<?php

$ALLOW_ADMIN_EMAIL_LOGIN = (preg_match(
  "/^([yY][eE][sS]|[yY])+$/",
  $_ENV["ALLOW_ADMIN_EMAIL_LOGIN"]
));

$session_var_user_allowed = 'sogo-sso-user-allowed';
$session_var_pass = 'sogo-sso-pass';

// validate credentials for basic auth requests
if (isset($_SERVER['PHP_AUTH_USER'])) {
  // load prerequisites only when required
  require_once $_SERVER['DOCUMENT_ROOT'] . '/inc/prerequisites.inc.php';

  $username = $_SERVER['PHP_AUTH_USER'];
  $password = $_SERVER['PHP_AUTH_PW'];

  // Determine service type for protocol access check
  $service = 'NONE';
  $original_uri = isset($_SERVER['HTTP_X_ORIGINAL_URI']) ? $_SERVER['HTTP_X_ORIGINAL_URI'] : '';
  if (preg_match('/^(\/SOGo|)\/dav.*/', $original_uri) === 1) {
    $service = 'DAV';
  }
  elseif (preg_match('/^(\/SOGo|)\/Microsoft-Server-ActiveSync.*/', $original_uri) === 1) {
    $service = 'EAS';
  }

  $login_check = check_login($username, $password, array('service' => $service));
  if ($login_check === 'user') {
    header("X-User: $username");
    header("X-Auth: Basic ".base64_encode("$username:$password"));
    header("X-Auth-Type: Basic");
    exit;
  } else {
    header('HTTP/1.0 401 Unauthorized');
    echo 'Invalid login';
    exit;
  }
}
// check permissions and redirect for direct GET ?login=xy requests
elseif (isset($_GET['login'])) {
  // load prerequisites only when required
  require_once $_SERVER['DOCUMENT_ROOT'] . '/inc/prerequisites.inc.php';
  // check if dual_login is active
  $is_dual = (!empty($_SESSION["dual-login"]["username"])) ? true : false;
  // check permissions (if dual_login is active, deny sso when acl is not given)
  $login = html_entity_decode(rawurldecode($_GET["login"]));
  if (isset($_SESSION['mailcow_cc_role']) &&
    (($_SESSION['acl']['login_as'] == "1" && $ALLOW_ADMIN_EMAIL_LOGIN !== 0) || ($is_dual === false && $login == $_SESSION['mailcow_cc_username']))) {
    if (filter_var($login, FILTER_VALIDATE_EMAIL)) {
      if (user_get_alias_details($login) !== false) {
        // register username in session
        $_SESSION[$session_var_user_allowed][] = $login;
        // set dual login
        if ($_SESSION['acl']['login_as'] == "1" && $ALLOW_ADMIN_EMAIL_LOGIN !== 0 && $is_dual === false && $_SESSION['mailcow_cc_role'] != "user"){
          $_SESSION["dual-login"]["username"] = $_SESSION['mailcow_cc_username'];
          $_SESSION["dual-login"]["role"]     = $_SESSION['mailcow_cc_role'];
          $_SESSION['mailcow_cc_username']    = $login;
          $_SESSION['mailcow_cc_role']        = "user";
        }
        // update sasl logs
        $stmt = $pdo->prepare("REPLACE INTO sasl_log (`service`, `app_password`, `username`, `real_rip`) VALUES ('SSO', 0, :username, :remote_addr)");
        $stmt->execute(array(
          ':username' => $login,
          ':remote_addr' => ($_SERVER['HTTP_X_REAL_IP'] ?? $_SERVER['REMOTE_ADDR'])
        ));
        // redirect to sogo (sogo will get the correct credentials via nginx auth_request
        header("Location: /SOGo/so/");
        exit;
      }
    }
  }
  header("Location: /");
  exit;
}
// only check for admin-login on sogo GUI requests
elseif (isset($_SERVER['HTTP_X_ORIGINAL_URI']) && strcasecmp(substr($_SERVER['HTTP_X_ORIGINAL_URI'], 0, 9), "/SOGo/so/") === 0) {
  // this is an nginx auth_request call, we check for existing sogo-sso session variables
  require_once $_SERVER['DOCUMENT_ROOT'] . '/inc/vars.inc.php';
  if (file_exists($_SERVER['DOCUMENT_ROOT'] . '/inc/vars.local.inc.php')) {
    include_once $_SERVER['DOCUMENT_ROOT'] . '/inc/vars.local.inc.php';
  }
  require_once $_SERVER['DOCUMENT_ROOT'] . '/inc/sessions.inc.php';

  $email_list = array(
      ($_SESSION['mailcow_cc_username'] ?? ''),     // Current user
      ($_SESSION["dual-login"]["username"] ?? ''),  // Dual login user
  );
  foreach($email_list as $email) {
    // check if this email is in session allowed list
    if (
        !empty($email) &&
        filter_var($email, FILTER_VALIDATE_EMAIL) &&
        is_array($_SESSION[$session_var_user_allowed]) &&
        in_array($email, $_SESSION[$session_var_user_allowed]) &&
        !$_SESSION['pending_pw_update']
    ) {
      $username = $email;
      $password = file_get_contents("/etc/sogo-sso/sogo-sso.pass");
      header("X-User: $username");
      header("X-Auth: Basic ".base64_encode("$username:$password"));
      header("X-Auth-Type: Basic");
      exit;
    }
  }
}

// if username is empty, SOGo will use the normal login methods / login form
header("X-User: ");
header("X-Auth: ");
header("X-Auth-Type: ");