Noptin_Background_Mailer::prepare_campaign_data( $item )

	public function prepare_campaign_data( $item ) {

		// A unique key for this campaign.
		$key = time() . wp_generate_password( 6, false );

		// If this is a normal campaign, ensure it is published.
		if ( isset( $item['campaign_id'] ) ) {

			// Set the unique key to the campaign id.
			$key = $item['campaign_id'];

			// Fetch the post and ensure it is a published campaign.
			$post = get_post( $item['campaign_id'] );
			if ( 'noptin-campaign' !== $post->post_type || 'publish' !== $post->post_status ) {
				return false;
			}
		}

		if ( empty( $item['key'] ) ) {
			$item['key'] = $key;
		}

		// Fetch the next recipient of this campaign.
		$next_recipient = false;

		// User can set recipients to be an array of subcriber ids or emails...
		if ( isset( $item['recipients'] ) ) {
			$next_recipient = array_shift( $item['recipients'] );
		} else if ( isset( $item['subscribers_query'] ) ) {
			// Or a WHERE query to be executed on the subscribers table.
			$next_recipient = $this->fetch_subscriber_from_query( $item );
		}

		// If there is no other subscriber, abort.
		if ( empty( $next_recipient ) ) {

			if ( ! empty( $item['campaign_id'] ) ) {
				update_post_meta( $item['campaign_id'], 'completed', 1 );
			}

			do_action( 'noptin_background_mailer_complete', $item );

			return false;
		}

		$item['current_recipient'] = $next_recipient;

		// Recipient data.
		$item['next_recipient_data'] = array();
		if ( isset( $item['campaign_data'] ) ) {
			$item['next_recipient_data'] = $item['campaign_data'];
		}

		// If this is a campaign, fetch the email body and subject.
		if ( isset( $item['campaign_id'] ) && empty( $item['next_recipient_data']['email_body'] ) ) {

			// Email body is the post content
			$item['next_recipient_data']['email_body'] = $post->post_content;

			// Email subject is the post title for newsletters and post_meta for campaign automations.
			if ( 'newsletter' === get_post_meta( $post->ID, 'campaign_type', true ) ) {
				$item['next_recipient_data']['email_subject'] = $post->post_title;
			} else {
				$item['next_recipient_data']['email_subject'] = get_post_meta( $post->ID, 'email_subject', true );
			}

			// Finally, fetch the preview text.
			$item['next_recipient_data']['preview_text'] = get_post_meta( $post->ID, 'preview_text', true );

		}

		// Maybe fetch a subscriber from an email...
		if ( is_email( $next_recipient ) ) {
			$item['next_recipient_data']['email'] = $next_recipient;
		}

		// Or a subscriber id.
		if ( is_scalar( $next_recipient ) ) {
			$subscriber = get_noptin_subscriber( $next_recipient );
		}

		// Prepare the email merge tags.
		if ( empty( $item['next_recipient_data']['merge_tags'] ) ) {
			$item['next_recipient_data']['merge_tags'] = array();
		}

		if ( isset( $item['custom_merge_tags'] ) ) {
			$item['next_recipient_data']['merge_tags'] = array_merge( $item['next_recipient_data']['merge_tags'], $item['custom_merge_tags'] );
		}

		// Add the subscriber details as merge tags.
		if ( $subscriber->exists() ) {

			$item['next_recipient_data']['email']         = $subscriber->email;
			$item['next_recipient_data']['subscriber_id'] = $subscriber->id;

			$item['next_recipient_data']['merge_tags'] = array_merge( $item['next_recipient_data']['merge_tags'], get_noptin_subscriber_merge_fields( $subscriber ) );

		}

		return $item;
	}