<?php
/**
 * Visitor-facing consent: early head script, banner, preferences and cookie policy dialogs.
 *
 * @package GoConsent
 */

namespace GoConsent\Frontend;

use GoConsent\Scanner\Classifier;
use GoConsent\Scanner\Cookies;
use GoConsent\Settings;

defined( 'ABSPATH' ) || exit;

/**
 * Consent UI and state.
 */
class Consent {

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

	/**
	 * Constructor.
	 *
	 * @param Settings $settings Settings.
	 */
	public function __construct( Settings $settings ) {
		$this->settings = $settings;
	}

	/**
	 * Hook into WordPress.
	 */
	public function register() {
		add_action( 'wp_head', array( $this, 'head_script' ), -1000 );
		add_action( 'wp_enqueue_scripts', array( $this, 'assets' ) );
		add_action( 'wp_footer', array( $this, 'markup' ), 5 );
		add_shortcode( 'goconsent_choices', array( $this, 'choices_shortcode' ) );
	}

	/**
	 * Early inline script: consent state, Google Consent Mode v2 defaults and the browser guard.
	 * Printed before any other script so trackers always see "denied" first.
	 */
	public function head_script() {
		if ( Skip::request() ) {
			return;
		}
		$classifier = new Classifier( $this->settings );
		$config     = array(
			'v'     => (string) $this->settings->get( 'version' ),
			'gpc'   => (bool) $this->settings->get( 'gpc' ),
			'ad'    => (bool) $this->settings->get( 'analytics_default' ),
			'md'    => (bool) $this->settings->get( 'media_default' ),
			'rg'    => (bool) $this->settings->get( 'region_defaults' ),
			'nb'    => BannerMode::active( $this->settings ),
			'guard' => $this->settings->get( 'block' ) ? $classifier->guard_config() : null,
			'maps'  => MapsGate::enabled() ? MapsGate::needles() : null,
		);
		$js         = 'window.GoConsentConfig=' . wp_json_encode( $config ) . ';' . file_get_contents( GOCONSENT_DIR . 'assets/js/consent-head.js' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- local plugin file.
		wp_print_inline_script_tag( $js, array( 'data-goconsent-skip' => '1' ) );
	}

	/**
	 * Front-end assets.
	 */
	public function assets() {
		if ( Skip::request() ) {
			return;
		}
		// The version is also in the file address (gcv), so plugins that rewrite "ver" can't leave browsers on old files.
		wp_enqueue_style( 'goconsent', GOCONSENT_URL . 'assets/css/consent.css?gcv=' . rawurlencode( GOCONSENT_VERSION ), array(), GOCONSENT_VERSION );
		wp_add_inline_style( 'goconsent', ':root{' . self::tokens( (string) $this->settings->get( 'banner_color' ) ) . '}' );
		wp_enqueue_script(
			'goconsent',
			GOCONSENT_URL . 'assets/js/consent.js?gcv=' . rawurlencode( GOCONSENT_VERSION ),
			array(),
			GOCONSENT_VERSION,
			array(
				'in_footer' => true,
				'strategy'  => 'defer',
			)
		);
		// Stylesheet for the banner's shadow root (sealed off from theme CSS); consent.js adopts it.
		wp_add_inline_script( 'goconsent', 'window.GoConsentUICSS=' . wp_json_encode( self::ui_css( (string) $this->settings->get( 'banner_color' ) ) ) . ';', 'before' );
		wp_localize_script(
			'goconsent',
			'GoConsentFront',
			array(
				'traffic'         => $this->settings->get( 'traffic' ) && ( $this->settings->get( 'traffic_admins' ) || ! current_user_can( 'manage_options' ) ),
				'endpoint'        => esc_url_raw( rest_url( 'goconsent/v1/hit' ) ),
				'consentEndpoint' => esc_url_raw( rest_url( 'goconsent/v1/consent' ) ),
				'mapSelectors'    => MapsGate::enabled() ? implode( ',', MapsGate::selectors() ) : '',
				'mapTriggers'     => MapsGate::enabled() ? MapsGate::triggers() : array(),
				'i18n'            => array(
					'mapText'   => __( 'This map is provided by Google Maps. Loading it shares your IP address with Google and may set their cookies.', 'goconsent' ),
					'mapLoad'   => __( 'Load map', 'goconsent' ),
					'mapCancel' => __( 'Not now', 'goconsent' ),
					/* translators: %s: date and time the choice was saved. */
					'saved'     => __( 'Saved %s', 'goconsent' ),
					/* translators: %s: list of allowed categories, e.g. "Analytics, Maps & videos". */
					'allowed'   => __( 'Allowed: %s', 'goconsent' ),
					'necessary' => __( 'Only necessary cookies', 'goconsent' ),
					'copy'      => __( 'Copy ID', 'goconsent' ),
					'copied'    => __( 'Copied', 'goconsent' ),
					'cats'      => array_map(
						static function ( $l ) {
							return $l[1];
						},
						Cookies::labels()
					),
				),
			)
		);
	}

