I’m working on a project and one of my controllers is getting quite large and hard to maintain or add to. I’m having trouble deciding what belongs in the controller and what I can move to the model. What can I change to improve this?

class Job_update extends MY_Controller {  function __construct() {     parent::__construct();     $  this->load->helper('form');     $  this->load->library('email');     $  this->load->helper('html');     $  this->load->model('jobs_model'); } /**  * Reassigns a tradie to the work order sending appropriate emails out  * @param int $  job_id   */ public function reassign_tradie($  job_id) {     $  this->load->model('send_emails_model');     $  this->load->model('tradie_model');     $  this->load->model('notes_model');     //get tradie ids via get or post     if ($  this->input->get("tradie")) {         $  tradie_id = $  this->input->get("tradie");         $  prev_tradie =  $  this->input->get("prev_tradie");     } else {         $  tradie_id = $  this->input->post("tradie");         $  prev_tradie = $  this->input->post("prev_tradie");     }      if ($  tradie_id == $  prev_tradie) {         $  this->session->set_flashdata('error', "That tradesman is already assigned to this job");         redirect('job_update/job_id/'.$  job_id);         return;     }      //retrieve data for both tradies     $  data = $  this->tradie_model->get($  tradie_id); //new tradie     $  prev_tradie_data = $  this->tradie_model->get($  prev_tradie);//prev tradie      //update the status to pending and set the new tradie     $  this->jobs_model->update($  job_id, array(         "status" => "Pending",         "tradie" => $  tradie_id,         "job_tradie_response" => 0     ));      //add a note to the job documenting the change     $  job_note_message = "Tradesman has been changed from " . $  prev_tradie_data->tradie_firstname .      " to ". $  data->tradie_firstname . " Reason: " .  $  this->input->post("reason");     $  this->notes_model->insert($  job_id, $  job_note_message);      //select the new job data     $  job_data = $  this->jobs_model->with_site_location()->with_tradie()->get($  job_id);      //send the tradie an email of the work order     $  tradie_email = $  this->jobs_model->build_tradie_email($  job_id, $  job_data);     $  this->send_emails_model->insert($  tradie_email);      //if the prev tradie didn't decline the job we need to send a cancellation email     if ($  job_data->status != "Declined") {         $  this->load->model('tradie_model');          $  tradie_data = $  this->tradie_model->get($  prev_tradie);          $  cancelled_email = $  this->jobs_model->build_job_cancelled_email($  job_id, $  tradie_data);         $  this->send_emails_model->insert($  cancelled_email);     }      //redirect     $  this->session->set_flashdata('msg', "Tradesman has been successfully changed");     redirect('job_update/job_id/'.$  job_id); }  /**  * Resends the work order to the assigned plumber also updates the status to pending  * @param int $  job_id   */ public function resend_work_order($  job_id) {     $  this->load->model('notes_model');     $  this->load->model('send_emails_model');     //updates status of job     $  job_update = array("status" => "Pending", "job_tradie_response" => 0);     $  this->jobs_model->update($  job_update, $  job_id);      //Sends email to tradesman     $  job_data = $  this->jobs_model->with_site_location()->with_tradie()->get($  job_id);     $  result = $  this->jobs_model->build_tradie_email($  job_id, $  job_data);      $  this->send_emails_model->insert($  result);      //addes note to system talking about change     $  data = array(     'note' => "Job has been resent to the plumber. Status changed to Pending",     'notes_job_id' => $  job_id,     'datestamp' => date("Y-m-d H:i:s"),     'user_id' => $  this->session->userdata('username')     );     $  this->notes_model->insert($  data);      $  this->session->set_flashdata('msg', 'Resent Work Order to '. $  job_data->tradie->tradie_firstname);     redirect('job_update/job_id/'.$  job_id); }  /**  * Inserts a new note from post data  * @param int $  job_id   */ public function job_add_note($  job_id) {     $  this->_add_note($  job_id, $  this->input->post('job_notes'));      $  this->session->set_flashdata('msg', 'Job Note Added Successfully');     redirect('job_update/job_id/'.