<?php

namespace Yipresser\AdminOptimizer\Modules;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Technical consent collection and explicit optional-service gating.
 */
class Consent_Manager {
	const OPTION_NAME    = 'adminoptim_consent_manager';
	const COOKIE_NAME    = 'adminoptim_consent';
	const SCHEMA_VERSION = 1;
	const MODULE_URL     = ADMINOPTIMIZER_MODULES_URI . 'site-traffic-manager/';

	/**
	 * Current consent settings.
	 *
	 * @var array
	 */
	private $options = [];
	
	/**
	 * Services registered for consent gating, keyed by service ID.
	 *
	 * @var array<string,array>
	 */
	private static $services = [];

	/**
	 * Cached, request-scoped copy of the module's options.
	 *
	 * @var array
	 */
	private static $runtime_options = [];

	/**
	 * Start the engine running.
	 *
	 * @return void
	 */
	public function __construct() {
		$this->options         = wp_parse_args( get_option( self::OPTION_NAME, [] ), self::get_default_settings() );
		self::$runtime_options = $this->options;
		add_action( 'init', [ $this, 'prepare_translated_options' ], 0 );
		add_action( 'wp_enqueue_scripts', [ $this, 'enqueue_frontend_assets' ], 100 );
		add_action( 'wp_footer', [ $this, 'render_frontend' ], 5 );
		add_shortcode( 'adminoptim_consent_preferences', [ $this, 'render_preferences_shortcode' ] );
	}

	/**
	 * Get the consent defaults without translated strings.
	 *
	 * @return array
	 */
	public static function get_default_settings(): array {
		return [
			'enable_banner'          => 1,
			'expiry_days'            => 180,
			'banner_title'           => 'Your privacy choices',
			'banner_message'         => 'We use optional services only when you allow their category. You can change your choices at any time.',
			'accept_label'           => 'Accept All',
			'reject_label'           => 'Reject Optional',
			'manage_label'           => 'Manage Preferences',
			'preferences_title'      => 'Consent preferences',
			'preferences_text'       => 'Choose which optional categories you allow. Necessary services are always active.',
			'save_label'             => 'Save Preferences',
			'necessary_description'  => 'Required for the site to function and cannot be switched off.',
			'functional_enabled'     => 1,
			'functional_description' => 'Supports optional site features and preferences.',
			'analytics_enabled'      => 1,
			'analytics_description'  => 'Helps measure how visitors use the site.',
			'marketing_enabled'      => 1,
			'marketing_description'  => 'Supports advertising and campaign measurement.',
		];
	}

	/**
	 * Get defaults after translations have loaded.
	 *
	 * @return array
	 */
	public static function get_translated_default_settings(): array {
		$defaults                           = self::get_default_settings();
		$defaults['banner_title']           = __( 'Your privacy choices', 'admin-optimizer' );
		$defaults['banner_message']         = __( 'We use optional services only when you allow their category. You can change your choices at any time.', 'admin-optimizer' );
		$defaults['accept_label']           = __( 'Accept All', 'admin-optimizer' );
		$defaults['reject_label']           = __( 'Reject Optional', 'admin-optimizer' );
		$defaults['manage_label']           = __( 'Manage Preferences', 'admin-optimizer' );
		$defaults['preferences_title']      = __( 'Consent preferences', 'admin-optimizer' );
		$defaults['preferences_text']       = __( 'Choose which optional categories you allow. Necessary services are always active.', 'admin-optimizer' );
		$defaults['save_label']             = __( 'Save Preferences', 'admin-optimizer' );
		$defaults['necessary_description']  = __( 'Required for the site to function and cannot be switched off.', 'admin-optimizer' );
		$defaults['functional_description'] = __( 'Supports optional site features and preferences.', 'admin-optimizer' );
		$defaults['analytics_description']  = __( 'Helps measure how visitors use the site.', 'admin-optimizer' );
		$defaults['marketing_description']  = __( 'Supports advertising and campaign measurement.', 'admin-optimizer' );
		return $defaults;
	}

