#!/usr/bin/env node
/**
 * Email Extractor for Node.js
 * Extract and validate email addresses using JavaScript
 */

const fs = require('fs').promises;
const readline = require('readline');

const EMAIL_REGEX = /\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,}\b/g;

async function extractEmailsFromFile(filePath) {
    const emails = new Set();

    const fileStream = require('fs').createReadStream(filePath);
    const rl = readline.createInterface({
        input: fileStream,
        crlfDelay: Infinity
    });

    for await (const line of rl) {
        const found = line.match(EMAIL_REGEX);
        if (found) {
            found.forEach(email => emails.add(email.toLowerCase()));
        }
    }

    return Array.from(emails).sort();
}

async function extractFromJSON(filePath) {
    const content = await fs.readFile(filePath, 'utf8');
    const data = JSON.parse(content);
    const emails = new Set();

    function findEmails(obj) {
        if (typeof obj === 'string') {
            const found = obj.match(EMAIL_REGEX);
            if (found) found.forEach(e => emails.add(e.toLowerCase()));
        } else if (Array.isArray(obj)) {
            obj.forEach(findEmails);
        } else if (obj && typeof obj === 'object') {
            Object.values(obj).forEach(findEmails);
        }
    }

    findEmails(data);
    return Array.from(emails).sort();
}

if (require.main === module) {
    const args = process.argv.slice(2);
    extractEmailsFromFile(args[0]).then(emails => {
        console.log(`Found ${emails.length} unique emails`);
    });
}