#include <iostream>
#include <fstream>
#include <string>

using namespace std;

struct person {
	string ssn, dob, zip, title, fname, lname, street, town, state;
	person(string s, string d, string z, string ti, string f, string l, string str, string to, string st) {
		ssn = s;
		dob = d;
		zip = z;
		title = ti;
		fname = f;
		lname = l;
		street = str;
		town = to;
		state = st;
	}
};

struct List {
	protected:
	struct Link {
		person* data;
		Link* next;
		Link(person* d, Link* n = NULL) {
			data = d;
			next = n;
		}
		~Link() {
			delete data;
			next = NULL;
		}
	};
	Link* first;
	Link* last;
	int length;
	public:
	List() {
		first = NULL;
		last = NULL;
		length = 0;
	}
	~List() {
		Link* prev = NULL;
		while (first != NULL) {
			prev = first;
			first = prev->next;
			delete prev;
		}
		first = NULL;
		last = NULL;
		length = 0;
	}

	void add_to_front(person*);
	void add_to_end(person*);
	void read_file(string);
	void printall();
	List* user_query();
};		

void List::add_to_front(person* x) {
	first = new Link(x, first);
	if (last==NULL) last = first;
	length++;
}

void List::add_to_end(person* x) {
	Link* n = new Link(x, NULL);
	if (last != NULL) last->next = n;
	else first = n;
	last = n;
	length++;
}

void List::read_file(string file) {
	ifstream f(file.c_str());
	if (f.fail()) {
		cout << "Error opening file\n";
		return;
	}
	int counter = 0;
	for (int i=0; i<5000; i++) {
		string ssn, dob, zip, title, fname, lname, street, town, state;
		f >> ssn >> dob >> title >> fname >> lname >> street >> town >> state >> zip;
		person* p = new person(ssn, dob, zip, title, fname, lname, street, town, state);
		add_to_end(p);
		counter++;
		if (f.fail()) break;
	}
	f.close();
}

void List::printall() {
	if (first==NULL) cout << "Empty list\n";
	else {
		Link* temp = first;
		while (temp!=NULL) {
			cout << temp->data->ssn << " " << temp->data->dob << " " << temp->data->title << " " << temp->data->fname << " " << temp->data->lname << " " << temp->data->street << " " << temp->data->town << " " << temp->data->state << " " << temp->data->zip << "\n";
			temp = temp->next;
		}
	}
}

bool equal(person* a, string b, string attribute) {
	if (attribute=="ssn") {
		if (a->ssn==b) return true; }
	else if (attribute=="dob") {
		if (a->dob==b) return true; }
	else if (attribute=="title") {
		if (a->title==b) return true; }
	else if (attribute=="fname") {
		if (a->fname==b) return true; }
	else if (attribute=="lname") { 
		if (a->lname==b) return true; }
	else if (attribute=="street") {
		if (a->street==b) return true; }
	else if (attribute=="town") {
		if (a->town==b) return true; }
	else if (attribute=="state") {
		if (a->state==b) return true; }
	else if (attribute=="zip") {
		if (a->zip==b) return true; }
	return false;
}

bool begin(person* a, string b, string attribute) {
	int length = b.length();
	if (attribute=="ssn") {
		for (int i=0; i<length; i++)
			if (a->ssn[i] != b[i]) return false;
		return true;
	}
	else if (attribute=="dob") {
		for (int i=0; i<length; i++)
			if (a->dob[i] != b[i]) return false;
		return true;
	}
	else if (attribute=="title") {
		for (int i=0; i<length; i++)
			if (a->title[i] != b[i]) return false;
		return true;
	}
	else if (attribute=="fname") {
		for (int i=0; i<length; i++)
			if (a->fname[i] != b[i]) return false;
		return true;
	}
	else if (attribute=="lname") {
		for (int i=0; i<length; i++)
			if (a->lname[i] != b[i]) return false;
		return true;
	}
	else if (attribute=="street") {
		for (int i=0; i<length; i++)
			if (a->street[i] != b[i]) return false;
		return true;
	}
	else if (attribute=="town") {
		for (int i=0; i<length; i++)
			if (a->town[i] != b[i]) return false;
		return true;
	}
	else if (attribute=="state") {
		for (int i=0; i<length; i++)
			if (a->state[i] != b[i]) return false;
		return true;
	}
	else if (attribute=="zip") {
		for (int i=0; i<length; i++)
			if (a->zip[i] != b[i]) return false;
		return true;
	}
	return false;
}
	
