/*******************************************************************************
 * Copyright (c) 2007, 2019 Association for Decentralized Information Management in
 * Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *     Semantum Oy - gitlab #82, gitlab #313
 *******************************************************************************/
package org.simantics.databoard.binding.factory;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

import org.simantics.databoard.binding.Binding;
import org.simantics.databoard.binding.reflection.BindingRequest;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class BindingRepository {

    private static final Logger LOGGER = LoggerFactory.getLogger(BindingRepository.class);
	/**
	 * This map contains all the bindings
	 */
	Map<BindingRequest, Binding> requestMap;
	
	/**
	 * This map contains bindings for non-generic classes. 
	 */
	Map<Class<?>, Binding> classMap;
	
	public BindingRepository() {		
		requestMap = new HashMap<BindingRequest, Binding>();
		classMap = new HashMap<Class<?>, Binding>();
	}
	
	public BindingRepository(Map<BindingRequest, Binding> requests) {
		this.requestMap = requests;
		for (Entry<BindingRequest, Binding> e : requests.entrySet()) {
			if ( isClassRequest( e.getKey() ) ) {
				registerClassMapping(e.getKey().getClazz(), e.getValue());
			}
		}
	}
	
	/**
	 * Get binding for a class. May return the class if it is in the class map.
	 * If not, the user should try request map with some arguments (component bindings)
	 * 
	 * @param clazz
	 * @return binding
	 */
	public synchronized Binding get(Class<?> clazz) {
		return classMap.get( clazz );
	}
	
	/**
	 * Get binding for a binding request
	 * 
	 * @param request
	 * @return binding or null
	 */
	public synchronized Binding get( BindingRequest request ) {
		return requestMap.get( request );
	}
	
	/**
	 * Adds binding to the repository. If the request has no arguments, the 
	 * class is added to classMap, and is available with class request.  
	 * 
	 * @param request
	 * @param binding
	 */
	public synchronized void put( BindingRequest request, Binding binding ) {
		if ( isClassRequest(request) ) {
		    registerClassMapping(request.getClazz(), binding);
		}
		Binding existing = requestMap.put( request, binding );
		if (existing != null && !existing.equals(binding)) {
		    LOGGER.error("Replacing existing binding with a different one! {} {} {}", request, binding, existing);
		}
	}

	@SuppressWarnings("unlikely-arg-type")
	public synchronized void remove(Binding binding) {
		for (Entry<BindingRequest, Binding> e : requestMap.entrySet()) {
			if (e.getValue() == binding) {
				requestMap.remove(e.getValue());
				break;
			}
		}
		
		for (Entry<Class<?>, Binding> e : classMap.entrySet()) {
			if (e.getValue() == binding) {
				classMap.remove(e.getValue());
				break;
			}
		}
}
	
	public synchronized boolean containsRequest( BindingRequest request ) {
		return requestMap.containsKey( request );
	}
	
	/**
	 * Checks if repository contains a class without arguments
	 * 
	 * @param clazz 
	 * @return true if contains class (without args)
	 */
	public synchronized boolean containsClass( Class<?> clazz ) {
		return classMap.containsKey( clazz );
	}
	
	public synchronized void clear() {
		requestMap.clear();
		classMap.clear();
	}

	boolean isClassRequest(BindingRequest request) {
		return (request.className != null && (request.annotations == null || request.annotations.length == 0));
	}

	public void registerClassMapping(Class<?> clazz, Binding binding) {
		Binding previous = classMap.putIfAbsent(clazz, binding);
		if (previous != null) {
			LOGGER.warn("WARN: Can not put same key again to classMap! {} mapping {} not replaced by {}", clazz, previous, binding);
		}
	}

}