<?php

namespace app\Libraries;

use CodeIgniter\Encryption\EncrypterInterface;
use Config\OSPOS;
use Config\Services;

/**
 * MailChimp API v3 REST client Connector
 *
 * Interface for communicating with the Mailchimp v3 API
 *
 * Inspired by the work of:
 *   - Rajitha Bandara: https://github.com/rajitha-bandara/ci-mailchimp-v3-rest-client
 *   - Stefan Ashwell: https://github.com/stef686/codeigniter-mailchimp-api-v3
 *
 * @property encrypterinterface encrypter
 */
class MailchimpConnector
{
    /**
     * API Key
     *
     * @var    string[]
     */
    private $_api_key = '';    // TODO: Hungarian notation

    /**
     * API Endpoint
     *
     * @var    string[]
     */
    private $_api_endpoint = 'https://<dc>.api.mailchimp.com/3.0/';    // TODO: Hungarian notation

    /**
     * Constructor
     */
    public function __construct(string $api_key = '')
    {
        $config = config(OSPOS::class)->settings;

        $encrypter = Services::encrypter();

        $mailchimp_api_key = (isset($this->config['mailchimp_api_key']) && !empty($this->config['mailchimp_api_key']))
            ? $this->config['mailchimp_api_key']
            : '';

        if (!empty($mailchimp_api_key)) {
            $this->_api_key = empty($api_key)
                ? $encrypter->decrypt($mailchimp_api_key)    // TODO: Hungarian notation
                : $api_key;    // TODO: Hungarian notation
        }

        if (!empty($this->_api_key)) {    // TODO: Hungarian notation
            // Replace <dc> with correct datacenter obtained from the last part of the api key
            $strings = explode('-', $this->_api_key);    // TODO: Hungarian notation
            if (is_array($strings) && !empty($strings[1])) {
                $this->_api_endpoint = str_replace('<dc>', $strings[1], $this->_api_endpoint);    // TODO: Hungarian notation
            }
        }
    }

    /**
     * Call an API method. Every request needs the API key
     * @param string $httpVerb The HTTP method to be used
     * @param string $method The API method to call, e.g. 'lists/list'
     * @param array $args An array of arguments to pass to the method. Will be json-encoded for you.
     * @return array|bool Associative array of json decoded API response or false on error.
     */
    public function call(string $method, string $httpVerb = 'POST', array $args = []): bool|array
    {
        if (!empty($this->_api_key)) {    // TODO: Hungarian notation
            return $this->_request($httpVerb, $method, $args);    // TODO: Hungarian notation
        }

        return false;
    }

    /**
     * Builds the request URL based on request type
     * @param  string $httpVerb The HTTP method to be used
     * @param  string $method   The API method to be called
     * @param  array  $args     Assoc array of parameters to be passed
     * @return string           Request URL
     */
    private function _build_request_url(string $method, string $httpVerb = 'POST', array $args = []): string    // TODO: Hungarian notation.
    {
        if ($httpVerb == 'GET') {
            return $this->_api_endpoint . $method . '?' . http_build_query($args);    // TODO: Hungarian notation
        }

        return $this->_api_endpoint . $method;    // TODO: Hungarian notation
    }

    /**
     * Performs the underlying HTTP request.
     * @param string $httpVerb The HTTP method to be used
     * @param string $method The API method to be called
     * @param array $args Assoc array of parameters to be passed
     * @return bool|array Assoc array of decoded result or False
     */
    private function _request(string $httpVerb, string $method, array $args = []): bool|array    // TODO: Hungarian notation
    {
        $result = false;

        if (($ch = curl_init()) !== false) {
            curl_setopt($ch, CURLOPT_URL, $this->_build_request_url($method, $httpVerb, $args));
            curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
            curl_setopt($ch, CURLOPT_USERPWD, "user:" . $this->_api_key);
            curl_setopt($ch, CURLOPT_USERAGENT, 'PHP-MCAPI/3.0');
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_TIMEOUT, 10);
            curl_setopt($ch, CURLOPT_POST, true);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($args));
            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $httpVerb);

            $result = curl_exec($ch);

            curl_close($ch);
        }

        return $result ? json_decode($result, true) : false;
    }
}


/**
 * Mailchimp library, usable from CI code
 *
 * Library with utility queries to interface Mailchimp v3 API
 *
 * Inspired by the work of ThinkShout: https://github.com/thinkshout/mailchimp-api-php
 */

class Mailchimp_lib    // TODO: IMO We need to stick to the one class per file principle.
{
    private $_connector;    // TODO: Hungarian notation

    /**
     * @param array $params
     */
    public function __construct(array $params = [])
    {
        $api_key = (count($params) > 0 && !empty($params['api_key'])) ? $params['api_key'] : '';
        $this->_connector = new MailchimpConnector($api_key);
    }

    /**
     * Gets information about all lists owned by the authenticated account.
     *
     * @param array $parameters
     *   Associative array of optional request parameters.
     *   By the default it places a simple query to list name & id and count of members & merge_fields
     *   NOTE: no space between , and next word is allowed. You will not get the filter to work in full but just the first tag
     * @return array|bool
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/#read-get_lists
     */
    public function getLists(array $parameters = ['fields' => 'lists.id,lists.name,lists.stats.member_count,lists.stats.merge_field_count']): bool|array
    {
        return $this->_connector->call('/lists', 'GET', $parameters);    // TODO: Hungarian notation
    }

