/* -*- mode: JDE; c-basic-offset: 2; indent-tabs-mode: nil -*-
    *
    * $Id: SourceForgeClient.java,v 1.6 2004/07/27 20:20:36 ljnelson Exp $
    *
    * Copyright (c) 2003, 2004 Laird Jarrett Nelson.
    *
    * Permission is hereby granted, free of charge, to any person obtaining a copy
    * of this software and associated documentation files (the "Software"), to deal
    * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense and/or sell 
   * copies of the Software, and to permit persons to whom the Software is 
   * furnished to do so, subject to the following conditions:
   * 
   * The above copyright notice and this permission notice shall be included in 
   * all copies or substantial portions of the Software.
   * 
   * THIS SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   *
   * The original copy of this license is available at
   * http://www.opensource.org/license/mit-license.html.
   */
  package sfutils;
  
  import java.io.IOException;
  
  import java.net.MalformedURLException;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Map;
  import java.util.WeakHashMap;
  
  import com.meterware.httpunit.ClientProperties;
  import com.meterware.httpunit.GetMethodWebRequest;
  import com.meterware.httpunit.HttpUnitOptions;
  import com.meterware.httpunit.WebConversation;
  import com.meterware.httpunit.WebRequest;
  import com.meterware.httpunit.WebResponse;
  import com.meterware.httpunit.WebForm;
  import com.meterware.httpunit.WebLink;
  
  import org.xml.sax.SAXException;
  
  public class SourceForgeClient {
  
    /***
     * The {@link String} that represents the URL to use to log in to <a
     * href="http://sourceforge.net/">SourceForge</a>.
     */
    private static final String LOGIN_URL = 
      "http://sourceforge.net/account/login.php";
  
    /***
     * The leading portion of the URL required to access a <a
     * href="http://sourceforge.net/">SourceForge</a> project.
     */
    private static final String PROJECT_PREFIX = 
      "http://sourceforge.net/projects/";
  
    /***
     * A {@link Map} of project IDs indexed by project short names.  This field is
     * thread-safe.
     */
    private static final Map PROJECT_ID_MAP = 
      Collections.synchronizedMap(new WeakHashMap());
  
    /***
     * Static initializer; initializes various class fields.
     */
    static {
      HttpUnitOptions.setExceptionsThrownOnScriptError(false);
      HttpUnitOptions.setScriptingEnabled(false);
    }
  
    /***
     * The {@link WebConversation} to use to represent a session with the <a
     * href="http://sourceforge.net/">SourceForge</a> website.  This field will
     * never be <code>null</code>.
     */
    private final WebConversation wc;
  
    private boolean loggedIn;
  
    public SourceForgeClient() {
      super();
      this.wc = new WebConversation();
      final ClientProperties clientProperties = this.wc.getClientProperties();
      if (clientProperties != null) {
        clientProperties.setAcceptGzip(false);
      }
    }
  
   public SourceForgeClient(final String user,
                            final String password)
     throws InvalidCredentialsException, SourceForgeException {
     this();
     this.login(user, password);
   }
 
   protected WebConversation getWebConversation() {
     return this.wc;
   }
 
   protected WebResponse getCurrentPage() {
     final WebConversation wc = this.getWebConversation();
     if (wc != null) {
       return wc.getCurrentPage();
     }
     return null;
   }
   
   public boolean isLoggedIn() {
     return this.loggedIn;
   }
 
   protected void setLoggedIn(final boolean loggedIn) {
     this.loggedIn = loggedIn;
   }
 
   public boolean login(final String user,
                        final String password)
     throws InvalidCredentialsException, SourceForgeException
   {
 
     // If we're logged in already, don't do it again.
     if (this.isLoggedIn()) {
       return false;
     }
 
     // Reject null or empty users, but just null passwords.  We might actually
     // want to allow null passwords; not sure.
     if (user == null || 
         user.trim().equals("") ||
         password == null) {
       throw new InvalidCredentialsException(user, password);
     }
 
