package org.codehaus.modello.plugins.xml;

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

import org.codehaus.modello.ModelloRuntimeException;
import org.codehaus.modello.model.ModelClass;
import org.codehaus.modello.model.ModelField;
import org.codehaus.modello.model.Version;
import org.codehaus.modello.plugin.AbstractModelloGenerator;
import org.codehaus.modello.plugins.xml.metadata.XmlAssociationMetadata;
import org.codehaus.modello.plugins.xml.metadata.XmlClassMetadata;
import org.codehaus.modello.plugins.xml.metadata.XmlFieldMetadata;

/*
 * Copyright (c) 2004, Codehaus.org
 *
 * 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.
 *
 * THE 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.
 */

/**
 * Helper methods to deal with XML representation of the model.
 *
 * @author <a href="mailto:hboutemy@codehaus.org">Hervé Boutemy</a>
 */
class XmlModelHelpers {
    /**
     * Resolve XML tag name for a class. Note: only root class needs such a resolution.
     *
     * @param modelClass the model class
     * @return the XML tag name for the class
     */
    static String resolveTagName(ModelClass modelClass) {
        XmlClassMetadata xmlClassMetadata = (XmlClassMetadata) modelClass.getMetadata(XmlClassMetadata.ID);

        String tagName;
        if ((xmlClassMetadata == null) || (xmlClassMetadata.getTagName() == null)) {
            tagName = AbstractModelloGenerator.uncapitalise(modelClass.getName());
        } else {
            // tag name is overridden by xml.tagName attribute
            tagName = xmlClassMetadata.getTagName();
        }
        return tagName;
    }

    /**
     * Resolve XML tag name for a field.
     *
     * @param modelField the model field
     * @param xmlFieldMetadata the XML metadata of the field
     * @return the XML tag name for the field
     */
    static String resolveTagName(ModelField modelField, XmlFieldMetadata xmlFieldMetadata) {
        String tagName;
        if ((xmlFieldMetadata == null) || (xmlFieldMetadata.getTagName() == null)) {
            tagName = modelField.getName();
        } else {
            // tag name is overridden by xml.tagName attribute
            tagName = xmlFieldMetadata.getTagName();
        }
        return tagName;
    }

    /**
     * Resolve XML tag name for an item in an association with many multiplicity.
     *
     * @param fieldTagName the XML tag name of the field containing the association
     * @param xmlAssociationMetadata the XML metadata of the association
     * @return the XML tag name for items
     */
    static String resolveTagName(String fieldTagName, XmlAssociationMetadata xmlAssociationMetadata) {
        String tagName;
        if ((xmlAssociationMetadata == null) || (xmlAssociationMetadata.getTagName() == null)) {
            tagName = AbstractModelloGenerator.singular(fieldTagName);
        } else {
            // tag name is overridden by xml.tagName attribute
            tagName = xmlAssociationMetadata.getTagName();
        }
        return tagName;
    }

    /**
     * Get the field which type is <code>Content</code> if any.
     *
     * @param modelFields the fields to check
     * @return the field, or <code>null</code> if no field is <code>Content</code>
     */
    static ModelField getContentField(List<ModelField> modelFields) {
        if (modelFields == null) {
            return null;
        }
        for (ModelField field : modelFields) {
            XmlFieldMetadata xmlFieldMetadata = (XmlFieldMetadata) field.getMetadata(XmlFieldMetadata.ID);

            if (xmlFieldMetadata.isContent()) {
                return field;
            }
        }
        return null;
    }

    /**
     * Gets all fields that are not marked as XML attribute.
     *
     * @param modelFields The collection of model fields from which to extract the XML attributes, must not be
     *            <code>null</code>.
     * @return The list of XML attributes fields, can be empty but never <code>null</code>.
     */
    static List<ModelField> getXmlAttributeFields(List<ModelField> modelFields) {
        List<ModelField> xmlAttributeFields = new ArrayList<ModelField>();

        for (ModelField field : modelFields) {
            XmlFieldMetadata xmlFieldMetadata = (XmlFieldMetadata) field.getMetadata(XmlFieldMetadata.ID);

            if (xmlFieldMetadata.isAttribute()) {
                xmlAttributeFields.add(field);
            }
        }

        return xmlAttributeFields;
    }

    /**
     * Return the XML fields of this class, with proper XML order and no XML transient fields.
     *
     * @param modelClass current class
     * @param version the version of the class to use
     * @return the list of XML fields of this class
     */
    static List<ModelField> getFieldsForXml(ModelClass modelClass, Version version) {
        List<ModelClass> classes = new ArrayList<ModelClass>();

        // get the full inheritance
        while (modelClass != null) {
            classes.add(modelClass);

            String superClass = modelClass.getSuperClass();
            if (superClass != null) {
                // superClass can be located outside (not generated by modello)
                modelClass = modelClass.getModel().getClass(superClass, version, true);
            } else {
                modelClass = null;
            }
        }

        List<ModelField> fields = new ArrayList<ModelField>();

        for (int i = classes.size() - 1; i >= 0; i--) {
            modelClass = classes.get(i);

            Iterator<ModelField> parentIter = fields.iterator();

            fields = new ArrayList<ModelField>();

            for (ModelField field : modelClass.getFields(version)) {
                XmlFieldMetadata xmlFieldMetadata = (XmlFieldMetadata) field.getMetadata(XmlFieldMetadata.ID);

                if (xmlFieldMetadata.isTransient()) {
                    // just ignore xml.transient fields
                    continue;
                }

                if (xmlFieldMetadata.getInsertParentFieldsUpTo() != null) {
                    // insert fields from parent up to the specified field
                    boolean found = false;

                    while (!found && parentIter.hasNext()) {
                        ModelField parentField = parentIter.next();

                        fields.add(parentField);

                        found = parentField.getName().equals(xmlFieldMetadata.getInsertParentFieldsUpTo());
                    }

                    if (!found) {
                        // interParentFieldsUpTo not found
                        throw new ModelloRuntimeException("parent field not found: class " + modelClass.getName()
                                + " xml.insertParentFieldUpTo='" + xmlFieldMetadata.getInsertParentFieldsUpTo() + "'");
                    }
                }

                fields.add(field);
            }

            // add every remaining fields from parent class
            while (parentIter.hasNext()) {
                fields.add(parentIter.next());
            }
        }

        return fields;
    }
}
