<?php
/**
 * The page visitors see while the site is closed.
 *
 * @package ForensixDigital
 */

declare(strict_types=1);

namespace ForensixDigital\Apps\Maintenance;

defined( 'ABSPATH' ) || exit;

/**
 * Plain HTML without the theme, so it works whatever the theme or page builder is doing.
 */
final class MaintenancePage {

	/**
	 * The page's CSS. It is printed through the WordPress style queue (handle fxd-maintenance).
	 *
	 * @param array<string, mixed> $extra Same as for html().
	 */
	public static function css( array $extra = array() ): string {
		$colours = array();
		foreach ( MaintenanceConfig::COLOURS as $key => $fallback ) {
			$value           = isset( $extra[ $key ] ) ? (string) $extra[ $key ] : '';
			$colours[ $key ] = 1 === preg_match( '/^#[0-9a-fA-F]{6}$/', $value ) ? $value : $fallback;
		}
		$image = isset( $extra['image'] ) ? (string) $extra['image'] : '';
		$style = self::image_style( $extra );

		$css = ':root{--fxd-bg:' . $colours['color_background'] . ';--fxd-box:' . $colours['color_box'] . ';--fxd-text:' . $colours['color_text'] . ';--fxd-accent:' . $colours['color_accent'] . '}'
			. '*{box-sizing:border-box}body{margin:0;min-height:100vh;display:flex;flex-direction:column;background:var(--fxd-bg);color:var(--fxd-text);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif}'
			. '.fxd-wrap{flex:1;display:flex;align-items:center;justify-content:center;padding:2rem 1rem}'
			. 'main{width:100%;max-width:34rem;padding:2.5rem;background:var(--fxd-box);border-radius:12px;box-shadow:0 2px 16px rgba(0,0,0,.08);text-align:center}'
			. '.fxd-logo{display:block;max-width:220px;max-height:90px;width:auto;height:auto;margin:0 auto 1.5rem}'
			. 'h1{margin:0 0 1rem;font-size:1.8rem;line-height:1.25}p{margin:0;line-height:1.6;font-size:1.05rem}'
			. 'a{color:var(--fxd-accent)}'
			. 'footer{display:flex;flex-wrap:wrap;gap:.5rem 1.25rem;justify-content:center;padding:1rem;font-size:.85rem}footer a{color:inherit;opacity:.8}'
			. '.fxd-extra{margin-top:1.75rem;text-align:left}'
			. '.fxd-extra input:not([type=checkbox]):not([type=radio]),.fxd-extra textarea,.fxd-extra select{width:100%;padding:.6rem;border:1px solid rgba(0,0,0,.25);border-radius:6px;font:inherit}'
			. '.fxd-extra button,.fxd-extra input[type=submit]{background:var(--fxd-accent);color:#fff;border:0;border-radius:6px;padding:.7rem 1.4rem;font:inherit;cursor:pointer}'
			. '.fxd-extra label{display:block;margin:.75rem 0 .25rem;font-weight:600}';
		if ( MaintenanceConfig::IMAGE_BACKGROUND === $style ) {
			$css .= 'body{background:var(--fxd-bg) url("' . esc_url( $image ) . '") center/cover no-repeat fixed}';
		} elseif ( MaintenanceConfig::IMAGE_SIDE === $style ) {
			$css .= '.fxd-split{flex:1;display:grid;grid-template-columns:1fr 1fr}.fxd-side{background:url("' . esc_url( $image ) . '") center/cover no-repeat;min-height:40vh}'
				. '@media(max-width:780px){.fxd-split{grid-template-columns:1fr}}';
		}

		return $css;
	}

	/**
	 * The image layout that applies: none when there is no image.
	 *
	 * @param array<string, mixed> $extra Same as for html().
	 */
	private static function image_style( array $extra ): string {
		$image = isset( $extra['image'] ) ? (string) $extra['image'] : '';
		return '' === $image ? MaintenanceConfig::IMAGE_NONE : (string) ( $extra['image_style'] ?? MaintenanceConfig::IMAGE_NONE );
	}

	/**
	 * The HTML document.
	 *
	 * @param string               $site    Site name.
	 * @param string               $title   Heading.
	 * @param string               $message Text, line breaks are kept.
	 * @param string               $lang    Language code.
	 * @param bool                 $noindex Whether search engines are told to skip the page.
	 * @param array<string, mixed> $extra   Optional look and parts: logo and image (URLs), image_style,
	 *                                      the colours of MaintenanceConfig::COLOURS, legal (label => URL),
	 *                                      styles (the printed style queue, see MaintenanceApp),
	 *                                      and head / after (HTML from add-ons, already escaped).
	 */
	public static function html( string $site, string $title, string $message, string $lang, bool $noindex, array $extra = array() ): string {
		$logo  = isset( $extra['logo'] ) ? (string) $extra['logo'] : '';
		$style = self::image_style( $extra );

		$box = '<main>'
			. ( '' !== $logo ? '<img class="fxd-logo" src="' . esc_url( $logo ) . '" alt="' . esc_attr( $site ) . '">' : '' )
			. '<h1>' . esc_html( $title ) . '</h1><p>' . nl2br( esc_html( $message ) ) . '</p>'
			. (string) ( $extra['after'] ?? '' )
			. '</main>';

		$links = '';
		foreach ( (array) ( $extra['legal'] ?? array() ) as $label => $url ) {
			$links .= '<a href="' . esc_url( (string) $url ) . '">' . esc_html( (string) $label ) . '</a>';
		}
		$footer = '' !== $links ? '<footer>' . $links . '</footer>' : '';

		$body = MaintenanceConfig::IMAGE_SIDE === $style
			? '<div class="fxd-split"><div class="fxd-side" aria-hidden="true"></div><div class="fxd-wrap">' . $box . '</div></div>'
			: '<div class="fxd-wrap">' . $box . '</div>';

		return '<!DOCTYPE html><html lang="' . esc_attr( $lang ) . '"><head><meta charset="utf-8">'
			. '<meta name="viewport" content="width=device-width, initial-scale=1">'
			. ( $noindex ? '<meta name="robots" content="noindex, nofollow">' : '' )
			. '<title>' . esc_html( $title . ' - ' . $site ) . '</title>'
			. (string) ( $extra['styles'] ?? '' )
			. (string) ( $extra['head'] ?? '' )
			. '</head><body>' . $body . $footer . '</body></html>';
	}
}