/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.apache.camel.component.file;

import java.io.File;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Map;

import org.apache.camel.Exchange;
import org.apache.camel.WrappedFile;
import org.apache.camel.util.FileUtil;
import org.apache.camel.util.ObjectHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Generic File. Specific implementations of a file based endpoint need to
 * provide a File for transfer.
 */
public class GenericFile<T> implements WrappedFile<T>  {
    private static final Logger LOG = LoggerFactory.getLogger(GenericFile.class);

    private String copyFromAbsoluteFilePath;
    private String endpointPath;
    private String fileName;
    private String fileNameOnly;
    private String relativeFilePath;
    private String absoluteFilePath;
    private long fileLength;
    private long lastModified;
    private T file;
    private GenericFileBinding<T> binding;
    private boolean absolute;
    private boolean directory;
    private String charset;

    public char getFileSeparator() {
        return File.separatorChar;
    }

    /**
     * Creates a copy based on the source
     *
     * @param source the source
     * @return a copy of the source
     */
    @SuppressWarnings("unchecked")
    public GenericFile<T> copyFrom(GenericFile<T> source) {
        GenericFile<T> result;
        try {
            result = source.getClass().newInstance();
        } catch (Exception e) {
            throw ObjectHelper.wrapRuntimeCamelException(e);
        }
        result.setCopyFromAbsoluteFilePath(source.getAbsoluteFilePath());
        result.setEndpointPath(source.getEndpointPath());
        result.setAbsolute(source.isAbsolute());
        result.setDirectory(source.isDirectory());
        result.setAbsoluteFilePath(source.getAbsoluteFilePath());
        result.setRelativeFilePath(source.getRelativeFilePath());
        result.setFileName(source.getFileName());
        result.setFileNameOnly(source.getFileNameOnly());
        result.setFileLength(source.getFileLength());
        result.setLastModified(source.getLastModified());
        result.setFile(source.getFile());
        result.setBody(source.getBody());
        result.setBinding(source.getBinding());
        result.setCharset(source.getCharset());

        copyFromPopulateAdditional(source, result);
        return result;
    }

    /**
     * Copies additional information from the source to the result.
     * <p/>
     * Inherited classes can override this method and copy their specific data.
     *
     * @param source  the source
     * @param result  the result
     */
    public void copyFromPopulateAdditional(GenericFile<T> source, GenericFile<T> result) {
        // noop
    }

    /**
     * Bind this GenericFile to an Exchange
     */
    public void bindToExchange(Exchange exchange) {
        Map<String, Object> headers;

        exchange.setProperty(FileComponent.FILE_EXCHANGE_FILE, this);
        GenericFileMessage<T> msg = new GenericFileMessage<T>(this);
        if (exchange.hasOut()) {
            headers = exchange.getOut().hasHeaders() ? exchange.getOut().getHeaders() : null;
            exchange.setOut(msg);
        } else {
            headers = exchange.getIn().hasHeaders() ? exchange.getIn().getHeaders() : null;
            exchange.setIn(msg);
        }

        // preserve any existing (non file) headers, before we re-populate headers
        if (headers != null) {
            msg.setHeaders(headers);
            // remove any file related headers, as we will re-populate file headers
            msg.removeHeaders("CamelFile*");
        }
        populateHeaders(msg);
    }

    /**
     * Populates the {@link GenericFileMessage} relevant headers
     *
     * @param message the message to populate with headers
     */
    public void populateHeaders(GenericFileMessage<T> message) {
        if (message != null) {
            message.setHeader(Exchange.FILE_NAME_ONLY, getFileNameOnly());
            message.setHeader(Exchange.FILE_NAME, getFileName());
            message.setHeader(Exchange.FILE_NAME_CONSUMED, getFileName());
            message.setHeader("CamelFileAbsolute", isAbsolute());
            message.setHeader("CamelFileAbsolutePath", getAbsoluteFilePath());
            
            if (file instanceof File) {
                File f = (File) file;
                Path path = f.toPath();
                try {
                    message.setHeader(Exchange.FILE_CONTENT_TYPE, Files.probeContentType(path));
                } catch (Exception ex) {
                    // just ignore the exception
                }
            }
    
            if (isAbsolute()) {
                message.setHeader(Exchange.FILE_PATH, getAbsoluteFilePath());
            } else {
                // we must normalize path according to protocol if we build our own paths
                String path = normalizePathToProtocol(getEndpointPath() + File.separator + getRelativeFilePath());
                message.setHeader(Exchange.FILE_PATH, path);
            }
    
            message.setHeader("CamelFileRelativePath", getRelativeFilePath());
            message.setHeader(Exchange.FILE_PARENT, getParent());
    
            if (getFileLength() >= 0) {
                message.setHeader(Exchange.FILE_LENGTH, getFileLength());
            }
            if (getLastModified() > 0) {
                message.setHeader(Exchange.FILE_LAST_MODIFIED, getLastModified());
            }
        }
    }
    
    protected boolean isAbsolute(String name) {
        return FileUtil.isAbsolute(new File(name));
    }
    
    protected String normalizePath(String name) {
        return FileUtil.normalizePath(name);
    }
   
    /**
     * Changes the name of this remote file. This method alters the absolute and
     * relative names as well.
     *
     * @param newName the new name
     */
    public void changeFileName(String newName) {
        LOG.trace("Changing name to: {}", newName);

        // Make sure the names is normalized.
        String newFileName = FileUtil.normalizePath(newName);
        String newEndpointPath = FileUtil.normalizePath(endpointPath);

