package com.walker.infrastructure.utils;

import com.walker.infrastructure.core.FileNotFoundException;
import com.walker.infrastructure.core.NestedRuntimeException;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.RandomAccessFile;
import java.util.ArrayList;
import java.util.List;

public class FileUtils {

	public static final String OS_NAME = "os.name";
	public static final String OS_WINDOWS_NAME = "windows";
	public static final String FILE_SEPARATOR = "/";
	
	/**
	 * 缩略图文件名的后缀：_s 表示小图
	 */
	public static final String THUMB_SUFFIX = "_s";
	
//	private static final String FILE_ROOT_WINDOWS = "file://";
//	private static final String FILE_ROOT_UNIX = "file:///";
	private static final String FILE_ROOT_WINDOWS = "";
	private static final String FILE_ROOT_UNIX = "/";

	/**
	 * 从文件路径中，截取文件ID，文件用id命名。
	 * @param videoPath 文件绝对路径，如 /opt/ai/video/20220921/landscape_01.mp4 或 d:\demo\movie.jpg
	 * @return 返回文件名，没有路径和后缀，如: landscape_01 或 movie
	 */
	public static final String getFileNameWithoutSuffix(String videoPath, String suffix){
		// 如果存在windows反斜杠，先转换成正斜杠。2022-10-11
		videoPath = videoPath.replaceAll("\\\\", StringUtils.FOLDER_SEPARATOR);
		String[] array = videoPath.split(StringUtils.FOLDER_SEPARATOR);
		if(array == null || array.length == 0){
			System.out.println("文件名称截取id错误:" + videoPath);
			return null;
		}
		String fileName = array[array.length-1];
//        String[] idValue = fileName.split(".");
		return fileName.replaceAll(suffix, StringUtils.EMPTY_STRING);
	}

	/**
	 * 返回文件路径地址中的路径部分，如: d:/demo/file.txt --> d:/demo/
	 * @param url
	 * @return
	 * @date 2023-02-15
	 */
	public static final String getFilePathWithoutName(String url){
		if(StringUtils.isEmpty(url)){
			return null;
		}
		int lastSeparatorIndex = url.lastIndexOf(StringUtils.FOLDER_SEPARATOR);
		if(lastSeparatorIndex < 0){
			System.out.println("url中不包含文件路径:" + url);
			return null;
		}
		return url.substring(0, lastSeparatorIndex);
	}

	/**
	 * 返回路径中文件名，如: d:/demo/file.txt --> file.txt
	 * @param url
	 * @return
	 */
	public static final String getFileNameWithoutPath(String url){
		int fileNameIndex = url.lastIndexOf(StringUtils.FOLDER_SEPARATOR) + 1;
		if(fileNameIndex < 0){
			System.out.println("url中不包含文件路径:" + url);
			return null;
		}
		return url.substring(fileNameIndex, url.length());
	}

	/**
	 * 文件夹或文件是否存在。
	 * @param fileOrFolder 文件(或文件夹)绝对路径
	 * @return
	 * @date 2022-10-11
	 */
	public static final boolean isExist(String fileOrFolder){
		if(StringUtils.isEmpty(fileOrFolder)){
			return false;
		}
		File file = new File(fileOrFolder);
		return file.exists();
	}

	public static final boolean isWindows(){
		String osName = System.getProperty(OS_NAME);
		if(osName != null && osName.toLowerCase().indexOf(OS_WINDOWS_NAME) >= 0){
			return true;
		}
		return false;
	}
	
	public static final String getFileSystemRoot(){
		if(isWindows()){
			return FILE_ROOT_WINDOWS;
		} else
			return FILE_ROOT_UNIX;
	}
	
	/**
	 * 检查目录，如果不存在将会创建新目录，包括子目录。
	 * @param path
	 */
	public static final void checkDir(String path){
		File file = new File(path);
		if(!file.exists()){
			file.mkdirs();
		}
	}
	
	private static final String FILE_EXT_SEPARATOR = ".";
	
	/**
	 * 返回文件名的扩展名，如果不存在返回<code>null</code>，如: txt
	 * @param filename
	 * @return
	 */
	public static final String getFileExt(String filename){
		int extIndex = filename.lastIndexOf(FILE_EXT_SEPARATOR);
		if(extIndex > 0){
			// filename.txt
			return filename.substring(extIndex + 1);
		}
		return null;
	}
	
	/**
	 * 返回文件字节信息，通常适用于读取较小文件。
	 * @param file
	 * @return
	 */
	public static final byte[] getFileBytes(File file){
		assert (file != null);
		InputStream in = null;
		try {
			in = new BufferedInputStream(new FileInputStream(file));
//			int byteCount = 0;
			byte[] buffer = new byte[in.available()];
//			int bytesRead = -1;
//			while ((bytesRead = in.read(buffer)) != -1) {
//				byteCount += bytesRead;
//			}
			in.read(buffer, 0, buffer.length);
			return buffer;
			
