#include "CityConnector.h"


CityConnector::CityConnector(string InputFileName)
{
	cityID = 0;
	LoadPairs(InputFileName.c_str() );
	initialized = true;
	
}
CityConnector::CityConnector(void)
{
	initialized = false;
	cityID = 0;
}

void CityConnector::LoadFile(const char * filename)
{
	LoadPairs(filename);
	initialized = true;
}

void CityConnector::ReportConnectedCities()
{
	if(!initialized)
	{
		cout << "CityConnector is not initialized(no file loaded)... Exiting..." << endl;
		system("pause");
		exit(-1);
	}

	UnionConnections();
	Print();
}

bool CityConnector::CheckConnection(string city_1, string city_2)
{
	if(!initialized)
	{
		cout << "CityConnector is not initialized(no file loaded)... Exiting..." << endl;
		system("pause");
		exit(-1);
	}

	int c1 = city2int[city_1];
	int c2 = city2int[city_2];

	c1 = djs.Find(c1);
	c2 = djs.Find(c2);

	if(c1 == c2)
	{
		cout << "YES" << endl;
		return 1;
	}

	cout << "NO" << endl;
	return 0;
}





void CityConnector::LoadPairs(const char *filename)
{
	ifstream istream;
	
	string line, city1, city2;
	int pos;

	istream.open(filename, ios_base::in);


	if(!istream)
	{
		cout << "Error opening file: " << filename << endl;
		system("pause");
		exit(0);
	}

	while (!istream.eof())
	{
		//get string
		getline(istream, line);
		
		//split string
		pos = line.find(',');
		city1 = line.substr(0, pos);
		city2 = line.substr(pos+2);

		//If the cities isn't in our maps... map them
		map<string, int>::iterator it = city2int.find(city1);
		if (it == city2int.end())
		{
			city2int.insert(make_pair(city1, cityID) );
			int2city.insert(make_pair(cityID++, city1) );
		}
		
		it = city2int.find(city2);
		if (it == city2int.end())
		{
			city2int.insert(make_pair(city2, cityID) );
			int2city.insert(make_pair(cityID++, city2) );
		}


		//store the connection
		connections.push_back( make_pair(city1, city2) );
		

	}
	istream.close();

	//Make union-find(disjoint-sets) structure with size of our elements
	//and set them all in their own equivalence class (setting each to -1)
	djs.Init(cityID);

}

void CityConnector::UnionConnections(void)
{
	if(!initialized)
	{
		cout << "CityConnector is not initialized(no file loaded)... Exiting..." << endl;
		system("pause");
		exit(-1);
	}

	vector<pair<string,string> >::iterator it;
	
	for (it = connections.begin(); it != connections.end(); ++it)
	{
		int first, second;

		first = city2int[it->first];
		second = city2int[it->second];

		djs.Union(first, second);
	}

}

void CityConnector::Print(void)
{
	if(!initialized)
	{
		cout << "CityConnector is not initialized(no file loaded)... Exiting..." << endl;
		system("pause");
		exit(-1);
	}

	string heading = "Equivalence Class #";

	//Load final node to root mapping for each node
	for(unsigned int i = 0; i<djs.s.size(); i++)
	{
		node2root.insert(make_pair(djs.Find(i), i) );
	}

	int headingNum = 1;
		
	for(unsigned int i = 0; i<djs.s.size(); i++)
	{
		//if root
		if(djs.s[i] < 0)
		{
			pair<hash_multimap<int,int>::iterator, hash_multimap<int,int>::iterator> itPair;
			
			//get all nodes with root i
			itPair = node2root.equal_range(i);

			//print heading
			cout << endl << heading << headingNum++ << endl << endl;

			//print every city attatched to root i, including i
			hash_multimap<int,int>::iterator iter;
			for(iter = itPair.first; iter != itPair.second; ++iter)
			{
				cout << int2city[iter->second] << endl;
			}
		}
	}


}