Upload de arquivos no cakephp...

FileWriter.php

<?php

App::uses('HttpSocket', 'Network/Http'); 
App::uses('File', 'Utility');
App::uses('Folder', 'Utility');

class FileWriter {
	
	public function write($image=array(), $filename=null) {

		if(!$image || ($image['error']!=0) && ($image['size']==0)) {
				throw new NotImplementedException('Image not found.');
		}

		$directory = 'files/upload/'. (new DateTime())->format('Y').'/';

		$folder = new Folder();
		if (!is_dir($directory)){
			$folder->create($directory);
		}

		$image_info = pathinfo($directory.$image['name']);
		if(!$filename) {
			$name = strtolower(Inflector::slug($image_info['filename'],'_'));
		} else {
			$name = strtolower(Inflector::slug($filename,'_'));
		}
		$name = $name . '.' . $image_info['extension'];

		$sequence = 2;
		while (file_exists($directory.$name)) {
			if(!$filename) {
				$name  = strtolower(Inflector::slug($image_info['filename'] . '(' . $sequence . ')','_'));
			} else {
				$name  = strtolower(Inflector::slug($filename . '(' . $sequence . ')','_'));
			}
			$name = $name . '.' . $image_info['extension'];
			$sequence++;
		}


		$image['name'] = $name;
		$directory = $directory.$image['name'];

		$file_output = new File($image['tmp_name']);
		$file_output->copy($directory);
		$file_output->close();

		return $directory;

	}

}

TestModel.php

<?php

App::uses('AppModel', 'Model');
App::import('Vendor', 'IOStream/FileWriter');

class TestModel extends AppModel {

	public function beforeSave($options = array()) { 

	    if(!empty($this->data['Movie']['image']['name'])) {  

			$FileWriter = new FileWriter();
			$path = $FileWriter->write($this->data['Movie']['image']);
			$this->data['Movie']['image'] = Router::url('/', true) . $path;
			
	    } else {  
	        unset($this->data['Movie']['image']);  
	    }  
	}

}

Basta criar o arquivo FileWriter na pasta Vendor, e depois colocar os importa na sua classe Model.