/***********************************************************************
 * This file is part of iDempiere ERP Open Source                      *
 * http://www.idempiere.org                                            *
 *                                                                     *
 * Copyright (C) Contributors                                          *
 *                                                                     *
 * This program is free software; you can redistribute it and/or       *
 * modify it under the terms of the GNU General Public License         *
 * as published by the Free Software Foundation; either version 2      *
 * of the License, or (at your option) any later version.              *
 *                                                                     *
 * This program is distributed in the hope that it will be useful,     *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of      *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the        *
 * GNU General Public License for more details.                        *
 *                                                                     *
 * You should have received a copy of the GNU General Public License   *
 * along with this program; if not, write to the Free Software         *
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,          *
 * MA 02110-1301, USA.                                                 *
 *                                                                     *
 * Contributors:                                                       *
 * - hengsin                         								   *
 **********************************************************************/
package org.adempiere.report.jasper;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardCopyOption;
import java.util.Arrays;
import java.util.Optional;
import java.util.logging.Level;

import org.compiere.util.CLogger;
import org.compiere.util.Language;
import org.compiere.utils.DigestOfFile;
import org.osgi.framework.Bundle;
import org.osgi.framework.wiring.BundleWiring;

/**
 * 
 * Get report resources from class path
 * @author hengsin
 *
 */
public class ClassResourceLoader {

	private final static CLogger log = CLogger.getCLogger(ClassResourceLoader.class);

	private String destinationFolder;

	private String resourcePath;

	private static final String RESOURCE_PATH_PREFIX = "resource:";

	/**
	 * 
	 * @param destinationFolder
	 */
	public ClassResourceLoader(String destinationFolder) {
		this.destinationFolder = destinationFolder;
	}

	/**
	 * @param path
	 * @return File or URL
	 */
	public Object getResource(String path) {
		boolean empty = true;
		URL url = null;
		File reportFile = null;
		String resourceName = path.startsWith(RESOURCE_PATH_PREFIX) ? path.substring(RESOURCE_PATH_PREFIX.length()).trim() : path.trim();
		Bundle bundle = null;
		//if resource name include optional bundle symbolic name (syntax -> resource:bundleSymbolicName:jasperReportFileName), find the specific bundle 
		if (resourceName.indexOf(":") > 0) {
			String symbolicName = resourceName.substring(0, resourceName.indexOf(":"));
			resourceName = resourceName.substring(resourceName.indexOf(":")+1);
			Optional<Bundle> optional = Arrays.stream(Activator.getBundleContext().getBundles()).filter(b -> b.getSymbolicName().equals(symbolicName)).findFirst();
			if (optional.isPresent())
				bundle = optional.get();
		}		
		ClassLoader classLoader = null;
		//if resource name include optional bundle symbolic name, use classLoader of the specific bundle
		if (bundle != null) {
			classLoader = bundle.adapt(BundleWiring.class).getClassLoader();
		} else {
			classLoader = getClass().getClassLoader();
		}
		//only copy to tmp if reportPath is jrxml file (for compilation)
		if (resourceName.endsWith(".jrxml")) {
			String localResourceName = toLocalName(resourceName);
			String localAbsolutePathName = destinationFolder + localResourceName;
			reportFile = new File(localAbsolutePathName);
			String localPathName = localAbsolutePathName.substring(0, localAbsolutePathName.lastIndexOf(File.separator)+1);
			Path localAbsolutePath = Path.of(localPathName);
			try {
				if (!Files.exists(localAbsolutePath))
					Files.createDirectory(localAbsolutePath);
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
			String localFileName = localAbsolutePathName.substring(localAbsolutePathName.lastIndexOf(File.separator)+1);
			String extension = localFileName.substring(localFileName.lastIndexOf("."));
			File tmpOutputFile = null;
			
			url = classLoader.getResource(resourceName);
			if (url != null) {
				try (InputStream inputStream = url.openStream()) {
					if (inputStream != null) {
						if (!reportFile.exists()) {
							reportFile.createNewFile();
							tmpOutputFile = reportFile;
						} else {
							tmpOutputFile = File.createTempFile(localFileName.substring(0, localFileName.lastIndexOf(".")), extension, localAbsolutePath.toFile());
						}
						try (OutputStream out = new FileOutputStream(tmpOutputFile);) {
							if (out != null) {
								byte buf[] = new byte[1024];
								int len;
								while ((len = inputStream.read(buf)) > 0) {
									empty = false;
									out.write(buf, 0, len);
								}
							}
						}
					}
				} catch (Exception e) {
					log.log(Level.SEVERE, e.getMessage(), e);
					empty = true;
				}
				if (!empty && tmpOutputFile != reportFile) {
					if (!DigestOfFile.md5HashCompare(reportFile, tmpOutputFile)) {
						Path to = reportFile.toPath();
						Path from = tmpOutputFile.toPath();
						try {
							Files.copy(from, to, StandardCopyOption.REPLACE_EXISTING);
						} catch (IOException e) {
							log.log(Level.SEVERE, e.getMessage(), e);
							return null;
						}
					}
					try {
						Files.delete(tmpOutputFile.toPath());
					} catch (IOException e) {}
				}
			}
		} else {
			url = classLoader.getResource(resourceName);
			empty = (url == null);
		}

		if (empty)
			return null;

		if (url != null) {
			resourcePath = url.toString();
			if (resourcePath != null && resourcePath.lastIndexOf("/") > 0)
				resourcePath = resourcePath.substring(0, resourcePath.lastIndexOf("/")+1);
		}
		
		return reportFile != null ? reportFile : url;
	}

	private String toLocalName(String name) {
		String localName = name;
		if (localName.startsWith("/"))
			localName = localName.substring(1);
		if (localName.lastIndexOf("/") > 0) {
			String path = localName.substring(0, localName.lastIndexOf("/"));
			localName = localName.substring(localName.lastIndexOf("/")+1);
			path = path.replace('/', '_');
			localName = path + File.separator + localName;
		}
		return localName;
	}

	/**
	 * Get property resource file from resources
	 * 
	 * @param bundleName
	 * @param currLang
	 * @return URL
	 */
	public URL getResourceBundle(String bundleName, Language currLang) {
		String resourceName = bundleName + "_" + currLang.getLocale().getLanguage() + "_" + currLang.getLocale().getCountry()
				+ ".properties";
		URL resourceURL = null;
		try {
			resourceURL = (URL) getResource(resourceName);
		} catch (Exception e) {
			// ignore exception - file couldn't exist
		}
		if (resourceURL == null) {
			resourceName = bundleName + "_" + currLang.getLocale().getLanguage() + ".properties";
			try {
				resourceURL = (URL) getResource(resourceName);
			} catch (Exception e) {
				// ignore exception - file couldn't exist
			}
			if (resourceURL == null) {
				resourceName = bundleName + ".properties";
				try {
					resourceURL = (URL) getResource(resourceName);
				} catch (Exception e) {
					// ignore exception - file couldn't exist
				}
			}
		}
		return resourceURL;
	}

	/**
	 * @param path The full path to the parent report
	 * @return File[0]
	 */
	public File[] getSubreports(String path) {
		return new File[0];
	}
	
	/**
	 * 
	 * @return url path to load subreports, images and resource bundle
	 */
	public String getRelatedResourcesPath() {
		return resourcePath;
	}
	
	/**
	 * 
	 * @param path
	 * @return true if path is "resource:*"
	 */
	public static boolean isClassResourcePath(String path) {
		return path != null && path.startsWith(RESOURCE_PATH_PREFIX);
	}
}