<?php

class Qs_Mailchimp
{
    const HTTP_OK = 200;
    const CURL_REQUEST_GET = 'get';
    const CURL_REQUEST_POST = 'post';
    const CURL_REQUEST_PUT = 'put';
    const MAILCHIMP_STATUS_SUBSCRIBED = 'subscribed';
    const MAILCHIMP_STATUS_UNSUBSCRIBED = 'unsubscribed';
    const MAILCHIMP_STATUS_PENDING = 'pending';
    const MAILCHIMP_STATUS_CLEANED = 'cleaned';

    protected static $_curlHandle = null;

    /**
     * @var Zend_Config
     */
    protected $_config;

    /**
     * @param null|string $field
     * @param mixed $default
     * @return mixed|Zend_Config
     */
    public function getConfig($field = null, $default = null)
    {
        if (null === $this->_config) {
            $this->_config = Qs_Config::getByInstance($this);
        }
        if (null === $field) {
            return $this->_config;
        }
        return $this->_config->get($field, $default);
    }

    /**
     * @param $url
     * @param array|string $body
     * @param array $headers
     * @param $method
     * @return mixed
     */
    protected function getCurlData($urlSuffix, $body = [], $headers = [], $method = self::CURL_REQUEST_GET)
    {
        $curlHandle = self::_getCurlHandle();
        if ($method == self::CURL_REQUEST_POST) {
            curl_setopt($curlHandle, CURLOPT_POST, 1);
            curl_setopt($curlHandle, CURLOPT_POSTFIELDS, $body);
        } elseif ($method == self::CURL_REQUEST_PUT) {
            curl_setopt($curlHandle, CURLOPT_CUSTOMREQUEST, 'PUT');
            curl_setopt($curlHandle, CURLOPT_POSTFIELDS, $body);
        } else {
            curl_setopt($curlHandle, CURLOPT_POST, 0);
            if (is_array($body) && count($body)) {
                $urlSuffix .= '?' . http_build_query($body);
            }
        }
        curl_setopt($curlHandle, CURLOPT_URL, $this->getConfig('endPoint') . $urlSuffix);
        curl_setopt($curlHandle, CURLOPT_USERPWD, 'username:' . $this->getConfig('apiKey'));
        curl_setopt($curlHandle, CURLOPT_RETURNTRANSFER, true);
        if (count($headers)) {
            curl_setopt($curlHandle, CURLOPT_HTTPHEADER, $headers);
        }
        $response = curl_exec($curlHandle);
        if (self::HTTP_OK == curl_getinfo($curlHandle, CURLINFO_HTTP_CODE)) {
            $data = json_decode($response, true);
        } else {
            $data = null;
        }
        return $data;
    }

    protected static function _getCurlHandle()
    {
        if (null === self::$_curlHandle) {
            self::$_curlHandle = curl_init();
            curl_setopt(self::$_curlHandle, CURLOPT_HEADER, false);
        }

        return self::$_curlHandle;
    }

    public function getMember($email)
    {
        $urlSuffix = 'lists/' . $this->getConfig('listId') . '/members/' . md5(strtolower($email));
        return $this->getCurlData($urlSuffix);
    }

    public function addMember($data)
    {
        $urlSuffix = 'lists/' . $this->getConfig('listId') . '/members/';

        $fullName = explode(' ', $data['fullName'], 2);
        $params = [
            'email_address' => $data['email'],
            'status' => self::MAILCHIMP_STATUS_SUBSCRIBED,
            'merge_fields' => [
                'FNAME' => $data['firstName'] ?: Qs_Array::get($fullName, 0, ''),
                'LNAME' => $data['lastName'] ?: Qs_Array::get($fullName, 1, ''),
            ]
        ];
        return $this->getCurlData($urlSuffix, json_encode($params), [], self::CURL_REQUEST_POST);
    }

    public function setSubscribed($email)
    {
        $urlSuffix = 'lists/' . $this->getConfig('listId') . '/members/' . md5(strtolower($email));
        return $this->getCurlData($urlSuffix, json_encode([
            'status' => self::MAILCHIMP_STATUS_SUBSCRIBED
        ]), [], self::CURL_REQUEST_PUT);
    }

    public function subscribeMember($data)
    {
        if (null !== ($member = $this->getMember($data['email']))) {
            if ($member['status'] != self::MAILCHIMP_STATUS_SUBSCRIBED) {
                return $this->setSubscribed($data['email']);
            }
            return false;
        } else {
            return $this->addMember($data);
        }
    }

}