command.end());
		}
		if (command == "clear")
		{
			while (!messages.empty())
				messages.pop();
			initmsg = "Wall cleared.\n\n";
			send(clientSocket, initmsg.c_str(), initmsg.size(), 0);
			printWall(messages, clientSocket);
		}
		else if (command == "post")
		{
			post(size, messages, clientSocket);
			printWall(messages, clientSocket);
		}
		else if (command == "kill")
		{
			initmsg = "Closing socket and terminating server. Bye!\n";
			send(clientSocket, initmsg.c_str(), initmsg.size(), 0);
			close(clientSocket);
		}
		else if (command == "quit")
		{
			initmsg = "Come back soon. Bye!\n";
			send(clientSocket, initmsg.c_str(), initmsg.size(), 0);
			close(clientSocket);
			goto start;
		}
		else
		{
			initmsg = "Invalid command.\n";
			send(clientSocket, initmsg.c_str(), initmsg.size(), 0);
		}
	}
	return 0;
}