    /**
     * Gets a MailChimp list.
     *
     * @param string $list_id
     *   The ID of the list.
     * @param array $parameters Associative array of optional request parameters.
     * @return array|bool
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/#read-get_lists_list_id
     */
    public function getList(string $list_id, array $parameters = ['fields' => 'id,name,stats.member_count,stats.merge_field_count']): bool|array
    {
        return $this->_connector->call("/lists/$list_id", 'GET', $parameters);    // TODO: Hungarian notation
    }

    /**
     * Gets information about all members of a MailChimp list.
     *
     * @param string $list_id
     *   The ID of the list.
     * @param array $parameters
     *   Associative array of optional request parameters.
     * @return array|bool
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/#read-get_lists_list_id_members
     */
    public function getMembers(string $list_id, int $count, int $offset, array $parameters = ['fields' => 'members.id,members.email_address,members.unique_email_id,members.status,members.merge_fields']): bool|array
    {
        $parameters += [
            'count'  => $count,
            'offset' => $offset
        ];

        return $this->_connector->call("/lists/$list_id/members", 'GET', $parameters);    // TODO: Hungarian notation
    }

    /**
     * Gets information about a member of a MailChimp list.
     *
     * @param string $list_id
     *   The ID of the list.
     * @param string $md5id
     *   The member's email address md5 hash which is the id.
     * @param array $parameters
     *   Associative array of optional request parameters.
     * @return array|bool
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/#read-get_lists_list_id_members_subscriber_hash
     */
    public function getMemberInfoById(string $list_id, string $md5id, array $parameters = ['fields' => 'email_address,status,merge_fields']): bool|array
    {
        return $this->_connector->call("/lists/$list_id/members/$md5id", 'GET', $parameters);    // TODO: Hungarian notation
    }

    /**
     * Gets information about a member of a MailChimp list.
     *
     * @param string $list_id
     *   The ID of the list.
     * @param string $email
     *   The member's email address.
     * @param array $parameters
     *   Associative array of optional request parameters.
     * @return array|bool
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/#read-get_lists_list_id_members_subscriber_hash
     */
    public function getMemberInfo(string $list_id, string $email, array $parameters = []): bool|array
    {
        return $this->_connector->call("/lists/$list_id/members/" . md5(strtolower($email)), 'GET', $parameters);
    }

    /**
     * Gets activity related to a member of a MailChimp list.
     *
     * @param string $list_id The ID of the list.
     * @param string $email The member's email address.
     * @param array $parameters Associative array of optional request parameters.
     * @return array|bool Associative array of results or false.
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/activity/#read-get_lists_list_id_members_subscriber_hash_activity
     */
    public function getMemberActivity(string $list_id, string $email, array $parameters = []): bool|array
    {
        return $this->_connector->call("/lists/$list_id/members/" . md5(strtolower($email)) . '/activity', 'GET', $parameters);    // TODO: Hungarian notation
    }

    /**
     * Adds a new member to a MailChimp list.
     *
     * @param string $list_id
     *   The ID of the list.
     * @param string $email
     *   The email address to add.
     * @param array $parameters
     *   Associative array of optional request parameters.
     * @return array|bool
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/#create-post_lists_list_id_members
     */
    public function addMember(string $list_id, string $email, string $first_name, string $last_name, array $parameters = []): bool|array
    {
        $parameters += [
            'email_address' => $email,
            'status'        => 'subscribed',
            'merge_fields'  => [
                'FNAME' => $first_name,
                'LNAME' => $last_name
            ]
        ];

        return $this->_connector->call("/lists/$list_id/members/", 'POST', $parameters);    // TODO: Hungarian notation
    }

    /**
     * Removes a member from a MailChimp list.
     *
     * @param string $list_id
     *   The ID of the list.
     * @param string $email
     *   The member's email address.
     * @return array|bool
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/#delete-delete_lists_list_id_members_subscriber_hash
     */
    public function removeMember(string $list_id, string $email): bool|array
    {
        return $this->_connector->call("/lists/$list_id/members/" . md5(strtolower($email)), 'DELETE');    // TODO: Hungarian notation
    }

    /**
     * Updates a member of a MailChimp list.
     *
     * @param string $list_id
     *   The ID of the list.
     * @param string $email
     *   The member's email address.
     * @param array $parameters
     *   Associative array of optional request parameters.
     * @return array|bool
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/#edit-patch_lists_list_id_members_subscriber_hash
     */
    public function updateMember(string $list_id, string $email, string $first_name, string $last_name, array $parameters = []): bool|array
    {
        $parameters += [
            'status'       => 'subscribed',
            'merge_fields' => [
                'FNAME' => $first_name,
                'LNAME' => $last_name
            ]
        ];

        return $this->_connector->call("/lists/$list_id/members/" . md5(strtolower($email)), 'PATCH', $parameters);    // TODO: Hungarian notation
    }

    /**
     * Adds a new or update an existing member of a MailChimp list.
     *
     * @param string $list_id
     *   The ID of the list.
     * @param string $email
     *   The member's email address.
     * @param array $parameters
     *   Associative array of optional request parameters.
     * @return array|bool
     * @see http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/#edit-put_lists_list_id_members_subscriber_hash
     */
    public function addOrUpdateMember(string $list_id, string $email, string $first_name, string $last_name, string $status, array $parameters = []): bool|array
    {
        $parameters += [
            'email_address' => $email,
            'status'        => $status,
            'status_if_new' => 'subscribed',
            'merge_fields'  => [
                'FNAME' => $first_name,
                'LNAME' => $last_name
            ]
        ];

        return $this->_connector->call("/lists/$list_id/members/" . md5(strtolower($email)), 'PUT', $parameters);    // TODO: Hungarian notation
    }
}