<?php
/**
 * Border block support flag.
 *
 * @package WordPress
 * @since 5.8.0
 */

/**
 * Registers the style attribute used by the border feature if needed for block
 * types that support borders.
 *
 * @since 5.8.0
 * @since 6.1.0 Improved conditional blocks optimization.
 * @access private
 *
 * @param WP_Block_Type $block_type Block Type.
 */
function wp_register_border_support( $block_type ) {
    // Setup attributes and styles within that if needed.
    if ( ! $block_type->attributes ) {
        $block_type->attributes = array();
    }

    if ( block_has_support( $block_type, '__experimentalBorder' ) && ! array_key_exists( 'style', $block_type->attributes ) ) {
        $block_type->attributes['style'] = array(
            'type' => 'object',
        );
    }

    if ( wp_has_border_feature_support( $block_type, 'color' ) && ! array_key_exists( 'borderColor', $block_type->attributes ) ) {
        $block_type->attributes['borderColor'] = array(
            'type' => 'string',
        );
    }
}

/**
 * Adds CSS classes and inline styles for border styles to the incoming
 * attributes array. This will be applied to the block markup in the front-end.
 *
 * @since 5.8.0
 * @since 6.1.0 Implemented the style engine to generate CSS and classnames.
 * @access private
 *
 * @param WP_Block_Type $block_type       Block type.
 * @param array         $block_attributes Block attributes.
 * @return array Border CSS classes and inline styles.
 */
function wp_apply_border_support( $block_type, $block_attributes ) {
    if ( wp_should_skip_block_supports_serialization( $block_type, 'border' ) ) {
        return array();
    }

    $border_block_styles      = array();
    $has_border_color_support = wp_has_border_feature_support( $block_type, 'color' );
    $has_border_width_support = wp_has_border_feature_support( $block_type, 'width' );

    // Border radius.
    if (
        wp_has_border_feature_support( $block_type, 'radius' ) &&
        isset( $block_attributes['style']['border']['radius'] ) &&
        ! wp_should_skip_block_supports_serialization( $block_type, '__experimentalBorder', 'radius' )
    ) {
        $border_radius = $block_attributes['style']['border']['radius'];

        if ( is_numeric( $border_radius ) ) {
            $border_radius .= 'px';
        }

        $border_block_styles['radius'] = $border_radius;
    }

    // Border style.
    if (
        wp_has_border_feature_support( $block_type, 'style' ) &&
        isset( $block_attributes['style']['border']['style'] ) &&
        ! wp_should_skip_block_supports_serialization( $block_type, '__experimentalBorder', 'style' )
    ) {
        $border_block_styles['style'] = $block_attributes['style']['border']['style'];
    }

    // Border width.
    if (
        $has_border_width_support &&
        isset( $block_attributes['style']['border']['width'] ) &&
        ! wp_should_skip_block_supports_serialization( $block_type, '__experimentalBorder', 'width' )
    ) {
        $border_width = $block_attributes['style']['border']['width'];

        // This check handles original unitless implementation.
        if ( is_numeric( $border_width ) ) {
            $border_width .= 'px';
        }

        $border_block_styles['width'] = $border_width;
    }

    // Border color.
    if (
        $has_border_color_support &&
        ! wp_should_skip_block_supports_serialization( $block_type, '__experimentalBorder', 'color' )
    ) {
        $preset_border_color          = array_key_exists( 'borderColor', $block_attributes ) ? "var:preset|color|{$block_attributes['borderColor']}" : null;
        $custom_border_color          = $block_attributes['style']['border']['color'] ?? null;
        $border_block_styles['color'] = $preset_border_color ? $preset_border_color : $custom_border_color;
    }

    // Generates styles for individual border sides.
    if ( $has_border_color_support || $has_border_width_support ) {
        foreach ( array( 'top', 'right', 'bottom', 'left' ) as $side ) {
            $border                       = $block_attributes['style']['border'][ $side ] ?? null;
            $border_side_values           = array(
                'width' => isset( $border['width'] ) && ! wp_should_skip_block_supports_serialization( $block_type, '__experimentalBorder', 'width' ) ? $border['width'] : null,
                'color' => isset( $border['color'] ) && ! wp_should_skip_block_supports_serialization( $block_type, '__experimentalBorder', 'color' ) ? $border['color'] : null,
                'style' => isset( $border['style'] ) && ! wp_should_skip_block_supports_serialization( $block_type, '__experimentalBorder', 'style' ) ? $border['style'] : null,
            );
            $border_block_styles[ $side ] = $border_side_values;
        }
    }

    // Collect classes and styles.
    $attributes = array();
    $styles     = wp_style_engine_get_styles( array( 'border' => $border_block_styles ) );

    if ( ! empty( $styles['classnames'] ) ) {
        $attributes['class'] = $styles['classnames'];
    }

    if ( ! empty( $styles['css'] ) ) {
        $attributes['style'] = $styles['css'];
    }

    return $attributes;
}

/**
 * Checks whether the current block type supports the border feature requested.
 *
 * If the `__experimentalBorder` support flag is a boolean `true` all border
 * support features are available. Otherwise, the specific feature's support
 * flag nested under `experimentalBorder` must be enabled for the feature
 * to be opted into.
 *
 * @since 5.8.0
 * @access private
 *
 * @param WP_Block_Type $block_type    Block type to check for support.
 * @param string        $feature       Name of the feature to check support for.
 * @param mixed         $default_value Fallback value for feature support, defaults to false.
 * @return bool Whether the feature is supported.
 */
function wp_has_border_feature_support( $block_type, $feature, $default_value = false ) {
    // Check if all border support features have been opted into via `"__experimentalBorder": true`.
    if ( $block_type instanceof WP_Block_Type ) {
        $block_type_supports_border = $block_type->supports['__experimentalBorder'] ?? $default_value;
        if ( true === $block_type_supports_border ) {
            return true;
        }
    }

    // Check if the specific feature has been opted into individually
    // via nested flag under `__experimentalBorder`.
    return block_has_support( $block_type, array( '__experimentalBorder', $feature ), $default_value );
}

// Register the block support.
WP_Block_Supports::get_instance()->register(
    'border',
    array(
        'register_attribute' => 'wp_register_border_support',
        'apply'              => 'wp_apply_border_support',
    )
);