<?php

declare(strict_types=1);

namespace FlexaLocal\Support;

defined( 'ABSPATH' ) || exit;

/**
 * Sanitizers for values that end up inside CSS: an inline `style=""` attribute
 * or a custom property. esc_attr() only makes a value safe as HTML, so a color
 * of `red;background:url(x)` would still inject its own declarations. Each
 * helper here reduces a value to a shape that cannot escape its property.
 */
final class Css {

	/**
	 * A color the plugin keeps rather than stores literally: `palette:primary`
	 * or `palette:secondary` resolve through Settings, so changing the brand
	 * color changes every email that names it.
	 */
	public const REFERENCE = '/^palette:([a-z0-9_-]{1,40})$/';

	/**
	 * A #rgb or #rrggbb color, or $fallback when the value is anything else.
	 * Palette references resolve first.
	 */
	public static function hex_color( mixed $value, string $fallback = '' ): string {
		if ( is_string( $value ) && preg_match( self::REFERENCE, trim( $value ), $match ) ) {
			$value = self::palette( $match[1] );
		}

		$color = is_string( $value ) ? sanitize_hex_color( trim( $value ) ) : null;

		return is_string( $color ) && '' !== $color ? $color : $fallback;
	}

	/**
	 * A color to store: a palette reference stays as it is, a hex color is
	 * sanitized, anything else becomes ''.
	 */
	public static function stored_color( mixed $value ): string {
		$value = is_string( $value ) ? trim( $value ) : '';
		if ( 1 === preg_match( self::REFERENCE, $value ) ) {
			return $value;
		}

		$color = sanitize_hex_color( $value );

		return is_string( $color ) ? $color : '';
	}

	/**
	 * A font-family stack: letters, digits, spaces, commas, hyphens and single
	 * quotes. Anything that could close the property (`;`, `}`, `(`, `"`) is
	 * stripped. Unquoted multi-word names like Helvetica Neue are valid CSS.
	 */
	public static function font_stack( mixed $value, string $fallback = '' ): string {
		$stack = is_string( $value ) ? trim( (string) preg_replace( '/[^A-Za-z0-9 ,\'-]/', '', $value ) ) : '';

		return '' !== $stack ? $stack : $fallback;
	}

	/**
	 * The hex color a palette key stands for, or '' when the key is unknown.
	 */
	private static function palette( string $key ): string {
		/** @var array<string,mixed> $colors */
		$colors = (array) Settings::get( 'colors', [] );

		/** @var array<string,mixed> $resolved */
		$resolved = (array) apply_filters( 'fxlc_email_palette', $colors );

		$value = $resolved[ $key ] ?? '';

		return is_string( $value ) ? $value : '';
	}
}