        LOG.trace("Normalized endpointPath: {}", newEndpointPath);
        LOG.trace("Normalized newFileName: ()", newFileName);

        File file = new File(newFileName);
        if (!absolute) {
            // for relative then we should avoid having the endpoint path duplicated so clip it
            if (ObjectHelper.isNotEmpty(newEndpointPath) && newFileName.startsWith(newEndpointPath)) {
                // clip starting endpoint in case it was added
                // use File.separatorChar as the normalizePath uses this as path separator so we should use the same
                // in this logic here
                if (newEndpointPath.endsWith("" + File.separatorChar)) {
                    newFileName = ObjectHelper.after(newFileName, newEndpointPath);
                } else {
                    newFileName = ObjectHelper.after(newFileName, newEndpointPath + File.separatorChar);
                }

                // reconstruct file with clipped name
                file = new File(newFileName);
            }
        }

        // store the file name only
        setFileNameOnly(file.getName());
        setFileName(file.getName());

        // relative path
        if (file.getParent() != null) {
            setRelativeFilePath(file.getParent() + getFileSeparator() + file.getName());
        } else {
            setRelativeFilePath(file.getName());
        }

        // absolute path
        if (isAbsolute(newFileName)) {
            setAbsolute(true);
            setAbsoluteFilePath(newFileName);
        } else {
            setAbsolute(false);
            // construct a pseudo absolute filename that the file operations uses even for relative only
            String path = ObjectHelper.isEmpty(endpointPath) ? "" : endpointPath + getFileSeparator();
            setAbsoluteFilePath(path + getRelativeFilePath());
        }

        if (LOG.isTraceEnabled()) {
            LOG.trace("FileNameOnly: {}", getFileNameOnly());
            LOG.trace("FileName: {}", getFileName());
            LOG.trace("Absolute: {}", isAbsolute());
            LOG.trace("Relative path: {}", getRelativeFilePath());
            LOG.trace("Absolute path: {}", getAbsoluteFilePath());
            LOG.trace("Name changed to: {}", this);
        }
    }

    public String getRelativeFilePath() {
        return relativeFilePath;
    }

    public void setRelativeFilePath(String relativeFilePath) {
        this.relativeFilePath = normalizePathToProtocol(relativeFilePath);
    }

    public String getFileName() {
        return fileName;
    }

    public void setFileName(String fileName) {
        this.fileName = normalizePathToProtocol(fileName);
    }

    public long getFileLength() {
        return fileLength;
    }

    public void setFileLength(long fileLength) {
        this.fileLength = fileLength;
    }

    public long getLastModified() {
        return lastModified;
    }

    public void setLastModified(long lastModified) {
        this.lastModified = lastModified;
    }

    public String getCharset() {
        return charset;
    }

    public void setCharset(String charset) {
        this.charset = charset;
    }

    @Override
    public T getFile() {
        return file;
    }

    public void setFile(T file) {
        this.file = file;
    }

    public Object getBody() {
        return getBinding().getBody(this);
    }

    public void setBody(Object os) {
        getBinding().setBody(this, os);
    }

    public String getParent() {
        String parent;
        if (isAbsolute()) {
            String name = getAbsoluteFilePath();
            File path = new File(name);
            parent = path.getParent();
        } else {
            String name = getRelativeFilePath();
            File path;
            if (name != null) {
                path = new File(endpointPath, name);
            } else {
                path = new File(endpointPath);
            }
            parent = path.getParent();
        }
        return normalizePathToProtocol(parent);
    }

    public GenericFileBinding<T> getBinding() {
        if (binding == null) {
            binding = new GenericFileDefaultBinding<T>();
        }
        return binding;
    }

    public void setBinding(GenericFileBinding<T> binding) {
        this.binding = binding;
    }

    public void setAbsoluteFilePath(String absoluteFilePath) {
        this.absoluteFilePath = normalizePathToProtocol(absoluteFilePath);
    }

    public String getAbsoluteFilePath() {
        return absoluteFilePath;
    }

    public boolean isAbsolute() {
        return absolute;
    }

    public void setAbsolute(boolean absolute) {
        this.absolute = absolute;
    }

    public String getEndpointPath() {
        return endpointPath;
    }

    public void setEndpointPath(String endpointPath) {
        this.endpointPath = normalizePathToProtocol(endpointPath);
    }

    public String getFileNameOnly() {
        return fileNameOnly;
    }

    public void setFileNameOnly(String fileNameOnly) {
        this.fileNameOnly = fileNameOnly;
    }

    public boolean isDirectory() {
        return directory;
    }

    public void setDirectory(boolean directory) {
        this.directory = directory;
    }

    public String getCopyFromAbsoluteFilePath() {
        return copyFromAbsoluteFilePath;
    }

    public void setCopyFromAbsoluteFilePath(String copyFromAbsoluteFilePath) {
        this.copyFromAbsoluteFilePath = copyFromAbsoluteFilePath;
    }

    /**
     * Fixes the path separator to be according to the protocol
     */
    protected String normalizePathToProtocol(String path) {
        if (ObjectHelper.isEmpty(path)) {
            return path;
        }
        path = path.replace('/', getFileSeparator());
        path = path.replace('\\', getFileSeparator());
        return path;
    }

    @Override
    public String toString() {
        return "GenericFile[" + (absolute ? absoluteFilePath : relativeFilePath) + "]";
    }
}