/**
 * The contents of this file are subject to the license and copyright
 * detailed in the LICENSE and NOTICE files at the root of the source
 * tree and available online at
 *
 * http://www.dspace.org/license/
 */
package org.purl.sword.base;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;

import nu.xom.Attribute;
import nu.xom.Element;
import nu.xom.Elements;
import org.apache.logging.log4j.Logger;
import org.purl.sword.atom.Accept;
import org.purl.sword.atom.ContentType;
import org.purl.sword.atom.Title;

/**
 * A representation of a SWORD Collection.
 *
 * @author Stuart Lewis
 * @author Neil Taylor
 */
public class Collection extends XmlElement implements SwordElementInterface {
    /**
     * Collection location, expressed as a URL.
     */
    private String location;

    /**
     * Holds the ATOM Title for the collection.
     */
    private Title title;

    /**
     * List of the APP:Accept elements.
     */
    private List<Accept> accepts;

    /**
     * Holds the SWORD Collection policy.
     */
    //private String collectionPolicy;

    /**
     * The SWORD mediation value. Indicates if mediation is allowed.
     */
    //private boolean mediation;
    private SwordMediation swordMediation;

    private SwordService swordService;

    private DcAbstract dcTermsAbstract;

    private SwordTreatment swordTreatment;

    private SwordCollectionPolicy swordCollectionPolicy;

    /**
     * The SWORD acceptsPackaging details.
     */
    private List<SwordAcceptPackaging> acceptPackaging;

    /**
     * The logger.
     */
    private static Logger log = org.apache.logging.log4j.LogManager.getLogger(Collection.class);

    /**
     * Label for the Href attribute.
     */
    public static final String ATTRIBUTE_HREF = "href";

    /**
     * Label for the local part of this element.
     */
    @Deprecated
    public static final String ELEMENT_NAME = "collection";

    private static final XmlName XML_NAME =
        new XmlName(Namespaces.PREFIX_APP, "collection", Namespaces.NS_APP);

    /**
     * Create a new instance.
     */
    public Collection() {
        super(XML_NAME);
        initialise();
    }

    public static XmlName elementName() {
        return XML_NAME;
    }

    protected final void initialise() {
        location = null;
        title = null;
        accepts = new ArrayList<Accept>();
        acceptPackaging = new ArrayList<SwordAcceptPackaging>();
        swordCollectionPolicy = null;
        swordMediation = null;
        swordService = null;
        dcTermsAbstract = null;
        swordTreatment = null;
    }

    /**
     * Create a new instance and set the initial location for the collection.
     *
     * @param location The initial location, expressed as a URL.
     */
    public Collection(String location) {
        this();
        this.location = location;
    }

    /**
     * Retrieve an array that holds all of the Accept details.
     *
     * @return An array of strings. Each string represents an
     * individual accept element. The array will have a length
     * of 0 if no accepts elements are stored in this collection.
     */
    public String[] getAccepts() {
        String[] values = new String[this.accepts.size()];
        Iterator<Accept> iterator = accepts.iterator();
        for (int i = 0; iterator.hasNext(); i++) {
            Accept accept = iterator.next();
            values[i] = accept.getContent();
        }
        return values;
    }

    /**
     * Retrieve an array that holds all of the Accept details.
     *
     * @return An array of strings. Each string represents an
     * individual accept element. The array will have a length
     * of 0 if no accepts elements are stored in this collection.
     */
    @Deprecated
    public List<String> getAcceptsList() {
        ArrayList<String> items = new ArrayList<String>();
        for (Accept item : accepts) {
            items.add(item.getContent());
        }
        return items;
    }

    /**
     * Return the list of accepts entries.
     *
     * @return the list of accepts entries
     */
    public List<Accept> getAcceptList() {
        return accepts;
    }

    /**
     * Add an accepts entry.
     *
     * @param accepts The accepts value.
     */
    public void addAccepts(String accepts) {
        this.accepts.add(new Accept(accepts));
    }

    /**
     * Remove all of the accepts associated with this Collection.
     */
    public void clearAccepts() {
        this.accepts.clear();
    }

    /**
     * Retrieve a hashtable that holds all the acceptsPackaging details.
     *
     * @return A hashtable. The keys are accepted packaging formats,
     * and the values the quality values (stored as QualityValue objects)
     */
    public List<SwordAcceptPackaging> getAcceptPackaging() {
        return acceptPackaging;
    }

    /**
     * Add an acceptPackaging format.
     *
     * @param acceptPackaging the packaging format.
     * @param qualityValue    the quality value of accepted packaging format.
     */
    public void addAcceptPackaging(String acceptPackaging, float qualityValue) {

        this.acceptPackaging.add(new SwordAcceptPackaging(acceptPackaging, qualityValue));
    }

