package com.lxyer.excel.poi;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.poifs.filesystem.OfficeXmlFileException;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.text.SimpleDateFormat;
import java.util.*;

/**
 * 使用poi报表导出工具类
 * 把poi的一个调用接口抽出来，便于导出功能的管理
 * @author LiangXianYou lxy208@126.com
 * @param 
 *
 */
public class ExcelKit {
	
	/**
	 * <b>导出list中map做载体的数据到excel</b><br>
	 * 参数说明：<br>
	 * 	list:存放了Map数据的集合<br>
	 * 	hdNames:表头列名<br>
	 * 	hds:对应表头的数据KEY<br>
	 *  xlsName:导出文件名<br>
	 * @author LiangXianYou
	 * @date 2015-6-25 上午10:22:51
	 */
	public static <T> boolean exportByMap(List<Map<String, Object>> list, String[] hdNames, String[] hds, String xlsName, HttpServletRequest request, HttpServletResponse response) throws Exception{
		
		Workbook wb = new XSSFWorkbook();			//创建工作薄
		Sheet sheet = wb.createSheet();				//创建工作表
		sheet.autoSizeColumn(( short ) 0 );			//自适应宽度
		//写入表头---Excel的第一行数据
		Row nRow = sheet.createRow(0);				//创建行
		for(int i=0;i<hdNames.length;i++){
			Cell nCell = nRow.createCell(i);			//创建单元格
			nCell.setCellValue(hdNames[i]);
		}  
		
		//写入每一行数据---一条记录就是一行数据
		for(int i=0;i<list.size();i++){
			for(int j=0;j<hds.length;j++){
				Object o = list.get(i).get(hds[j]);		//得到列的值
				data2Excel(sheet, o, i+1, j);			//将值写入Excel
			}
		}
		return downloadExcel(wb, xlsName, request, response);
	}

	/**
	 * Excels导出多个sheet
	 * @author LiangXianYou
	 * @date 2015-6-16 下午5:56:56
	 */
	//map:data,sheetName,hds,hdNames,xlsName;request,response
	public static <T> boolean exportExcels(List<Map<String, Object>> list,String xlsName, HttpServletRequest request, HttpServletResponse response) throws Exception{

		Workbook wb = new XSSFWorkbook();			//创建工作薄
		for(int i=0;i<list.size();i++){
			Map<String, Object> map = list.get(i);
			Sheet sheet = wb.createSheet();				//创建工作表
			String sheetName = (String) map.get("sheetName");
			wb.setSheetName(i, sheetName);
			//写入表头---Excel的第一行数据
			Row nRow = sheet.createRow(0);				//创建行
			String[] hdNames = (String[]) map.get("hdNames");
			for(int j=0;j<hdNames.length;j++){
				Cell nCell = nRow.createCell(j);			//创建单元格
				nCell.setCellValue(hdNames[j]);
			}
			
			//写入每一行数据---一条记录就是一行数据
			@SuppressWarnings("unchecked")
			List<T> data = (List<T>) map.get("data");
			String[] hds = (String[]) map.get("hds");
			for(int j=0;j<data.size();j++){
				for(int k=0;k<hds.length;k++){
					Object o = getFieldValue(data.get(j), hds[k]);	//得到列的值
					data2Excel(sheet, o, j+1, k);					//将值写入Excel
				}
			}
		}
		
		return downloadExcel(wb, xlsName, request, response);
	}
	
	/**
	 * 参数说明：
	 * list：list数据集合
	 * hdNames：表头需要显示的名称
	 * hds：表头对应的对象属性名称，和 hdNames一一对应
	 * xlsName：导出Excel的预定义名称
	 * request:	HttpServletRequest
	 * response：HttpServletResponse
	 * 通过数据构建Excel
	 * @author LiangXianYou
	 * @throws Exception 
	 * @date 2015-3-13 上午11:00:30
	 */
	public static <T> boolean exportExcel(List<T> list, String[] hdNames, String[] hds, String xlsName, HttpServletRequest request, HttpServletResponse response) throws Exception{

		Workbook wb = new XSSFWorkbook();			//创建工作薄
		Sheet sheet = wb.createSheet();				//创建工作表
		sheet.autoSizeColumn(( short ) 0 );			//自适应宽度
		//写入表头---Excel的第一行数据
		Row nRow = sheet.createRow(0);				//创建行
		for(int i=0;i<hdNames.length;i++){
			Cell nCell = nRow.createCell(i);			//创建单元格
			nCell.setCellValue(hdNames[i]);
		}
		
		//写入每一行数据---一条记录就是一行数据
		for(int i=0;i<list.size();i++){
			for(int j=0;j<hds.length;j++){
				Object o = getFieldValue(list.get(i), hds[j]);	//得到列的值
				data2Excel(sheet, o, i+1, j);						//将值写入Excel
			}
		}
		return downloadExcel(wb, xlsName, request, response);
	}
	
