package jungle.app.bbs;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Iterator;

import alice.jungle.datasegment.store.container.DefaultTreeOperationLogContainer;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.Jungle;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.JungleTree;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.JungleTreeEditor;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Node;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.Command;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.impl.DefaultNodePath;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.impl.logger.DefaultTreeOperationLog;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.impl.logger.TreeOperationLog;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.operations.NodeOperation;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.operations.TreeOperation;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Either;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Error;

public class JungleManager {
	private static JungleManager jm = new JungleManager();
	private Jungle jungle;

	private JungleManager() {

	}
	
	public static void setJungle(Jungle _j) {
		jm.jungle = _j;
	}
	
	public static Jungle getJungle() {
		return jm.jungle;
	}
	
	public static JungleTree createNewTree(String name) {
		return jm.jungle.createNewTree(name);		
	}

	public static Either<Error, JungleTreeEditor> edit(JungleTreeEditor _editor ,TreeOperationLog _log, int pos) {
		JungleTreeEditor editor = _editor;
		Either<Error, JungleTreeEditor> either = null;
		for (TreeOperation op : _log) { 
			either = _edit(editor, op, pos);
			if(either.isA()) {
				return either;
			}
			editor = either.b();
		}
		return either;
	}
	
	private static Either<Error, JungleTreeEditor> _edit(JungleTreeEditor editor,
			TreeOperation op, int pos) {
		DefaultNodePath path = new DefaultNodePath();
		NodeOperation nodeOp = op.getNodeOperation();
		Command c = nodeOp.getCommand();
		String key = "";
		switch (c) {
		case PUT_ATTRIBUTE:
			path = path.add(pos);
			key = nodeOp.getKey();
			ByteBuffer value = nodeOp.getValue();
			return editor.putAttribute(path, key, value);
		case DELETE_ATTRIBUTE:
			key = nodeOp.getKey();
			return editor.deleteAttribute(path, key);
		case APPEND_CHILD:
			return editor.addNewChildAt(path, pos);
		case DELETE_CHILD:
			return editor.deleteChildAt(path, 0);
		}
		return null;
	}
	
	public static Either<Error, JungleTreeEditor> update(DefaultTreeOperationLogContainer container) {
		DefaultTreeOperationLog log = null;
		try {
			log = container.convert();
		} catch (IOException e) {
			e.printStackTrace();
		}
		String treeName = container.getTreeName();
		if (JungleManager.getJungle().getTreeByName(treeName) == null) {
			if(null == JungleManager.getJungle().createNewTree(treeName)){
				throw new IllegalStateException();
			}
		}
		JungleTree tree = JungleManager.getJungle().getTreeByName(treeName);
		JungleTreeEditor editor = tree.getTreeEditor();
		int pos = checkTimeStamp(tree.getRootNode(), container.getTimeStamp(), container.getPosition());
		Either<Error, JungleTreeEditor> either = JungleManager.edit(editor, log, pos);
		if(either.isA()) {
			throw new IllegalStateException();
		}
		editor = either.b();
		either = editor.success();
		if(either.isA()) {
			throw new IllegalStateException();
		}
		return either;
	}
	
	private static int checkTimeStamp(Node node, long newNodeTimeStamp, int containerPosition) {
		int count = 0;
		long childTimeStamp = 0;
		for(Iterator<Node> iter = node.getChildren().iterator();iter.hasNext();) {
			Node n = iter.next();
			if(n.getAttributes().get("timestamp") == null) {
				return containerPosition;
			}
			if(n.getAttributes().get("timestamp") != null) {
				childTimeStamp = n.getAttributes().get("timestamp").getLong();
				if (newNodeTimeStamp < childTimeStamp) {
					break;
				}
			}
			count++;
		}
		return count;
	}
}