<?php

namespace EspressoDev;

class ESG_InstagramBasicDisplay
{
	const API_URL = 'https://graph.instagram.com/';

	const API_OAUTH_URL = 'https://api.instagram.com/oauth/authorize';

	const API_OAUTH_TOKEN_URL = 'https://api.instagram.com/oauth/access_token';

	const API_TOKEN_EXCHANGE_URL = 'https://graph.instagram.com/access_token';

	const API_TOKEN_REFRESH_URL = 'https://graph.instagram.com/refresh_access_token';

	private $_appId;

	private $_appSecret;

	private $_redirectUri;

	private $_accesstoken;

	private $_scopes = ['user_profile', 'user_media'];

	private $_userFields = 'account_type,id,media_count,username';

	private $_mediaFields = 'caption,id,media_type,media_url,permalink,thumbnail_url,timestamp,username';

	private $_mediaChildrenFields = 'id,media_type,media_url,permalink,thumbnail_url,timestamp,username';

	private $_timeout = 90000;

	private $_connectTimeout = 20000;

	public function __construct($config = null)
	{
		if (is_array($config)) {
			$this->setAppId($config['appId']);
			$this->setAppSecret($config['appSecret']);
			$this->setRedirectUri($config['redirectUri']);

			if (isset($config['timeout'])) {
				$this->setTimeout($config['timeout']);
			}

			if (isset($config['connectTimeout'])) {
				$this->setConnectTimeout($config['connectTimeout']);
			}
		} elseif (is_string($config)) {
			// For read-only
			$this->setAccessToken($config);
		} else {
			throw new ESG_InstagramBasicDisplayException('Error: __construct() - Configuration data is missing.');
		}
	}

	public function getLoginUrl($scopes = ['user_profile', 'user_media'], $state = '')
	{
		if (is_array($scopes) && count(array_intersect($scopes, $this->_scopes)) === count($scopes)) {
			return self::API_OAUTH_URL . '?client_id=' . $this->getAppId() . '&redirect_uri=' . urlencode($this->getRedirectUri()) . '&scope=' . implode(',',
					$scopes) . '&response_type=code' . ($state != '' ? '&state=' . $state : '');
		}

		throw new ESG_InstagramBasicDisplayException("Error: getLoginUrl() - The parameter isn't an array or invalid scope permissions used.");
	}

	public function getUserProfile($id = 0)
	{
		if ($id === 0) {
			$id = 'me';
		}

		return $this->_makeCall($id, ['fields' => $this->_userFields]);
	}

	public function getUserMedia($id = 'me', $limit = 0, $before = null, $after = null)
	{
		$params = [
			'fields' => $this->_mediaFields
		];

		if ($limit > 0) {
			$params['limit'] = $limit;
		}
		if (isset($before)) {
			$params['before'] = $before;
		}
		if (isset($after)) {
			$params['after'] = $after;
		}

		return $this->_makeCall($id . '/media', $params);
	}

	public function getMedia($id)
	{
		return $this->_makeCall($id, ['fields' => $this->_mediaFields]);
	}

	public function getMediaChildren($id)
	{
		return $this->_makeCall($id . '/children', ['fields' => $this->_mediaChildrenFields]);
	}

	public function pagination($obj)
	{
		if (is_object($obj) && !is_null($obj->paging)) {
			if (!isset($obj->paging->next)) {
				return;
			}

			$apiCall = explode('?', $obj->paging->next);

			if (count($apiCall) < 2) {
				return;
			}

			$function = str_replace(self::API_URL, '', $apiCall[0]);
			parse_str($apiCall[1], $params);

			// No need to include access token as this will be handled by _makeCall
			unset($params['access_token']);

			return $this->_makeCall($function, $params);
		}

		throw new ESG_InstagramBasicDisplayException("Error: pagination() | This method doesn't support pagination.");
	}

	public function getOAuthToken($code, $tokenOnly = false)
	{
		$apiData = array(
			'app_id' => $this->getAppId(),
			'app_secret' => $this->getAppSecret(),
			'grant_type' => 'authorization_code',
			'redirect_uri' => $this->getRedirectUri(),
			'code' => $code
		);

