<?php

namespace AdPresso\Modules\Adsense;

use AdPresso\Constants;
use AdPresso\Infrastructure\Params;
use AdPresso\Infrastructure\Settings;
use AdPresso\Notifications\NotificationManager;
use AdPresso\Placements\Types\Header as HeaderPlacement;
use AdPresso\RuntimeDebugger;
use WP_Post;

defined( 'ABSPATH' ) || exit;

/**
 * Handles all backend logic for the AdSense Module,
 * including settings UI registration and Auto Ads automation.
 */
class AdSenseService {

	private static ?AdSenseService $instance = null;

	public const OPTION_NAME = 'settings_adsense';

	/**
	 * Singleton instance getter.
	 *
	 * @return self|null
	 */
	public static function get(): ?self {
		if ( self::$instance === null ) {
			self::$instance = new self();
			self::$instance->hooks();
		}

		return self::$instance;
	}

	private function __construct() {
	}

	/**
	 * Registers all necessary hooks for the admin side of the module.
	 */
	public function hooks(): void {
		add_filter( 'display_post_states', [ $this, 'mark_auto_ads_post_states' ], 10, 2 );
		add_action( 'before_delete_post', [ $this, 'handle_auto_ads_deletion' ] );
	}

	/**
	 * Adds an 'AdSense Auto Ad' or 'AdSense Auto Placement' state to the post list table.
	 *
	 * @param array   $states
	 * @param WP_Post $post
	 *
	 * @return array
	 */
	public function mark_auto_ads_post_states( array $states, WP_Post $post ): array {
		$ad_id        = Settings::get_setting( 'auto_ads_ad_id', 0 );
		$placement_id = Settings::get_setting( 'auto_ads_placement_id', 0 );

		if ( $post->ID === $ad_id ) {
			$states['adpresso_adsense_ad'] = __( 'AdSense Auto Ad', 'adpresso' );
		} elseif ( $post->ID === $placement_id ) {
			$states['adpresso_adsense_placement'] = __( 'AdSense Auto Placement', 'adpresso' );
		}

		return $states;
	}

	/**
	 * Creates and publishes the necessary Ad and Placement for Auto Ads.
	 *
	 * @return void
	 */
	public function create_entities(): void {
		if ( ! check_ajax_referer( SettingsTab::CREATE_ENTITIES_AJAX_ACTION, '_ajax_nonce', false ) ) {
			wp_send_json_error( [ 'message' => __( 'Invalid nonce.', 'adpresso' ) ], 403 );
		}

		// Capability check (Admin-only)
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_send_json_error( [ 'message' => __( 'Permission denied.', 'adpresso' ) ], 403 );
		}

		$placement_id = Params::post()->getId( 'placement_id', 0 );
		$ad_id        = Params::post()->getId( 'ad_id', 0 );

		$placement_exists = $placement_id && get_post_status( $placement_id );
		$ad_exists        = $ad_id && get_post_status( $ad_id );

		if ( $placement_exists && $ad_exists ) {
			RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Placement and Ad already exist. Skipping creation.' );
			wp_update_post( [ 'ID' => $placement_id, 'post_status' => 'publish' ] );
			wp_update_post( [ 'ID' => $ad_id, 'post_status' => 'publish' ] );
			wp_send_json_error( [ 'message' => __( 'Ad and placement already exist.', 'adpresso' ) ], 403 );

			return;
		}

		$settings     = get_option( 'adpresso_settings_adsense' );
		$publisher_id = $settings['adsense_publisher_id'] ?? '';
		if ( empty( $publisher_id ) ) {
			wp_send_json_error( [ 'message' => __( 'Please set your Publisher ID first.', 'adpresso' ) ], 403 );

			return;
		}

		// Create ad
		$new_ad_id = $this->create_auto_ads_ad( $publisher_id );
		if ( ! $new_ad_id ) {
			RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Failed to create Ad. Skipping creation.' );
			wp_send_json_error( [ 'message' => __( 'Failed to create Ad. Skipping creation.', 'adpresso' ) ], 403 );

			return;
		}

		// Create placement
		$new_placement_id = $this->create_auto_ads_placement();
		if ( ! $new_placement_id ) {
			RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Failed to create Placement. Skipping creation.' );
			wp_send_json_error( [ 'message' => __( 'Failed to create Placement. Skipping creation.', 'adpresso' ) ], 403 );

			return;
		}

		$this->assign_ad_to_placement( $new_placement_id, $new_ad_id );

		RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Placement and Ad created successfully.' );
		$settings['auto_ads_placement_id']   = $new_placement_id;
		$settings['auto_ads_ad_id']          = $new_ad_id;
		$settings['adsense_enable_auto_ads'] = true;

		Settings::update_direct_option( self::OPTION_NAME, $settings );

		wp_send_json_success( [ 'message' => __( 'Entities are created successfully!', 'adpresso' ) ] );
	}

