/*-------------------------------------------------------------------------+
|                                                                          |
| Copyright 2005-2011 the ConQAT Project                                   |
|                                                                          |
| Licensed under the Apache License, Version 2.0 (the "License");          |
| you may not use this file except in compliance with the License.         |
| You may obtain a copy of the License at                                  |
|                                                                          |
|    http://www.apache.org/licenses/LICENSE-2.0                            |
|                                                                          |
| Unless required by applicable law or agreed to in writing, software      |
| distributed under the License is distributed on an "AS IS" BASIS,        |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and      |
| limitations under the License.                                           |
+-------------------------------------------------------------------------*/
package org.conqat.lib.commons.serialization.objects;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.ObjectStreamConstants;
import java.util.ArrayList;
import java.util.List;

import org.conqat.lib.commons.collections.Pair;
import org.conqat.lib.commons.serialization.SerializedEntityParser;
import org.conqat.lib.commons.serialization.SerializedEntityPool;
import org.conqat.lib.commons.serialization.SerializedEntitySerializer;
import org.conqat.lib.commons.serialization.classes.SerializedClass;
import org.conqat.lib.commons.serialization.classes.SerializedClassBase;
import org.conqat.lib.commons.serialization.classes.SerializedFieldBase;
import org.conqat.lib.commons.string.StringUtils;

/**
 * A serialized object.
 */
public class SerializedObject extends SerializedObjectBase {

        /**
         * The field values for this class organized as field sets. Each field set
         * corresponds to one class in the class hierarchy (from sub class to super
         * class).
         */
        private final List<SerializedClassValues> fieldSets = new ArrayList<>();

        /** Constructor. */
        public SerializedObject(DataInputStream din, SerializedEntityPool pool, SerializedEntityParser parser,
                        int classHandle) throws IOException {
                super(pool, classHandle);

                for (SerializedClass serializedClass : getPlainClassHierarchy()) {
                        fieldSets.add(new SerializedClassValues(serializedClass, din, parser));
                }
        }

        /** Constructor. */
        public SerializedObject(int classHandle, List<SerializedClassValues> fieldSets, SerializedEntityPool pool) {
                super(pool, classHandle);
                this.fieldSets.addAll(fieldSets);
        }

        /** {@inheritDoc} */
        @Override
        protected byte getObjectTagConstant() {
                return ObjectStreamConstants.TC_OBJECT;
        }

        /** {@inheritDoc} */
        @Override
        protected void serializeObjectContent(DataOutputStream dos, SerializedEntitySerializer serializer)
                        throws IOException {
                int index = 0;
                for (SerializedClass serializedClass : getPlainClassHierarchy()) {
                        SerializedClassValues fieldSet = fieldSets.get(index++);
                        fieldSet.serialize(serializedClass, pool, dos, serializer);
                }
        }

        /** {@inheritDoc} */
        @Override
        public String toString() {
                StringBuilder builder = new StringBuilder();
                String className = "<unknown>";
                try {
                        className = pool.getEntity(classHandle, SerializedClassBase.class).toString();
                        builder.append("Object " + getHandle() + ": " + className + StringUtils.LINE_SEPARATOR);

                        int index = 0;
                        for (SerializedClass serializedClass : getPlainClassHierarchy()) {
                                appendFieldSet(fieldSets.get(index++), serializedClass, builder);
                        }
                } catch (IOException e) {
                        builder.append("Could not resolve hierarchy for class " + className + ": " + e.getMessage());
                }
                return builder.toString();
        }

        /** Appends the information on a field set to the given builder. */
        private static void appendFieldSet(SerializedClassValues fieldSet, SerializedClass serializedClass,
                        StringBuilder builder) {
                if (fieldSet.hasFieldValues()) {
                        int fieldIndex = 0;
                        for (SerializedFieldBase field : serializedClass.getFields()) {
                                builder.append("  " + serializedClass.getName() + "#" + field.getName() + ": "
                                                + fieldSet.getValue(fieldIndex++) + StringUtils.LINE_SEPARATOR);
                        }
                } else {
                        builder.append("  " + serializedClass.getName() + ": <no data>");
                }
        }

        /**
         * Return the value object for the field with the given name.
         * 
         * @return The fields value or null if no field with the name was found
         */
        public Object getFieldValue(String name) throws IOException {
                Pair<SerializedClassValues, Integer> fieldSetAndValue = getFieldSetAndIndex(name);
                if (fieldSetAndValue == null) {
                        return null;
                }
                return fieldSetAndValue.getFirst().getValue(fieldSetAndValue.getSecond());
        }

        /** Sets the value object for the field with the given name. */
        public void setFieldValue(String name, Object value) throws IOException {
                Pair<SerializedClassValues, Integer> fieldSetAndValue = getFieldSetAndIndex(name);
                if (fieldSetAndValue != null) {
                        fieldSetAndValue.getFirst().setValue(fieldSetAndValue.getSecond(), value);
                }
        }

        /**
         * Removes the value object for the field with the given name. This does not
         * only set the vlaue to 0 or null, but corresponds to a deletion of the field.
         */
        public void removeFieldValue(String name) throws IOException {
                Pair<SerializedClassValues, Integer> fieldSetAndValue = getFieldSetAndIndex(name);
                if (fieldSetAndValue != null) {
                        fieldSetAndValue.getFirst().removeValue(fieldSetAndValue.getSecond());
                }
        }

        /**
         * Returns the field set and index within this fieldset for a field with given
         * name. Returns null if none is found.
         */
        private Pair<SerializedClassValues, Integer> getFieldSetAndIndex(String fieldName) throws IOException {
                int classIndex = 0;
                for (SerializedClass serializedClass : getPlainClassHierarchy()) {
                        SerializedFieldBase field = serializedClass.getField(fieldName);
                        if (field != null) {
                                int index = serializedClass.getFields().indexOf(field);
                                SerializedClassValues fieldSet = fieldSets.get(classIndex);
                                return new Pair<>(fieldSet, index);
                        }
                        classIndex++;
                }
                return null;
        }

        /** Returns number of field sets. */
        public int getFieldSetCount() {
                return fieldSets.size();
        }

        /** Returns field sets of given index. */
        public SerializedClassValues getFieldSet(int index) {
                return fieldSets.get(index);
        }
}