import java.util.Collection;
import java.util.Iterator;
import java.util.HashMap;



public class SimpAgentTreeTopo implements ISimpAgent<TreeConstraintState, TreeConstraintState> {

	/**
	 * Some design needs to happen here.
	 * Need to figure out how to send different things for sent messages
	 * than for states, despite the fact that the holder class in each
	 * case is of type TreeConstraintState
	 * Also : Need to send desired start number to children (different
	 * for each child), total descendants to parent, and store correct
	 * start num and num descendants.
	 * <p>
	 * <h2>Design</h2>
	 * Needs to store map from child to start number.
	 * Needs to set own start number to that send by parent.
	 * Needs to send child start number to appropriate child.
	 * </p>
	 * @author mds
	 *
	 */
	public static class TreeTopoInfo implements IMsg {
		int m_nId;
		int m_nNumDesc;
		int m_nStart;
		
		HashMap<Integer, Integer> m_mapStartId;

		public TreeTopoInfo() {
			m_nNumDesc = 1; // 1 for myself first visit, 1 for myself last visit
			m_mapStartId = new HashMap<Integer, Integer>(17);
		}
		
		public TreeTopoInfo(TreeTopoInfo src) {
			m_nId = src.m_nId;
			m_nNumDesc = src.m_nNumDesc;
			m_nStart = src.m_nStart;
			m_mapStartId = new HashMap<Integer, Integer>(src.m_mapStartId.size());
			Iterator<java.util.Map.Entry<Integer, Integer> > iter = 
				src.m_mapStartId.entrySet().iterator();
			while(iter.hasNext()) {
				java.util.Map.Entry<Integer, Integer> currEntry = iter.next();
				m_mapStartId.put(currEntry.getKey(), currEntry.getValue());
			}
		}
		
		public TreeTopoInfo makeCopy() {
			return new TreeTopoInfo(this);
		}
		
		public int getId() { return m_nId; }
		public void setId(int nId) { m_nId = nId; }
		public int getStart() { return m_nStart; }
		public void setStart(int nStart) { m_nStart = nStart; }
		public int getNumDesc() { return m_nNumDesc;}
		public void setNumDesc(int nNumDesc) { m_nNumDesc = nNumDesc; }
		public int incrDesc(int nIncrBy) { m_nNumDesc += nIncrBy; return m_nNumDesc; }
		
		public void handleParent(TreeTopoInfo infParent) {
			if(infParent == null) {
				return;
			}
			if(infParent.getId() == getId()) {
				m_nStart = 0;
				return;
			}
			if(infParent.m_mapStartId.containsKey(m_nId)) {
				m_nStart = infParent.m_mapStartId.get(m_nId) + infParent.getStart();
				return;
			}
			m_nStart = infParent.getStart()+infParent.getNumDesc(); // just a guess
		}
		
		public void handleChild(TreeTopoInfo infChild) {
			if(infChild == null) {
				return;
			}
			if(infChild.getId() == getId()) {
				return;
			}
			
			if(m_mapStartId.containsKey(infChild.getId())) {
				return;
			}
			int nDescs = infChild.getNumDesc();
			m_mapStartId.put(infChild.getId(), m_nNumDesc);
			m_nNumDesc += nDescs+1;
		}
		

		public boolean isDesc(TreeConstraintState compare) {
			TreeTopoInfo infoCompare = getInfo(compare);
			return isDesc(infoCompare);
		}
		
		public boolean isDesc(TreeTopoInfo compare) {
			if(compare == null) {
				return true;
			}
			if(getStart() < compare.getStart() && 
					getStart() + getNumDesc() > compare.getStart()) {
				return true;
			}
			if(getStart() < compare.getStart() +compare.getNumDesc() &&
					getStart() + getNumDesc() > 
					compare.getStart() + compare.getNumDesc()) {
				return true;
			}
			return false;
		}
	}
	
	public static TreeTopoInfo getInfo(TreeConstraintState state) {
		IMsg infoUncast = state.getMsgAddition(TreeTopoInfo.class);
		if(infoUncast == null) {
			return null;
		}
		return (TreeTopoInfo)infoUncast;
	}
	
	public TreeConstraintState getMsg(TreeConstraintState varsPrev, int idDst) {
		// TODO Auto-generated method stub
		// still don't need to fill this in -- dangerous to skip it, but don't
		// really need it.
		return null;
	}

	public TreeConstraintState stateNext(TreeConstraintState varsPrev,
			Collection<TreeConstraintState> bagMsg) {
		// TODO Auto-generated method stub
		
		IFuncObj<TreeConstraintState, Boolean> funcChildren = 
			new TreeConstraintAgent.SelectMsgWithParent(varsPrev.getId());

		IFuncObj<TreeConstraintState, Boolean> funcParent = 
			new TreeConstraintAgent.SelectMsgMatchingId(varsPrev.getParentId());

		
		Iterator<TreeConstraintState> childIter = 
			AgentMsgHelpers.getFilteredMsgs(funcChildren, bagMsg);
		Iterator<TreeConstraintState> parentIter = 
			AgentMsgHelpers.getFilteredMsgs(funcParent, bagMsg);

		TreeTopoInfo myInfo = getInfo(varsPrev);
		
		myInfo = new TreeTopoInfo();
		myInfo.setId(varsPrev.getId());
		
		
		while(parentIter.hasNext()) {
			TreeConstraintState currState = parentIter.next();
			TreeTopoInfo currVars = getInfo(currState);
			myInfo.handleParent(currVars);
		}
		while(childIter.hasNext()) {
			TreeConstraintState currState = childIter.next();
			TreeTopoInfo currVars = getInfo(currState);
			myInfo.handleChild(currVars);
		}
		TreeConstraintState stateNext = new TreeConstraintState(varsPrev);
		stateNext.setMsgAddition(TreeTopoInfo.class, myInfo);
		return stateNext;
	}

}