    /**
     * Add an acceptPackaging format. A default quality vale is given.
     *
     * @param acceptPackaging the packaging format.
     */
    public void addAcceptPackaging(String acceptPackaging) {
        this.acceptPackaging.add(new SwordAcceptPackaging(acceptPackaging, new QualityValue()));
    }

    /**
     * Remove all of the accepted packaging formats associated with this Collection.
     */
    public void clearAcceptPackaging() {
        this.acceptPackaging.clear();
    }

    /**
     * Get the collection policy.
     *
     * @return The SWORD collectionPolicy.
     */
    public String getCollectionPolicy() {
        if (swordCollectionPolicy == null) {
            return null;
        }
        return swordCollectionPolicy.getContent();
    }

    /**
     * Set the collection policy.
     *
     * @param collectionPolicy The collection policy.
     */
    public void setCollectionPolicy(String collectionPolicy) {
        swordCollectionPolicy = new SwordCollectionPolicy(collectionPolicy);
    }

    /**
     * Get the location.
     *
     * @return TShe location
     */
    public String getLocation() {
        return location;
    }

    /**
     * Set the location.
     *
     * @param location The location.
     */
    public void setLocation(String location) {
        this.location = location;
    }

    /**
     * Get the mediation value.
     *
     * @return The mediation
     */
    public boolean getMediation() {
        if (swordMediation == null) {
            return false;
        }
        return swordMediation.getContent();
    }

    public boolean isMediationSet() {
        if (swordMediation == null) {
            return false;
        }
        return swordMediation.isSet();
    }

    /**
     * Set the mediation value.
     *
     * @param mediation The mediation value.
     */
    public void setMediation(boolean mediation) {
        swordMediation = new SwordMediation(mediation);
    }

    /**
     * Get the DC Term abstract.
     *
     * @return The abstract.
     */
    public String getAbstract() {
        if (dcTermsAbstract == null) {
            return null;
        }
        return dcTermsAbstract.getContent();
    }

    /**
     * Set the abstract.
     *
     * @param abstractString The abstract.
     */
    public void setAbstract(String abstractString) {
        dcTermsAbstract = new DcAbstract(abstractString);
    }

    /**
     * Get the sword service.
     *
     * @return The service.
     */
    public String getService() {
        if (swordService == null) {
            return null;
        }
        return swordService.getContent();
    }

    /**
     * Set the sword service.
     *
     * @param serviceString The service.
     */
    public void setService(String serviceString) {
        swordService = new SwordService(serviceString);
    }

    /**
     * Set the title. This will set the title type to ContentType.TEXT.
     *
     * @param title The title.
     */
    public void setTitle(String title) {
        if (this.title == null) {
            this.title = new Title();
        }
        this.title.setContent(title);
        this.title.setType(ContentType.TEXT);
    }

    /**
     * Get the title.
     *
     * @return The title, or <code>null</code> if no title has been set.
     */
    public String getTitle() {
        if (title == null) {
            return null;
        }
        return title.getContent();
    }

    /**
     * Get the treatment value.
     *
     * @return The treatment.
     */
    public String getTreatment() {
        if (swordTreatment == null) {
            return null;
        }
        return swordTreatment.getContent();
    }

    /**
     * Set the treatment.
     *
     * @param treatment The treatment.
     */
    public void setTreatment(String treatment) {
        swordTreatment = new SwordTreatment(treatment);
    }

    /**
     * Get a string representation of this object. This is
     * equivalent to calling marshall().toString().
     */
    @Override
    public String toString() {
        Element element = marshall();
        return element.toString();
    }

    /**
     * Marshall the data in this object to an Element object.
     *
     * @return A XOM Element that holds the data for this Content element.
     */
    public Element marshall() {
        // convert data into XOM elements and return the 'root', i.e. the one
        // that represents the collection.
        Element collection = new Element(getQualifiedName(), Namespaces.NS_APP);
        Attribute href = new Attribute(ATTRIBUTE_HREF, location);
        collection.addAttribute(href);

        if (title == null) {
            title = new Title();
            title.setContent("Untitled");
        }
        collection.appendChild(title.marshall());

        for (Accept item : accepts) {
            collection.appendChild(item.marshall());
        }

        Iterator<SwordAcceptPackaging> apIterator = acceptPackaging.iterator();
        while (apIterator.hasNext()) {
            collection.appendChild(apIterator.next().marshall());
        }

        if (swordCollectionPolicy != null) {
            collection.appendChild(swordCollectionPolicy.marshall());
        }

        if (dcTermsAbstract != null) {
            collection.appendChild(dcTermsAbstract.marshall());
        }

        if (swordService != null) {
            collection.appendChild(swordService.marshall());
        }

        if (swordMediation != null) {
            collection.appendChild(swordMediation.marshall());
        }

        if (swordTreatment != null) {
            collection.appendChild(swordTreatment.marshall());
        }

        return collection;
    }

    /**
     * Unmarshall the content element into the data in this object.
     *
     * @throws UnmarshallException If the element does not contain a
     *                             content element or if there are problems
     *                             accessing the data.
     */
    public void unmarshall(Element collection)
        throws UnmarshallException {
        unmarshall(collection, null);
    }


    public SwordValidationInfo unmarshall(Element collection, Properties validationProperties)
        throws UnmarshallException {
        if (!isInstanceOf(collection, xmlName)) {
            return handleIncorrectElement(collection, validationProperties);
        }

