ATS PDF Resume Parser & Text Extractor

graph TD
    Upload[Candidate Uploads CV PDF] --> Extractor[Server Action: pdf-parse Extraction]
    Extractor --> TextCheck{Was text extracted?}
    
    TextCheck -- Yes --> ParseJSON[Google Gemini: Map to JSON resume schema]
    TextCheck -- No/Scanned Image --> OCR[OCR Pipeline: Extract text via Vision API]
    
    OCR --> ParseJSON
    ParseJSON --> Validate[Zod validation]
    Validate --> DB[Save to Firestore: resumes collection]

import { NextRequest, NextResponse } from "next/server";
import pdf from "pdf-parse";
import { generateObject } from "ai";
import { google } from "@ai-sdk/google";
import { z } from "zod";

// Define the schema for structured resume data
const resumeSchema = z.object({
  basics: z.object({
    name: z.string(),
    email: z.string().email(),
    phone: z.string(),
    summary: z.string(),
  }),
  work: z.array(z.object({
    company: z.string(),
    role: z.string(),
    startDate: z.string(),
    endDate: z.string().optional(),
    highlights: z.array(z.string()),
  })),
  skills: z.array(z.string()),
});

export async function POST(request: NextRequest) {
  try {
    const formData = await request.formData();
    const file = formData.get("file") as File;
    
    if (!file) {
      return NextResponse.json({ error: "Missing file parameter" }, { status: 400 });
    }

    // 1. Extract raw bytes from the file
    const arrayBuffer = await file.arrayBuffer();
    const buffer = Buffer.from(arrayBuffer);

    // 2. Parse text blocks from the PDF document
    const pdfData = await pdf(buffer);
    const rawText = pdfData.text;

    if (!rawText || rawText.trim().length === 0) {
      return NextResponse.json({ error: "No readable text found in PDF" }, { status: 422 });
    }

    // 3. Call Gemini to format the text into the Zod schema
    const { object } = await generateObject({
      model: google("gemini-2.5-flash"),
      schema: resumeSchema,
      prompt: `Parse this raw resume text into the required structured format.\n\nText:\n${rawText}`,
    });

    return NextResponse.json({ success: true, data: object });

  } catch (error) {
    console.error("Resume parsing handler encountered an error:", error);
    return NextResponse.json({ error: "Parsing pipeline failed" }, { status: 500 });
  }
}