A php script that takes an email formatted as a POST form and turns it into a Discord webhook

email-to-discord.php

<?php

namespace CarlBennett;

use \DateTime;
use \DateTimeZone;
use \Exception;
use \StdClass;

const GRAVATAR_BASE = 'https://secure.gravatar.com/avatar/';
const GRAVATAR_ARGS = '?s=256&d=identicon';

const TOKEN_SECRET = 'INSERT_SECRET_HERE';

function exit_here( $code = 500, $message = '' ) {
  http_response_code( $code );
  header( 'Content-Type: text/plain;charset=utf-8' );
  die( $message );
}

function get_name_and_email_address( $str ) {
  $name = '';
  $email = '';

  try {
    $addresses = \mailparse_rfc822_parse_addresses( $str );
    if ( count( $addresses ) > 0 ) {
      $name = $addresses[ 0 ][ 'display' ];
      $email = $addresses[ 0 ][ 'address' ];
    }
  } catch ( Exception $e ) {}

  return [ $name, $email ];
}

function get_avatar( $email ) {
  return GRAVATAR_BASE . hash( 'md5', trim( $email )) . GRAVATAR_ARGS;
}

function query_arg( $name, $default = null ) {
  return ( isset( $_REQUEST[ $name ]) ? $_REQUEST[ $name ] : $default );
}

$token = query_arg( 'token' );
$subject_filter = query_arg( 'subject_filter' );

$from = query_arg( 'from' );
$subject = query_arg( 'subject' );
$body_plain = query_arg( 'body_plain' );
$body_html = query_arg( 'body_html' );
$date = query_arg( 'date' );

$color = query_arg( 'color' );
$discord_webhook = query_arg( 'discord_webhook' );

if ( empty( $token ) && !empty( TOKEN_SECRET )) {
  exit_here( 400, 'Missing: token' );
}

if ( $token !== TOKEN_SECRET ) {
  exit_here( 401, 'Unauthorized' );
}

if ( empty( $discord_webhook )) {
  exit_here( 400, 'Missing: discord_webhook' );
}

if ( !empty( $subject_filter ) &&
  stripos( $subject, $subject_filter ) === false ) {
  exit_here( 204 );
}

if ( empty( $body_plain )) {
  $body = filter_var( $body_html, FILTER_SANITIZE_STRING );
} else {
  $body = $body_plain;
}

$color = trim( $color );
if ( preg_match( '/^\d{1,3},\d{1,3},\d{1,3},\d{1,3}$/', $color )) {
  // ARGB
  $colors = explode( ',', $color );
  $color = sprintf( '%02x%02x%02x%02x',
    $colors[ 0 ], $colors[ 1 ], $colors[ 2 ], $colors[ 3 ]
  );
  $color = hexdec( $color );
} else if ( preg_match( '/^\d{1,3},\d{1,3},\d{1,3}$/', $color )) {
  // RGB
  $colors = explode( ',', $color );
  $color = sprintf( '%02x%02x%02x',
    $colors[ 0 ], $colors[ 1 ], $colors[ 2 ]
  );
  $color = hexdec( $color );
} else if ( preg_match( '/^[A-Fa-f0-9]{1,8}$/', $color )) {
  // Hex
  $color = hexdec( $color );
}

try {
  $tz = new DateTimeZone( 'Etc/UTC' );
  $date_obj = new DateTime( $date, $tz );
  $date_str = $date_obj->format( DateTime::ISO8601 );
} catch ( Exception $e ) {
  $date_str = $date;
}

$from_info = get_name_and_email_address( $from );

$discord_data = [
  'embeds' => [
    [
      'author' => [
        'icon_url' => get_avatar( $from_info[ 1 ]),
        'name' => $from_info[ 0 ],
      ],
      'color' => $color,
      'description' => $body,
      'timestamp' => $date_str,
      'title' => $subject,
      'type' => 'rich',
    ],
  ],
  'wait' => true,
];

$curl = curl_init();
$time = microtime( true );

curl_setopt( $curl, CURLOPT_CONNECTTIMEOUT, 5 );
curl_setopt( $curl, CURLOPT_AUTOREFERER, true );
curl_setopt( $curl, CURLOPT_FOLLOWLOCATION, true );
curl_setopt( $curl, CURLOPT_MAXREDIRS, 10 );
curl_setopt( $curl, CURLOPT_POSTREDIR, 7 ); // redirect POST on 301,302,303

curl_setopt( $curl, CURLOPT_URL, $discord_webhook );
curl_setopt( $curl, CURLOPT_POST, true );
curl_setopt( $curl, CURLOPT_SAFE_UPLOAD, true );
curl_setopt( $curl, CURLOPT_POSTFIELDS, json_encode( $discord_data ));
curl_setopt( $curl, CURLOPT_HTTPHEADER, [
  'Content-Type: application/json;charset=utf-8'
]);
curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );

$r       = new StdClass();
$r->data = curl_exec( $curl );
$r->code = curl_getinfo( $curl, CURLINFO_HTTP_CODE );
$r->type = curl_getinfo( $curl, CURLINFO_CONTENT_TYPE );
$r->time = microtime( true ) - $time;

curl_close( $curl );

http_response_code( $r->code );
header( 'Content-Type: ' . $r->type );
echo $r->data;

// DEBUGGING
file_put_contents( __DIR__ . DIRECTORY_SEPARATOR . '.r.json',
  json_encode( $discord_data, JSON_PRETTY_PRINT ) . PHP_EOL .
  json_encode( $r, JSON_PRETTY_PRINT ) . PHP_EOL
);