package org.nutz.mvc.ioc;

import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

import javax.servlet.ServletRequest;

import org.nutz.ioc.IocContext;
import org.nutz.ioc.ObjectProxy;

/**
 * 
 * @author zozoh(zozohtnt@gmail.com)
 * @author wendal(wendal1985@gmail.com)
 */
public class RequestIocContext implements IocContext {

    private ServletRequest req;

    public RequestIocContext(ServletRequest req) {
        this.req = req;
    }

    public void clear() {
        synchronized (req) {
            @SuppressWarnings("unchecked")
            Enumeration<String> ems = req.getAttributeNames();
            List<String> keys = new ArrayList<String>();
            while (ems.hasMoreElements()) {
                String key = ems.nextElement();
                if (null == key)
                    continue;
                Object value = req.getAttribute(key);
                if (value instanceof ObjectProxy) {
                    keys.add(key);
                    ((ObjectProxy) value).depose();
                }
            }
            for (String key : keys) {
                req.removeAttribute(key);
            }
        }
    }

    public void depose() {
        clear();
        req = null;
    }

    public ObjectProxy fetch(String name) {
        Object re = req.getAttribute(name);
        if (re == null)
            return null;
        if (re instanceof ObjectProxy)
            return (ObjectProxy) re;
        return new ObjectProxy().setObj(re);
    }

    public boolean remove(String scope, String name) {
        if (null != scope && "request".equals(scope)) {
            req.removeAttribute(name);
            return true;
        }
        return false;
    }

    public boolean save(String scope, String name, ObjectProxy obj) {
        if (null != scope && "request".equals(scope)) {
            req.setAttribute(name, obj);
            return true;
        }
        return false;
    }
    
    public ServletRequest getReq() {
        return req;
    }

}