<?php

namespace AdPresso\Modules\Privacy;

use AdPresso\Entities\Ad;
use AdPresso\Entities\Entity;
use AdPresso\Entities\Group;
use AdPresso\Entities\Placement;
use AdPresso\Infrastructure\Util;
use AdPresso\Modules\ModuleManager;
use AdPresso\RuntimeDebugger;

defined( 'ABSPATH' ) || exit;

/**
 * The single place that decides whether an Ad/Group item needs consent before it can render.
 */
class ConsentPolicy {

	/**
	 * @param Entity         $item      The placement's resolved item (Ad or Group).
	 * @param Placement|null $placement Only used for debug-log context.
	 *
	 * @return bool True if the item requires consent (must be JS-rendered).
	 */
	public static function item_requires_consent( Entity $item, ?Placement $placement = null ): bool {
		$requires_consent = self::requires_consent( $item, $placement );

		if ( $requires_consent ) {
			$placement_id = $placement?->get_id() ?? '?';
			RuntimeDebugger::add_server_error_log_entry( "Privacy: Item #{$item->get_id()} in Placement #{$placement_id} requires consent, forcing JS." );
			RuntimeDebugger::note_js_forcing_reason( 'privacy', __( 'Privacy module active (forces JS for consent check, except Image/Dummy ads and ads with "Ignore Privacy Settings" enabled)', 'adpresso' ) );
		} elseif ( $item instanceof Ad && (bool) $item->get_meta( 'ignore_privacy_settings', 0 ) ) {
			RuntimeDebugger::add_server_error_log_entry( "Privacy: Ad #{$item->get_id()} has 'ignore_privacy_settings' enabled. Allowing SSR." );
		}

		return $requires_consent;
	}

	/**
	 * Adds the `requires_consent` flag to an item's JS config, so placement-controller.js doesn't re-derive the rule.
	 * Config-only decision, so it is safe in full-page-cached HTML. No-op while the Privacy module is off.
	 *
	 * @param array          $config    The item's frontend config.
	 * @param Entity         $item      The Ad or Group the config belongs to.
	 * @param Placement|null $placement Passed to the filter as context.
	 *
	 * @return array
	 */
	public static function add_js_flag( array $config, Entity $item, ?Placement $placement = null ): array {
		if ( ! apply_filters( 'adpresso_privacy_module_active', ModuleManager::is_active( PrivacyService::MODULE_ID ) ) ) {
			return $config;
		}

		$config['requires_consent'] = self::requires_consent( $item, $placement );

		// Each group child too: privacy-pro.js decides per ad in the NPA (partial) state.
		if ( $item instanceof Group && ! empty( $config['ads'] ) && is_array( $config['ads'] ) && method_exists( $item, 'get_valid_ads' ) ) {
			$child_ads = $item->get_valid_ads();
			foreach ( $config['ads'] as $ad_id => $ad_config ) {
				if ( is_array( $ad_config ) && ( $child_ads[ $ad_id ] ?? null ) instanceof Ad ) {
					$config['ads'][ $ad_id ]['requires_consent'] = self::requires_consent( $child_ads[ $ad_id ], $placement );
				}
			}
		}

		return $config;
	}

	/**
	 * The general fallback is the last resort and shows regardless of consent.
	 * The placement's custom code stays withheld without consent (placement-controller.js).
	 *
	 * @param array $config The fallback's frontend config.
	 *
	 * @return array
	 */
	public static function add_general_fallback_js_flag( array $config ): array {
		if ( ! apply_filters( 'adpresso_privacy_module_active', ModuleManager::is_active( PrivacyService::MODULE_ID ) ) ) {
			return $config;
		}

		$config['requires_consent']    = false;
		$config['is_general_fallback'] = true;

		// Group children too: privacy-pro.js checks each ad (partial consent, TCF vendor, CMP service).
		if ( ! empty( $config['ads'] ) && is_array( $config['ads'] ) ) {
			foreach ( $config['ads'] as $ad_id => $ad_config ) {
				if ( is_array( $ad_config ) ) {
					$config['ads'][ $ad_id ]['requires_consent']    = false;
					$config['ads'][ $ad_id ]['is_general_fallback'] = true;
				}
			}
		}

		return $config;
	}

	/**
	 * The decision itself, without debug side effects.
	 *
	 * @param Entity         $item
	 * @param Placement|null $placement Its custom placement code is printed with the item.
	 *
	 * @return bool
	 */
	private static function requires_consent( Entity $item, ?Placement $placement = null ): bool {
		if ( ( $item instanceof Ad || $item instanceof Group ) && $placement && self::has_output_custom_code( $placement, 'custom_placement_code' ) ) {
			$requires_consent = true;
		} elseif ( $item instanceof Ad ) {
			$requires_consent = ! self::ad_is_privacy_safe( $item );
		} elseif ( $item instanceof Group ) {
			$requires_consent = self::group_requires_consent( $item );
		} else {
			$requires_consent = false;
		}

		return (bool) apply_filters( 'adpresso_item_requires_consent', $requires_consent, $item, $placement );
	}

	/**
	 * Whether a single Ad can be rendered SSR without consent.
	 *
	 * @param Ad $ad
	 *
	 * @return bool
	 */
	private static function ad_is_privacy_safe( Ad $ad ): bool {
		if ( (bool) $ad->get_meta( 'ignore_privacy_settings', 0 ) ) {
			return true;
		}

		// A type-based exemption (Image/Dummy) only covers that type's own first-party output. custom_ad_code can carry arbitrary third-party markup on any ad type.
		if ( self::has_output_custom_code( $ad, 'custom_ad_code' ) ) {
			return false;
		}

		$allowed_privacy_types = apply_filters( 'adpresso_privacy_exceptional_ad_types', [ 'image', 'dummy' ] );

		return in_array( $ad->get_type(), $allowed_privacy_types, true );
	}

	/**
	 * Whether custom code is actually output: same Pro gate as Util::get_custom_code().
	 *
	 * @param Entity $entity
	 * @param string $meta_key
	 *
	 * @return bool
	 */
	private static function has_output_custom_code( Entity $entity, string $meta_key ): bool {
		return Util::is_pro_active() && (string) $entity->get_meta( $meta_key, '' ) !== '';
	}

	/**
	 * @param Group $group
	 *
	 * @return bool
	 */
	private static function group_requires_consent( Group $group ): bool {
		if ( ! method_exists( $group, 'get_valid_ads' ) ) {
			return true;
		}

		foreach ( $group->get_valid_ads() as $ad_in_group ) {
			if ( ! $ad_in_group instanceof Ad || ! self::ad_is_privacy_safe( $ad_in_group ) ) {
				return true;
			}
		}

		return false;
	}
}