		$result = $this->_makeOAuthCall(self::API_OAUTH_TOKEN_URL, $apiData);

		return !$tokenOnly ? $result : $result->access_token;
	}

	public function getLongLivedToken($token, $tokenOnly = false)
	{
		$apiData = array(
			'client_secret' => $this->getAppSecret(),
			'grant_type' => 'ig_exchange_token',
			'access_token' => $token
		);

		$result = $this->_makeOAuthCall(self::API_TOKEN_EXCHANGE_URL, $apiData, 'GET');

		return !$tokenOnly ? $result : $result->access_token;
	}

	public function refreshToken($token, $tokenOnly = false)
	{
		$apiData = array(
			'grant_type' => 'ig_refresh_token',
			'access_token' => $token
		);

		$result = $this->_makeOAuthCall(self::API_TOKEN_REFRESH_URL, $apiData, 'GET');

		return !$tokenOnly ? $result : $result->access_token;
	}

	protected function _makeCall($function, $params = null, $method = 'GET')
	{
		if (!isset($this->_accesstoken)) {
			throw new ESG_InstagramBasicDisplayException("Error: _makeCall() | $function - This method requires an authenticated users access token.");
		}

		$authMethod = '?access_token=' . $this->getAccessToken();

		$paramString = null;

		if (isset($params) && is_array($params)) {
			$paramString = '&' . http_build_query($params);
		}

		$apiCall = self::API_URL . $function . $authMethod . (('GET' === $method) ? $paramString : null);
		//replace encoded comma since api return error if not
		$apiCall = str_replace('%2C', ',', $apiCall);

		$headerData = array('Accept: application/json');

		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $apiCall);
		curl_setopt($ch, CURLOPT_HTTPHEADER, $headerData);
		curl_setopt($ch, CURLOPT_CONNECTTIMEOUT_MS, $this->_connectTimeout);
		curl_setopt($ch, CURLOPT_TIMEOUT_MS, $this->_timeout);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
		curl_setopt($ch, CURLOPT_HEADER, true);

		$jsonData = curl_exec($ch);

		if (!$jsonData) {
			throw new ESG_InstagramBasicDisplayException('Error: _makeCall() - cURL error: ' . curl_error($ch), curl_errno($ch));
		}

		list($headerContent, $jsonData) = explode("\r\n\r\n", $jsonData, 2);

		curl_close($ch);

		return json_decode($jsonData);
	}

	private function _makeOAuthCall($apiHost, $params, $method = 'POST')
	{
		$paramString = null;

		if (isset($params) && is_array($params)) {
			$paramString = '?' . http_build_query($params);
		}

		$apiCall = $apiHost . (('GET' === $method) ? $paramString : null);

		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $apiCall);
		curl_setopt($ch, CURLOPT_HTTPHEADER, array('Accept: application/json'));
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
		curl_setopt($ch, CURLOPT_TIMEOUT_MS, $this->_timeout);

		if ($method === 'POST') {
			curl_setopt($ch, CURLOPT_POST, count($params));
			curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($params));
		}

		$jsonData = curl_exec($ch);

		if (!$jsonData) {
			throw new ESG_InstagramBasicDisplayException('Error: _makeOAuthCall() - cURL error: ' . curl_error($ch));
		}

		curl_close($ch);

		return json_decode($jsonData);
	}

	public function setAccessToken($token)
	{
		$this->_accesstoken = $token;
	}

	public function getAccessToken()
	{
		return $this->_accesstoken;
	}

	public function setAppId($appId)
	{
		$this->_appId = $appId;
	}

	public function getAppId()
	{
		return $this->_appId;
	}

	public function setAppSecret($appSecret)
	{
		$this->_appSecret = $appSecret;
	}

	public function getAppSecret()
	{
		return $this->_appSecret;
	}

	public function setRedirectUri($redirectUri)
	{
		$this->_redirectUri = $redirectUri;
	}

	public function getRedirectUri()
	{
		return $this->_redirectUri;
	}

	public function setUserFields($fields)
	{
		$this->_userFields = $fields;
	}

	public function setMediaFields($fields)
	{
		$this->_mediaFields = $fields;
	}

	public function setMediaChildrenFields($fields)
	{
		$this->_mediaChildrenFields = $fields;
	}

	public function setTimeout($timeout)
	{
		$this->_timeout = $timeout;
	}

	public function setConnectTimeout($connectTimeout)
	{
		$this->_connectTimeout = $connectTimeout;
	}
}
