lab_migration.module

<?php

/**
 * Implements a helper function to capitalize words, handling delimiters.
 */
use Drupal\user\Entity\User;
function lm_ucname($string) {
  $string = ucwords(strtolower($string));
  foreach (array('-', '\'') as $delimiter) {
    if (strpos($string, $delimiter) !== false) {
      $string = implode($delimiter, array_map('ucfirst', explode($delimiter, $string)));
    }
  }
  return $string;
}

function lab_migration_mail($key, &$message, $params)
{
  global $user;
  $language = \Drupal::currentUser()->getPreferredLangcode();

  // If the language key is set in the params, use it, otherwise fallback to 'en' or any other default.
  $language = isset($params['language']) ? $params['language'] : $language;

  // Set the language for the message
  $message['langcode'] = $language;
  // $language = $message['$language'];
  //$language = user_preferred_language($user);
  switch ($key)
   {
  
     case 'proposal_received':
          /* initializing data */
          // $proposal_q = $db->query("SELECT * FROM {lab_migration_proposal} WHERE id = %d LIMIT 1", $params['proposal_received']['proposal_id']);
          // $proposal_data = $proposal_q->fetchObject();
          $query = \Drupal::database()->select('lab_migration_proposal');
          $query->fields('lab_migration_proposal');
          $query->condition('id', $params['proposal_received']['proposal_id']);
          $query->range(0, 1);
          $proposal_data = $query->execute()->fetchObject();
          /* $samplecodefilename = "";
          if (strlen($proposal_data->samplefilepath) >= 5)
          {
          $samplecodefilename = substr($proposal_data->samplefilepath, strrpos($proposal_data->samplefilepath, '/') + 1);
          }
          else
          {
          $samplecodefilename = "Not provided";
          }*/
          if ($proposal_data->solution_display == 1)
            {
              $solution_display = 'Yes';
            }
          else
            {
              $solution_display = 'No';
            }
          if ($proposal_data->solution_provider_uid == 0)
            {
              $solution_provider_user = 'Open';
            }
          else if ($proposal_data->solution_provider_uid == $proposal_data->uid)
            {
              $solution_provider_user = 'Proposer';
            }
          else
            {
              $solution_provider_user = 'Unknown';
            }
          // $experiment_q = $db->query("SELECT * FROM {lab_migration_experiment} WHERE proposal_id = %d ORDER BY number",
          //  $params['proposal_received']['proposal_id'], 1);
          $query = \Drupal::database()->select('lab_migration_experiment');
          $query->fields('lab_migration_experiment');
          $query->condition('proposal_id', $params['proposal_received']['proposal_id']);
          $query->orderBy('number', 'ASC');
          $experiment_q = $query->execute();
          $experiment_list = '';
          while ($experiment_data = $experiment_q->fetchObject())
            {
              $experiment_list .= '<p>' . $experiment_data->number . ') ' . $experiment_data->title . '<br> Description: ' . $experiment_data->description . '<br>';
              $experiment_list .= ' ';
              $experiment_list .= '</p>';
            }
          $user_data = User::load($params['proposal_received']['user_id']);
          // var_dump($user_data);die;
          $message['headers'] = $params['proposal_received']['headers'];
          $message['subject'] = $this->t('[!site_name] [Lab Migration Project]Your Lab migration proposal has been received  ', array(
              '@site_name' => \Drupal::config('site_name', '')
          ), array(
              'language' => '$language'
          ));
          $message['body'][] = 
              t('
Dear ' . $proposal_data->name . ',

We have received your proposal for lab migration with the following details:

Full Name: @full_name
Email: @user_email 
Contact No.: @contact no.
Department/Branch: 
University/Institute: @university/@Institute
City: @city
State: @state


Solution Provided By: ' . $solution_provider_user . '

List of experiments: ' . $experiment_list . '

The proposal is under review. You will be notified of the decision.  

Best Wishes,

!site_name Team
FOSSEE, IIT Bombay',[
                  '@site_name' => \Drupal::config('site_name')->get('name'),
                  'Full Name: @full_name' => $user_data->name
], [
                  'language' => '$language'
              ]
              );
          break;
        }
}