<?php
/**
 * MailChimp Handler
 */

// If this file is called directly, abort.
if ( ! defined( 'WPINC' ) ) {
	die;
}

if ( ! class_exists( 'Jet_Engine_Forms_MailChimp_Handler' ) ) {

	/**
	 * Define Jet_Engine_Forms_MailChimp_Handler class
	 */
	class Jet_Engine_Forms_MailChimp_Handler {

		private $api_base_url = '';
		private $api_key = '';
		private $api_request_args = array();
		public  $success_statuses = array( 'subscribed', 'pending' );

		/**
		 * Constructor for the class
		 *
		 * @param $api_key
		 */
		public function __construct( $api_key ) {

			if ( empty( $api_key ) ) {
				return new WP_Error( 'invalid_api_key' );
			}

			$api_key_data = explode( '-', $api_key );

			if ( empty( $api_key_data[1] ) || 0 !== strpos( $api_key_data[1], 'us' ) ) {
				return new WP_Error( 'invalid_api_key' );
			}

			$this->api_key = $api_key;
			$this->api_base_url = sprintf( 'https://%s.api.mailchimp.com/3.0/', $api_key_data[1] );
			$this->api_request_args = array(
				'headers' => array(
					'Authorization' => 'Basic ' . base64_encode( 'user:' . $this->api_key ),
				),
			);

		}

		public function request( $end_point, $request_args = array() ) {
			$args     = array_merge_recursive( $this->api_request_args, $request_args );
			$response = wp_remote_request( $this->api_base_url . $end_point, $args );

			if ( ! $response || is_wp_error( $response ) ) {
				return false;
			}

			$data = wp_remote_retrieve_body( $response );

			if ( ! $data ) {
				return array();
			}

			$data = json_decode( $data, true );

			return $data;
		}

		public function get_all_data() {
			$lists  = $this->get_lists();
			$groups = array();
			$fields = array();

			foreach ( $lists as $list_id => $list_name ) {
				$groups[ $list_id ] = $this->get_groups( $list_id );
				$fields[ $list_id ] = $this->get_fields( $list_id );
			}

			return array(
				'lists'  => $lists,
				'groups' => $groups,
				'fields' => $fields,
			);
		}

		public function get_lists() {
			$result = array();
			$lists  = $this->request( 'lists?count=999' );

			if ( ! empty( $lists['lists'] ) ) {
				foreach ( $lists['lists'] as $list ) {
					$result[ $list['id'] ] = $list['name'];
				}
			}

			return $result;
		}

		public function get_groups( $list_id ) {
			$groups     = array();
			$categories = $this->request( 'lists/' . $list_id . '/interest-categories?count=999' );

			if ( ! empty( $categories['categories'] ) ) {
				foreach ( $categories['categories'] as $category ) {
					$interests = $this->request( 'lists/' . $list_id . '/interest-categories/' . $category['id'] . '/interests?count=999' );

					foreach ( $interests['interests'] as $interest ) {
						$groups[] = array(
							'value' => $interest['id'],
							'label' => $category['title'] . ' - ' . $interest['name'],
						);
					}
				}
			}

			return $groups;
		}

		public function get_fields( $list_id ) {
			$result = array(
				'email' => array(
					'label'    => esc_html__( 'Email', 'jet-engine' ),
					'required' => true,
				)
			);

			$merge_fields = $this->request( 'lists/' . $list_id . '/merge-fields?count=999' );

			if ( ! empty( $merge_fields['merge_fields'] ) ) {
				foreach ( $merge_fields['merge_fields'] as $field ) {
					$result[ $field['tag'] ] = array(
						'label'    => $field['name'],
						'required' => $field['required'],
					);
				}
			}

			return $result;
		}
	}

}