package org.simantics.interop.test;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.simantics.db.Resource;
import org.simantics.db.Statement;

public class Path {
	private Resource begin;
	private Resource end;
	private List<Statement> statements = new ArrayList<Statement>(2);
	
	public Path(Statement s) {
		begin = s.getSubject();
		end = s.getObject();
		statements.add(s);
	}
	
	public Path(Path p) {
		begin = p.begin;
		end = p.end;
		statements.addAll(p.statements);
	}
	
	public Resource getBegin() {
		return begin;
	}
	
	public Resource getEnd() {
		return end;
	}
	
	public List<Statement> getStatements() {
		return statements;
	}
	
	public int getLength() {
		return statements.size();
	}
	
	public boolean add(Statement s) {
		if (!statements.get(statements.size()-1).getObject().equals(s.getSubject()))
			//throw new RuntimeException("Non continuous path. " + s.getSubject() + " does not match " + statements.get(statements.size()-1).getObject());
			return false;
		if (s.getObject().equals(begin))
			return false;
		for (Statement stm : statements) {
			if (stm.getObject().equals(s.getObject()))
				return false;
		}
		end = s.getObject();
		statements.add(s);
		return true;
	}
	
	public static Collection<Path> expand(Path path, Collection<Statement> statements) {
		Collection<Path> result = new ArrayList<Path>(statements.size());
		for (Statement s : statements) {
			Path p = new Path(path);
			p.add(s);
			result.add(p);
		}
		return result;
	}
	
	public static Collection<Path> create(Collection<Statement> statements) {
		Collection<Path> result = new ArrayList<Path>(statements.size());
		for (Statement s : statements) {
			Path p = new Path(s);
			result.add(p);
		}
		return result;
	}
	
	@Override
	public boolean equals(Object arg0) {
		if(!arg0.getClass().equals(getClass()))
			return false;
		Path other = (Path)arg0;
		if (!begin.equals(other.begin))
			return false;
		if (!end.equals(other.end))
			return false;
		if (statements.size() != other.statements.size())
			return false;
		for (int i = 0; i < statements.size(); i++) {
			if (!statements.get(i).getPredicate().equals(other.statements.get(i).getPredicate())||
			    !statements.get(i).getObject().equals(other.statements.get(i).getObject()))
				return false;
		}
		return true;
	}
	
	@Override
	public int hashCode() {
		return begin.hashCode() + end.hashCode();
	}
	
	@Override
	public String toString() {
		String s = "";
		for (int i = 0; i < statements.size() ; i++) {
			s += statements.get(i).getSubject();
			s += "<" + statements.get(i).getPredicate() +">";
			if (i == statements.size() -1)
				s += statements.get(i).getObject();
		}
		return s;
	}
}