/**
 * Copyright (c) 2026 Niolla
 * All rights reserved.
 *
 * This source code is proprietary and confidential.
 * Unauthorized copying, modification, distribution, or use
 * of this file, via any medium, is strictly prohibited.
 */

// app/utills/generateExcelTemplate.utill.js

const ExcelJS = require("exceljs");

exports.generateExcelTemplate = async (columns, vendors) => {
  const workbook = new ExcelJS.Workbook();

  // =========================
  // Template Sheet
  // =========================

  const worksheet = workbook.addWorksheet("Template");

  const headers = columns.map((col) =>
    col.is_required ? `${col.column_name} *` : col.column_name,
  );

  const headerRow = worksheet.addRow(headers);

  headerRow.eachCell((cell) => {
    cell.font = { bold: true };
    cell.alignment = { vertical: "middle", horizontal: "center" };
  });

  headers.forEach((header, i) => {
    worksheet.getColumn(i + 1).width = Math.max(header.length + 5, 20);
  });

  columns.forEach((col, index) => {
    const headerCell = worksheet.getCell(1, index + 1);

    if (col.is_required) {
      headerCell.fill = {
        type: "pattern",
        pattern: "solid",
        fgColor: { argb: "FFF4CCCC" },
      };

      headerCell.font = {
        bold: true,
        color: { argb: "FF000000" },
      };
    } else {
      headerCell.fill = {
        type: "pattern",
        pattern: "solid",
        fgColor: { argb: "FFFFF2CC" },
      };

      headerCell.font = {
        bold: true,
        color: { argb: "FF000000" },
      };
    }

    if (col.validation_type === "number") {
      for (let i = 2; i <= 100; i++) {
        worksheet.getCell(i, index + 1).dataValidation = {
          type: "whole",
          operator: "greaterThanOrEqual",
          formulae: [0],
          showErrorMessage: true,
          error: "Please enter a valid number",
        };
      }
    }
  });

  worksheet.views = [{ state: "frozen", ySplit: 1 }];

  // =========================
  // Vendors Sheet
  // =========================
  const vendorSheet = workbook.addWorksheet("Vendors");

  const vendorHeader = vendorSheet.addRow(["Supplier ID", "Supplier Name"]);

  vendorHeader.eachCell((cell) => {
    cell.font = {
      bold: true,
      color: { argb: "FFFFFFFF" },
    };

    cell.alignment = {
      vertical: "middle",
      horizontal: "center",
    };

    cell.fill = {
      type: "pattern",
      pattern: "solid",
      fgColor: { argb: "4472C4" },
    };
  });

  // Add vendor rows
  vendors.forEach((vendor) => {
    vendorSheet.addRow([vendor.vendor_id, vendor.name]);
  });

  // Optional styling
  vendorSheet.columns = [{ width: 25 }, { width: 35 }];

  vendorSheet.views = [{ state: "frozen", ySplit: 1 }];

  return workbook;
};