	/**
	 * Create the ad for the Auto Ads script.
	 *
	 * @param string $publisher_id
	 *
	 * @return int
	 */
	private function create_auto_ads_ad( string $publisher_id ): int {
		$script_content = $this->get_auto_ads_script_content( $publisher_id );
		$ad_id          = wp_insert_post( [
			'post_type'    => Constants::POST_TYPE_AD,
			'post_title'   => 'AdSense Auto Ads Script (Auto-Generated)',
			'post_content' => $script_content,
			'post_status'  => 'publish',
		] );
		RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Ad ID: ' . $ad_id );
		if ( is_wp_error( $ad_id ) ) {
			RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Ad creation failed.' );

			return 0;
		}
		RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Ad created successfully.' );

		update_post_meta( $ad_id, Constants::META_PREFIX . 'ad_type', 'html' );

		return $ad_id;
	}

	/**
	 * Creates a new header placement for the Auto Ads script.
	 *
	 * @return int
	 */
	private function create_auto_ads_placement(): int {
		$placement_id = wp_insert_post( [
			'post_type'   => Constants::POST_TYPE_PLACEMENT,
			'post_title'  => 'AdSense Auto Ads Placement (Auto-Generated)',
			'post_status' => 'publish',
		] );
		RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Placement ID: ' . $placement_id );
		if ( is_wp_error( $placement_id ) ) {
			RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Placement creation failed.' );

			return 0;
		}
		RuntimeDebugger::add_server_error_log_entry( 'Auto Ads: Placement created successfully.' );

		update_post_meta( $placement_id, Constants::META_PREFIX . 'placement_type', HeaderPlacement::ID );

		return $placement_id;
	}

	/**
	 * Assign ad to placement.
	 *
	 * @param int $placement_id
	 * @param int $ad_id
	 *
	 * @return void
	 */
	private function assign_ad_to_placement( int $placement_id, int $ad_id ): void {
		update_post_meta( $placement_id, Constants::META_PREFIX . 'placement_item_id', $ad_id );
	}

	/**
	 * Creates the Auto Ads script content based on the Publisher ID.
	 *
	 * @param string $publisher_id
	 *
	 * @return string
	 */
	private function get_auto_ads_script_content( string $publisher_id ): string {
		$normalized_id = $this->normalize_adsense_publisher_id( $publisher_id );

		return sprintf(
		// phpcs:ignore WordPress.WP.EnqueuedResources.NonEnqueuedScript -- don't allow any changes on Google AdSense code.
			'<script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=%s" crossorigin="anonymous"></script>',
			esc_attr( $normalized_id )
		);
	}

	/**
	 * Checks if a permanently deleted post is part of the Auto Ads setup,
	 * clears the IDs, disables the feature and notifies the user.
	 *
	 * @param int $post_id The ID of the post being deleted.
	 */
	public static function handle_auto_ads_deletion( int $post_id ): void {
		$post_type = get_post_type( $post_id );

		if ( ! in_array( $post_type, [ 'adpresso_ad', 'adpresso_placement' ], true ) ) {
			return;
		}

		$option_name = 'adpresso_settings_adsense';
		$settings    = get_option( $option_name, [] );

		if ( empty( $settings ) || ! is_array( $settings ) ) {
			return;
		}

		$is_dirty     = false;
		$deleted_type = '';

		if ( isset( $settings['auto_ads_ad_id'] ) && (int) $settings['auto_ads_ad_id'] === $post_id ) {
			$settings['auto_ads_ad_id'] = 0;
			$deleted_type               = __( 'Auto-Ad', 'adpresso' );
			$is_dirty                   = true;
		}

		if ( isset( $settings['auto_ads_placement_id'] ) && (int) $settings['auto_ads_placement_id'] === $post_id ) {
			$settings['auto_ads_placement_id'] = 0;
			$deleted_type                      = __( 'Auto-Ad Placement', 'adpresso' );
			$is_dirty                          = true;
		}

		if ( $is_dirty ) {
			$settings['adsense_enable_auto_ads'] = 0;
			update_option( $option_name, $settings );

			NotificationManager::get()->register(
				'adsense-autoad-deleted-' . $post_id,
				sprintf(
				/* translators: %s is the type of the deleted entity (Auto-Ad or Placement) */
					__( 'Your AdSense %s was permanently deleted. The Auto-Ads feature has been automatically disabled to prevent errors.', 'adpresso' ),
					$deleted_type
				),
				[
					'type'        => 'warning',
					'location'    => 'wp_notice',
					'dismissible' => true,
					'context'     => 'all',
				]
			);
		}
	}

	/**
	 * Normalizes the AdSense Publisher ID to a standard format.
	 *
	 * @param string $id
	 *
	 * @return string
	 */
	private function normalize_adsense_publisher_id( string $id ): string {
		$id = strtolower( trim( $id ) );

		// Removes common prefixes
		$id = preg_replace( '/^(ca-)?(pub-)?/', '', $id );

		// Only digits are allowed
		$id = preg_replace( '/\D/', '', $id );

		// Add the standard prefix if not present
		return 'ca-pub-' . $id;
	}
}