package cn.huanzi.qch.util;
import cn.hutool.json.JSONArray;
import cn.hutool.json.JSONObject;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.util.*;
/**
 * HExcel，一个简单通用的导入导出Excel工具类
 * 1、支持复杂表头导出（支持表头单元格水平合并、垂直合并，支持表头单元格个性化样式）
 * 2、支持导入读取sheet数据（只需要提供title与key的关系，不需要管列的顺序）
 *
 * PS：依赖 poi 以及 hutool
 *
 * 详情请戳：https://www.cnblogs.com/huanzi-qch/p/17797355.html
 */
public class HExcel {
    /**
     * 获取一个HExcel实例，并初始化空Workbook对象
     */
    public static HExcel newInstance(){
        HExcel hExcelUtil = new HExcel();
        hExcelUtil.hSSFWorkbook = new HSSFWorkbook();
        return hExcelUtil;
    }
    /**
     * 获取一个HExcel实例，并根据excelFile初始化Workbook对象
     */
    public static HExcel newInstance(File excelFile){
        HExcel hExcelUtil = new HExcel();
        try {
            hExcelUtil.hSSFWorkbook = new HSSFWorkbook(new FileInputStream(excelFile));
        } catch (IOException e) {
            throw new RuntimeException("【HExcel】 根据excelFile初始化Workbook对象异常",e);
        }
        return hExcelUtil;
    }
    /**
     * 导入并读取Excel
     *
     * @param sheetIndex 需要读取的sheet下标
     * @param firstDataRow 数据起始行
     * @param headerTitleKey title与key的关系json对象
     * @return 返回数据集合
     */
    public List<Map<String, Object>> readSheet(int sheetIndex,int firstDataRow,JSONObject headerTitleKey){
        //最终返回的数据集合
        ArrayList<Map<String, Object>> list = new ArrayList<>();
        //获取sheet
        HSSFSheet sheet = this.hSSFWorkbook.getSheetAt(sheetIndex);
        //获取title与col的对应关系
        HashMap<Integer, String> headerMap = new HashMap<>();
        int lastCellNum = sheet.getRow(0).getLastCellNum();
        for (int i = 0; i < lastCellNum; i++) {
            for (int j = firstDataRow-1; j >=0 ; j--) {
                HSSFCell cell = sheet.getRow(j).getCell(i);
                if(cell != null && !"".equals(cell.getStringCellValue())){
                    String title = cell.getStringCellValue();
                    headerMap.put(i,title);
                    break;
                }
            }
        }
        //获取数据
        for (int i = firstDataRow; i <= sheet.getLastRowNum(); i++) {
            HSSFRow row = sheet.getRow(i);
            LinkedHashMap<String, Object> dateMap = new LinkedHashMap<>();
            for (int j = 0; j < lastCellNum; j++) {
                String title = headerMap.get(j);
                String key = headerTitleKey.getStr(title);
                if(key != null && !"".equals(key)){
                    String value = row.getCell(j).getStringCellValue();
                    dateMap.put(key,value);
                }
            }
            list.add(dateMap);
        }
        return list;
    }
    /**
     * 构造一个sheet，以及生成复杂表头、表数据
     *
     * @param sheetName sheet名称
     * @param headers 复杂表头json数组对象
     * @param dataLists 表数据集合
     * @return HExcel
     */
    public HExcel buildSheet(String sheetName, JSONArray headers, List<Map<String, Object>> dataLists) {
        //建立新的sheet对象
        HSSFSheet sheet = this.hSSFWorkbook.createSheet(sheetName);//设置表单名
        //生成复杂表头
        int row = 0;//当前行
        int col = 0;//当前列
        HashMap<String, Object> hashMap = createHeader(sheet,row,col,headers);
        ArrayList<String> headerList = (ArrayList<String>) hashMap.get("keyList");
        row = (int) hashMap.get("maxRow");
        //取出水平合并区域数据
        List<CellRangeAddress> cellRangeAddressList = sheet.getMergedRegions();
        //垂直合并，单元格为空，且不属于水平合并区域
        //这里row-1是因为，生成所有表头结束后，maxRow比最大行+1，
        for (int i = 0; i < headerList.size(); i++) {
            for (int j = 0; j <= row-1; j++) {
                boolean flag = true;
                //单元格不为空
                HSSFCell cell = sheet.getRow(j).getCell(i);
                if(cell != null){
                    continue;
                }
                //检查合并区域
                for (CellRangeAddress cellAddresses : cellRangeAddressList) {
                    int OldFirstRow = cellAddresses.getFirstRow();
                    int OldLastRow = cellAddresses.getLastRow();
                    int OldFirstCol = cellAddresses.getFirstColumn();
                    int OldLastCol = cellAddresses.getLastColumn();
                    //与合并区域重叠
                    if ((OldFirstRow >= j && OldLastRow <= j) && (OldFirstCol >= i && OldLastCol <= i)) {
                        flag = false;
                        break;
                    }
                }
                //满足条件，将上一个单元格与最后一个单元格合并
                if(flag){
                    mergedCell(sheet,j-1,row-1,i,i);
                    break;
                }
            }
        }
        //开始填充数据
        HSSFCellStyle dataStyle = createDataStyle(sheet);
        for (Map<String, Object> map : dataLists) {
            //创建内容行
            HSSFRow dataHSSFRow = sheet.createRow(row);
