#include "Spooler.h"
#include <iostream>
#include <string>
#include <stdexcept>
#include <cstring>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <errno.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <dirent.h>
#include <fcntl.h>
#include <stdlib.h>

#include "Util.h"

#include "Exceptions.h"

const std::string spooldir = "/home/torben/smstool";

using namespace std;


void errnoException(std::string msg = "")
{
	if (msg != "")
		msg += ": ";
	msg += std::string(strerror(errno));
	throw std::runtime_error(msg);
}



void Spooler::enqueue(std::string recipient, std::string message)
{
	bool error = false;
	lock();
	std::string file = findSpoolFilename();
	std::ofstream out(file.c_str());
	if (out)
	{
		out << recipient << "\n" << message;
		out.close();
	}
	else
	{
		error = true;
	}
	unlock();

	if (error)
		throw std::runtime_error("Could not create spoolfile");
	this->filename = file;
}

std::string Spooler::dequeue()
{
	lock();

	DIR* dir = opendir( spooldir.c_str() );
	if (dir == 0)
		errnoException();

	string file;
	string message;
	dirent* entry;
	while ( (entry = readdir(dir)) != 0)
	{
		if (entry->d_name[0] == '.' )
		{
			continue;
		}
		else
		{
			file = spooldir + string(entry->d_name);
			break;
		}

	}

	closedir(dir);

	if (file != "")
	{
		message = Util::readfile(file);
		::unlink(file.c_str());
	}

	unlock();

	this->filename = file;

	if (file != "")
		return message;
	else
		throw filenotfoundexception();
}

std::string Spooler::findSpoolFilename()
{
	std::string file;
	std::stringstream ss;

	int retrycount = 0;

	while (1)
	{
		ss.str(std::string()); //clear
		ss << std::setw(8) << std::setfill('0') << std::uppercase  << std::hex << rand();

		string file = spooldir;
		file += ss.str().c_str();

		int fd = ::open(file.c_str(), O_WRONLY | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR | S_IRGRP| S_IROTH);
		retrycount ++;

		if (fd != -1)
		{
			::close(fd);
			return file;
		}
		int err = errno;
		::close(fd);

		if (err == EEXIST)
		{
			continue;
		}

		if (retrycount > 20)
			throw std::runtime_error("to many retry attempt at creating spool file");

		throw std::runtime_error("no access to spool directory");

	}
}

void Spooler::lock()
{
	lockfd = open(spooldir.c_str() , O_RDONLY);

	if (lockfd == -1)
	{
		errnoException("Couldn open lockfile");
	}

	int status = flock(lockfd, LOCK_EX);

	if (status == -1)
	{
		errnoException();
	}
}

void Spooler::unlock()
{
	flock(lockfd, LOCK_UN);
	close(lockfd);
}

string Spooler::getFilename()
{
	return filename;
}