<?php
/**
 * Decides whether the browser tag belongs on the current request.
 *
 * @package AdPix\Analytics
 */

declare( strict_types = 1 );

namespace AdPix\Analytics\Service;

use AdPix\Analytics\Model\Settings;

defined( 'ABSPATH' ) || exit;

/**
 * The exclusion rules, in one place.
 *
 * Kept out of the controller because "should this page be measured" is a question with real
 * consequences either way — an over-broad rule quietly removes traffic from the reports, and there
 * is no signal in the data to tell you it happened. Isolating it means the rule can be reasoned
 * about, and tested, without a page render.
 *
 * Note what this deliberately does not cover: server-reported conversions. Excluding a role stops
 * the excluded user's browsing from being measured; it does not discard an order they place. A shop
 * manager who buys from their own shop has still made a sale, and dropping it would understate
 * revenue in a way nobody would ever notice.
 */
final class TagVisibility {

	/**
	 * Whether the tag should be printed for this request.
	 *
	 * @param Settings $settings Current configuration.
	 * @return bool
	 */
	public function allows( Settings $settings ): bool {
		if ( ! $settings->can_inject_tag() || ! $this->passes_exclusions( $settings ) ) {
			return false;
		}

		/**
		 * Filters whether the AdPix tag is printed on this request.
		 *
		 * Runs last, so a theme can restore the tag on a view the settings excluded as well as remove
		 * it from one they allowed.
		 *
		 * @since 1.0.0
		 *
		 * @param bool     $should_inject Whether to print the tag.
		 * @param Settings $settings      Current configuration.
		 */
		return (bool) apply_filters( 'adpix_analytics_should_inject_tag', true, $settings );
	}

	/**
	 * Whether the site's own extra markup should be printed for this request.
	 *
	 * Held to the same exclusions as the tag, but not to the same credentials: a verification meta
	 * tag or a third-party snippet is a legitimate reason to use this field on a site that has not
	 * finished connecting, and refusing to print it until then would be surprising.
	 *
	 * @param Settings $settings Current configuration.
	 * @return bool
	 */
	public function allows_custom_code( Settings $settings ): bool {
		if ( '' === $settings->str( 'custom_code' ) || ! $this->passes_exclusions( $settings ) ) {
			return false;
		}

		/**
		 * Filters whether the site's custom code block is printed on this request.
		 *
		 * @since 1.0.0
		 *
		 * @param bool     $should_print Whether to print the block.
		 * @param Settings $settings     Current configuration.
		 */
		return (bool) apply_filters( 'adpix_analytics_should_print_custom_code', true, $settings );
	}

	/**
	 * The exclusion rules shared by everything this plugin prints to a page.
	 *
	 * @param Settings $settings Current configuration.
	 * @return bool
	 */
	private function passes_exclusions( Settings $settings ): bool {
		if ( is_admin() && ! $settings->flag( 'tag_admin_area' ) ) {
			return false;
		}

		if ( $this->is_excluded_user( $settings ) ) {
			return false;
		}

		return is_admin() || ! $this->is_excluded_view( $settings );
	}

	/**
	 * Whether the logged-in user holds a role that is excluded from measurement.
	 *
	 * @param Settings $settings Current configuration.
	 * @return bool
	 */
	private function is_excluded_user( Settings $settings ): bool {
		$excluded = $settings->arr( 'exclude_roles' );

		if ( array() === $excluded || ! is_user_logged_in() ) {
			return false;
		}

		$user = wp_get_current_user();

		return array() !== array_intersect( (array) $user->roles, $excluded );
	}

	/**
	 * Whether the view being rendered is one the settings exclude.
	 *
	 * @param Settings $settings Current configuration.
	 * @return bool
	 */
	private function is_excluded_view( Settings $settings ): bool {
		if ( $settings->flag( 'exclude_search_archive' ) && ( is_search() || is_archive() ) ) {
			return true;
		}

		$ids = $settings->excluded_post_ids();

		if ( array() === $ids ) {
			return false;
		}

		// get_queried_object_id() rather than get_the_ID(), so the rule matches the page the visitor
		// asked for and not whichever post the main loop happens to be on when the tag is enqueued.
		$current = (int) get_queried_object_id();

		return 0 !== $current && in_array( $current, $ids, true );
	}
}