        ArrayList<SwordValidationInfo> validationItems = new ArrayList<SwordValidationInfo>();
        ArrayList<SwordValidationInfo> attributeValidationItems = new ArrayList<SwordValidationInfo>();

        try {
            initialise();

            // retrieve the attributes
            int count = collection.getAttributeCount();
            Attribute a = null;
            for (int i = 0; i < count; i++) {
                a = collection.getAttribute(i);
                if (ATTRIBUTE_HREF.equals(a.getQualifiedName())) {
                    location = a.getValue();
                    SwordValidationInfo info = new SwordValidationInfo(xmlName, new XmlName(a));
                    info.setContentDescription(location);
                    attributeValidationItems.add(info);
                } else {
                    SwordValidationInfo info = new SwordValidationInfo(xmlName, new XmlName(a),
                                                                       SwordValidationInfo.UNKNOWN_ATTRIBUTE,
                                                                       SwordValidationInfoType.INFO);
                    info.setContentDescription(a.getValue());
                    attributeValidationItems.add(info);
                }
            }

            // retrieve all of the sub-elements
            Elements elements = collection.getChildElements();
            Element element = null;
            int length = elements.size();

            for (int i = 0; i < length; i++) {
                element = elements.get(i);
                if (isInstanceOf(element, Title.elementName())) {
                    if (title == null) {
                        title = new Title();
                        validationItems.add(title.unmarshall(element, validationProperties));
                    } else if (validationProperties != null) {
                        SwordValidationInfo info = new SwordValidationInfo(
                            Title.elementName(),
                            SwordValidationInfo.DUPLICATE_ELEMENT,
                            SwordValidationInfoType.INFO);
                        info.setContentDescription(element.getValue());
                        validationItems.add(info);
                    }
                } else if (isInstanceOf(element, Accept.elementName())) {
                    Accept accept = new Accept();
                    SwordValidationInfo info = accept.unmarshall(element, validationProperties);
                    accepts.add(accept);
                    validationItems.add(info);
                } else if (isInstanceOf(element, SwordAcceptPackaging.elementName())) {
                    SwordAcceptPackaging packaging = new SwordAcceptPackaging();
                    validationItems.add(packaging.unmarshall(element, validationProperties));
                    acceptPackaging.add(packaging);
                } else if (isInstanceOf(element, SwordCollectionPolicy.elementName())) {
                    if (swordCollectionPolicy == null) {
                        swordCollectionPolicy = new SwordCollectionPolicy();
                        validationItems.add(swordCollectionPolicy.unmarshall(element, validationProperties));
                    } else if (validationProperties != null) {
                        SwordValidationInfo info = new SwordValidationInfo(
                            SwordCollectionPolicy.elementName(),
                            SwordValidationInfo.DUPLICATE_ELEMENT,
                            SwordValidationInfoType.INFO);
                        info.setContentDescription(element.getValue());
                        validationItems.add(info);
                    }

