<?php
// Configuration
$password = "SuperSecretPassword";  // Change this!
$appendFile = "authorized_keys.txt";

// Get posted data
$inputText = $_POST['text'] ?? null;
$inputPassword = $_POST['password'] ?? null;
$deleteLine = isset($_POST['delete_line']) ? intval($_POST['delete_line']) : null;

if (!$inputPassword) {
    http_response_code(400);
    echo "Missing 'password' parameter.";
    exit;
}

// Validate password
if ($inputPassword !== $password) {
    http_response_code(401);
    echo "Invalid password.";
    exit;
}

// Handle deletion
if ($deleteLine !== null) {
    if (!file_exists($appendFile)) {
        http_response_code(404);
        echo "File not found.";
        exit;
    }

    $lines = file($appendFile, FILE_IGNORE_NEW_LINES);
    if ($deleteLine < 0 || $deleteLine >= count($lines)) {
        http_response_code(400);
        echo "Invalid line number.";
        exit;
    }

    // Remove specified line
    array_splice($lines, $deleteLine, 1);

    // Save back to file
    $result = file_put_contents($appendFile, implode(PHP_EOL, $lines) . PHP_EOL);
    if ($result === false) {
        http_response_code(500);
        echo "Failed to update file.";
        exit;
    }

    echo "Line deleted successfully.";
    exit;
}

// Handle appending
if (!$inputText) {
    http_response_code(400);
    echo "Missing 'text' parameter for appending.";
    exit;
}

$fileHandle = fopen($appendFile, "a");
if ($fileHandle === false) {
    http_response_code(500);
    echo "Failed to open file.";
    exit;
}

fwrite($fileHandle, $inputText . PHP_EOL);
fclose($fileHandle);

echo "Text appended successfully.";