package net.sourceforge.solexatools.webapp.controller;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sourceforge.seqware.common.business.FileService;
import net.sourceforge.seqware.common.model.File;
import net.sourceforge.seqware.common.model.Registration;
import net.sourceforge.seqware.common.util.Log;
import net.sourceforge.seqware.common.util.filetools.FileTools;
import net.sourceforge.seqware.common.util.filetools.ProvisionFilesUtil;
import net.sourceforge.solexatools.Security;
import net.sourceforge.solexatools.util.BulkUtil;

import org.apache.commons.io.FileUtils;
import org.springframework.util.FileCopyUtils;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.BaseCommandController;

/**
 * <p>
 * BulkDownloaderController class.
 * </p>
 * 
 * @author boconnor
 * @version $Id: $Id
 */
public class BulkDownloaderController extends BaseCommandController {

    private FileService fileService;
    /** Constant <code>BUFFERSIZE=500*1024</code> */
    public static final int BUFFERSIZE = 500 * 1024; // 512K buffer
    private static final String SEPARATOR = java.io.File.separator;

    /**
     * <p>
     * Constructor for BulkDownloaderController.
     * </p>
     */
    public BulkDownloaderController() {
        super();
        setSupportedMethods(new String[] { METHOD_GET });
    }

    /**
     * {@inheritDoc}
     * 
     * @return
     * @throws java.lang.Exception
     */
    @Override
    protected ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response) throws Exception {

        Registration registration = Security.getRegistration(request);
        if (registration == null) return new ModelAndView("redirect:/login.htm");

        // These are the files to include in the ZIP file
        List<File> filesToZip = BulkUtil.getFiles(request, "unknow");

        if (filesToZip.isEmpty()) {
            return new ModelAndView("redirect:/myStudyList.htm");
        }

        // Create the ZIP file
        ServletContext context = this.getServletContext();
        String folderStore = context.getInitParameter("path.to.upload.directory");

        String outFilename = folderStore + "outfile-" + new Date() + ".zip";

        String contextPath = this.getServletContext().getContextPath();

        Date dateNow = new Date();
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMddHHmmssSSS");
        String strNow = dateFormat.format(dateNow);

        String pathToTempStore = "webapps" + contextPath + SEPARATOR + "temp" + SEPARATOR + registration.getEmailAddress() + SEPARATOR
                + strNow + SEPARATOR;

        java.io.File tempStore = new java.io.File(pathToTempStore);

        if (!tempStore.exists()) {
            tempStore.mkdir();
        } else {
            FileUtils.deleteDirectory(tempStore);
            tempStore.mkdir();
        }

        ProvisionFilesUtil filesUtil = new ProvisionFilesUtil();
        downloadRemoteFiles(filesUtil, filesToZip, pathToTempStore);

        Collection<java.io.File> filesInTemp = FileUtils.listFiles(tempStore, null, false);
        java.io.File out = new java.io.File(outFilename);
        FileTools.zipListFileRecursiveOld(new ArrayList<>(filesInTemp), out, pathToTempStore, null, false);

        Log.info("OUTNAME=" + outFilename);
        java.io.File realFile = new java.io.File(outFilename);
        int fileSize = (int) realFile.length();
        String shortName = outFilename.substring(outFilename.lastIndexOf('/') + 1);
        response.setBufferSize(BUFFERSIZE);
        response.setContentType(this.getServletContext().getMimeType(outFilename));
        response.setHeader("Content-Disposition", "attachment; filename=\"" + shortName + "\"");
        response.setContentLength(fileSize);

        try (BufferedInputStream in = new BufferedInputStream(new FileInputStream(realFile))) {
            FileCopyUtils.copy(in, response.getOutputStream());
        }
        response.getOutputStream().flush();
        response.getOutputStream().close();

        // delete file
        realFile.delete();
        FileUtils.deleteDirectory(tempStore);

        return null;
    }

    private void downloadRemoteFiles(ProvisionFilesUtil util, List<File> filesToZip, String targetPath) throws Exception {
        long size = determineSize(util, filesToZip);
        long maxSize = getMaxBulkDownloadFilesSize();
        if (size > maxSize) {
            throw new Exception("The files you have chosen to download total > " + maxSize
                    + " and cannot be zipped on this web server.  Please download individually.");
        }

        for (File file : filesToZip) {
            BufferedInputStream input = util.getSourceReader(file.getFilePath(), BUFFERSIZE, 0);
            util.copyToFile(input, targetPath, BUFFERSIZE, file.getFilePath());
        }
    }

    private long determineSize(ProvisionFilesUtil util, List<File> filesToZip) throws Exception {
        long size = 0;
        for (File file : filesToZip) {
            size += ProvisionFilesUtil.getFileSize(file.getFilePath());
        }
        return size;
    }

    private long getMaxBulkDownloadFilesSize() {
        ServletContext context = this.getServletContext();
        String maxSizeStr = context.getInitParameter("bulk.download.max.file.size");
        long maxSize = 200 * 1024 * 1024;
        try {
            maxSize = Integer.parseInt(maxSizeStr);
        } catch (NumberFormatException e) {
            e.printStackTrace();
        }
        return maxSize;
    }

    /**
     * <p>
     * Getter for the field <code>fileService</code>.
     * </p>
     * 
     * @return a {@link net.sourceforge.seqware.common.business.FileService} object.
     */
    public FileService getFileService() {
        return fileService;
    }

    /**
     * <p>
     * Setter for the field <code>fileService</code>.
     * </p>
     * 
     * @param fileService
     *            a {@link net.sourceforge.seqware.common.business.FileService} object.
     */
    public void setFileService(FileService fileService) {
        this.fileService = fileService;
    }
}