                } else if (isInstanceOf(element, DcAbstract.elementName())) {
                    if (dcTermsAbstract == null) {
                        dcTermsAbstract = new DcAbstract();
                        validationItems.add(dcTermsAbstract.unmarshall(element, validationProperties));
                    } else if (validationProperties != null) {
                        SwordValidationInfo info = new SwordValidationInfo(DcAbstract.elementName(),
                                                                           SwordValidationInfo.DUPLICATE_ELEMENT,
                                                                           SwordValidationInfoType.INFO);
                        info.setContentDescription(element.getValue());
                        validationItems.add(info);
                    }
                } else if (isInstanceOf(element, SwordService.elementName())) {
                    if (swordService == null) {
                        swordService = new SwordService();
                        validationItems.add(swordService.unmarshall(element, validationProperties));
                    } else if (validationProperties != null) {
                        SwordValidationInfo info = new SwordValidationInfo(SwordService.elementName(),
                                                                           SwordValidationInfo.DUPLICATE_ELEMENT,
                                                                           SwordValidationInfoType.INFO);
                        info.setContentDescription(element.getValue());
                        validationItems.add(info);
                    }
                } else if (isInstanceOf(element, SwordMediation.elementName())) {
                    if (swordMediation == null) {
                        swordMediation = new SwordMediation();
                        validationItems.add(swordMediation.unmarshall(element, validationProperties));
                    } else if (validationProperties != null) {
                        SwordValidationInfo info = new SwordValidationInfo(SwordMediation.elementName(),
                                                                           SwordValidationInfo.DUPLICATE_ELEMENT,
                                                                           SwordValidationInfoType.WARNING);
                        info.setContentDescription(element.getValue());
                        validationItems.add(info);
                    }
                } else if (isInstanceOf(element, SwordTreatment.elementName())) {
                    if (swordTreatment == null) {
                        swordTreatment = new SwordTreatment();
                        validationItems.add(swordTreatment.unmarshall(element, validationProperties));
                    } else if (validationProperties != null) {
                        SwordValidationInfo info = new SwordValidationInfo(SwordTreatment.elementName(),
                                                                           SwordValidationInfo.DUPLICATE_ELEMENT,
                                                                           SwordValidationInfoType.WARNING);
                        info.setContentDescription(element.getValue());
                        validationItems.add(info);
                    }
                } else if (validationProperties != null) {
                    SwordValidationInfo info = new SwordValidationInfo(new XmlName(element),
                                                                       SwordValidationInfo.UNKNOWN_ELEMENT,
                                                                       SwordValidationInfoType.INFO);
                    info.setContentDescription(element.getValue());
                    validationItems.add(info);
                }
            }
        } catch (Exception ex) {
            log.error("Unable to parse an element in collection: " + ex.getMessage());
            throw new UnmarshallException("Unable to parse an element in Collection", ex);
        }

        SwordValidationInfo result = null;
        if (validationProperties != null) {
            result = validate(validationItems, attributeValidationItems, validationProperties);
        }
        return result;

    }

    /**
     *
     */
    @Override
    public SwordValidationInfo validate(Properties validationContext) {
        return validate(null, null, validationContext);
    }

    /**
     * @param existing          add results to this.
     * @param attributes        FIXME: PLEASE DOCUMENT.
     * @param validationContext FIXME: PLEASE DOCUMENT.
     * @return SWORD validation info
     */
    protected SwordValidationInfo validate(List<SwordValidationInfo> existing,
                                           List<SwordValidationInfo> attributes,
                                           Properties validationContext) {
        boolean validateAll = (existing == null);

        SwordValidationInfo result = new SwordValidationInfo(xmlName);

        if (accepts == null || accepts.size() == 0) {
            result.addValidationInfo(new SwordValidationInfo(Accept.elementName(),
                                                             SwordValidationInfo.MISSING_ELEMENT_ERROR,
                                                             SwordValidationInfoType.WARNING));
        }

        if (location == null) {
            XmlName attribute = new XmlName(Namespaces.PREFIX_ATOM,
                                            ATTRIBUTE_HREF,
                                            Namespaces.NS_ATOM);

            result.addAttributeValidationInfo(new SwordValidationInfo(xmlName,
                                                                      attribute,
                                                                      SwordValidationInfo.MISSING_ATTRIBUTE_WARNING,
                                                                      SwordValidationInfoType.WARNING));
        }

        if (swordMediation == null) {
            result.addValidationInfo(new SwordValidationInfo(SwordMediation.elementName(),
                                                             SwordValidationInfo.MISSING_ELEMENT_WARNING,
                                                             SwordValidationInfoType.WARNING));
        }

        if (validateAll) {
            if (accepts.size() > 0) {
                Iterator<Accept> acceptIterator = accepts.iterator();
                while (acceptIterator.hasNext()) {
                    result.addValidationInfo(acceptIterator.next().validate(validationContext));
                }
            }

            if (acceptPackaging.size() > 0) {
                Iterator<SwordAcceptPackaging> apIterator = acceptPackaging.iterator();
                while (apIterator.hasNext()) {
                    result.addValidationInfo(apIterator.next().validate(validationContext));
                }
            }

            if (location != null) {
                result.addAttributeValidationInfo(createValidAttributeInfo(ATTRIBUTE_HREF, location));
            }

            if (title != null) {
                result.addValidationInfo(title.validate(validationContext));
            }

            if (swordMediation != null) {
                result.addValidationInfo(swordMediation.validate(validationContext));
            }

            if (swordService != null) {
                result.addValidationInfo(swordService.validate(validationContext));
            }

            if (swordTreatment != null) {
                result.addValidationInfo(swordTreatment.validate(validationContext));
            }

            if (swordCollectionPolicy != null) {
                result.addValidationInfo(swordCollectionPolicy.validate(validationContext));
            }

            if (dcTermsAbstract != null) {
                result.addValidationInfo(dcTermsAbstract.validate(validationContext));
            }
        }

        result.addUnmarshallValidationInfo(existing, attributes);
        return result;
    }
}