/*
 * Copyright (c) 2019, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. licenses this file to you 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.wso2.carbon.inbound.endpoint.protocol.file;

import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.util.UUIDGenerator;
import org.apache.axis2.Constants;
import org.apache.axis2.builder.Builder;
import org.apache.axis2.builder.BuilderUtil;
import org.apache.axis2.builder.SOAPBuilder;
import org.apache.axis2.context.MessageContext;
import org.apache.axis2.format.DataSourceMessageBuilder;
import org.apache.axis2.format.ManagedDataSource;
import org.apache.axis2.format.ManagedDataSourceFactory;
import org.apache.axis2.transport.TransportUtils;
import org.apache.commons.io.input.AutoCloseInputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.vfs2.FileObject;
import org.apache.synapse.SynapseConstants;
import org.apache.synapse.SynapseException;
import org.apache.synapse.commons.vfs.FileObjectDataSource;
import org.apache.synapse.commons.vfs.VFSConstants;
import org.apache.synapse.core.SynapseEnvironment;
import org.apache.synapse.inbound.InboundEndpoint;
import org.apache.synapse.mediators.base.SequenceMediator;
import org.apache.synapse.transport.customlogsetter.CustomLogSetter;

import java.io.IOException;
import java.io.InputStream;
import java.util.Map;
import java.util.Properties;
import javax.mail.internet.ContentType;
import javax.mail.internet.ParseException;

public class FileInjectHandler {

    private static final Log log = LogFactory.getLog(FileInjectHandler.class);

    private String injectingSeq;
    private String onErrorSeq;
    private boolean sequential;
    private Properties vfsProperties;
    private SynapseEnvironment synapseEnvironment;
    private Map<String, Object> transportHeaders;

    public FileInjectHandler(String injectingSeq, String onErrorSeq, boolean sequential,
                             SynapseEnvironment synapseEnvironment, Properties vfsProperties) {
        this.injectingSeq = injectingSeq;
        this.onErrorSeq = onErrorSeq;
        this.sequential = sequential;
        this.synapseEnvironment = synapseEnvironment;
        this.vfsProperties = vfsProperties;
    }

    /**
     * Inject the message to the sequence
     */
    public boolean invoke(Object object, String name) throws SynapseException {

        ManagedDataSource dataSource = null;
        ;
        FileObject file = (FileObject) object;
        InputStream in = null;
        try {
            org.apache.synapse.MessageContext msgCtx = createMessageContext();
            msgCtx.setProperty(SynapseConstants.INBOUND_ENDPOINT_NAME, name);
            msgCtx.setProperty(SynapseConstants.IS_INBOUND, true);
            InboundEndpoint inboundEndpoint = msgCtx.getConfiguration().getInboundEndpoint(name);
            CustomLogSetter.getInstance().setLogAppender(inboundEndpoint.getArtifactContainerName());
            String contentType = vfsProperties.getProperty(VFSConstants.TRANSPORT_FILE_CONTENT_TYPE);
            if (contentType == null || contentType.trim().equals("")) {
                if (file.getName().getExtension().toLowerCase().endsWith("xml")) {
                    contentType = "text/xml";
                } else if (file.getName().getExtension().toLowerCase().endsWith("txt")) {
                    contentType = "text/plain";
                }
            } else {
                // Extract the charset encoding from the configured content type and
                // set the CHARACTER_SET_ENCODING property as e.g. SOAPBuilder relies on this.
                String charSetEnc = null;
                try {
                    if (contentType != null) {
                        charSetEnc = new ContentType(contentType).getParameter("charset");
                    }
                } catch (ParseException ex) {
                    // ignore
                }
                msgCtx.setProperty(Constants.Configuration.CHARACTER_SET_ENCODING, charSetEnc);
            }
            if (log.isDebugEnabled()) {
                log.debug("Processed file : " + file + " of Content-type : " + contentType);
            }
            MessageContext axis2MsgCtx = ((org.apache.synapse.core.axis2.Axis2MessageContext) msgCtx)
                    .getAxis2MessageContext();
            // Determine the message builder to use
            Builder builder;
            if (contentType == null) {
                log.debug("No content type specified. Using SOAP builder.");
                builder = new SOAPBuilder();
            } else {
                int index = contentType.indexOf(';');
                String type = index > 0 ? contentType.substring(0, index) : contentType;
                builder = BuilderUtil.getBuilderFromSelector(type, axis2MsgCtx);
                if (builder == null) {
                    if (log.isDebugEnabled()) {
                        log.debug("No message builder found for type '" + type + "'. Falling back to SOAP.");
                    }
                    builder = new SOAPBuilder();
                }
            }

