ValidSubjectCodePlugin.java

package de.uni_passau.fim.infosun.prophet.plugin.plugins;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.StandardCharsets;
import java.util.Scanner;

import de.uni_passau.fim.infosun.prophet.Constants;
import de.uni_passau.fim.infosun.prophet.experimentViewer.EViewer;
import de.uni_passau.fim.infosun.prophet.plugin.Plugin;
import de.uni_passau.fim.infosun.prophet.util.language.UIElementNames;
import de.uni_passau.fim.infosun.prophet.util.qTree.Attribute;
import de.uni_passau.fim.infosun.prophet.util.qTree.QTreeNode;
import de.uni_passau.fim.infosun.prophet.util.settings.Setting;
import de.uni_passau.fim.infosun.prophet.util.settings.SettingsList;
import de.uni_passau.fim.infosun.prophet.util.settings.components.CheckBoxSetting;
import de.uni_passau.fim.infosun.prophet.util.settings.components.PathChooserSetting;
import de.uni_passau.fim.infosun.prophet.util.settings.components.TextAreaSetting;

import static de.uni_passau.fim.infosun.prophet.util.qTree.QTreeNode.Type.EXPERIMENT;

/**
 * <code>Plugin</code> that is used to check the subject code the user input against a list of valid codes.
 * Will only allow advancing past the first node of the experiment if the code matches one of the valid codes.
 */
public class ValidSubjectCodePlugin implements Plugin {

    private static final String KEY = "valid_code";
    private static final String KEY_CODES = "codes";
    private static final String KEY_PATH = "path";
    private static final String KEY_IGNORE_CASE = "ignorecase";

    @Override
    public Setting getSetting(QTreeNode node) {

        if (node.getType() != EXPERIMENT) {
            return null;
        }

        Attribute mainAttribute = node.getAttribute(KEY);
        SettingsList settingsList = new SettingsList(mainAttribute, getClass().getSimpleName(), true);
        settingsList.setCaption(UIElementNames.getLocalized("SUBJECT_CODE_CHECK_SUBJECT_CODE"));

        TextAreaSetting textAreaSetting = new TextAreaSetting(mainAttribute.getSubAttribute(KEY_CODES), null);
        textAreaSetting.setCaption(UIElementNames.getLocalized("SUBJECT_CODE_VALID_CODES"));
        settingsList.addSetting(textAreaSetting);

        PathChooserSetting filePathChooser = new PathChooserSetting(mainAttribute.getSubAttribute(KEY_PATH), null);
        filePathChooser.setCaption(UIElementNames.getLocalized("SUBJECT_CODE_CODE_FILE"));
        settingsList.addSetting(filePathChooser);

        CheckBoxSetting checkBoxSetting = new CheckBoxSetting(mainAttribute.getSubAttribute(KEY_IGNORE_CASE), null);
        checkBoxSetting.setCaption(UIElementNames.getLocalized("SUBJECT_CODE_IGNORE_CASE"));
        settingsList.addSetting(checkBoxSetting);

        return settingsList;
    }

    @Override
    public void experimentViewerRun(EViewer experimentViewer) {

    }

    @Override
    public boolean denyEnterNode(QTreeNode node) {
        return false;
    }

    @Override
    public void enterNode(QTreeNode node) {

    }

    @Override
    public String denyNextNode(QTreeNode currentNode) {
        Attribute mainAttribute = currentNode.getAttribute(KEY);

        if (currentNode.getType() != EXPERIMENT || !Boolean.parseBoolean(mainAttribute.getValue())) {
            return null;
        }

        String[] answers = currentNode.getAnswers(Constants.KEY_SUBJECT_CODE);

        if (answers == null || answers.length < 1) {
            return UIElementNames.getLocalized("SUBJECT_CODE_MESSAGE_CODE_NOT_FOUND");
        }

        String subjectCode = answers[0];
        boolean ignoreCase = Boolean.parseBoolean(mainAttribute.getSubAttribute(KEY_IGNORE_CASE).getValue());

        String codes = mainAttribute.getSubAttribute(KEY_CODES).getValue();
        if (codes != null && !codes.isEmpty()) {
            if (contains(subjectCode, new Scanner(codes), ignoreCase)) {
                return null;
            }
        }

        String path = mainAttribute.getSubAttribute(KEY_PATH).getValue();
        if (path != null && !path.isEmpty()) {
            CharsetDecoder dec = StandardCharsets.UTF_8.newDecoder();

            try (Reader reader = new InputStreamReader(new FileInputStream(path), dec)) {
                if (contains(subjectCode, new Scanner(reader), ignoreCase)) {
                    return null;
                }
            } catch (FileNotFoundException e) {
                return UIElementNames.getLocalized("SUBJECT_CODE_MESSAGE_FILE_NOT_FOUND");
            } catch (IOException e) {
                // may occur when trying to close the FileReader
            }
        }

        return UIElementNames.getLocalized("SUBJECT_CODE_MESSAGE_CODE_NOT_FOUND");
    }

    /**
     * Checks whether any <code>String</code> returned by the given <code>Scanner</code> matches the given
     * <code>subjectCode</code>.
     *
     * @param subjectCode the subject code to search for
     * @param sc the <code>Scanner</code> to search through
     * @param ignoreCase whether to ignore case considerations
     * @return true iff the <code>Scanner</code> returned the <code>subjectCode</code>
     */
    private boolean contains(String subjectCode, Scanner sc, boolean ignoreCase) {

        while (sc.hasNext()) {
            String line = sc.next();
            if (ignoreCase) {
                if (line.equalsIgnoreCase(subjectCode)) {
                    return true;
                }
            } else {
                if (line.equals(subjectCode)) {
                    return true;
                }
            }
        }

        return false;
    }

    @Override
    public void exitNode(QTreeNode node) {

    }

    @Override
    public String finishExperiment() {
        return null;
    }
}