/**
* PDF Reader - Wrapper for pdf-extraction MCP server
*/
import { Client } from '@modelcontextprotocol/sdk/client/index.js';
import { StdioClientTransport } from '@modelcontextprotocol/sdk/client/stdio.js';
export class PDFReader {
private client: Client | null = null;
private transport: StdioClientTransport | null = null;
private connectionPromise: Promise<void> | null = null;
constructor() {}
private async ensureConnected(): Promise<void> {
if (this.client) return;
// Prevent multiple simultaneous connection attempts
if (this.connectionPromise) {
await this.connectionPromise;
return;
}
this.connectionPromise = (async () => {
try {
// Use the exact Python command configured in Claude Code
this.transport = new StdioClientTransport({
command: '/home/sallvain/.pyenv/versions/3.12.8/bin/python',
args: ['-m', 'pdf_extraction']
});
this.client = new Client({
name: 'ngss-mcp-pdf-client',
version: '1.0.0'
}, {
capabilities: {}
});
await this.client.connect(this.transport);
} catch (error) {
this.client = null;
this.transport = null;
throw new Error(`Failed to connect to pdf-extraction MCP: ${error}`);
} finally {
this.connectionPromise = null;
}
})();
await this.connectionPromise;
}
async extractPages(pdfPath: string, pages: string): Promise<string> {
await this.ensureConnected();
try {
const result = await this.client!.callTool({
name: 'extract-pdf-contents',
arguments: {
pdf_path: pdfPath,
pages: pages
}
});
// Extract text from MCP tool result
if (Array.isArray(result.content) && result.content.length > 0) {
const firstContent = result.content[0];
if (firstContent && typeof firstContent === 'object' && 'type' in firstContent && firstContent.type === 'text' && 'text' in firstContent) {
return (firstContent as { type: string; text: string }).text;
}
}
throw new Error('Unexpected result format from pdf-extraction');
} catch (error) {
throw new Error(`PDF extraction failed for pages ${pages}: ${error}`);
}
}
async extractAll(pdfPath: string): Promise<string> {
await this.ensureConnected();
try {
const result = await this.client!.callTool({
name: 'extract-pdf-contents',
arguments: {
pdf_path: pdfPath
// No pages parameter = extract all
}
});
if (Array.isArray(result.content) && result.content.length > 0) {
const firstContent = result.content[0];
if (firstContent && typeof firstContent === 'object' && 'type' in firstContent && firstContent.type === 'text' && 'text' in firstContent) {
return (firstContent as { type: string; text: string }).text;
}
}
throw new Error('Unexpected result format from pdf-extraction');
} catch (error) {
throw new Error(`PDF extraction failed: ${error}`);
}
}
async extractPageRange(
pdfPath: string,
startPage: number,
endPage: number
): Promise<string> {
const pages = Array.from(
{ length: endPage - startPage + 1 },
(_, i) => startPage + i
).join(',');
return this.extractPages(pdfPath, pages);
}
async close(): Promise<void> {
if (this.client) {
try {
await this.client.close();
} catch (error) {
console.error('Error closing MCP client:', error);
} finally {
this.client = null;
this.transport = null;
}
}
}
}
export interface PageContent {
pageNumber: number;
content: string;
}
export function parsePageContent(
extractedText: string,
requestedPages: string
): PageContent[] {
const pageRegex = /Page (\d+):\s*([\s\S]*?)(?=Page \d+:|$)/g;
const pages: PageContent[] = [];
let match;
while ((match = pageRegex.exec(extractedText)) !== null) {
if (match[1] && match[2]) {
pages.push({
pageNumber: parseInt(match[1]),
content: match[2].trim()
});
}
}
return pages;
}
