/*******************************************************************************
* Copyright 2013 SAP AG
*
* 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 com.sap.core.odata.core.ep.producer;
import java.net.URI;
import java.util.Date;
import java.util.List;
import java.util.Map;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import com.sap.core.odata.api.commons.InlineCount;
import com.sap.core.odata.api.edm.Edm;
import com.sap.core.odata.api.edm.EdmFacets;
import com.sap.core.odata.api.edm.EdmLiteralKind;
import com.sap.core.odata.api.edm.EdmSimpleTypeException;
import com.sap.core.odata.api.ep.EntityProviderException;
import com.sap.core.odata.api.ep.EntityProviderWriteProperties;
import com.sap.core.odata.api.ep.callback.TombstoneCallback;
import com.sap.core.odata.api.ep.callback.TombstoneCallbackResult;
import com.sap.core.odata.core.commons.Encoder;
import com.sap.core.odata.core.edm.EdmDateTimeOffset;
import com.sap.core.odata.core.ep.aggregator.EntityInfoAggregator;
import com.sap.core.odata.core.ep.util.FormatXml;
/**
* Serializes an ATOM feed.
* @author SAP AG
*/
public class AtomFeedProducer {
private final EntityProviderWriteProperties properties;
public AtomFeedProducer(final EntityProviderWriteProperties properties) {
this.properties = properties == null ? EntityProviderWriteProperties.serviceRoot(null).build() : properties;
}
public void append(final XMLStreamWriter writer, final EntityInfoAggregator eia, final List<Map<String, Object>> data, final boolean isInline) throws EntityProviderException {
try {
writer.writeStartElement(FormatXml.ATOM_FEED);
TombstoneCallback callback = null;
if (!isInline) {
writer.writeDefaultNamespace(Edm.NAMESPACE_ATOM_2005);
writer.writeNamespace(Edm.PREFIX_M, Edm.NAMESPACE_M_2007_08);
writer.writeNamespace(Edm.PREFIX_D, Edm.NAMESPACE_D_2007_08);
callback = getTombstoneCallback();
if (callback != null) {
writer.writeNamespace(TombstoneCallback.PREFIX_TOMBSTONE, TombstoneCallback.NAMESPACE_TOMBSTONE);
}
}
writer.writeAttribute(Edm.PREFIX_XML, Edm.NAMESPACE_XML_1998, FormatXml.XML_BASE, properties.getServiceRoot().toASCIIString());
// write all atom infos (mandatory and optional)
appendAtomMandatoryParts(writer, eia);
appendAtomSelfLink(writer, eia);
if (properties.getInlineCountType() == InlineCount.ALLPAGES) {
appendInlineCount(writer, properties.getInlineCount());
}
appendEntries(writer, eia, data);
if (callback != null) {
appendDeletedEntries(writer, eia, callback);
}
if (properties.getNextLink() != null) {
appendNextLink(writer, properties.getNextLink());
}
writer.writeEndElement();
} catch (XMLStreamException e) {
throw new EntityProviderException(EntityProviderException.COMMON, e);
}
}
private TombstoneCallback getTombstoneCallback() {
if (properties.getCallbacks() != null && properties.getCallbacks().containsKey(TombstoneCallback.CALLBACK_KEY_TOMBSTONE)) {
TombstoneCallback callback = (TombstoneCallback) properties.getCallbacks().get(TombstoneCallback.CALLBACK_KEY_TOMBSTONE);
return callback;
} else {
return null;
}
}
private void appendDeletedEntries(final XMLStreamWriter writer, final EntityInfoAggregator eia, final TombstoneCallback callback) throws EntityProviderException {
TombstoneCallbackResult callbackResult = callback.getTombstoneCallbackResult();
List<Map<String, Object>> tombstoneData = callbackResult.getDeletedEntriesData();
if (tombstoneData != null) {
TombstoneProducer tombstoneProducer = new TombstoneProducer();
tombstoneProducer.appendTombstones(writer, eia, properties, tombstoneData);
}
String deltaLink = callbackResult.getDeltaLink();
if (deltaLink != null) {
try {
writer.writeStartElement(FormatXml.ATOM_LINK);
writer.writeAttribute(FormatXml.ATOM_REL, FormatXml.ATOM_DELTA_LINK);
writer.writeAttribute(FormatXml.ATOM_HREF, deltaLink);
