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package edu.harvard.iq.dataverse;

import edu.harvard.iq.dataverse.authorization.Permission;
import edu.harvard.iq.dataverse.authorization.users.User;
import edu.harvard.iq.dataverse.engine.command.Command;
import edu.harvard.iq.dataverse.engine.command.impl.*;
import java.util.HashMap;
import java.util.Map;
import javax.ejb.EJB;
import javax.faces.view.ViewScoped;
import javax.inject.Inject;
import javax.inject.Named;

/**
 *
 * @author gdurand
 */
@ViewScoped
@Named
public class PermissionsWrapper implements java.io.Serializable {

    @EJB
    PermissionServiceBean permissionService;

    @Inject
    DataverseSession session;

    private Map<Long, Map<Class<? extends Command>, Boolean>> commandMap = new HashMap<>();

    // Map to track whether a DvObject has "Permission.DownloadFile" 
    //
    private Map<Long, Boolean> fileDownloadPermissionMap = new HashMap<>(); // { DvObject.id : Boolean }

    /**
     * Check if the current Dataset can Issue Commands
     *
     * @param commandName
     */
    private boolean canIssueCommand(DvObject dvo, Class<? extends Command> command) {
        if ((dvo==null) || (dvo.getId()==null)){
            return false;
        }
        if (command==null){
            return false;
        }

        if (commandMap.containsKey(dvo.getId())) {
            Map<Class<? extends Command>, Boolean> dvoCommandMap = this.commandMap.get(dvo.getId());
            if (dvoCommandMap.containsKey(command)) {
                return dvoCommandMap.get(command);
            } else {
                return addCommandtoDvoCommandMap(dvo, command, dvoCommandMap);
            }

        } else {
            Map newDvoCommandMap = new HashMap();
            commandMap.put(dvo.getId(), newDvoCommandMap);
            return addCommandtoDvoCommandMap(dvo, command, newDvoCommandMap);
        }
    }

    private boolean addCommandtoDvoCommandMap(DvObject dvo, Class<? extends Command> command, Map<Class<? extends Command>, Boolean> dvoCommandMap) {
        if ( dvo==null || (dvo.getId()==null) ){
            return false;
        }
        if (command==null){
            return false;
        }
        
        boolean canIssueCommand;
        canIssueCommand = permissionService.on(dvo).canIssue(command);
        dvoCommandMap.put(command, canIssueCommand);
        return canIssueCommand;
    }

    /* Dataverse Commands */

    public boolean canIssueUpdateDataverseCommand(DvObject dvo) {
        return canIssueCommand(dvo, UpdateDataverseCommand.class);
    }

    public boolean canIssuePublishDataverseCommand(DvObject dvo) {
        return canIssueCommand(dvo, PublishDataverseCommand.class);
    }

    public boolean canIssueDeleteDataverseCommand(DvObject dvo) {
        return canIssueCommand(dvo, DeleteDataverseCommand.class);
    }
    
    public boolean canIssueCreateDataverseCommand(DvObject dvo) {
        return canIssueCommand(dvo, CreateDataverseCommand.class);
    }
    
    
    public boolean canManagePermissions(DvObject dvo) {
        if (dvo==null || (dvo.getId()==null) ){
            return false;
        }
        
        User u = session.getUser();
        return dvo instanceof Dataverse
                ? canManageDataversePermissions(u, (Dataverse) dvo)
                : canManageDatasetPermissions(u, (Dataset) dvo);
    }
    
    public boolean canManageDataversePermissions(User u, Dataverse dv) {
        if ( dv==null || (dv.getId()==null)){
            return false;
        }
        if (u==null){            
            return false;
        }
        return permissionService.userOn(u, dv).has(Permission.ManageDataversePermissions);
    }
    
    public boolean canManageDatasetPermissions(User u, Dataset ds) {
        if ( ds==null || (ds.getId()==null)){
            return false;
        }
        if (u==null){            
            return false;
        }
        return permissionService.userOn(u, ds).has(Permission.ManageDatasetPermissions);
    }

    /**
     *  Does this dvoObject have "Permission.DownloadFile"?
     * @param dvo
     * @return 
     */
    public boolean hasDownloadFilePermission(DvObject dvo){
        
        if ((dvo==null)||(dvo.getId() == null)){
            return false;
        }
        
        // Has this check already been done? Check the hash
        //
        if (this.fileDownloadPermissionMap.containsKey(dvo.getId())){
            // Yes, return previous answer
            return this.fileDownloadPermissionMap.get(dvo.getId());
        }

        // Check permissions
        //
        if (this.permissionService.on(dvo).has(Permission.DownloadFile)){

            // Yes, has permission, store result
            //
            this.fileDownloadPermissionMap.put(dvo.getId(), true);
            return true;
        }else {
        
            // No permission, store result
            //
            this.fileDownloadPermissionMap.put(dvo.getId(), false);
            return false;
        }
    }
    

    
    /* -----------------------------------
        Dataset Commands 
     ----------------------------------- */
    
    // CREATE DATASET
    public boolean canIssueCreateDatasetCommand(DvObject dvo){
        return canIssueCommand(dvo, CreateDatasetCommand.class);
    }

    // UPDATE DATASET
    public boolean canIssueUpdateDatasetCommand(DvObject dvo){
        return canIssueCommand(dvo, UpdateDatasetCommand.class);
    }

    // DELETE DATASET
    public boolean canIssueDeleteDatasetCommand(DvObject dvo){
        return canIssueCommand(dvo, DeleteDatasetCommand.class);
    }
    
    // PLUBLISH DATASET
    public boolean canIssuePublishDatasetCommand(DvObject dvo){
        return canIssueCommand(dvo, PublishDatasetCommand.class);
    }
    
    

}