<?php

namespace AdPresso\Infrastructure;

use AdPresso\Constants;
use AdPresso\Entities\Ad;

/**
 * Link Handler class to handle the generation of links for ads.
 */
class LinkHandler {

	/** Query arg carrying "placementId-groupId" to LinkRedirector; stripped before the redirect. */
	public const CONTEXT_PARAM = 'adp_ctx';

	/**
	 * Builds the final URL for an ad, handling cloaking and custom bases.
	 *
	 * @param Ad $ad The ad entity.
	 *
	 * @return string The final URL (cloaked or raw).
	 */
	public static function get_final_url( Ad $ad ): string {
		$raw_link = trim( (string) $ad->get_meta( 'target_url', '' ) );

		if ( empty( $raw_link ) ) {
			return '';
		}

		/**
		 * Filter to enable link masking/cloaking for a specific ad.
		 *
		 * @param bool $is_cloaked Whether the ad's link should be cloaked. Default false.
		 * @param Ad   $ad         The ad entity.
		 */
		$is_cloaked = (bool) apply_filters( 'adpresso_ad_link_masking_enabled', false, $ad );

		if ( ! $is_cloaked ) {
			return $raw_link;
		}

		$global_base = Settings::get_setting( 'linkbase', Constants::LINK_MASKING_LINKBASE );
		$ad_base     = trim( (string) $ad->get_meta( 'linkbase_override', '' ) );
		$base        = ! empty( $ad_base ) ? $ad_base : $global_base;

		$custom_slug = trim( (string) $ad->get_meta( 'custom_link_slug', '' ) );
		$identifier  = ! empty( $custom_slug ) ? $custom_slug : $ad->get_id();

		return home_url( '/' . trailingslashit( sanitize_title( $base ) ) . sanitize_title( $identifier ) );
	}

	/**
	 * The link's target attribute value.
	 *
	 * @param Ad $ad The ad entity.
	 *
	 * @return string
	 */
	public static function get_target( Ad $ad ): string {
		return Util::get_effective_setting( $ad, 'target_blank' ) ? '_blank' : '_self';
	}

	/**
	 * The link's rel attribute value.
	 *
	 * @param Ad $ad The ad entity.
	 *
	 * @return string
	 */
	public static function get_rel( Ad $ad ): string {
		$sponsored = self::adds_link_attribute( $ad, 'add_sponsored' ) ? ' sponsored' : '';
		$nofollow  = self::adds_link_attribute( $ad, 'add_nofollow' ) ? ' nofollow' : '';

		return 'noopener noreferrer' . $sponsored . $nofollow;
	}

	/**
	 * The ad's own Yes/No, else whether the global "Add Link Attributes" list contains the attribute.
	 *
	 * @param Ad     $ad
	 * @param string $key 'add_sponsored' or 'add_nofollow'.
	 *
	 * @return bool
	 */
	private static function adds_link_attribute( Ad $ad, string $key ): bool {
		$own = (string) $ad->get_meta( $key );
		if ( $own === '1' || $own === '0' ) {
			return $own === '1';
		}

		$global = Settings::get_setting( 'add_link_attributes', [ 'add_nofollow' ] );

		return in_array( $key, Util::get_checked_keys( $global ), true );
	}

	/**
	 * Builds the dynamic link attributes (target, rel).
	 *
	 * @param Ad $ad The ad entity.
	 *
	 * @return string The link attributes.
	 */
	public static function get_link_attributes( Ad $ad ): string {
		return sprintf(
			'target="%s" rel="%s"',
			self::get_target( $ad ),
			self::get_rel( $ad )
		);
	}

	/**
	 * Whether this ad's click should be counted at the redirect itself rather than by the frontend's click listener.
	 *
	 * @param Ad     $ad
	 * @param string $final_url The already-resolved return value of get_final_url().
	 *
	 * @return bool
	 */
	public static function is_redirect_tracked( Ad $ad, string $final_url ): bool {
		if ( ! (bool) $ad->get_meta( 'redirect_click_tracking', false ) ) {
			return false;
		}

