"use client";

import React, { FC } from "react";
import Image from "next/image";
import { useToast } from "@/hooks/use-toast";
import { toast as toastMessage } from "sonner";
import ExcelJS from "exceljs";
import { saveAs } from "file-saver";
import { Button } from "@/components/ui/button";
import { DataTableColumnJSON } from "./form-data-table-columns";

interface VarListDownloadBtnProps {
  columnsJSON: DataTableColumnJSON[];
  formCode: string;
}

export const VarListDownloadBtn: FC<VarListDownloadBtnProps> = ({
  columnsJSON,
  formCode,
}) => {
  const { toast } = useToast();

  const downloadReportVarList = async () => {
    try {
      // Create a new workbook
      const workbook = new ExcelJS.Workbook();

      // 데이터 시트 생성
      const worksheet = workbook.addWorksheet("Data");

      // 유효성 검사용 숨김 시트 생성
      const validationSheet = workbook.addWorksheet("ValidationData");
      validationSheet.state = "hidden"; // 시트 숨김 처리

      // 1. 데이터 시트에 헤더 추가
      const headers = ["Table Column Label", "Report Variable"];
      worksheet.addRow(headers);

      // 헤더 스타일 적용
      const headerRow = worksheet.getRow(1);
      headerRow.font = { bold: true };
      headerRow.alignment = { horizontal: "center" };
      headerRow.eachCell((cell) => {
        cell.fill = {
          type: "pattern",
          pattern: "solid",
          fgColor: { argb: "FFCCCCCC" },
        };
      });

      // 2. 데이터 행 추가
      columnsJSON.forEach((row) => {
        const { displayLabel, label } = row;

        const labelConvert = label.replaceAll(" ", "_");

        worksheet.addRow([displayLabel, labelConvert]);
      });

      // 3. 컬럼 너비 자동 조정
      headers.forEach((col, idx) => {
        const column = worksheet.getColumn(idx + 1);

        // 최적 너비 계산
        let maxLength = col.length;
        columnsJSON.forEach((row) => {
          const valueKey = idx === 0 ? "displayLabel" : "label";

          const value = row[valueKey];
          if (value !== undefined && value !== null) {
            const valueLength = String(value).length;
            if (valueLength > maxLength) {
              maxLength = valueLength;
            }
          }
        });

        // 너비 설정 (최소 10, 최대 50)
        column.width = Math.min(Math.max(maxLength + 2, 10), 50);
      });

      const buffer = await workbook.xlsx.writeBuffer();
      saveAs(new Blob([buffer]), `${formCode}_report_varible_list.xlsx`);
      toastMessage.success("Report Varible List File 다운로드 완료!");
    } catch (err) {
      console.log(err);
      toast({
        title: "Error",
        description: "Variable List 파일을 찾을 수가 없습니다.",
        variant: "destructive",
      });
    }
  };

  return (
    <Button
      variant="ghost"
      className="relative p-2"
      aria-label="Variable List Download"
      onClick={downloadReportVarList}
    >
      <Image
        src="/icons/var_list_icon.svg"
        alt="Template Sample Download Icon"
        width={20}
        height={20}
      />
    </Button>
  );
};