package pt.ist.renderers.components.state;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

import pt.ist.renderers.model.UserIdentity;
import pt.ist.renderers.model.UserIdentityFactory;

public class EditRequest extends HttpServletRequestWrapper {

    private List<IViewState> viewStates;

    private String publicModuleName = "publico";

    public EditRequest(HttpServletRequest request) {
	super(request);
    }

    public List<IViewState> getAllViewStates() throws IOException, ClassNotFoundException {
	if (this.viewStates == null) {
	    String[] encodedViewStates = getParameterValues(LifeCycleConstants.VIEWSTATE_PARAM_NAME);
	    if (encodedViewStates != null) {
		this.viewStates = new ArrayList<IViewState>();

		for (int i = 0; i < encodedViewStates.length; i++) {
		    String encodedSingleViewState = encodedViewStates[i];

		    IViewState viewState = ViewState.decodeFromBase64(encodedSingleViewState);
		    this.viewStates.add(viewState);
		}
	    } else {
		this.viewStates = ViewState.decodeListFromBase64(getParameter(LifeCycleConstants.VIEWSTATE_LIST_PARAM_NAME));
	    }
	}

	String contextPath = ((HttpServletRequest) getRequest()).getContextPath();
	String requestURI = ((HttpServletRequest) getRequest()).getRequestURI().toString();

	UserIdentity userIdentity = UserIdentityFactory.create(this);
	for (IViewState viewState : this.viewStates) {
	    viewState.setRequest(this);

	    checkUserIdentity(viewState, userIdentity, requestURI, contextPath);
	}

	return this.viewStates;
    }

    private void checkUserIdentity(IViewState viewState, UserIdentity userIdentity, String requestURI, String contextPath) {
	if (!requestURI.startsWith(contextPath + "/" + publicModuleName + "/") && !viewState.getUser().equals(userIdentity)) {
	    throw new ViewStateUserChangedException();
	}
    }

    public static class ViewStateUserChangedException extends RuntimeException {

	public ViewStateUserChangedException() {
	    super("viewstate.user.changed");
	}
    }
}