/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * 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 org.eclipse.ui.actions;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;

import org.eclipse.core.resources.ICommand;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspace;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.resources.IncrementalProjectBuilder;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.internal.ide.IDEInternalPreferences;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;
import org.eclipse.ui.internal.ide.IDEWorkbenchPlugin;
import org.eclipse.ui.internal.ide.IIDEHelpContextIds;
import org.eclipse.ui.internal.ide.actions.BuildUtilities;

/**
 * Standard actions for full and incremental builds of the selected project(s).
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 */
public class BuildAction extends WorkspaceAction {

    /**
     * The id of an incremental build action.
     */
    public static final String ID_BUILD = PlatformUI.PLUGIN_ID + ".BuildAction";//$NON-NLS-1$

    /**
     * The id of a rebuild all action.
     */
    public static final String ID_REBUILD_ALL = PlatformUI.PLUGIN_ID
            + ".RebuildAllAction";//$NON-NLS-1$

    private int buildType;

    /**
     * The list of IProjects to build (computed lazily).
     */
    private List projectsToBuild = null;

    /**
     * Creates a new action of the appropriate type. The action id is 
     * <code>ID_BUILD</code> for incremental builds and <code>ID_REBUILD_ALL</code>
     * for full builds.
     *
     * @param shell the shell for any dialogs
     * @param type the type of build; one of
     *  <code>IncrementalProjectBuilder.INCREMENTAL_BUILD</code> or 
     *  <code>IncrementalProjectBuilder.FULL_BUILD</code>
     */
    public BuildAction(Shell shell, int type) {
        super(shell, "");//$NON-NLS-1$

        if (type == IncrementalProjectBuilder.INCREMENTAL_BUILD) {
            setText(IDEWorkbenchMessages.BuildAction_text);
            setToolTipText(IDEWorkbenchMessages.BuildAction_toolTip);
            setId(ID_BUILD);
            PlatformUI.getWorkbench().getHelpSystem().setHelp(this,
                    IIDEHelpContextIds.INCREMENTAL_BUILD_ACTION);
        } else {
            setText(IDEWorkbenchMessages.RebuildAction_text);
            setToolTipText(IDEWorkbenchMessages.RebuildAction_tooltip);
            setId(ID_REBUILD_ALL);
            PlatformUI.getWorkbench().getHelpSystem().setHelp(this,
					IIDEHelpContextIds.FULL_BUILD_ACTION);
        }

        this.buildType = type;
    }

    /**
     * Adds the given project and all of its prerequisities, transitively,
     * to the provided set.
     */
    private void addAllProjects(IProject project, HashSet projects) {
        if (project == null || !project.isAccessible()
                || projects.contains(project))
            return;
        projects.add(project);
        try {
            IProject[] preReqs = project.getReferencedProjects();
            for (int i = 0; i < preReqs.length; i++)
                addAllProjects(preReqs[i], projects);
        } catch (CoreException e) {
            //ignore inaccessible projects
        }
    }

    /* (non-Javadoc)
     * Method declared on WorkspaceAction.
     */
    protected List getActionResources() {
        return getProjectsToBuild();
    }

    /* (non-Javadoc)
     * Method declared on WorkspaceAction.
     */
    protected String getOperationMessage() {
        return IDEWorkbenchMessages.BuildAction_operationMessage;
    }

    /* (non-Javadoc)
     * Method declared on WorkspaceAction.
     */
    protected String getProblemsMessage() {
        return IDEWorkbenchMessages.BuildAction_problemMessage;
    }

    /* (non-Javadoc)
     * Method declared on WorkspaceAction.
     */
    protected String getProblemsTitle() {
        return IDEWorkbenchMessages.BuildAction_problemTitle;
    }

    /**
     * Returns the projects to build.
     * This contains the set of projects which have builders, across all selected resources.
     */
    List getProjectsToBuild() {
        if (projectsToBuild == null) {
            projectsToBuild = new ArrayList(3);
            for (Iterator i = getSelectedResources().iterator(); i.hasNext();) {
                IResource resource = (IResource) i.next();
                IProject project = resource.getProject();
                if (project != null) {
                    if (!projectsToBuild.contains(project)) {
                        if (hasBuilder(project)) {
                            projectsToBuild.add(project);
                        }
                    }
                }
            }
        }
        return projectsToBuild;
    }