     // Fire up a "browser".
     final WebConversation wc = this.getWebConversation();
     assertNotNull(wc, "wc");
 
     // Get the login page, or whatever resides at its address.  We'll validate
     // it later.
     WebResponse loginPageResponse = null;
     try {
       loginPageResponse =
         wc.getResponse(new GetMethodWebRequest("http://sourceforge.net/account/login.php"));
     } catch (final IOException kaboom) {
       throw new SourceForgeException(kaboom);
     } catch (final SAXException kaboom) {
       throw new SourceForgeException(kaboom);
     }
     assertNotNull(loginPageResponse, "loginPageResponse");
 
     // Try to get forms off the page.  Obviously if there are none, then we
     // aren't looking at what we think we're looking at.
     WebForm[] forms = null;
     try {
       forms = loginPageResponse.getForms();
     } catch (final SAXException kaboom) {
       throw new SourceForgeException(kaboom);
     }
     assertArrayFull(forms, "forms");
 
     // Find the login form out of all the forms we got back.
     final WebForm loginForm =
       this.findFormWithAction(forms,
                               "https://sourceforge.net/account/login.php");
     assertNotNull(loginForm, "loginForm");
 
     // Set our login name, our password and that we want the login to be
     // persistent.  It is not necessary to stay in SSL after this initial login
     // and, moreover, could lead to problems in some JVMs.
     loginForm.setParameter("form_loginname", user);
     loginForm.setParameter("form_pw", password);
     loginForm.removeParameter("stay_in_ssl");
     loginForm.setParameter("persistent_login", "1");
 
     // Submit the form and log in.
     final WebRequest loginSubmissionRequest = loginForm.getRequest("login");
     assertNotNull(loginSubmissionRequest, "loginSubmissionRequest");    
     WebResponse loginResponse = null;
     try {
       loginResponse =
         wc.getResponse(loginSubmissionRequest);
     } catch (final IOException kaboom) {
       throw new SourceForgeException(kaboom);
     } catch (final SAXException kaboom) {
       throw new SourceForgeException(kaboom);
     }
     assertNotNull(loginResponse, "loginResponse");
 
     // Make sure we logged in successfully.
     String text = null;
     try {
       text = loginResponse.getText();
     } catch (final IOException kaboom) {
       throw new SourceForgeException(kaboom);
     }
     if (text == null || text.indexOf("Invalid Password or User Name") >= 0) {
       throw new InvalidCredentialsException(user, password);
     }
 
     // Everything's good; return appropriately.
     this.setLoggedIn(true);
     return true;
 
   }
 
   /***
    * Returns the <a href="http://sourceforge.net/">SourceForge</a> project
    * identifier given a project short name, or <code>-1</code> if the project
    * does not exist.
    *
    * @param      projectShortName
    *               the name of the project whose identifier should be returned;
    *               may be <code>null</code> in which case <code>-1</code> will
    *               be returned
    * @return     the identifier corresponding to the <a
    *               href="http://sourceforge.net/">SourceForge</a> project with
    *               the supplied short name, or <code>-1</code>
    * @exception  SourceForgeException
    *               if an error occurs 
    */
   public int getProjectID(final String projectShortName) 
     throws SourceForgeException {
     if (projectShortName == null) {
       return -1;
     }
 
     // Look up this project in the cache first.
     final Integer projectIDInteger = (Integer)PROJECT_ID_MAP.get(projectShortName);
     if (projectIDInteger != null) {
       return projectIDInteger.intValue();
     }
 
     // Otherwise, connect to SourceForge.
     final WebConversation webConversation = this.getWebConversation();
     assertNotNull(webConversation, "webConversation");
 
     // Go hit the main project page
     // (http://sourceforge.net/projects/projectShortName).
     WebResponse summaryPage = null;
     try {
       summaryPage = 
         webConversation.getResponse(new GetMethodWebRequest(PROJECT_PREFIX +
                                                             projectShortName));
     } catch (final IOException kaboom) {
       throw new SourceForgeException(kaboom);
     } catch (final SAXException kaboom) {
       throw new SourceForgeException(kaboom);
     }
     assertNotNull(summaryPage, "summaryPage");
 
