<?php
/**
 * Term Data source for Block Bindings.
 *
 * @since 6.9.0
 * @package WordPress
 * @subpackage Block Bindings
 */

/**
 * Gets value for Term Data source.
 *
 * @since 6.9.0
 * @access private
 *
 * @param array    $source_args    Array containing source arguments used to look up the override value.
 *                                 Example: array( "field" => "name" ).
 * @param WP_Block $block_instance The block instance.
 * @return mixed The value computed for the source.
 */
function _block_bindings_term_data_get_value( array $source_args, $block_instance ) {
    if ( empty( $source_args['field'] ) ) {
        return null;
    }

    /*
     * BACKWARDS COMPATIBILITY: Hardcoded exception for navigation blocks.
     * Required for WordPress 6.9+ navigation blocks. DO NOT REMOVE.
     */
    $block_name          = $block_instance->name ?? '';
    $is_navigation_block = in_array(
        $block_name,
        array( 'core/navigation-link', 'core/navigation-submenu' ),
        true
    );

    if ( $is_navigation_block ) {
        // Navigation blocks: read from block attributes.
        $term_id = $block_instance->attributes['id'] ?? null;
        $type    = $block_instance->attributes['type'] ?? '';
        // Map UI shorthand to taxonomy slug when using attributes.
        $taxonomy = ( 'tag' === $type ) ? 'post_tag' : $type;
    } else {
        // All other blocks: use context
        $term_id  = $block_instance->context['termId'] ?? null;
        $taxonomy = $block_instance->context['taxonomy'] ?? '';
    }

    // If we don't have required identifiers, bail early.
    if ( empty( $term_id ) || empty( $taxonomy ) ) {
        return null;
    }

    // Get the term data.
    $term = get_term( $term_id, $taxonomy );
    if ( is_wp_error( $term ) || ! $term ) {
        return null;
    }

    // Check if taxonomy exists and is publicly queryable.
    $taxonomy_object = get_taxonomy( $taxonomy );
    if ( ! $taxonomy_object || ! $taxonomy_object->publicly_queryable ) {
        if ( ! current_user_can( 'read' ) ) {
            return null;
        }
    }

    switch ( $source_args['field'] ) {
        case 'id':
            return esc_html( (string) $term_id );

        case 'name':
            return esc_html( $term->name );

        case 'link':
            // Only taxonomy entities are supported by Term Data.
            $term_link = get_term_link( $term );
            return is_wp_error( $term_link ) ? null : esc_url( $term_link );

        case 'slug':
            return esc_html( $term->slug );

        case 'description':
            return wp_kses_post( $term->description );

        case 'parent':
            return esc_html( (string) $term->parent );

        case 'count':
            return esc_html( (string) $term->count );

        default:
            return null;
    }
}

/**
 * Registers Term Data source in the block bindings registry.
 *
 * @since 6.9.0
 * @access private
 */
function _register_block_bindings_term_data_source() {
    if ( get_block_bindings_source( 'core/term-data' ) ) {
        // The source is already registered.
        return;
    }

    register_block_bindings_source(
        'core/term-data',
        array(
            'label'              => _x( 'Term Data', 'block bindings source' ),
            'get_value_callback' => '_block_bindings_term_data_get_value',
            'uses_context'       => array( 'termId', 'taxonomy' ),
        )
    );
}

add_action( 'init', '_register_block_bindings_term_data_source' );