/**
 * 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/validateExcel.utill.js

const ExcelJS = require("exceljs");

exports.validateExcel = async (buffer, columns) => {
  const workbook = new ExcelJS.Workbook();
  await workbook.xlsx.load(buffer);
  const worksheet = workbook.worksheets[0];

  if (!worksheet) {
    throw { status: 400, message: "Excel sheet is empty" };
  }

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

  const headerRow = worksheet.getRow(1);

  for (let i = 1; i <= expectedHeaders.length; i++) {
    const cellValue = (headerRow.getCell(i).value || "").toString().trim();

    if (cellValue !== expectedHeaders[i - 1]) {
      throw {
        status: 400,
        message: `Invalid header in column ${i}`,
        expected: expectedHeaders[i - 1],
        received: cellValue,
      };
    }
  }

  const errors = [];
  const validData = [];

  worksheet.eachRow((row, rowNumber) => {
    if (rowNumber === 1) return;

    let rowData = {};
    let rowHasError = false;

    columns.forEach((col, index) => {
      let value = row.getCell(index + 1).value;

      if (value && typeof value === "object") {
        value = value.text || value.result || "";
      }

      value = value?.toString().trim() || "";

      if (col.is_required && !value) {
        errors.push({
          row: rowNumber,
          column: col.column_name,
          message: "Required field is missing",
        });
        rowHasError = true;
      }

      if (value) {
        if (col.validation_type === "number" && isNaN(value)) {
          errors.push({
            row: rowNumber,
            column: col.column_name,
            message: "Must be a number",
          });
          rowHasError = true;
        }

        if (
          col.validation_type === "boolean" &&
          !["true", "false"].includes(value.toLowerCase())
        ) {
          errors.push({
            row: rowNumber,
            column: col.column_name,
            message: "Must be true or false",
          });
          rowHasError = true;
        }
      }

      rowData[col.column_name] = value;
    });

    if (!rowHasError) {
      validData.push(rowData);
    }
  });

  return { errors, validData };
};