<?php
/**
 * Tool executor — runs tool configs against WordPress data.
 *
 * @package Wlconduit
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Orchestrates tool execution by iterating blocks and executing each.
 * Delegates to the query builder when joins are configured.
 *
 * @since 1.0.0
 */
class Wlconduit_Tool_Executor {

	/**
	 * Query builder instance.
	 *
	 * @since 1.0.0
	 * @var Wlconduit_Query_Builder
	 */
	private Wlconduit_Query_Builder $query_builder;

	/**
	 * Constructor.
	 *
	 * @since 1.0.0
	 *
	 * @param Wlconduit_Query_Builder $query_builder Query builder instance.
	 */
	public function __construct( Wlconduit_Query_Builder $query_builder ) {
		$this->query_builder = $query_builder;
	}

	/**
	 * Execute a tool configuration.
	 *
	 * Iterates through the tool's blocks, executes each one.
	 * If a block has joins configured, delegates to the query builder.
	 *
	 * @since 1.0.0
	 *
	 * @param array $tool_config The full tool configuration from CPT meta.
	 * @param array $arguments   The LLM-provided input arguments.
	 * @return array MCP content response array.
	 */
	public function execute( array $tool_config, array $arguments ): array {
		$blocks          = $tool_config['blocks'] ?? array();
		$results         = array();
		$selected_blocks = $arguments['_blocks'] ?? null;

		foreach ( $blocks as $index => $block_entry ) {
			$block_type = $block_entry['block_type'] ?? '';
			$block      = Wlconduit_Block_Registry::get( $block_type );

			if ( ! $block ) {
				continue;
			}

			$block_config = $block_entry['config'] ?? array();

			// Build a unique result key. Only Posts blocks key by post_type (so
			// distinct post types in the same tool get distinct keys); other block
			// types key by block_type, ignoring any phantom post_type from legacy
			// UI-saved configs.
			$result_key = ( 'posts' === $block_type && ! empty( $block_config['post_type'] ) )
				? $block_config['post_type']
				: $block_type;
			if ( isset( $results[ $result_key ] ) ) {
				$result_key = $result_key . '_' . $index;
			}

			// If _blocks is specified, skip blocks not in the list.
			if ( is_array( $selected_blocks ) && ! in_array( $result_key, $selected_blocks, true ) ) {
				continue;
			}

			// Extract arguments scoped to this block by stripping the result_key prefix.
			$prefix      = $result_key . '_';
			$prefix_len  = strlen( $prefix );
			$block_args  = array();
			foreach ( $arguments as $key => $value ) {
				if ( str_starts_with( $key, $prefix ) ) {
					$block_args[ substr( $key, $prefix_len ) ] = $value;
				}
			}

			// If joins are configured, use the query builder.
			if ( ! empty( $block_config['joins'] ) ) {
				$results[ $result_key ] = $this->query_builder->execute( $block_entry, $block_args );
			} else {
				$results[ $result_key ] = $block->execute( $block_config, $block_args );
			}
		}

		return array(
			'content' => array(
				array(
					'type' => 'text',
					'text' => wp_json_encode( $results ),
				),
			),
		);
	}
}