	/**
	 * 传递一个Wookbook，给定文件名，以及request和response下载Excel文档 
	 * @author LiangXianYou
	 * @throws IOException
	 * @date 2015-3-13 上午9:00:36
	 */
	@SuppressWarnings("all")
	private static boolean downloadExcel(Workbook wb, String xlsName, HttpServletRequest request, HttpServletResponse response) throws IOException{
			if(request.getHeader("user-agent").indexOf("MSIE") != -1) {   
				xlsName = java.net.URLEncoder.encode(xlsName,"utf-8") + ".xls"; 
			} else {
			    xlsName = new String(xlsName.getBytes("utf-8"),"iso-8859-1")+ ".xls";   
			}
			OutputStream os = response.getOutputStream();
			response.setContentType("application/vnd.ms-excel");
			response.setHeader("Content-disposition", "attachment;filename="+xlsName);    
			
			wb.write(os);
			return true;
	}
	
	/**
	 * 通过泛型实例对象得到某一字段值
	 * @author LiangXianYou
	 * @date 2015-3-13 上午10:53:32
	 */
	private static <T> Object  getFieldValue(T t, String fieldName) throws Exception{
		if(t == null){
			return null;
		}
		Field field = t.getClass().getDeclaredField(fieldName);
		field.setAccessible(true);//暴力反射
		Object o = field.get(t);//得到字段数据的值
		return o;
	}
	
	/**
	 * 将数据写到Excel中
	 * @author LiangXianYou
	 * @date 2015-3-13 上午10:37:55
	 */
	private static void data2Excel(Sheet sheet, Object o, Integer r, Integer c){
		//通过获得sheet中的某一列，有得到，没有创建
		Row nRow = sheet.getRow(r);
		if(nRow == null){
			nRow = sheet.createRow(r);
		}
//		nRow.setColumnWidth(r, arg1);
		
		Cell nCell = nRow.createCell(c);
		
		
		//根据不同类型进行转化，如有其它类型没有考虑周全的，使用发现的时候添加
		char type = 'x';
		if(o instanceof Integer){
			type = 1;
		}else if(o instanceof Double){
			type = 2;
		}else if(o instanceof Float){
			type = 3;
		}else if(o instanceof String){
			type = 4;
		}else if(o instanceof Date){
			type = 5;
		}else if(o instanceof Calendar){
			type = 6;
		}else if(o instanceof Boolean){
			type = 7;
		}else if(o == null) {
			type = 8;
		}
		
		switch (type) {
			case 1:nCell.setCellValue((Integer)o);break;
			case 2:nCell.setCellValue((Double)o);break;
			case 3:nCell.setCellValue((Float)o);break;
			case 4:nCell.setCellValue((String)o);break;
			case 5:nCell.setCellValue(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(o));break;
			case 6:nCell.setCellValue((Calendar)o);break;
			case 7:nCell.setCellValue((Boolean)o);break;
			case 8:nCell.setCellValue("");break;
			default:nCell.setCellValue(o + "");break;
		}
	}

	//======================= 读取excel ===============================

	/**
	 * read excel head
	 * @param file
	 * @param fields
	 * @param lastRowNum hope get row count
	 * @return
	 * @throws IOException
	 */
	public static List<Map> readExcelHead(File file, String[] fields, int lastRowNum) throws IOException {
		return readExcel(file, fields, lastRowNum, null);
	}

	//read excel sheet[0]
	public static List<Map> readExcel(File file, String[] fields) throws IOException {
		return readExcel(file, fields, -1, null);
	}

	//read excel sheet[0] no fields
	public static List<Map> readExcel(File file) throws IOException {
		return readExcel(file, null, -1, null);
	}

	//read excel by sheetName
	public static List<Map> readExcel(File file, String[] fields, String sheetName) throws IOException {
		return readExcel(file, fields, -1, sheetName);
	}

	//read excel by sheetName no fields
	public static List<Map> readExcel(File file, String sheetName) throws IOException {
		return readExcel(file, null, -1, sheetName);
	}

	//read excel all sheet
	public static Map<String, List<Map>> readExcelAll(File file, String[] fields) throws IOException {
		return readExcelAll(file, fields, -1);
	}

	//read all excel no fields
	public static Map<String, List<Map>> readExcelAll(File file) throws IOException {
		return readExcelAll(file, null, -1);
	}

