bun add @google/genai

import { GoogleGenerativeAI } from '@google/genai';
import fs from 'fs';

const ai = new GoogleGenerativeAI(process.env.GOOGLE_AI_API_KEY);

// Create store
const fileStore = await ai.fileSearchStores.create({
  config: { displayName: 'my-knowledge-base' }
});

// Upload document
const operation = await ai.fileSearchStores.uploadToFileSearchStore({
  name: fileStore.name,
  file: fs.createReadStream('./manual.pdf'),
  config: {
    displayName: 'Installation Manual',
    chunkingConfig: {
      whiteSpaceConfig: {
        maxTokensPerChunk: 500,
        maxOverlapTokens: 50
      }
    }
  }
});

// Poll until done
while (!operation.done) {
  await new Promise(resolve => setTimeout(resolve, 1000));
  operation = await ai.operations.get({ name: operation.name });
}

// Query documents
const model = ai.getGenerativeModel({
  model: 'gemini-2.5-pro',  // Only 2.5 Pro/Flash supported
  tools: [{
    fileSearchTool: {
      fileSearchStores: [fileStore.name]
    }
  }]
});

const result = await model.generateContent('How do I install the product?');
console.log(result.response.text());

// Get citations
const grounding = result.response.candidates[0].groundingMetadata;
if (grounding) {
  console.log('Sources:', grounding.groundingChunks);
}

// Find and delete old version
const docs = await ai.fileSearchStores.documents.list({
  parent: fileStore.name
});
const oldDoc = docs.documents.find(d => d.displayName === 'manual.pdf');
if (oldDoc) {
  await ai.fileSearchStores.documents.delete({
    name: oldDoc.name,
    force: true
  });
}

// Upload new version
await ai.fileSearchStores.uploadToFileSearchStore({
  name: fileStore.name,
  file: fs.createReadStream('manual-v2.pdf'),
  config: { displayName: 'manual.pdf' }
});

const fileSize = fs.statSync('data.pdf').size;
const estimatedStorage = fileSize * 3;  // Embeddings + metadata

if (estimatedStorage > 1e9) {
  console.warn('⚠️ May exceed free tier 1 GB limit');
}

// ✅ CORRECT
const model = ai.getGenerativeModel({
  model: 'gemini-2.5-pro',  // or gemini-2.5-flash
  tools: [{ fileSearchTool: { fileSearchStores: [storeName] } }]
});

// ❌ WRONG
const model = ai.getGenerativeModel({
  model: 'gemini-1.5-pro',  // Not supported!
  tools: [{ fileSearchTool: { fileSearchStores: [storeName] } }]
});

// Upload support docs with metadata
await ai.fileSearchStores.uploadToFileSearchStore({
  name: fileStore.name,
  file: fs.createReadStream('troubleshooting.pdf'),
  config: {
    displayName: 'Troubleshooting Guide',
    customMetadata: {
      doc_type: 'support',
      category: 'troubleshooting',
      language: 'en'
    }
  }
});

const files = ['doc1.pdf', 'doc2.md', 'doc3.docx'];
const uploadPromises = files.map(file =>
  ai.fileSearchStores.uploadToFileSearchStore({
    name: fileStore.name,
    file: fs.createReadStream(file),
    config: { displayName: file }
  })
);
const operations = await Promise.all(uploadPromises);

// Poll all operations
for (const op of operations) {
  let operation = op;
  while (!operation.done) {
    await new Promise(resolve => setTimeout(resolve, 1000));
    operation = await ai.operations.get({ name: operation.name });
  }
  console.log('✅', operation.response.displayName);
}

// 1. List existing documents
const docs = await ai.fileSearchStores.documents.list({
  parent: fileStore.name
});

// 2. Delete old version
const oldDoc = docs.documents.find(d => d.displayName === 'manual.pdf');
if (oldDoc) {
  await ai.fileSearchStores.documents.delete({
    name: oldDoc.name,
    force: true
  });
}

// 3. Upload new version
const operation = await ai.fileSearchStores.uploadToFileSearchStore({
  name: fileStore.name,
  file: fs.createReadStream('manual-v2.pdf'),
  config: {
    displayName: 'manual.pdf',
    customMetadata: {
      version: '2.0',
      updated_at: new Date().toISOString()
    }
  }
});

// 4. Poll until done
while (!operation.done) {
  await new Promise(resolve => setTimeout(resolve, 1000));
  operation = await ai.operations.get({ name: operation.name });
}

chunkingConfig: {
  whiteSpaceConfig: {
    maxTokensPerChunk: 500,  // Smaller = more precise
    maxOverlapTokens: 50     // 10% overlap recommended
  }
}