     // Find a link on that page titled "[View Members]".  We go after the [View
     // Members] link because it is the least likely to change or be removed
     // during a UI change.  Really, any link off the main project page that
     // contains "group_id=123456" would work.
     WebLink viewMembersLink = null;
     try {
       viewMembersLink = summaryPage.getLinkWith("[View Members]");
     } catch (final SAXException kaboom) {
       throw new SourceForgeException(kaboom);
     }
     if (viewMembersLink == null) {
       // Couldn't find the [View Members] link.  That can't happen for a valid
       // project.  Maybe there was no project by that name?
       String text = null;
       try {
         text = summaryPage.getText();
       } catch (final IOException kaboom) {
         throw new SourceForgeException(kaboom);
       }
       assertNotNull(text, "text");
       if (text.indexOf("Invalid Project") >= 0) {
         throw new NoSuchProjectException(projectShortName);
       }
       // Treat any other kind of error as a UI change.
       throw new SourceForgeUIChangeException();
     }
 
     // Examine the link's destination URL to see what the project ID is.
     // Sometimes SourceForge calls projects projects, and sometimes it calls
     // them groups.  In this case we're looking for the value of the "group_id"
     // parameter.
     final String linkText = viewMembersLink.getURLString();
     assertNotNull(linkText, "linkText");
     final int groupIDIndex = linkText.indexOf("?group_id=");
     if (groupIDIndex < 0) {
       throw new SourceForgeUIChangeException();
     }
     int projectID = -1;
     final String projectIDString = 
       linkText.substring(groupIDIndex + "?group_id=".length());
 
     // If we found a group/project ID, convert it to an integer, stuff it in the
     // cache, and return it.
     if (projectIDString != null) {
       try {
         projectID = Integer.parseInt(projectIDString);
       } catch (final NumberFormatException kaboom) {
         projectID = -1;
       }
     }
     PROJECT_ID_MAP.put(projectShortName, new Integer(projectID));
     return projectID;
   }
 
   /***
    * Extracts a {@link WebForm} from the supplied array of {@link WebForm}s,
    * provided that its {@linkplain WebForm#getAction() action} is equal to the
    * supplied {@link String}.  This method may return <code>null</code>.
    *
    * @param      forms
    *               the array of {@link WebForm}s to consider; if
    *               <code>null</code> then <code>null</code> will be returned
    * @param      action
    *               the action {@link String} to which a given {@link WebForm}'s
    *               {@linkplain WebForm#getAction() action} must be equal in
    *               order for that {@link WebForm} to be returned; if
    *               <code>null</code> then <code>null</code> will be returned
    * @return     a {@link WebForm} from the supplied array of {@link WebForm}s,
    *               provided that its {@linkplain WebForm#getAction() action} is
    *               equal to the supplied {@link String}, or <code>null</code>
    */
   protected WebForm findFormWithAction(final WebForm[] forms,
                                        final String action) {
     if (forms == null || forms.length <= 0) {
       return null;
     }
     WebForm form;
     String formAction;
     for (int i = 0; i < forms.length; i++) {
       form = forms[i];
       if (form != null) {
         formAction = form.getAction();
         if (formAction == null) {
           if (action == null) {
             return null;
           }
         } else {
           if (formAction.equals(action)) {
             return form;
           }
         }
       }
     }
     return null;
   }
 