	//read excel sheet[0]
	private static List<Map> readExcel(File file, String[] fields, int lastRowNum, String sheetName) throws IOException {
		Workbook wk;
		try {
			wk = new HSSFWorkbook(new FileInputStream(file));//if excel version 2007+ will throws OfficeXmlFileException
		}catch (OfficeXmlFileException e){
			wk = new XSSFWorkbook(new FileInputStream(file));
		}
		Sheet sheet = sheetName == null ? wk.getSheetAt(0) : wk.getSheet(sheetName);
		if (sheet == null) throw new OfficeXmlFileException("sheet["+sheetName+"] can't find");
		return readExcel(sheet, fields, lastRowNum);
	}

	/**
	 * read excel all sheet,
	 * can read excel 2007+ and 2007-
	 * @param file
	 * @param fields
	 * @param lastRowNum
	 * @return
	 * @throws IOException
	 */
	private static Map<String, List<Map>> readExcelAll(File file, String[] fields, int lastRowNum) throws IOException {
		Workbook wk;
		try {
			wk = new HSSFWorkbook(new FileInputStream(file));//if excel version 2007+ will throws OfficeXmlFileException
		}catch (OfficeXmlFileException e){
			wk = new XSSFWorkbook(new FileInputStream(file));
		}

		Map<String, List<Map>> data = new LinkedHashMap<>();
		//reading all sheet
		for (int i = 0; i < wk.getNumberOfSheets(); i++) {
			Sheet sheet = wk.getSheetAt(i);
			List<Map> maps = readExcel(sheet, fields, lastRowNum);

			//move head
			if (lastRowNum < 0 && maps.size() > 0){
				maps.remove(0);
			}
			data.put(sheet.getSheetName(), maps);
		}
		return data;
	}

	/**
	 * read excel
	 * @author Lxyer 2016/8/1 10:32.
	 */
	private static List<Map> readExcel(Sheet sheet, String[] fields, int lastRowNum) throws OfficeXmlFileException {
		if (fields == null || fields.length == 0){
			return readExcel(sheet, lastRowNum);
		}

		List<Map> list = new ArrayList<>();
		if (lastRowNum < 0 || lastRowNum > sheet.getLastRowNum()){
			lastRowNum = sheet.getLastRowNum();
		}

		int t = 0;
		r:for (int i=0; i<=lastRowNum; i++){
			Row row = sheet.getRow(i);
			if (row == null) continue ;
			short cellNum = row.getLastCellNum();
			//空跳过/连续三行为空结束
			if (isEmptyRow(row, fields.length)) {
				if (t++ > 3) break;
				continue ;
			}

			Map map = new HashMap();
			for (int j=0; j<cellNum && j<fields.length; j++){
				Cell cell = row.getCell(j);
				if (cell == null){
					map.put(fields[j], "");
					continue;
				}

				if (cell.getCellTypeEnum() == CellType.NUMERIC){
					map.put(fields[j], (long)cell.getNumericCellValue()+"");
				}else {
					map.put(fields[j], cell.getStringCellValue());
				}
			}
			list.add(map);
		}
		return list;
	}

	/**
	 *
	 * @author Lxyer 2016/9/21 00:38.
	 */
	private static List<Map> readExcel(Sheet sheet, int lastRowNum) throws OfficeXmlFileException {
		List<Map> list = new ArrayList<>();
		if (lastRowNum < 0 || lastRowNum > sheet.getLastRowNum()){
			lastRowNum = sheet.getLastRowNum();
		}

		int t = 0;
		r:for (int i=0; i<=lastRowNum; i++){
			Row row = sheet.getRow(i);
			if (row == null) continue ;
			short cellNum = row.getLastCellNum();
			//空跳过/连续三行为空结束
			if (isEmptyRow(row, 3)) {
				if (t++ > 3) break;
				continue ;
			}

			Map map = new HashMap();
			for (int j=0; j < cellNum; j++){
				String field = (char)((j/26 ==0? ' ' : 'a')+j/26) + "" +(char)('a'+j%26);
				field = field.replace(" ","");
				Cell cell = row.getCell(j);
				if (cell == null){
					map.put(field, "");
					continue;
				}

				if (cell.getCellTypeEnum() == CellType.NUMERIC){
					map.put(field, (long)cell.getNumericCellValue()+"");
				}else {
					map.put(field, cell.getStringCellValue());
				}
			}
			list.add(map);
		}
		return list;
	}

	//空跳过/连续三行为空结束
	private static boolean isEmptyRow(Row row, int len){
		for (int i = 0; i< row.getLastCellNum() && i < len; i++) {
			Cell cell = row.getCell(i);//列
			if (cell != null){
				if (cell.getCellTypeEnum() != CellType.NUMERIC && cell.getStringCellValue() != null && !cell.getStringCellValue().isEmpty()){
					return false;
				}else if (cell.getCellTypeEnum() == CellType.NUMERIC && cell.getNumericCellValue() != 0){
					return false;
				}
			}
		}
		return true;
	}
	
}