<?php
/**
 * First-run setup.
 *
 * @package AIBlackout
 */

namespace AIBlackout\Admin;

use AIBlackout\Core\Settings;
use AIBlackout\Crawlers\Policy;
use AIBlackout\Crawlers\Registry;

defined( 'ABSPATH' ) || exit;

/**
 * The three answers to the plugin's one question.
 *
 * @since 1.0.0
 */
class Onboarding {

	/**
	 * Capability required to act here.
	 *
	 * @var string
	 */
	const CAPABILITY = 'manage_options';

	/**
	 * Transient that sends a freshly activated site here once.
	 *
	 * @var string
	 */
	const REDIRECT_TRANSIENT = 'aiblackout_activation_redirect';

	/**
	 * Refuse everything an AI company sends.
	 *
	 * @var string
	 */
	const CHOICE_EVERYTHING = 'everything';

	/**
	 * Refuse training and scraping, keep AI search.
	 *
	 * @var string
	 */
	const CHOICE_TRAINING = 'training';

	/**
	 * Block nothing; declare everything.
	 *
	 * @var string
	 */
	const CHOICE_DECLARE = 'declare';

	/**
	 * Plugin settings.
	 *
	 * @var Settings
	 */
	private $settings;

	/**
	 * Policy resolver.
	 *
	 * @var Policy
	 */
	private $policy;

	/**
	 * Crawler registry.
	 *
	 * @var Registry
	 */
	private $registry;

	/**
	 * Constructor.
	 *
	 * @param Settings $settings Plugin settings.
	 * @param Policy   $policy   Policy resolver.
	 * @param Registry $registry Crawler registry.
	 */
	public function __construct( Settings $settings, Policy $policy, Registry $registry ) {
		$this->settings = $settings;
		$this->policy   = $policy;
		$this->registry = $registry;
	}

	/**
	 * Registers hooks.
	 *
	 * @return void
	 */
	public function register(): void {
		add_action( 'admin_init', array( $this, 'maybe_redirect' ) );
	}

	/**
	 * Sends a freshly activated site to the screen, once.
	 *
	 * @return void
	 */
	public function maybe_redirect(): void {
		if ( ! get_transient( self::REDIRECT_TRANSIENT ) ) {
			return;
		}

		delete_transient( self::REDIRECT_TRANSIENT );

		if ( ! current_user_can( self::CAPABILITY ) || wp_doing_ajax() ) {
			return;
		}

		// Never redirect out of a bulk activation.
		// the results for every other plugin in the batch.
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Reading the core plugins screen's own request, to stay out of its way.
		if ( isset( $_GET['activate-multi'] ) ) {
			return;
		}

		wp_safe_redirect( $this->get_screen_url() );
		exit;
	}

	/**
	 * Whether setup has been completed.
	 *
	 * @return bool True when a choice has been applied.
	 */
	public function is_complete(): bool {
		return (bool) $this->settings->get( 'onboarding_complete', false );
	}

	/**
	 * Returns the answer currently in force.
	 *
	 * @return string One of the CHOICE_* constants.
	 */
	public function current_choice(): string {
		$stored = (string) $this->settings->get( 'onboarding_choice', '' );

		return in_array( $stored, array( self::CHOICE_EVERYTHING, self::CHOICE_TRAINING, self::CHOICE_DECLARE ), true )
			? $stored
			: self::CHOICE_TRAINING;
	}

	/**
	 * Returns the URL of the screen this used to be a page of its own for.
	 *
	 * @param array $args Optional query arguments to add.
	 * @return string Admin URL.
	 */
	public function get_screen_url( array $args = array() ): string {
		return MainScreen::url( $args );
	}

	/**
	 * Whether every search-affecting crawler has already been confirmed.
	 *
	 * @return bool True when the confirmation has been given.
	 */
	public function has_accepted_search_loss(): bool {
		$found = false;

		foreach ( $this->registry->get_agents() as $agent ) {
			if ( 'none' === $agent['search_impact'] ) {
				continue;
			}

			$found = true;

			if ( ! $this->settings->has_search_impact_ack( $agent['ua'] ) ) {
				return false;
			}
		}

		return $found;
	}

	/**
	 * Applies a quick-choice preset.
	 *
	 * @param string $choice               One of the CHOICE_* constants.
	 * @param bool   $accepts_search_loss  Whether search-impact loss was confirmed.
	 * @return string[] Messages for anything the model refused.
	 */
	public function apply_choice( string $choice, bool $accepts_search_loss ): array {
		if ( ! in_array( $choice, array( self::CHOICE_EVERYTHING, self::CHOICE_TRAINING, self::CHOICE_DECLARE ), true ) ) {
			return array();
		}

		foreach ( $this->registry->get_agents() as $agent ) {
			if ( 'none' === $agent['search_impact'] ) {
				continue;
			}

			if ( $accepts_search_loss ) {
				$this->settings->add_search_impact_ack( $agent['ua'] );
			} else {
				$this->settings->remove_search_impact_ack( $agent['ua'] );
			}
		}

		// A preset clears any per-crawler choices made earlier.
		$this->settings->set(
			'policies',
			array(
				'groups' => array(),
				'agents' => array(),
			)
		);

		$refusals = $this->apply_purposes( $choice );

		$this->apply_declarations();

		$this->settings->set( 'onboarding_complete', true );
		$this->settings->set( 'onboarding_choice', $choice );

		return $refusals;
	}

	/**
	 * Writes the purpose defaults a choice implies.
	 *
	 * @param string $choice One of the CHOICE_* constants.
	 * @return string[] Messages for anything the model refused.
	 */
	private function apply_purposes( string $choice ): array {
		$presets = array(
			self::CHOICE_EVERYTHING => array(
				'training'      => Policy::BLOCK,
				'dataset'       => Policy::BLOCK,
				'scraping-tool' => Policy::BLOCK,
				'search'        => Policy::BLOCK,
				'user-fetch'    => Policy::BLOCK,
			),
			self::CHOICE_TRAINING   => array(
				'training'      => Policy::BLOCK,
				'dataset'       => Policy::BLOCK,
				'scraping-tool' => Policy::BLOCK,
				'search'        => Policy::ALLOW,
				'user-fetch'    => Policy::ALLOW,
			),
			self::CHOICE_DECLARE    => array(
				'training'      => Policy::SIGNAL_ONLY,
				'dataset'       => Policy::SIGNAL_ONLY,
				'scraping-tool' => Policy::SIGNAL_ONLY,
				'search'        => Policy::ALLOW,
				'user-fetch'    => Policy::ALLOW,
			),
		);

		$refusals = array();

		foreach ( $presets[ $choice ] as $purpose => $policy ) {
			$result = $this->policy->set_purpose_default( $purpose, $policy );

			if ( ! is_wp_error( $result ) ) {
				continue;
			}

			$refusals[] = $result->get_error_message();

			$this->policy->set_purpose_default( $purpose, Policy::ALLOW );
		}

		return $refusals;
	}

	/**
	 * Publishes the declarations.
	 *
	 * @return void
	 */
	private function apply_declarations(): void {
		$declarations = $this->settings->get( 'declarations', array() );
		$declarations = is_array( $declarations ) ? $declarations : array();

		$this->settings->set(
			'declarations',
			array_merge(
				$declarations,
				array(
					'tdm_reservation' => true,
					'content_signals' => true,
					'signal_search'   => Settings::SIGNAL_YES,
					'signal_ai_input' => Settings::SIGNAL_NO,
					'signal_ai_train' => Settings::SIGNAL_NO,
					'noai'            => true,
					'noimageai'       => true,
				)
			)
		);
	}
}