            for (int i = 0; i < headerList.size(); i++) {
                String key = headerList.get(i);
                Object val = map.get(key);
                createCell(dataHSSFRow, i, dataStyle, val == null ? "" : String.valueOf(val));
            }
            row++;
        }
        return this;
    }
    /**
     * 保存成File文件
     *
     * @param path 完整文件路径+文件名
     */
    public void toFile(String path) {
        //try-catch语法糖
        try (FileOutputStream out = new FileOutputStream(path);){
            this.hSSFWorkbook.write(out);
        }catch (IOException e){
            throw new RuntimeException("【HExcel】 Workbook对象文件流写入File异常",e);
        }
    }
    /**
     * 保存到HttpServletResponse
     *
     * @param fileName 文件名
     * @param response HttpServletResponse对象
     */
    public void toHttpServletResponse(String fileName, HttpServletResponse response) {
        //try-catch语法糖
        try (ServletOutputStream outputStream = response.getOutputStream();){
            response.setHeader("Accept-Ranges", "bytes");
            response.setHeader("Content-disposition", "attachment; filename=\"" + URLEncoder.encode(fileName, "UTF-8") + "\"");
            response.setContentType("application/octet-stream");
            this.hSSFWorkbook.write(outputStream);
        }catch (Exception e){
            throw new RuntimeException("【HExcel】 Workbook对象文件流写入Response异常",e);
        }
    }
    /**
     * 关闭Workbook
     */
    public void close(){
        try{
            //关闭Workbook
            this.hSSFWorkbook.close();
        } catch (Exception e) {
            throw new RuntimeException("【HExcel】 关闭Workbook异常",e);
        }
    }
    /*          已下设置私有，对外隐藏实现细节           */
 
    /**
     * Workbook对象
     */
    private HSSFWorkbook hSSFWorkbook;
    /**
     * 构造表头
     *
     * @param sheet sheet
     * @param row 当前操作行
     * @param col 当前操作列
     * @param headers 表头数据
     * @return 返回一个map对象，供上级表头获取最新当前操作行、列、key集合
     */
    private HashMap<String,Object> createHeader(HSSFSheet sheet, int row, int col, JSONArray headers){
        //最终返回对象
        HashMap<String, Object> hashMap = new HashMap<>();
        //key集合
        ArrayList<String> keyList = new ArrayList<>();
        HSSFWorkbook wb = sheet.getWorkbook();
        HSSFRow headerHSSFRow = sheet.getRow(row);
        if(headerHSSFRow == null){
            headerHSSFRow = sheet.createRow(row);
        }
        for (Object object : headers) {
            JSONObject header = (JSONObject) object;
            String title = (String) header.get("title");
            String key = (String) header.get("key");
            Object width = header.get("width");
            Object align = header.get("align");
            Object backgroundColor = header.get("background-color");
            Object color = header.get("color");
            Object children = header.get("children");
            //单元格样式
            HSSFCellStyle headerStyle = createHeaderStyle(sheet);
            //自定义单元格背景色
            if(backgroundColor != null){
                headerStyle.setFillForegroundColor(Short.parseShort(backgroundColor+""));
            }
            //自定义单元格字体颜色
            if(color != null){
                headerStyle.getFont(wb).setColor(Short.parseShort(color+""));
            }
            //默认单元格宽度，20
            sheet.setColumnWidth(col, 20 * 256);
            if(width != null){
                //自定义单元格宽度
                sheet.setColumnWidth(col, (int) width * 256);
            }
            //默认水平对齐方式（水平居中）
            if(align != null){
                //自定义水平对齐方式
                HorizontalAlignment alignment;
                switch (String.valueOf(align).toUpperCase()){
                    case "LEFT":
                        alignment = HorizontalAlignment.LEFT;
                        break;
                    case "RIGHT":
                        alignment = HorizontalAlignment.RIGHT;
                        break;
                    default:
                        alignment = HorizontalAlignment.CENTER;
                        break;
                }
                headerStyle.setAlignment(alignment);
            }
            //System.out.println(title + " " + key + " " + row + " " + col);
            //生成单元格同时设置内容
            createCell(headerHSSFRow, col, headerStyle, title);
            //无子级表头
            if(children == null){
                //保留顺序，方便后面设置数据
                keyList.add(key);
                //当前列+1
                col++;
            }
            //有子级表头
            else{
                //递归生成子级表头前，保存父级表头col，用于水平合并
                int firstCol = col;
                //递归调用
                HashMap<String, Object> hashMap1 = createHeader(sheet, row + 1, col, (JSONArray) children);
                //获取最新col、key集合
