hash.php

<?php
/**
 * Hash Visualization CLI (SVG generator)
 *
 * Based on ideas from Perrig & Song "Hash Visualization".
 *
 * Usage:
 *   php hash.php "your input string" [--outfile=out.svg]
 *   php hash.php -o out.svg "your input string"
 *
 * - Deterministic: same input => same image
 * - Output: SVG with circular form (transparent background),
 *   overlapping basic shapes (triangle, square, circle) in a 20‑color palette.
 * - No external libraries required.
 */

require __DIR__ . '/vendor/autoload.php';

use ANSCD\ShapeHash\Generator;

// Ensure CLI
if (php_sapi_name() !== 'cli') {
    fwrite(STDERR, "This script must be run from the command line." . PHP_EOL);
    exit(1);
}

// -----------------------------
// Option parsing
// -----------------------------
$argvCopy = $argv;
array_shift($argvCopy); // remove script name

$inputString = null;
$outFile = 'out.svg';

for ($i = 0; $i < count($argvCopy); $i++) {
    $arg = $argvCopy[$i];
    if ($arg === '-h' || $arg === '--help') {
        usage();
        exit(0);
    }
    if (strncmp($arg, '--outfile=', 10) === 0) {
        $outFile = basename(substr($arg, 10));
        continue;
    }
    if ($arg === '-o' || $arg === '--outfile') {
        $i++;
        if ($i >= count($argvCopy)) {
            fwrite(STDERR, "Missing value after $arg." . PHP_EOL);
            usage(1);
        }
        $outFile = basename($argvCopy[$i]);
        continue;
    }
    // The first non-option is the input string
    if ($inputString === null) {
        $inputString = $arg;
        continue;
    }
    // If there's more than one positional argument, join them with space (allows unquoted multi-word input)
    $inputString .= ' ' . $arg;
}

if ($inputString === null) {
    fwrite(STDERR, "Error: missing input string." . PHP_EOL);
    usage(1);
}


function usage(int $code = 0): void {
    $msg = <<<TXT
Hash Visualization (SVG)
Usage:
  php hash.php "your input" [--outfile=out.svg]
  php hash.php -o out.svg "your input"

Options:
  -o, --outfile <path>   Output file path (default: out.svg)
  -h, --help             Show this help
TXT;
    if ($code === 0) {
        fwrite(STDOUT, $msg . PHP_EOL);
    } else {
        fwrite(STDERR, $msg . PHP_EOL);
        exit($code);
    }
}

// -----------------------------
// Generate and write SVG
// -----------------------------
$svg = Generator::generateSvg($inputString);

$result = @file_put_contents($outFile, $svg);
if ($result === false) {
    fwrite(STDERR, "Failed to write to '$outFile'." . PHP_EOL);
    exit(2);
}

fwrite(STDOUT, "SVG generated: $outFile" . PHP_EOL);