/**
 * 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.util.Arrays;
import java.util.List;

import org.apache.camel.Processor;
import org.apache.camel.util.FileUtil;
import org.apache.camel.util.ObjectHelper;

/**
 * File consumer.
 */
public class FileConsumer extends GenericFileConsumer<File> {

    private String endpointPath;

    public FileConsumer(GenericFileEndpoint<File> endpoint, Processor processor, GenericFileOperations<File> operations) {
        super(endpoint, processor, operations);
        this.endpointPath = endpoint.getConfiguration().getDirectory();
    }

    @Override
    protected boolean pollDirectory(String fileName, List<GenericFile<File>> fileList, int depth) {
        log.trace("pollDirectory from fileName: {}", fileName);

        depth++;

        File directory = new File(fileName);
        if (!directory.exists() || !directory.isDirectory()) {
            log.debug("Cannot poll as directory does not exists or its not a directory: {}", directory);
            if (getEndpoint().isDirectoryMustExist()) {
                throw new GenericFileOperationFailedException("Directory does not exist: " + directory);
            }
            return true;
        }

        log.trace("Polling directory: {}", directory.getPath());
        File[] dirFiles = directory.listFiles();
        if (dirFiles == null || dirFiles.length == 0) {
            // no files in this directory to poll
            if (log.isTraceEnabled()) {
                log.trace("No files found in directory: {}", directory.getPath());
            }
            return true;
        } else {
            // we found some files
            if (log.isTraceEnabled()) {
                log.trace("Found {} in directory: {}", dirFiles.length, directory.getPath());
            }
        }
        List<File> files = Arrays.asList(dirFiles);

        for (File file : files) {
            // check if we can continue polling in files
            if (!canPollMoreFiles(fileList)) {
                return false;
            }

            // trace log as Windows/Unix can have different views what the file is?
            if (log.isTraceEnabled()) {
                log.trace("Found file: {} [isAbsolute: {}, isDirectory: {}, isFile: {}, isHidden: {}]",
                        new Object[]{file, file.isAbsolute(), file.isDirectory(), file.isFile(), file.isHidden()});
            }

            // creates a generic file
            GenericFile<File> gf = asGenericFile(endpointPath, file, getEndpoint().getCharset());

            if (file.isDirectory()) {
                if (endpoint.isRecursive() && depth < endpoint.getMaxDepth() && isValidFile(gf, true, files)) {
                    // recursive scan and add the sub files and folders
                    String subDirectory = fileName + File.separator + file.getName();
                    boolean canPollMore = pollDirectory(subDirectory, fileList, depth);
                    if (!canPollMore) {
                        return false;
                    }
                }
            } else {
                // Windows can report false to a file on a share so regard it always as a file (if its not a directory)
                if (depth >= endpoint.minDepth && isValidFile(gf, false, files)) {
                    log.trace("Adding valid file: {}", file);
                    // matched file so add
                    fileList.add(gf);
                }

            }
        }

        return true;
    }

    @Override
    protected boolean isMatched(GenericFile<File> file, String doneFileName, List<File> files) {
        String onlyName = FileUtil.stripPath(doneFileName);
        // the done file name must be among the files
        for (File f : files) {
            if (f.getName().equals(onlyName)) {
                return true;
            }
        }
        log.trace("Done file: {} does not exist", doneFileName);
        return false;
    }

    /**
     * Creates a new GenericFile<File> based on the given file.
     *
     * @param endpointPath the starting directory the endpoint was configured with
     * @param file the source file
     * @return wrapped as a GenericFile
     */
    public static GenericFile<File> asGenericFile(String endpointPath, File file, String charset) {
        GenericFile<File> answer = new GenericFile<File>();
        // use file specific binding
        answer.setBinding(new FileBinding());

        answer.setCharset(charset);
        answer.setEndpointPath(endpointPath);
        answer.setFile(file);
        answer.setFileNameOnly(file.getName());
        answer.setFileLength(file.length());
        answer.setDirectory(file.isDirectory());
        // must use FileUtil.isAbsolute to have consistent check for whether the file is
        // absolute or not. As windows do not consider \ paths as absolute where as all
        // other OS platforms will consider \ as absolute. The logic in Camel mandates
        // that we align this for all OS. That is why we must use FileUtil.isAbsolute
        // to return a consistent answer for all OS platforms.
        answer.setAbsolute(FileUtil.isAbsolute(file));
        answer.setAbsoluteFilePath(file.getAbsolutePath());
        answer.setLastModified(file.lastModified());

        // compute the file path as relative to the starting directory
        File path;
        String endpointNormalized = FileUtil.normalizePath(endpointPath);
        if (file.getPath().startsWith(endpointNormalized + File.separator)) {
            // skip duplicate endpoint path
            path = new File(ObjectHelper.after(file.getPath(), endpointNormalized + File.separator));
        } else {
            path = new File(file.getPath());
        }

        if (path.getParent() != null) {
            answer.setRelativeFilePath(path.getParent() + File.separator + file.getName());
        } else {
            answer.setRelativeFilePath(path.getName());
        }

        // the file name should be the relative path
        answer.setFileName(answer.getRelativeFilePath());

        // use file as body as we have converters if needed as stream
        answer.setBody(file);
        return answer;
    }

    @Override
    public FileEndpoint getEndpoint() {
        return (FileEndpoint) super.getEndpoint();
    }
}