	/**
	 * Privacy policy URL.
	 *
	 * @return string
	 */
	private function privacy_url() {
		$id = $this->settings->privacy_page_id();
		return $id ? (string) get_permalink( $id ) : '';
	}

	/**
	 * Banner, preferences dialog, cookie policy dialog and optional footer link.
	 */
	public function markup() {
		if ( Skip::request() ) {
			return;
		}
		$privacy  = $this->privacy_url();
		$position = $this->settings->get( 'banner_position' );
		$ad       = (bool) $this->settings->get( 'analytics_default' );
		$labels   = Cookies::labels();
		$decl     = Cookies::declaration( $this->settings );

		/*
		 * The banner and dialogs render inside a Shadow DOM: consent.js attaches a shadow root to
		 * <goconsent-root> and moves this template into it, so theme and page-builder CSS can't
		 * reach them. Browsers without Shadow DOM get the same markup in the page, styled by
		 * the scoped consent.css.
		 */
		echo '<goconsent-root id="goconsent-root"></goconsent-root><template id="goconsent-ui">';
		include GOCONSENT_DIR . 'templates/frontend/banner.php';
		include GOCONSENT_DIR . 'templates/frontend/preferences.php';
		include GOCONSENT_DIR . 'templates/frontend/policy.php';
		if ( $this->settings->get( 'badge' ) ) {
			echo wp_kses( self::badge( (string) $this->settings->get( 'badge_position' ), (int) $this->settings->get( 'badge_offset' ) ), Kses::allowed() );
		}
		echo '</template>';

		/**
		 * Whether GoConsent prints its own "Your Privacy Choices" link.
		 * Integrations that place the link in their own footer return false.
		 *
		 * @param bool $show Default from settings.
		 */
		if ( apply_filters( 'goconsent_render_footer_link', (bool) $this->settings->get( 'footer_link' ) ) ) {
			echo '<div class="gc-footer-link">' . wp_kses( Choices::link(), Kses::allowed() ) . '</div>';
		}
	}

	/**
	 * Floating privacy button (GoConsent shield) that reopens Your Privacy Choices after a choice.
	 *
	 * @param string $side   left|right.
	 * @param int    $offset Distance from the bottom of the screen, in px.
	 * @return string
	 */
	private static function badge( $side, $offset ) {
		$side   = 'right' === $side ? 'right' : 'left';
		$offset = max( 12, min( 160, (int) $offset ) );
		$label  = __( 'Your Privacy Choices', 'goconsent' );
		$svg    = '<svg aria-hidden="true" focusable="false" width="24" height="29" viewBox="0 0 350 420"><path fill="#231f20" d="M261.53649,219.8211c-.96515.97234-1.51206,2.28393-1.52387,3.6545l-.26092,30.28363c-.18535,15.14302-7.12682,29.18661-19.0517,38.53527l-78.94128,61.91015c-3.61853,2.83785-8.70486,2.83788-12.32342.00006l-78.93788-61.9063c-11.92731-9.35161-18.86929-23.39513-19.05464-38.53725l-1.26473-146.73212c-.03896-4.52061,2.9523-8.49617,7.30202-9.71445,26.36101-7.38321,60.40663-19.49635,93.08775-38.68352,3.10215-1.82128,6.95223-1.81829,10.05436.00303,23.31108,13.68634,47.32329,23.77302,68.74132,31.11095,1.8942.64896,3.98989.14644,5.40094-1.27514l31.26816-31.5016c2.80439-2.82532,1.57241-7.63656-2.25136-8.73835-28.04194-8.08009-64.08724-21.77806-95.70564-44.21232-7.4323-5.27346-17.36506-5.39889-24.79342-.11986C100.31422,34.4333,49.15314,48.82058,20.97533,54.88478,8.63423,57.53009-.1473,68.51671.00187,81.14585l1.49209,173.13065c.34099,30.25035,14.38719,58.70861,38.19527,77.37504l110.0925,86.33992c3.415,2.67806,8.21524,2.67806,11.63024,0l110.09244-86.33992c23.80814-18.66643,37.85434-47.1247,38.19533-77.37504l.61028-70.81512c.04056-4.7068-5.651-7.08426-8.96551-3.74505l-39.80803,40.10477Z"/><path class="gc-badge-check" d="M156.94819,277.59308c-3.33429,0-6.46842-1.30679-8.82568-3.67853l-67.2009-67.61297c-2.35726-2.37173-3.6556-5.5256-3.6556-8.87938,0-3.35476,1.29834-6.50862,3.65608-8.88035l18.81546-18.93097c2.35726-2.37173,5.49188-3.67853,8.82568-3.67853s6.46842,1.30679,8.82568,3.67853l34.94458,35.15863c1.23243,1.2395,2.87098,1.92313,4.61469,1.92313,1.74323,0,3.38178-.68363,4.61469-1.92313L309.8771,55.54378c2.35823-2.37173,5.49188-3.67853,8.82617-3.67853,3.33332,0,6.46793,1.30679,8.8252,3.67853l18.81546,18.93194c2.35823,2.37173,3.65608,5.52462,3.65608,8.87938s-1.29785,6.50862-3.65608,8.88035l-180.57053,181.6791c-2.35726,2.37173-5.4914,3.67853-8.8252,3.67853Z"/></svg>';
		return '<button type="button" class="gc-badge gc-badge--' . esc_attr( $side ) . ' gc-open-prefs" aria-label="' . esc_attr( $label ) . '" title="' . esc_attr( $label ) . '" aria-haspopup="dialog" style="bottom:' . (int) $offset . 'px" hidden>' . $svg . '</button>';
	}