$  job_id); }  /**  * Loads the photos page for a certain job  * @param int $  job_id  */ public function photos($  job_id) {     $  data = array('job_id' => $  job_id);     $  this->load->view('job_photos_view', $  data); }   public function set_flash_for_bookin($  job_id) {     $  this->session->set_flashdata('msg', 'Date/Time has been successfully set');     redirect('job_update/job_id/'.$  job_id); }  /**  * Saves the work order details (checkboxes, job_description)  * @param int $  job_id   */ public function submit_work_order($  job_id) {     $  data = $  this->update_checkboxes($  job_id); //get all checkbox data     $  this->jobs_model->update($  data, $  job_id); //save to db     $  this->session->set_flashdata('msg', 'Work Order Updated Successfully');     redirect('job_update/job_id/'.$  job_id); }   /**  * Resends the customer confirmation email  * @param string (email) $  c_email   * @param int $  job_id   */ public function resend_confirmation_email($  c_email, $  job_id) {     $  this->load->model('send_emails_model');     $  this->job_update_model->update_send_email(array("email_sent" => 0), urldecode($  c_email));      $  this->session->set_flashdata('msg', 'Email Successfully Sent');     redirect('job_update/job_id/'.$  job_id); }  /**  * Sets the date for a checkbox  * @param string $  post_data   * @param date $  current_date_in_db   * @param bool (0,1) $  is_checked   * @return date string format YYYY-MM-DD  */ private function checkbox_helper($  post_data, $  current_date_in_db, $  is_checked) {     if($  post_data == false)         return "0000-00-00";     else if($  post_data != false && $  is_checked === "0")         return date("Y-m-d");     else         return $  current_date_in_db; }  /**  * returns an array with checkbox data  * @param int $  job_id   * @return array   */ public function update_checkboxes($  job_id) {     $  job_data = $  this->jobs_model->get($  job_id);      $  current_date = date('Y-m-d');     $  current_time = date('H:i:s');      //if 1 box is checked if 0 box is not checked     $  data = array(     'box_customer_called' => ($  this->input->post('checkbox1') == false ? '0' : '1'),     'box_customer_called_date' => $  this->checkbox_helper($  this->input->post('checkbox1'), $  job_data->box_customer_called_date, $  job_data->box_customer_called),     'box_photos_reviewed' => ($  this->input->post('checkbox2') == false ? '0' : '1'),     'box_photos_received_date' => $  this->checkbox_helper($  this->input->post('checkbox2'), $  job_data->box_photos_received_date, $  job_data->box_photos_reviewed),     'box_photos_received' => ($  this->input->post('checkbox6') == false ? '0' : '1'),     'box_photos_received_date' => $  this->checkbox_helper($  this->input->post('checkbox6'), $  job_data->box_photos_received_date, $  job_data->box_photos_received),     'box_completed' => ($  this->input->post('checkbox7') == false ? '0' : '1'),     'box_completed_date' => $  this->checkbox_helper($  this->input->post('checkbox7'), $  job_data->box_completed_date, $  job_data->box_completed),     'box_completion_certificate' => ($  this->input->post('checkbox3') == false ? '0' : '1'),     'box_completion_certificate_date' => $  this->checkbox_helper($  this->input->post('checkbox3'), $  job_data->box_completion_certificate_date, $  job_data->box_completion_certificate),     'box_invoiced' => ($  this->input->post('checkbox4') == false ? '0' : '1'),     'box_invoiced_date' => $  this->checkbox_helper($  this->input->post('checkbox4'), $  job_data->box_invoiced_date, $  job_data->box_invoiced),     'box_warranty' => ($  this->input->post('checkbox5') == false ? '0' : '1'),     'box_warranty_date' => $  this->checkbox_helper($  this->input->post('checkbox5'), $  job_data->box_warranty_date, $  job_data->box_warranty),     'job_description' => $  this->input->post('job_description_new'),     );      //if the job was completed and is now unticked change the status     if($  job_data->box_completed == 0 && $  this->input->post('checkbox7') == "Completed")         $  data['status'] = "Completed";      if($  job_data->box_completed == 1 && $  this->input->post('checkbox7') != "Completed")         $  data['status'] = "Accepted";      return $  data; }  /**  * Inserts an email into