/******************************************************************************
 * Copyright (c) 2002 - 2012 IBM Corporation.
 * 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:
 *     IBM Corporation - initial API and implementation
 *****************************************************************************/
package com.ibm.wala.cast.js.callgraph.fieldbased.flowgraph.vertices;

import java.util.Collection;
import java.util.Map;

import com.ibm.wala.cast.js.ssa.JavaScriptInvoke;
import com.ibm.wala.classLoader.CallSiteReference;
import com.ibm.wala.classLoader.IClass;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.types.TypeReference;
import com.ibm.wala.util.collections.HashMapFactory;
import com.ibm.wala.util.collections.Pair;

/**
 * A vertex factory is associated with a flow graph. It manages its vertex set, making sure that
 * vertices aren't unnecessarily created twice.
 *  
 * @author mschaefer
 *
 */
public class VertexFactory {
	private final Map<Pair<FuncVertex, CallSiteReference>, CallVertex> callVertexCache = HashMapFactory.make();
	private final Map<IClass, FuncVertex> funcVertexCache = HashMapFactory.make();
	private final Map<Pair<FuncVertex, Integer>, ParamVertex> paramVertexCache = HashMapFactory.make();
	private final Map<String, PropVertex> propVertexCache = HashMapFactory.make();
	private final Map<FuncVertex, RetVertex> retVertexCache = HashMapFactory.make();
  private final Map<FuncVertex, ArgVertex> argVertexCache = HashMapFactory.make();
	private final Map<Pair<FuncVertex, Integer>, VarVertex> varVertexCache = HashMapFactory.make();
	private final Map<Pair<String, String>, LexicalVarVertex> lexicalAccessVertexCache = HashMapFactory.make();
	private final Map<Pair<IMethod,Integer>, CreationSiteVertex> creationSites = HashMapFactory.make();
	
	public CallVertex makeCallVertex(FuncVertex func, JavaScriptInvoke invk) {
		CallSiteReference site = invk.getCallSite();
		Pair<FuncVertex, CallSiteReference> key = Pair.make(func, site);
		CallVertex value = callVertexCache.get(key);
		if(value == null)
			callVertexCache.put(key, value = new CallVertex(func, site, invk));
		return value;
	}
	
	public Iterable<CallVertex> getCallVertices() {
		return callVertexCache.values();
	}

	public CreationSiteVertex makeCreationSiteVertex(IMethod method, int instruction, TypeReference createdType) {
	  Pair<IMethod, Integer> key = Pair.make(method, instruction);
    CreationSiteVertex value = creationSites.get(key);
	  if (value == null) {
	    creationSites.put(key, value = new CreationSiteVertex(method, instruction, createdType));
	  }
	  return value;
	}
	
	public Collection<CreationSiteVertex> creationSites() {
	  return creationSites.values();
	}
	
	public FuncVertex makeFuncVertex(IClass klass) {
		FuncVertex value = funcVertexCache.get(klass);
		if(value == null)
			funcVertexCache.put(klass, value = new FuncVertex(klass));
		return value;
	}

	public Collection<FuncVertex> getFuncVertices() {
	  return funcVertexCache.values();
	}

	public ParamVertex makeParamVertex(FuncVertex func, int index) {
		Pair<FuncVertex, Integer> key = Pair.make(func, index);
		ParamVertex value = paramVertexCache.get(key);
		if(value == null)
			paramVertexCache.put(key, value = new ParamVertex(func, index));
		return value;
	}

	public PropVertex makePropVertex(String name) {
		PropVertex value = propVertexCache.get(name);
		if(value == null)
			propVertexCache.put(name, value = new PropVertex(name));
		return value;
	}
	
	public Iterable<PropVertex> getPropVertices() {
	  return propVertexCache.values();
	}

	public RetVertex makeRetVertex(FuncVertex func) {
		RetVertex value = retVertexCache.get(func);
		if(value == null)
			retVertexCache.put(func, value = new RetVertex(func));
		return value;
	}

	public ArgVertex makeArgVertex(FuncVertex func) {
    ArgVertex value = argVertexCache.get(func);
    if(value == null)
      argVertexCache.put(func, value = new ArgVertex(func));
    return value;
  }

	public UnknownVertex makeUnknownVertex() {
		return UnknownVertex.INSTANCE;
	}

	public VarVertex makeVarVertex(FuncVertex func, int valueNumber) {
		Pair<FuncVertex, Integer> key = Pair.make(func, valueNumber);
		VarVertex value = varVertexCache.get(key);
		if(value == null)
			varVertexCache.put(key, value = new VarVertex(func, valueNumber));
		return value;
	}

	public LexicalVarVertex makeLexicalAccessVertex(String definer, String name) {
		Pair<String, String> key = Pair.make(definer, name);
		LexicalVarVertex value = lexicalAccessVertexCache.get(key);
		if(value == null)
			lexicalAccessVertexCache.put(key, value = new LexicalVarVertex(definer, name));
		return value;
	}
	
	private GlobalVertex global = GlobalVertex.instance();
	
	public GlobalVertex global() {
	  return global;
	}
}