List* List::user_query() {
	if (first==NULL) {
		cout << "Empty list\n";
		return NULL;
	}
	
	List* results = new List;
	results->read_file("/home/www/class/een218/ass7f132.txt");
		
	cout << "Input field, 'equal' or 'begins', and a value\n";

	while (true) {
		string field, comparison, value, attribute, filename;
		cin >> field;
		if (field=="print" || field=="Print") {
			results->printall();
		}
		else if (field=="clear" || field=="Clear") {
			delete results;
			List* results = new List;
			results->read_file("/home/www/class/een218/ass7f132.txt");
			cout << "Search cleared.\n";
		}
		else if (field=="exit" || field=="Exit") {
			return this;
		}
		else if (field=="save" || field=="Save") {
			cin >> filename;
			ofstream fo(filename.c_str());
			if (fo.fail()) {
				cout << "Error creating file\n";
				exit(1);
			}
			Link* cur = results->first;
			if (cur==NULL) break;
			while (cur != NULL) {
				fo << cur->data->ssn << " " << cur->data->dob << " " << cur->data->title << " " << cur->data->fname << " " << cur->data->lname << " " << cur->data->street << " " << cur->data->town << " " << cur->data->state << " " << cur->data->zip << "\n";
				cur = cur->next;
			}
			fo.close();
			cout << "File saved.\n";					
		}
		else cin >> comparison >> value;

		if (field=="dob" || field=="birthday" || field=="Dob" || field=="DOB") attribute = "dob";
		else if (field=="ssn" || field=="SSN" || field=="Ssn") attribute = "ssn";
		else if (field=="title" || field=="Title" || field=="prefix" || field=="Prefix") attribute = "title";
		else if (field=="fname" || field=="Fname" || field=="firstname" || field=="First" || field=="first") attribute = "fname";
		else if (field=="lname" || field=="Lastname" || field=="lastname" || field=="Last" || field=="last") attribute = "lname";
		else if (field=="street" || field=="Street" || field=="Address" || field=="address") attribute = "street";
		else if (field=="town" || field=="Town" || field=="city" || field=="City") attribute = "town";
		else if (field=="state" || field=="State") attribute = "state";
		else if (field=="zip" || field=="Zip" || field=="zipcode" || field=="Zipcode") attribute = "zip";

		Link* prev = NULL;
		Link* curr = results->first;
		if (comparison=="equal" || comparison=="Equal" || comparison=="equals" || comparison=="Equals") {
			if (curr==NULL) break;
			while (curr != NULL) {
				if (equal(curr->data,value,attribute)==false) {
					results->length = results->length-1;
					if (prev==NULL) {
						results->first = curr->next;
						Link* temp = curr;
						curr = curr->next;
						delete temp;
					}
					else if (curr->next==NULL) {
						results->last = prev;
						prev->next = NULL;
						delete curr;
						curr = NULL;
					}
					else {
						prev->next = curr->next;
						delete curr;
						curr = prev->next;
					}	
				}
				else {
					prev = curr;
					curr = curr->next;
				}
			}
			cout << "Your search returned " << results->length << " results.\n";
		}
		else if (comparison=="begin" || comparison=="Begin" || comparison=="begins" || comparison=="Begins") {
			if (curr==NULL) break;
			while (curr != NULL) {
				if (begin(curr->data,value,attribute)==false) {
					results->length = results->length-1;
					if (prev==NULL) {
						results->first = curr->next;
						Link* temp = curr;
						curr = curr->next;
						delete temp;
					}
					else if (curr->next==NULL) {
						results->last = prev;
						prev->next = NULL;
						delete curr;
						curr = NULL;
					}
					else {
						prev->next = curr->next;
						delete curr;
						curr = prev->next;
					}	
				}
				else {
					prev = curr;
					curr = curr->next;
				}
			}
			cout << "Your search returned " << results->length << " results.\n";	
		}
	}
}

void main() {
	List* a = new List;
	a->read_file("/home/www/class/een218/ass7f132.txt");
	a->printall();
	a->user_query();	
}