            // set the message payload to the message context
            String streaming = vfsProperties.getProperty(VFSConstants.STREAMING);

            if (builder instanceof DataSourceMessageBuilder && "true".equals(streaming)) {
                dataSource = ManagedDataSourceFactory.create(new FileObjectDataSource(file, contentType));
                in = null;
            } else {
                in = new AutoCloseInputStream(file.getContent().getInputStream());
                dataSource = null;
            }

            //Inject the message to the sequence.

            OMElement documentElement;
            if (in != null) {
                documentElement = builder.processDocument(in, contentType, axis2MsgCtx);
            } else {
                documentElement = ((DataSourceMessageBuilder) builder)
                        .processDocument(dataSource, contentType, axis2MsgCtx);
            }

            if ("true".equals(vfsProperties.getProperty(VFSConstants.TRANSPORT_BUILD))) {
                documentElement.build();
            }
            msgCtx.setEnvelope(TransportUtils.createSOAPEnvelope(documentElement));

            if (injectingSeq == null || injectingSeq.equals("")) {
                log.error("Sequence name not specified. Sequence : " + injectingSeq);
            }
            SequenceMediator seq = (SequenceMediator) synapseEnvironment.getSynapseConfiguration()
                    .getSequence(injectingSeq);
            if (seq != null) {
                if (log.isDebugEnabled()) {
                    log.debug("injecting message to sequence : " + injectingSeq);
                }
                if (!seq.isInitialized()) {
                    seq.init(synapseEnvironment);
                }
                seq.setErrorHandler(onErrorSeq);
                if (!synapseEnvironment.injectInbound(msgCtx, seq, sequential)) {
                    return false;
                }
            } else {
                log.error("Sequence: " + injectingSeq + " not found");
            }
        } catch (SynapseException se) {
            throw se;
        } catch (Exception e) {
            log.error("Error while processing the file/folder", e);
            throw new SynapseException("Error while processing the file/folder", e);
        } finally {
            if (dataSource != null) {
                dataSource.destroy();
            }
            try {
                if (in != null) {
                    in.close();
                }
            } catch (IOException e) {
                log.error("Error while closing the input stream", e);
            }
        }
        return true;
    }

    /**
     * @param transportHeaders the transportHeaders to set
     */
    public void setTransportHeaders(Map<String, Object> transportHeaders) {
        this.transportHeaders = transportHeaders;
    }

    /**
     * Create the initial message context for the file
     */
    private org.apache.synapse.MessageContext createMessageContext() {

        org.apache.synapse.MessageContext msgCtx = synapseEnvironment.createMessageContext();
        MessageContext axis2MsgCtx = ((org.apache.synapse.core.axis2.Axis2MessageContext) msgCtx)
                .getAxis2MessageContext();
        axis2MsgCtx.setServerSide(true);
        axis2MsgCtx.setMessageID(UUIDGenerator.getUUID());
        axis2MsgCtx.setProperty(MessageContext.TRANSPORT_HEADERS, transportHeaders);
        msgCtx.setProperty(MessageContext.CLIENT_API_NON_BLOCKING, true);
        return msgCtx;
    }

}