		} catch (java.io.FileNotFoundException e) {
			throw new FileNotFoundException();
		} catch(IOException ioe){
			throw new NestedRuntimeException(null, ioe);
		} finally {
			if(in != null){
				try {
					in.close();
				} catch (IOException e) {}
			}
		}
	}

	/**
     * 读文本内容，按行读取，返回集合。
	 * @param filePath 文件绝对路径
	 * @return
	 */
	public static List<String> getFileLines(String filePath){
		File file = new File(filePath);
		if(!file.exists()){
			System.out.println("文件不存在，无法读取内容：" + filePath);
			return null;
		}
//		String encoding = "utf-8";
		List<String> content = new ArrayList<>(64);
		try (InputStreamReader read = new InputStreamReader(new FileInputStream(file), StringUtils.DEFAULT_CHARSET_UTF8);
			 BufferedReader bufferedReader = new BufferedReader(read)) {
			//判断文件是否存在
			if (file.isFile() && file.exists()) {
				String lineTxt;
				while ((lineTxt = bufferedReader.readLine()) != null) {
//					System.out.println(lineTxt);
					content.add(lineTxt);
				}
			} else {
				System.out.println("找不到指定的文件");
			}
		} catch (Exception e) {
			e.printStackTrace();
			System.out.println("读取文件内容出错");
		}
		return content;
	}
	
	public static final void writeFile(byte[] content, String filename){
		throw new UnsupportedOperationException();
	}
	
	/**
	 * 删除一个文件
	 * @param file 文件（不能是目录）
	 * @return
	 */
	public static final boolean deleteFile(File file){
		if(file != null){
			try{
				if(file.isDirectory()){
					throw new UnsupportedOperationException("File must be not a directory!");
				}
				return file.delete();
			} catch(Exception e){
				throw new NestedRuntimeException(null, e);
			}
		}
		return false;
	}
	
	/**
	 * 把字符串内容写入到一个文件中。
	 * @param content
	 * @param fileName
	 * @return
	 * @throws Exception
	 */
	public static boolean writeTxtFile(String content,File fileName)throws Exception{  
		RandomAccessFile mm=null;  
		boolean flag=false;  
//		FileOutputStream o=null;  
		try {  
//			o = new FileOutputStream(fileName);  
//			o.write(content.getBytes("GBK"));  
//			o.close();  
			mm=new RandomAccessFile(fileName,"rw");  
			mm.writeBytes(content);  
			flag=true;  
		} catch (java.io.FileNotFoundException e) {  
			throw new FileNotFoundException("not found file: " + fileName, e);
		}finally{  
			if(mm!=null){  
				mm.close();  
			}  
		}  
		return flag;  
	}
	
	/**
	 * 创建空文件
	 * @param filepath
	 * @throws IOException
	 */
	public static final void createEmptyFile(String filepath) throws IOException{
		File file = new File(filepath);
		if(!file.exists()){
			file.createNewFile();
		} else
			System.out.println("file exist: " + filepath);
	}
	
	/**
	 * 给定文件相对路径，返回缩略图路径，如：2014/3/aaa_123456_s.jpg
	 * @param path
	 * @param ext
	 * @return
	 */
	@Deprecated
	public static final String getThumbNailsName(String path, String ext){
		StringBuilder thumb = new StringBuilder();
		thumb.append(path.subSequence(0, path.lastIndexOf(StringUtils.SYMBOL_DOT)));
		thumb.append("_s.").append(ext);
		return thumb.toString();
	}
	
	/**
	 * 给定文件相对路径，返回缩略图路径，如：2014/3/aaa_123456_s.jpg
	 * @param path
	 * @return
	 */
	public static final String getThumbNailsName(String path){
		StringBuilder thumb = new StringBuilder();
		thumb.append(path.subSequence(0, path.lastIndexOf(StringUtils.SYMBOL_DOT)));
		thumb.append("_s.").append(FileUtils.getFileExt(path));
		return thumb.toString();
	}
	
	public static void main(String[] args){
//		System.out.println(FileUtils.getFileExt("myfile.txt"));
//		System.out.println(FileUtils.getFileExt("myfile-111.2012.txt"));
//		System.out.println(FileUtils.getFileExt("myfiletxt"));
//		System.out.println("file: " + FileUtils.getFileBytes(new File("d:/sso-1.jpg")));
//		System.out.println(getThumbNailsName("2014/3/aaa_123456.jpg"));
//		System.out.println(getFileExt("d:/test/demo.jpg"));
		System.out.println(getFilePathWithoutName("d:/test/demo.jpg"));
		System.out.println(getFileNameWithoutPath("d:/test/demo.jpg"));
	}
}