	/**
	 * Normalize raw consent settings into stable stored values.
	 *
	 * @param mixed $input Raw settings input.
	 * @return array
	 */
	public static function normalize_settings( $input ): array {
		$defaults  = self::get_default_settings();
		$input     = is_array( $input ) ? $input : [];
		$sanitized = [
			'enable_banner'      => empty( $input['enable_banner'] ) ? 0 : 1,
			'functional_enabled' => empty( $input['functional_enabled'] ) ? 0 : 1,
			'analytics_enabled'  => empty( $input['analytics_enabled'] ) ? 0 : 1,
			'marketing_enabled'  => empty( $input['marketing_enabled'] ) ? 0 : 1,
			'expiry_days'        => isset( $input['expiry_days'] ) ? max( 1, min( 365, absint( $input['expiry_days'] ) ) ) : $defaults['expiry_days'],
		];

		foreach ( [ 'banner_title', 'accept_label', 'reject_label', 'manage_label', 'preferences_title', 'save_label', 'necessary_description', 'functional_description', 'analytics_description', 'marketing_description' ] as $field ) {
			$sanitized[ $field ] = isset( $input[ $field ] ) ? sanitize_text_field( $input[ $field ] ) : $defaults[ $field ];
		}
		foreach ( [ 'banner_message', 'preferences_text' ] as $field ) {
			$sanitized[ $field ] = isset( $input[ $field ] ) ? sanitize_textarea_field( $input[ $field ] ) : $defaults[ $field ];
		}

		return $sanitized;
	}

	/**
	 * Refresh translated defaults on init.
	 *
	 * @return void
	 */
	public function prepare_translated_options(): void {
		$this->options         = wp_parse_args( get_option( self::OPTION_NAME, [] ), self::get_translated_default_settings() );
		self::$runtime_options = $this->options;
	}

	/**
	 * Normalize an arbitrary value into a known consent category slug.
	 *
	 * @param mixed $category Category value to normalize.
	 * @return string Normalized category slug, or an empty string if invalid.
	 */
	public static function normalize_category( $category ): string {
		$category = is_string( $category ) ? sanitize_key( $category ) : '';
		return in_array( $category, [ 'necessary', 'functional', 'analytics', 'marketing' ], true ) ? $category : '';
	}

	/**
	 * Check whether a consent category is enabled in settings.
	 *
	 * @param mixed      $category Category to check.
	 * @param array|null $options  Options to check against. Defaults to the current module options.
	 * @return bool
	 */
	public static function is_category_enabled( $category, ?array $options = null ): bool {
		$category = self::normalize_category( $category );
		if ( 'necessary' === $category ) {
			return true; }
		$options = null === $options ? self::options() : $options;
		return '' !== $category && ! empty( $options[ $category . '_enabled' ] );
	}

	/**
	 * Decode and validate a raw consent cookie value.
	 *
	 * @param mixed      $raw     Raw (still URL-encoded) cookie value.
	 * @param array|null $options Options to validate against. Defaults to the current module options.
	 * @param int|null   $now     Current timestamp to validate against. Defaults to time().
	 * @return array|null Normalized consent data, or null if the cookie is missing, malformed, or expired.
	 */
	public static function normalize_cookie( $raw, ?array $options = null, ?int $now = null ): ?array {
		$options = null === $options ? self::options() : wp_parse_args( $options, self::get_default_settings() );
		$now     = null === $now ? time() : $now;
		if ( ! is_string( $raw ) || '' === $raw ) {
			return null; }
		$data = json_decode( rawurldecode( $raw ), true );
		if ( ! is_array( $data ) || self::SCHEMA_VERSION !== ( $data['version'] ?? null ) || ! isset( $data['timestamp'], $data['consent'] ) || ! is_int( $data['timestamp'] ) || ! is_array( $data['consent'] ) ) {
			return null; }
		$expiry = max( 1, (int) $options['expiry_days'] ) * DAY_IN_SECONDS;
		if ( $data['timestamp'] > $now + 300 || $data['timestamp'] + $expiry < $now ) {
			return null; }
		$state = [ 'necessary' => true ];
		foreach ( [ 'functional', 'analytics', 'marketing' ] as $category ) {
			$state[ $category ] = self::is_category_enabled( $category, $options ) && true === ( $data['consent'][ $category ] ?? false );
		}
		return [
			'version'   => self::SCHEMA_VERSION,
			'consent'   => $state,
			'timestamp' => $data['timestamp'],
		];
	}