    /**
     * Returns whether there are builders configured on the given project.
     *
     * @return <code>true</code> if it has builders,
     *   <code>false</code> if not, or if this couldn't be determined
     */
    boolean hasBuilder(IProject project) {
        try {
            ICommand[] commands = project.getDescription().getBuildSpec();
            if (commands.length > 0) {
                return true;
            }
        } catch (CoreException e) {
            // this method is called when selection changes, so
            // just fall through if it fails.
            // this shouldn't happen anyway, since the list of selected resources
            // has already been checked for accessibility before this is called
        }
        return false;
    }

    /* (non-Javadoc)
     * Method declared on WorkspaceAction.
     */
    protected void invokeOperation(IResource resource, IProgressMonitor monitor)
            throws CoreException {
        ((IProject) resource).build(buildType, monitor);
    }
    
    /* (non-Javadoc)
     * Method declared on Action
     */
    public boolean isEnabled() {
    	//update enablement based on active window and part
		IWorkbenchWindow window = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
		if (window != null) {
			selectionChanged(new StructuredSelection(BuildUtilities.findSelectedProjects(window)));
		}
		return super.isEnabled();
	}
    
    /**
     * Returns whether the user's preference is set to automatically save modified
     * resources before a manual build is done.
     *
     * @return <code>true</code> if Save All Before Build is enabled
     */
    public static boolean isSaveAllSet() {
        IPreferenceStore store = IDEWorkbenchPlugin.getDefault()
                .getPreferenceStore();
        return store.getBoolean(IDEInternalPreferences.SAVE_ALL_BEFORE_BUILD);
    }

    /* (non-Javadoc)
     * Method declared on WorkspaceAction.
     *
     * Change the order of the resources so that
     * it matches the build order. Closed and
     * non existant projects are eliminated. Also,
     * any projects in cycles are eliminated.
     */
    List pruneResources(List resourceCollection) {
        //recursively compute project prerequisites
        HashSet toBuild = new HashSet();
        for (Iterator it = resourceCollection.iterator(); it.hasNext();)
            addAllProjects((IProject) it.next(), toBuild);

        // Optimize...
        if (toBuild.size() < 2)
            return resourceCollection;

        // Try the workspace's description build order if specified
        String[] orderedNames = ResourcesPlugin.getWorkspace().getDescription()
                .getBuildOrder();
        if (orderedNames != null) {
            List orderedProjects = new ArrayList(toBuild.size());
            IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
            for (int i = 0; i < orderedNames.length; i++) {
                IProject handle = root.getProject(orderedNames[i]);
                if (toBuild.contains(handle)) {
                    orderedProjects.add(handle);
                    toBuild.remove(handle);
                }
            }
            //Add anything not specified before we return
            orderedProjects.addAll(toBuild);
            return orderedProjects;
        }

        // Try the project prerequisite order then
        IProject[] projects = new IProject[toBuild.size()];
        projects = (IProject[]) toBuild.toArray(projects);
        IWorkspace.ProjectOrder po = ResourcesPlugin.getWorkspace()
                .computeProjectOrder(projects);
        ArrayList orderedProjects = new ArrayList();
        orderedProjects.addAll(Arrays.asList(po.projects));
        return orderedProjects;
    }

    /* (non-Javadoc)
     * Method declared on IAction; overrides method on WorkspaceAction.
     * This override allows the user to save the contents of selected
     * open editors so that the updated contents will be used for building.
     */
    public void run() {
	    List projects = getProjectsToBuild();
	    if (projects == null || projects.isEmpty())
	        return;

	    // Save all resources prior to doing build
        BuildUtilities.saveEditors(projects);
        runInBackground(ResourcesPlugin.getWorkspace().getRuleFactory()
                .buildRule(), ResourcesPlugin.FAMILY_MANUAL_BUILD);
    }

    /* (non-Javadoc)
     * Method declared on WorkspaceAction.
     */
    protected boolean shouldPerformResourcePruning() {
        return true;
    }

    /**
     * The <code>BuildAction</code> implementation of this
     * <code>SelectionListenerAction</code> method ensures that this action is
     * enabled only if all of the selected resources have buildable projects.
     */
    protected boolean updateSelection(IStructuredSelection s) {
        projectsToBuild = null;
        IProject[] projects = (IProject[]) getProjectsToBuild().toArray(new IProject[0]);
        return BuildUtilities.isEnabled(projects, IncrementalProjectBuilder.INCREMENTAL_BUILD);
    }
}