		$raw_link = trim( (string) $ad->get_meta( 'target_url', '' ) );

		return $final_url !== '' && $final_url !== $raw_link;
	}

	/**
	 * Adds the placement/group context to a redirect-tracked link, so the redirect can store it with the click.
	 *
	 * @param string $url     The masked URL.
	 * @param array  $context Render context (placement_id, group_id).
	 *
	 * @return string
	 */
	public static function with_click_context( string $url, array $context ): string {
		$placement_id = (int) ( $context['placement_id'] ?? 0 );
		$group_id     = (int) ( $context['group_id'] ?? 0 );
		if ( $placement_id <= 0 && $group_id <= 0 ) {
			return $url;
		}

		return add_query_arg( self::CONTEXT_PARAM, max( 0, $placement_id ) . '-' . max( 0, $group_id ), $url );
	}

	/**
	 * Replaces %link% (and %link_attributes%) in author-written content with the ad's final URL.
	 *
	 * @param Ad     $ad      The ad entity.
	 * @param string $content The ad content.
	 * @param array  $context Render context (placement_id, group_id) for redirect-tracked links.
	 *
	 * @return string
	 */
	public static function resolve_placeholders( Ad $ad, string $content, array $context = [] ): string {
		if ( ! str_contains( $content, '%link%' ) ) {
			return $content;
		}

		$url = self::get_final_url( $ad );
		if ( empty( $url ) ) {
			return $content;
		}

		if ( self::is_redirect_tracked( $ad, $url ) ) {
			// The click context joins an author query after the placeholder (%link%?utm=x) instead of breaking it.
			$content = (string) preg_replace_callback(
				'/%link%(\?[^"\'\s<>#]*)?/',
				static fn( array $m ): string => esc_url( self::with_click_context( $url . ( $m[1] ?? '' ), $context ) ),
				$content
			);
		} else {
			$content = str_replace( '%link%', esc_url( $url ), $content );
		}
		if ( str_contains( $content, '%link_attributes%' ) ) {
			$content = str_replace( '%link_attributes%', self::get_link_attributes( $ad ), $content );
		}

		return $content;
	}

	/**
	 * The magic wrapper. Takes the content and wraps it based on the settings.
	 *
	 * @param Ad     $ad              The ad entity.
	 * @param string $inner_content   The inner content of the ad.
	 * @param string $item_attributes The attributes of the ad item.
	 * @param bool   $is_inline       True for an inline-overridden placement/shortcode
	 * @param array  $context         Render context (placement_id, group_id) for redirect-tracked links.
	 *
	 * @return string The wrapped content.
	 */
	public static function wrap( Ad $ad, string $inner_content, string $item_attributes = '', bool $is_inline = false, array $context = [] ): string {
		$url        = self::get_final_url( $ad );
		$tag        = $is_inline ? 'span' : 'div';
		$is_tracked = self::is_redirect_tracked( $ad, $url );
		$prefix     = sanitize_html_class( Settings::get_setting( 'frontend_prefix', Constants::DEFAULT_FRONTEND_PREFIX ) );

		if ( ! empty( $url ) && str_contains( $inner_content, '%link%' ) ) {
			// The author wrote the <a>, so tracking.js recognises the redirect link by this URL instead of an attribute on it.
			if ( $is_tracked ) {
				$item_attributes .= sprintf( ' data-%s-rurl="%s"', $prefix, esc_url( $url ) );
			}

			return sprintf( '<%1$s %2$s>%3$s</%1$s>', $tag, $item_attributes, self::resolve_placeholders( $ad, $inner_content, $context ) );
		}

		if ( empty( $url ) ) {
			return sprintf( '<%1$s %2$s>%3$s</%1$s>', $tag, $item_attributes, $inner_content );
		}

		$click_src_attr = '';
		if ( $is_tracked ) {
			$click_src_attr = sprintf( ' data-%s-click-src="redirect"', $prefix );
			$url            = self::with_click_context( $url, $context );
		}

		// display:block goes into the item's own style attribute; a second style attribute would be dropped.
		// Prepended, so the ad's own inline CSS can still override it.
		if ( ! $is_inline ) {
			$item_attributes = str_contains( $item_attributes, 'style="' )
				? preg_replace( '/\bstyle="/', 'style="display:block; ', $item_attributes, 1 )
				: trim( $item_attributes . ' style="display:block;"' );
		}

		return sprintf(
			'<a href="%s" %s %s%s>%s</a>',
			esc_url( $url ),
			self::get_link_attributes( $ad ),
			$item_attributes,
			$click_src_attr,
			$inner_content
		);
	}
}