	/**
	 * Get the current visitor's normalized consent state from the request cookie.
	 *
	 * @return array|null
	 */
	public static function get_consent(): ?array {
		$raw = isset( $_COOKIE[ self::COOKIE_NAME ] ) ? sanitize_text_field( wp_unslash( $_COOKIE[ self::COOKIE_NAME ] ) ) : '';
		return self::normalize_cookie( $raw );
	}

	/**
	 * Check whether the current visitor has consented to a category.
	 *
	 * @param mixed $category Category to check.
	 * @return bool
	 */
	public static function has_consent( $category ): bool {
		$category = self::normalize_category( $category );
		if ( 'necessary' === $category ) {
			return true; }
		if ( ! self::is_category_enabled( $category ) ) {
			return false; }
		$state = self::get_consent();
		return null !== $state && ! empty( $state['consent'][ $category ] );
	}

	/**
	 * Register an optional service for consent gating.
	 *
	 * @param array $service {
	 *     Service definition.
	 *
	 *     @type string $id          Unique service ID.
	 *     @type string $name        Service display name. Defaults to the ID.
	 *     @type string $category    Consent category the service belongs to.
	 *     @type string $description Service description.
	 *     @type string $src         Service script URL. Must use the http or https scheme.
	 * }
	 * @return bool True on successful registration, false if the service definition is invalid.
	 */
	public static function register_service( array $service ) {
		$id       = isset( $service['id'] ) ? sanitize_key( $service['id'] ) : '';
		$category = self::normalize_category( $service['category'] ?? '' );
		$src      = isset( $service['src'] ) ? esc_url_raw( $service['src'], [ 'http', 'https' ] ) : '';
		$scheme   = is_string( $src ) ? strtolower( (string) wp_parse_url( $src, PHP_URL_SCHEME ) ) : '';
		if ( '' === $id || ! in_array( $category, [ 'functional', 'analytics', 'marketing' ], true ) || ! in_array( $scheme, [ 'http', 'https' ], true ) ) {
			return false; }
		self::$services[ $id ] = [
			'id'          => $id,
			'name'        => sanitize_text_field( $service['name'] ?? $id ),
			'category'    => $category,
			'description' => sanitize_text_field( $service['description'] ?? '' ),
			'src'         => $src,
		];
		return true;
	}

	/**
	 * Get all services registered for consent gating.
	 *
	 * @return array
	 */
	public static function get_registered_services(): array {
		return array_values( self::$services ); }

	/**
	 * Enqueue the frontend banner assets and localize the consent config.
	 *
	 * @return void
	 */
	public function enqueue_frontend_assets(): void {
		if ( empty( $this->options['enable_banner'] ) ) {
			return; }
		do_action( 'adminoptim_consent_register_services' );
		wp_enqueue_style( 'adminoptim-consent-manager', self::MODULE_URL . 'assets/css/consent-manager.min.css', [], ADMINOPTIMIZER_VERSION );
		wp_enqueue_script( 'adminoptim-consent-manager', self::MODULE_URL . 'assets/js/consent-manager.min.js', [], ADMINOPTIMIZER_VERSION, true );
		wp_localize_script( 'adminoptim-consent-manager', 'AdminOptimizerConsentConfig', $this->frontend_config() );
	}

