handler.php

<?php
session_start(); #like session_state, cookies to remember this session

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    
    // Store user selection
    if (isset($_POST['userSelection'])) { #if the browser sent something w/ this key
        $_SESSION['searchType'] = $_POST['userSelection']; #save it here
    }

    // Handle form submission
    if (isset($_POST['request1'])) { #if at least request1 is filled in
        $requests = [];
        $likes = [];

        # Save requests and likes in PHP list
        for ($i = 1; $i <= 5; $i++) { #loop through all 5 boxes
            if (!empty($_POST["request$i"])) {
                $requests[] = escapeshellarg($_POST["request$i"]); #clean and append
            }
            if (!empty($_POST["likes$i"])) {
                $likes[] = escapeshellarg($_POST["likes$i"]);
            }
        }

        # Prepare everything for command-line
        $searchType = $_SESSION['searchType'] ?? 'keyword'; #use this value, but if it's not set, fall back to 'keyword'
        $requestsArg = implode(',', $requests); #joins the array back into a single comma-separated string ("'key1', 'key2'")
        $likesArg = implode(',', $likes);

        # Run command on the server (e.g., python3.10 backend.py 'keyword' 'bts,jensen' '1000,500')
        $output = shell_exec("arch -arm64 /Library/Frameworks/Python.framework/Versions/3.10/bin/python3.10 backend.py " .
                escapeshellarg($searchType) . " " .
                escapeshellarg($requestsArg) . " " .
                escapeshellarg($likesArg) . " 2>&1");

        # Prev. ^ goes through scraper -> summarizer, returns result JSON
        $result = json_decode($output, true);
        $summaries = $result['bullets'] ?? [];
        
        # Send to broswer
        header('Content-Type: application/json'); # HTTP response header
        echo json_encode(['summaries' => $summaries]); #PHP array -> JSON string
        exit; #stop script after sending response
    }
}
?>