the send que  * @param string $  message   * @param string $  email   * @param string $  name   * @param string $  email_subject   */ public function email($  message, $  email, $  name, $  email_subject) {     $  this->load->model('send_emails_model');      $  data = array('message' => $  message,         'email' => $  email,         'name' => $  name,         'email_subject' => $  email_subject);      $  this->send_emails_model->insert($  data); }  /**  * Uploads a photo to the job directotry  * @param int $  job_id   */ public function upload_images($  job_id) {      $  name_array = array();      if (!is_dir('assets/job_photos/'.add_prefix($  job_id))) {//create directory is it doesn't exist         mkdir('./assets/job_photos/'.add_prefix($  job_id), 0777, true);         $  dir_exist = false; // dir not exist     }      $  count = count($  _FILES['userfile']['size']);     foreach ($  _FILES as $  key => $  value) {         for ($  s=0; $  s<=$  count-1; $  s++) {             $  _FILES['userfile']['name']=$  value['name'][$  s];             $  _FILES['userfile']['type']    = $  value['type'][$  s];             $  _FILES['userfile']['tmp_name'] = $  value['tmp_name'][$  s];             $  _FILES['userfile']['error']       = $  value['error'][$  s];             $  _FILES['userfile']['size']    = $  value['size'][$  s];             $  config['upload_path'] = './assets/job_photos/'.add_prefix($  job_id).'/';             $  config['allowed_types'] = 'gif|jpg|png|jpeg|pdf|PNG|JPG|JPEG';             $  this->load->library('upload', $  config);             if (! $  this->upload->do_upload()) {                 $  this->session->set_flashdata('error', $  this->upload->display_errors());             } else {                 $  this->session->set_flashdata('msg', 'Successully Uploaded');             }         }     }     redirect(site_url('job_update/job_id/'.$  job_id)); }  public function job_id($  job_id)  {     $  this->load->model('user_model');     $  this->load->model('tradie_model');     $  this->load->model('send_emails_model');     $  this->load->model('notes_model');      //gather all data required for display     $  job_data = $  this->jobs_model->with_site_location()->with_tradie()->with_job_notes()->get($  job_id);      $  all_users['users'] = $  this->user_model->select_all_users();     $  tradies['tradies'] = $  this->tradie_model->get_all();      $  email = $  this->send_emails_model->where('email', $  job_data->site_location->tenant_email)->get();       //if job isn't found job data will be empty so we load a blank page and return     if (empty($  job_data)) {         $  this->headerlib->load_header();         return;     }      //change all 1's to checked for view     foreach ($  job_data as $  key => &$  value) {         //filter thourgh all table coloumns to find the boxes coloumns         if(strpos($  key, 'box') !== false && strpos($  key, 'date') === false) {             if($  value == 1)                 $  value = "checked";         }     }      $  data = array_merge((array)$  job_data, (array)$  all_users, (array)$  job_emails, (array)$  tradies);      $  this->headerlib->load_header();     $  this->footerlib->load_footer();     $  this->load->view('job_update_view', $  data); }  /**  * Deletes a job  * @param int $  job_id job_id you wish to delete  */ public function delete_job($  job_id) {     $  this->load->model('send_emails_model');     $  this->load->model('tradie_model');      if($  this->session->userdata('user_team_id') != 40)     {         $  this->session->set_flashdata('error', 'You do not have permission to delete this job');         redirect($  _SERVER['HTTP_REFERER']);         return;     }      $  data = $  this->jobs_model->with_tradie()->get($  job_id);      $  tradie_data = $  this->tradie_model->get($  data->tradie->tradie_id);      $  cancelled_email = $  this->jobs_model->build_job_cancelled_email($  job_id, $  tradie_data);     $  this->send_emails_model->insert($  cancelled_email);      if ($  this->jobs_model->delete($  job_id)) {         $  this->session->set_flashdata('msg', 'Job has been successfully deleted');     } else {         $  this->session->set_flashdata('error', 'Something went wrong, contact an administrator');     }      redirect($  _SERVER['HTTP_REFERER']); } } 

Thanks for the help!