	/**
	 * Build the frontend config localized to the consent manager script.
	 *
	 * @return array
	 */
	private function frontend_config(): array {
		$categories = [];
		foreach ( [ 'necessary', 'functional', 'analytics', 'marketing' ] as $category ) {
			if ( self::is_category_enabled( $category, $this->options ) ) {
				$categories[] = $category; }
		}
		$services = array_values(
			array_filter(
				self::get_registered_services(),
				function ( $service ) {
					return self::is_category_enabled( $service['category'], $this->options );
				}
			)
		);
		return [
			'cookieName'      => self::COOKIE_NAME,
			'version'         => self::SCHEMA_VERSION,
			'expiryDays'      => (int) $this->options['expiry_days'],
			'categories'      => $categories,
			'services'        => $services,
			'existingConsent' => self::get_consent(),
		];
	}

	/**
	 * Render the consent banner and preferences dialog markup in the footer.
	 *
	 * @return void
	 */
	public function render_frontend(): void {
		if ( empty( $this->options['enable_banner'] ) ) {
			return; }
		$category_labels = [
			'necessary'  => __( 'Necessary', 'admin-optimizer' ),
			'functional' => __( 'Functional', 'admin-optimizer' ),
			'analytics'  => __( 'Analytics', 'admin-optimizer' ),
			'marketing'  => __( 'Marketing', 'admin-optimizer' ),
		];
		?>
		<div class="adminoptim-consent" data-adminoptim-consent hidden>
			<section class="adminoptim-consent__banner" aria-label="<?php esc_attr_e( 'Consent choices', 'admin-optimizer' ); ?>">
				<h2><?php echo esc_html( $this->options['banner_title'] ); ?></h2><p><?php echo esc_html( $this->options['banner_message'] ); ?></p>
				<div class="adminoptim-consent__actions"><button type="button" data-ao-consent-action="accept"><?php echo esc_html( $this->options['accept_label'] ); ?></button><button type="button" data-ao-consent-action="reject"><?php echo esc_html( $this->options['reject_label'] ); ?></button><button type="button" data-ao-consent-action="manage"><?php echo esc_html( $this->options['manage_label'] ); ?></button></div>
			</section>
			<div class="adminoptim-consent__backdrop" data-ao-consent-close hidden></div>
			<section class="adminoptim-consent__dialog" role="dialog" aria-modal="true" aria-labelledby="ao-consent-title" hidden tabindex="-1">
				<button class="adminoptim-consent__close" type="button" data-ao-consent-close aria-label="<?php esc_attr_e( 'Close preferences', 'admin-optimizer' ); ?>">&times;</button>
				<h2 id="ao-consent-title"><?php echo esc_html( $this->options['preferences_title'] ); ?></h2><p><?php echo esc_html( $this->options['preferences_text'] ); ?></p>
				<?php
				foreach ( [ 'necessary', 'functional', 'analytics', 'marketing' ] as $category ) :
					if ( ! self::is_category_enabled( $category, $this->options ) ) {
						continue; }
					?>
				<label class="adminoptim-consent__category"><span><strong><?php echo esc_html( $category_labels[ $category ] ); ?></strong><small><?php echo esc_html( $this->options[ $category . '_description' ] ); ?></small></span><span><input type="checkbox" data-ao-consent-category="<?php echo esc_attr( $category ); ?>" <?php checked( 'necessary', $category ); ?> <?php disabled( 'necessary', $category ); ?>><em><?php echo 'necessary' === $category ? esc_html__( 'Always active', 'admin-optimizer' ) : ''; ?></em></span></label>
				<?php endforeach; ?>
				<button type="button" data-ao-consent-action="save"><?php echo esc_html( $this->options['save_label'] ); ?></button>
			</section>
		</div>
		<?php
	}

	/**
	 * Render the [adminoptim_consent_preferences] shortcode.
	 *
	 * @return string
	 */
	public function render_preferences_shortcode(): string {
		return '<button type="button" class="adminoptim-consent-preferences-link" data-ao-consent-open>' . esc_html__( 'Cookie preferences', 'admin-optimizer' ) . '</button>';
	}

	/**
	 * Get the module's current options, falling back to stored or default settings.
	 *
	 * @return array
	 */
	private static function options(): array {
		if ( ! empty( self::$runtime_options ) ) {
			return self::$runtime_options; }
		return wp_parse_args( get_option( self::OPTION_NAME, [] ), self::get_default_settings() );
	}
}