writer.writeEndElement();
} catch (XMLStreamException e) {
throw new EntityProviderException(EntityProviderException.COMMON, e);
}
}
}
private void appendNextLink(final XMLStreamWriter writer, final String nextLink) throws EntityProviderException {
try {
writer.writeStartElement(FormatXml.ATOM_LINK);
writer.writeAttribute(FormatXml.ATOM_HREF, nextLink);
writer.writeAttribute(FormatXml.ATOM_REL, FormatXml.ATOM_NEXT_LINK);
writer.writeEndElement();
} catch (XMLStreamException e) {
throw new EntityProviderException(EntityProviderException.COMMON, e);
}
}
private void appendEntries(final XMLStreamWriter writer, final EntityInfoAggregator eia, final List<Map<String, Object>> data) throws EntityProviderException {
AtomEntryEntityProducer entryProvider = new AtomEntryEntityProducer(properties);
for (Map<String, Object> singleEntryData : data) {
entryProvider.append(writer, eia, singleEntryData, false, true);
}
}
private void appendInlineCount(final XMLStreamWriter writer, final Integer inlineCount) throws EntityProviderException {
if (inlineCount == null || inlineCount < 0) {
throw new EntityProviderException(EntityProviderException.INLINECOUNT_INVALID);
}
try {
writer.writeStartElement(Edm.NAMESPACE_M_2007_08, FormatXml.M_COUNT);
writer.writeCharacters(String.valueOf(inlineCount));
writer.writeEndElement();
} catch (XMLStreamException e) {
throw new EntityProviderException(EntityProviderException.COMMON, e);
}
}
private void appendAtomSelfLink(final XMLStreamWriter writer, final EntityInfoAggregator eia) throws EntityProviderException {
URI self = properties.getSelfLink();
String selfLink = "";
if (self == null) {
selfLink = createSelfLink(eia);
} else {
selfLink = self.toASCIIString();
}
try {
writer.writeStartElement(FormatXml.ATOM_LINK);
writer.writeAttribute(FormatXml.ATOM_HREF, selfLink);
writer.writeAttribute(FormatXml.ATOM_REL, Edm.LINK_REL_SELF);
writer.writeAttribute(FormatXml.ATOM_TITLE, eia.getEntitySetName());
writer.writeEndElement();
} catch (XMLStreamException e) {
throw new EntityProviderException(EntityProviderException.COMMON, e);
}
}
private String createSelfLink(final EntityInfoAggregator eia) throws EntityProviderException {
StringBuilder sb = new StringBuilder();
if (!eia.isDefaultEntityContainer()) {
final String entityContainerName = Encoder.encode(eia.getEntityContainerName());
sb.append(entityContainerName).append(Edm.DELIMITER);
}
final String entitySetName = Encoder.encode(eia.getEntitySetName());
sb.append(entitySetName);
return sb.toString();
}
private void appendAtomMandatoryParts(final XMLStreamWriter writer, final EntityInfoAggregator eia) throws EntityProviderException {
try {
writer.writeStartElement(FormatXml.ATOM_ID);
writer.writeCharacters(createAtomId(eia));
writer.writeEndElement();
writer.writeStartElement(FormatXml.ATOM_TITLE);
writer.writeAttribute(FormatXml.M_TYPE, FormatXml.ATOM_TEXT);
writer.writeCharacters(eia.getEntitySetName());
writer.writeEndElement();
writer.writeStartElement(FormatXml.ATOM_UPDATED);
Object updateDate = null;
EdmFacets updateFacets = null;
updateDate = new Date();
writer.writeCharacters(EdmDateTimeOffset.getInstance().valueToString(updateDate, EdmLiteralKind.DEFAULT, updateFacets));
writer.writeEndElement();
writer.writeStartElement(FormatXml.ATOM_AUTHOR);
writer.writeStartElement(FormatXml.ATOM_AUTHOR_NAME);
writer.writeEndElement();
writer.writeEndElement();
} catch (XMLStreamException e) {
throw new EntityProviderException(EntityProviderException.COMMON, e);
} catch (EdmSimpleTypeException e) {
throw new EntityProviderException(EntityProviderException.COMMON, e);
}
}
private String createAtomId(final EntityInfoAggregator eia) throws EntityProviderException {
return properties.getServiceRoot() + createSelfLink(eia);
}
}