                col = (int) hashMap1.get("col");
                hashMap.put("maxRow",hashMap1.get("maxRow"));
                keyList.addAll((ArrayList<String>) hashMap1.get("keyList"));
                //水平合并，这里col-1是因为，生成子级表头结束后，col比最后一个下级表头+1，
                if(!(firstCol == col-1)){
                    mergedCell(sheet,row,row,firstCol,col-1);
                }
            }
        }
        //将数据设置到对象中，返回上一层
        hashMap.put("maxRow",(hashMap.get("maxRow") != null ? Integer.parseInt(hashMap.get("maxRow")+"") : 0) + 1);//最大行
        hashMap.put("row",row);//当前操作行
        hashMap.put("col",col);//当前操作列
        hashMap.put("keyList",keyList);//key集合
 
        return hashMap;
    }
    /**
     * 创建一个单元格
     *
     * @param hSSFRow 当前行对象
     * @param col 当前列
     * @param cellStyle 单元格样式对象
     * @param text 单元格内容，目前只支持字符串，如需支持更多格式可自行扩展
     */
    private void createCell(HSSFRow hSSFRow, int col, HSSFCellStyle cellStyle, String text) {
        HSSFCell cell = hSSFRow.createCell(col);  // 创建单元格
        cell.setCellStyle(cellStyle); // 设置单元格样式
        cell.setCellValue(text);  // 设置值
    }
    /**
     * 构造表头、数据样式
     *
     * @param sheet sheet
     * @return 返回一个单元格样式对象
     */
    private HSSFCellStyle createHeaderStyle(HSSFSheet sheet){
        HSSFWorkbook wb = sheet.getWorkbook();
        //表头的样式
        HSSFCellStyle headerStyle = wb.createCellStyle();
        headerStyle.setAlignment(HorizontalAlignment.CENTER);//水平居中
        headerStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
        //列名的字体
        HSSFFont dataFont = wb.createFont();
        dataFont.setFontHeightInPoints((short) 12);
        dataFont.setFontName("新宋体");
        headerStyle.setFont(dataFont);// 把字体 应用到当前样式
        headerStyle.setWrapText(true);//自动换行
        //填充样式，前景色、天空蓝
        headerStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        headerStyle.setFillForegroundColor(IndexedColors.PALE_BLUE.getIndex());
        // 设置边框
        headerStyle.setBorderBottom(BorderStyle.THIN);
        headerStyle.setBorderLeft(BorderStyle.THIN);
        headerStyle.setBorderRight(BorderStyle.THIN);
        headerStyle.setBorderTop(BorderStyle.THIN);
        return headerStyle;
    }
    private HSSFCellStyle createDataStyle(HSSFSheet sheet){
        HSSFWorkbook wb = sheet.getWorkbook();
        //内容的样式
        HSSFCellStyle dataStyle = wb.createCellStyle();
        dataStyle.setAlignment(HorizontalAlignment.CENTER);//水平居中
        dataStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
        //内容的字体
        HSSFFont font3 = wb.createFont();
        font3.setFontHeightInPoints((short) 12);
        font3.setFontName("新宋体");
        dataStyle.setFont(font3);// 把字体 应用到当前样式
        dataStyle.setWrapText(true);//自动换行
        //默认无填充
        dataStyle.setFillPattern(FillPatternType.NO_FILL);
        // 设置边框
        dataStyle.setBorderBottom(BorderStyle.THIN);
        dataStyle.setBorderLeft(BorderStyle.THIN);
        dataStyle.setBorderRight(BorderStyle.THIN);
        dataStyle.setBorderTop(BorderStyle.THIN);
        return dataStyle;
    }
    /**
     * 合并单元格
     *
     * @param sheet sheet
     * @param firstRow 起始行
     * @param lastRow 结束行
     * @param firstCol 起始列
     * @param lastCol 结束列
     */
    private void mergedCell(HSSFSheet sheet,int firstRow, int lastRow, int firstCol, int lastCol){
        //一个单元格无需合并，例如：[0,0,0,0]
        if(firstRow == lastRow && firstCol == lastCol){
            return;
        }
        //先取出合并前的单元格样式
        HSSFCellStyle cellStyle = sheet.getRow(firstRow).getCell(firstCol).getCellStyle();
        //合并
        sheet.addMergedRegion(new CellRangeAddress(firstRow, lastRow, firstCol, lastCol));
        //解决合并后的边框等样式问题
        int first;
        int end;
        //垂直合并
        if(firstCol == lastCol){
            first = firstRow;
            end = lastRow+1;
            for (int i = first; i < end; i++) {
                HSSFRow row = sheet.getRow(i);
                if(row == null){
                    row = sheet.createRow(i);
                }
                HSSFCell cell = row.getCell(firstCol);
                if(cell == null){
                    cell = row.createCell(firstCol);
                }
                cell.setCellStyle(cellStyle);
            }
        }
        //水平合并
        else{
            first = firstCol;
            end = lastCol+1;
            for (int i = first; i < end; i++) {
                HSSFRow row = sheet.getRow(firstRow);
                if(row == null){
                    row = sheet.createRow(firstRow);
                }
                HSSFCell cell = row.getCell(i);
                if(cell == null){
                    cell = row.createCell(i);
                }
                cell.setCellStyle(cellStyle);
            }
        }
    }
}