<?php

/***************************
* Custom implementation of the Embedly service
****************************/
class Embedly_WordPress_Integration {

	private $cache_ttl = WEEK_IN_SECONDS;
	private $embedly_uri = 'http://api.embed.ly/1/oembed';

	public function __construct() {

		// Register additional handlers
		wp_embed_register_handler('amazon', '#https?:\/\/([a-z0-9]+[.])?amazon.com\/(.*)#i', array($this, 'embedly_handler'), 100);

	}

	//
	// Handle an embed request of any kind
	public function embedly_handler($matches, $attr, $url, $rawattr) {

		// Check for cached data
		if (false !== $data = $this->cache_get($url)) {
			return $data;
		}

		// Get new data
		if (false !== $data = $this->fetch_new_data($url)) {
			$html = $data['html'];
			$this->cache_set($url, $html);
			return $html;
		}

		// Failure
		return false;
		
	}

	private function fetch_new_data($url) {

		// Try to fetch new data
		$args = array(
			'timeout'     => 3,
			'blocking'    => true,
			'headers'     => array('Content-type' => 'application/json'),
			'sslverify'   => true
		);

		$params = array('url' => $url);

		if (false) $params['key'] = 'KEY';

		$request_uri = $this->embedly_uri . '?' . http_build_query($params, '', '&');
		$response = wp_remote_get($request_uri, $args);
		return json_decode(wp_remote_retrieve_body($response), true);
	}

	//
	// Retrieve cached response if available
	private function cache_get($url) {
		$key = $this->hash($url); 
		return is_multisite() ? get_site_transient($key) : get_transient($key);
	}

	//
	// Store cached response
	private function cache_set($url, $result) {
		$key = $this->hash($url);
		return is_multisite() ? set_site_transient($key, $result, $this->cache_ttl) : set_transient($key, $result, $this->cache_ttl);
	}

	private function hash($string) {
		return 'embedlyx'.md5($string);
	}

}

new Embedly_WordPress_Integration();