import { SupportedFileType } from "@superglue/shared";
import * as XLSX from "xlsx";
import * as unzipper from "unzipper";
import { DetectionPriority, FileParsingStrategy } from "../strategy.js";
export class ExcelStrategy implements FileParsingStrategy {
readonly fileType = SupportedFileType.EXCEL;
readonly priority = DetectionPriority.ZIP_BASED_SPECIFIC;
async canHandle(buffer: Buffer): Promise<boolean> {
// Must be a ZIP file first (PK signature)
if (buffer.length < 4) return false;
const signature = buffer.subarray(0, 4).toString("hex");
if (signature !== "504b0304") return false;
// Check for Excel-specific files inside the ZIP (xl/ folder is Excel-only)
try {
const zipStream = await unzipper.Open.buffer(buffer);
const hasExcelSignature = zipStream.files.some(
(f) => f.path === "xl/workbook.xml" || f.path.startsWith("xl/worksheets/"),
);
return hasExcelSignature;
} catch (error) {
return false;
}
}
async parse(buffer: Buffer): Promise<any> {
return parseExcel(buffer);
}
}
export async function parseExcel(buffer: Buffer): Promise<{ [sheetName: string]: any[] }> {
try {
const parsePromise = new Promise<XLSX.WorkBook>((resolve, reject) => {
try {
const workbook = XLSX.read(buffer, {
type: "buffer",
cellDates: true,
dense: false,
cellStyles: false,
});
resolve(workbook);
} catch (error) {
reject(error);
}
});
const timeoutPromise = new Promise<never>((_, reject) => {
setTimeout(() => reject(new Error("Excel parsing timeout after 60 seconds")), 60000);
});
const workbook = await Promise.race([parsePromise, timeoutPromise]);
const result: { [sheetName: string]: any[] } = {};
for (const sheetName of workbook.SheetNames) {
const worksheet = workbook.Sheets[sheetName];
const rawRows = XLSX.utils.sheet_to_json<any>(worksheet, {
raw: false,
header: 1,
defval: null,
blankrows: true,
});
if (!rawRows?.length) {
result[sheetName] = [];
continue;
}
let headerRowIndex = 0;
for (let i = 0; i < Math.min(rawRows.length, 10); i++) {
const row = rawRows[i] || [];
const nonNullCount = row.filter(
(v: any) => v !== null && v !== undefined && v !== "",
).length;
if (nonNullCount >= 2) {
headerRowIndex = i;
break;
}
}
const headers = rawRows[headerRowIndex].map((header: any, index: number) =>
header ? String(header).trim() : `Column ${index + 1}`,
);
const processedRows = rawRows.slice(headerRowIndex + 1).map((row: any) => {
const obj: { [key: string]: any } = {};
headers.forEach((header: string, index: number) => {
if (header && row[index] !== undefined) {
obj[header] = row[index];
}
});
return obj;
});
result[sheetName] = processedRows;
}
return result;
} catch (error) {
console.error("Failed parsing Excel file:", error);
throw error;
}
}
