<?php

namespace Favicon;

/**
 * DataAccess is a wrapper used to read/write data locally or remotly
 * Aside from SOLID principles, this wrapper is also useful to mock remote resources in unit tests
 * Note: remote access warning are silenced because we don't care if a website is unreachable
 **/
class DataAccess {
	public function retrieveUrl($url) {
	    $this->set_context();
	    return @file_get_contents($url);
	}
	
	public function retrieveHeader($url) {
	    $this->set_context();
		$headers = @get_headers($url, 1);
		return is_array($headers) ? array_change_key_case($headers) : array();
	}
	
    public function saveCache($file, $data) {
        file_put_contents($file, $data);
    }
    
    public function readCache($file) {
    	return file_get_contents($file);
    }
    
    private function set_context() {
        stream_context_set_default(
            array(
                'http' => array(
                    'method' => 'GET',
                    'follow_location' => 0,
                    'max_redirects' => 1,
                    'timeout' => 10,
                    'header' => "User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:20.0; Favicon; +https://github.com/ArthurHoaro/favicon) Gecko/20100101 Firefox/32.0\r\n",
                )
            )
        );
    }
}