Create a MemberPress Member

members.php

<?php

/**
 * Create a MemberPress Member trans and subscr record to activate a user.
 *
 * @param int $user_id WP_User id.
 * @param int $membership_id WP_Post id.
 * @return void
 */
function create_memberpress_member( $user_id, $membership_id ) {
	global $wpdb;

	$key = "memberpressproduct_{$membership_id}_meta";

	if ( wp_cache_get( $key ) ) {
		$meta = wp_cache_get( $key );
	} else {
		$meta = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT meta_key, meta_value
				FROM $wpdb->postmeta
				WHERE post_id = %s",
				$membership_id
			), ARRAY_N
		);
		wp_cache_set( $key, $meta );
	}

	if ( ! $meta ) {
		return;
	} else {
		$metadata = [];
		foreach ( $meta as $m ) {
			$metadata[ $m[0] ] = $m[1];
		}
	}

	// Create subscription.
	$table = $wpdb->prefix . 'mepr_subscriptions';
	$data  = [
		'user_id'             => $user_id,
		'product_id'          => (int) $membership_id,
		'subscr_id'           => 'mp-sub-' . uniqid(),
		'price'               => $metadata['_mepr_product_price'],
		'total'               => $metadata['_mepr_product_price'],
		'gateway'             => 'manual',
		'period'              => $metadata['_mepr_product_period'],
		'period_type'         => $metadata['_mepr_product_period_type'],
		'limit_cycles_num'    => $metadata['_mepr_product_limit_cycles_num'],
		'limit_cycles_action' => $metadata['_mepr_product_limit_cycles_action'],
		'status'              => 'active',
		'created_at'          => date( 'Y-m-d H:i:s' ),
	];

	$inserted = $wpdb->insert( $table, $data );
	$sub_id   = $wpdb->insert_id;

	$increment = $metadata['_mepr_expire_after'] . ' ' . $metadata['_mepr_expire_unit'];
	$expire    = date( 'Y-m-d H:i:s', strtotime( "+$increment", time() ) );

	// Create transaction.
	$table = $wpdb->prefix . 'mepr_transactions';
	$data  = [
		'amount'          => $metadata['_mepr_product_price'],
		'total'           => $metadata['_mepr_product_price'],
		'user_id'         => $user_id,
		'product_id'      => (int) $membership_id,
		'trans_num'       => 'mp-txn-' . uniqid(),
		'status'          => 'complete',
		'gateway'         => 'manual',
		'subscription_id' => $sub_id,
		'created_at'      => date( 'Y-m-d H:i:s' ),
		'expires_at'      => $expire,
	];

	$inserted  = $wpdb->insert( $table, $data );
	$insert_id = $wpdb->insert_id;

}