	/**
	 * Color tokens from the banner color, adjusted so text always meets WCAG AA (4.5:1):
	 * --gc-on-accent is the button text color (white or near-black, whichever reads better),
	 * --gc-accent-text is the accent darkened as needed for links and outline buttons on white.
	 *
	 * @param string $accent Banner color (hex).
	 * @return string CSS custom properties.
	 */
	public static function tokens( $accent ) {
		$accent = sanitize_hex_color( (string) $accent );
		$accent = $accent ? $accent : '#0e7a52';
		$rgb    = self::rgb( $accent );
		$on     = self::contrast( $rgb, array( 255, 255, 255 ) ) >= self::contrast( $rgb, array( 17, 17, 17 ) ) ? '#fff' : '#111';
		$text   = $rgb;
		for ( $i = 0; $i < 40 && self::contrast( $text, array( 255, 255, 255 ) ) < 4.5; $i++ ) {
			$text = array_map(
				static function ( $c ) {
					return (int) floor( $c * 0.9 );
				},
				$text
			);
		}
		return '--gc-accent:' . $accent . ';--gc-on-accent:' . $on . ';--gc-accent-text:' . vsprintf( '#%02x%02x%02x', $text ) . ';';
	}

	/**
	 * Hex color to [r, g, b].
	 *
	 * @param string $hex #rgb or #rrggbb.
	 * @return int[]
	 */
	private static function rgb( $hex ) {
		$hex = ltrim( $hex, '#' );
		if ( 3 === strlen( $hex ) ) {
			$hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
		}
		return array( hexdec( substr( $hex, 0, 2 ) ), hexdec( substr( $hex, 2, 2 ) ), hexdec( substr( $hex, 4, 2 ) ) );
	}

	/**
	 * WCAG contrast ratio between two colors.
	 *
	 * @param int[] $a First color.
	 * @param int[] $b Second color.
	 * @return float
	 */
	private static function contrast( array $a, array $b ) {
		$lum = static function ( array $c ) {
			$l = array();
			foreach ( $c as $v ) {
				$v   = $v / 255;
				$l[] = $v <= 0.03928 ? $v / 12.92 : pow( ( $v + 0.055 ) / 1.055, 2.4 );
			}
			return 0.2126 * $l[0] + 0.7152 * $l[1] + 0.0722 * $l[2];
		};
		$x = $lum( $a );
		$y = $lum( $b );
		return ( max( $x, $y ) + 0.05 ) / ( min( $x, $y ) + 0.05 );
	}

	/**
	 * Stylesheet for the shadow root: consent.css without the page-scope prefix.
	 *
	 * @param string $accent Banner color.
	 * @return string
	 */
	private static function ui_css( $accent ) {
		static $css = null;
		if ( null === $css ) {
			$css = (string) file_get_contents( GOCONSENT_DIR . 'assets/css/consent.css' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- local plugin file.
			$css = str_replace(
				array( 'html.gc-strict:not(#gc-scope) body:not(#gc-scope) ', 'html:not(#gc-scope) body:not(#gc-scope) ', ':root {' ),
				array( ':host(.gc-strict) ', '', ':host {' ),
				$css
			);
			$css = (string) preg_replace( '#/\*.*?\*/#s', '', $css );
			$css = (string) preg_replace( '/\s+/', ' ', $css );
		}
		// Reset everything the page would pass in (font, color, line height...), then our tokens.
		return ':host{all:initial;display:block}' . $css . ':host{' . self::tokens( $accent ) . '}';
	}

	/**
	 * [goconsent_choices text="..."] link.
	 *
	 * @param array $atts Attributes.
	 * @return string
	 */
	public function choices_shortcode( $atts ) {
		$atts = shortcode_atts( array( 'text' => __( 'Your Privacy Choices', 'goconsent' ) ), $atts, 'goconsent_choices' );
		return Choices::link( $atts['text'] );
	}
}