   /***
    * Returns an array of {@link WebForm}s whose elements are those {@link
    * WebForm}s extracted from the supplied {@link WebForm} array with
    * {@linkplain WebForm#getAction() actions} equal to the supplied {@link
    * String}.  This method never returns <code>null</code>.
    *
    * @param      forms
    *               the {@link WebForm} array in which to find candidates; may 
    *               be <code>null</code>
    * @param      action
    *               the {@linkplain WebForm#getAction() action} {@link String} to
    *               match; may be <code>null</code>
    * @return     an array of {@link WebForm}s whose elements are those {@link
    *               WebForm}s extracted from the supplied {@link WebForm} array
    *               with {@linkplain WebForm#getAction() actions} equal to the
    *               supplied {@link String}; never <code>null</code>
    */
   protected WebForm[] retainFormsWithAction(final WebForm[] forms,
                                             final String action) {
     if (forms == null || forms.length <= 0) {
       return new WebForm[0];
     }
     final Collection returnForms = new ArrayList(forms.length);
     WebForm form;
     String formAction;
     for (int i = 0; i < forms.length; i++) {
       form = forms[i];
       if (form != null) {
         formAction = form.getAction();
         if (formAction == null) {
           if (action == null) {
             returnForms.add(form);
           }
         } else {
           if (formAction.equals(action)) {
             returnForms.add(form);
           }
         }
       }
     }
     return (WebForm[])returnForms.toArray(new WebForm[returnForms.size()]);
   }
 
   protected WebForm[] retainFormsWithParameterNamed(final WebForm[] forms,
                                                     final String parameter) {
     if (forms == null || forms.length <= 0) {
       return new WebForm[0];
     }
     final Collection returnForms = new ArrayList(forms.length);
     WebForm form;
     for (int i = 0; i < forms.length; i++) {
       form = forms[i];
       if (form != null && form.hasParameterNamed(parameter)) {
         returnForms.add(form);
       }
     }
     return (WebForm[])returnForms.toArray(new WebForm[returnForms.size()]);
   }
 
   protected WebForm[] retainFormsWithParameterValue(final WebForm[] forms,
                                                     final String parameter,
                                                     final String value) {
     if (forms == null || forms.length <= 0) {
       return new WebForm[0];
     }
     final Collection returnForms = new ArrayList(forms.length);
     WebForm form;
     String parameterValue;
     for (int i = 0; i < forms.length; i++) {
       form = forms[i];
       if (form != null) {
         parameterValue = form.getParameterValue(parameter);
         if (parameterValue != null && parameterValue.equals(value)) {
           returnForms.add(form);
         }
       }
     }
     return (WebForm[])returnForms.toArray(new WebForm[returnForms.size()]);
   }
 
   /***
    * A convenience method that throws a {@link SourceForgeException} if the
    * supplied {@link Object} is <code>null</code>.  This method is primarily
    * used to check method arguments and in other cases where a checked {@link
    * Exception} is preferred to the usual {@link IllegalArgumentException}
    * alternative.
    *
    * @param      object
    *               the {@link Object} to check; if <code>null</code> a {@link
    *               SourceForgeException} will be thrown
    * @param      message
    *               a message describing the problem if the supplied {@link
    *               Object} is <code>null</code>; may be <code>null</code>
    * @exception  SourceForgeException
    *               if the supplied {@link Object} is <code>null</code>
    */
   protected static final void assertNotNull(final Object object,
                                             final String message)
     throws SourceForgeException {
     if (object == null) {
       throw new SourceForgeException(message);
     }
   }
 
   /***
    * A convenience metohd that throws either a {@link SourceForgeException} or an
    * {@link SourceForgeException} if the supplied {@link Object} array is
    * <code>null</code> or has a length less than or equal to <code>0</code>
    * respectively.
    *
    * @param      object
    *               the {@link Object} array to check; if <code>null</code> or
    *               empty a {@link SourceForgeException} will be thrown
    * @param      message
    *               a message describing the problem if the supplied {@link
    *               Object} array is <code>null</code> or empty; may be
    *               <code>null</code>
    * @exception  SourceForgeException
    *               if the supplied {@link Object} array is <code>null</code> or
    *               empty
    */
   protected static final void assertArrayFull(final Object[] object,
                                               final String message)
     throws SourceForgeException, SourceForgeException {
     assertNotNull(object, message);
     if (object.length <= 0) {
       throw new SourceForgeException(message);
     }
   }
 
 }