<?php
namespace AdvancedAddons;

class McpAbilities {

	public function __construct() {
		add_action( 'wp_abilities_api_categories_init', array( $this, 'register_categories' ) );
		add_action( 'wp_abilities_api_init', array( $this, 'register_abilities' ) );
		add_action( 'init', array( $this, 'maybe_init_adapter' ), 5 );
	}

	/**
	 * Initialize the MCP adapter if installed as a Composer dependency.
	 */
	public function maybe_init_adapter() {
		if ( class_exists( 'WP\MCP\Core\McpAdapter' ) ) {
			\WP\MCP\Core\McpAdapter::instance();
		}
	}

	/**
	 * Register the ability category (runs on wp_abilities_api_categories_init).
	 */
	public function register_categories() {
		Compat::register_ability_category( 'ai-builder', array(
			'label'       => 'AI Builder',
			'description' => 'WP AI Builder abilities for page building with HTML, Tailwind CSS, and native WordPress blocks.',
		) );
	}

	/**
	 * Register WordPress abilities for MCP exposure (runs on wp_abilities_api_init).
	 */
	public function register_abilities() {
		$this->register_html_to_blocks();
		$this->register_blocks_to_html();
		$this->register_read_selection();
		$this->register_update_selection();
	}

	private function register_html_to_blocks() {

		Compat::register_ability( 'wp-ai-builder/html-to-blocks', array(
			'label'       => 'HTML to Blocks',
			'description' => 'Convert HTML content with Tailwind CSS classes or serialized WordPress block markup into block data for page building.',
			'category'    => 'ai-builder',
			'input_schema'  => array(
				'type'       => 'object',
				'properties' => array(
					'html' => array(
						'type'        => 'string',
						'description' => 'HTML content with Tailwind CSS classes or serialized WordPress block markup to convert to block data.',
					),
				),
				'required' => array( 'html' ),
			),
			'output_schema' => array(
				'type'  => 'array',
				'items' => array(
					'type'       => 'object',
					'properties' => array(
						'name'        => array( 'type' => 'string' ),
						'attributes'  => array( 'type' => 'object' ),
						'innerBlocks' => array( 'type' => 'array' ),
					),
				),
			),
			'execute_callback' => function ( $input ) {
				$html = $input['html'] ?? '';
				if ( empty( $html ) ) {
					return array();
				}
				return HtmlToBlocks::convert( $html );
			},
			'permission_callback' => function () {
				return Security::can_edit_posts();
			},
			'meta' => array(
				'mcp' => array( 'public' => true ),
			),
		) );
	}

	private function register_blocks_to_html() {
		Compat::register_ability( 'wp-ai-builder/blocks-to-html', array(
			'label'       => 'Blocks to HTML',
			'description' => 'Convert block data arrays back to HTML. Supports tailwind/html blocks and native WordPress blocks. Useful for reading existing page content so it can be understood and modified.',
			'category'    => 'ai-builder',
			'input_schema'  => array(
				'type'       => 'object',
				'properties' => array(
					'blocks' => array(
						'type'        => 'array',
						'description' => 'Array of block data objects with name, attributes, and innerBlocks.',
						'items'       => array(
							'type'       => 'object',
							'properties' => array(
								'name'        => array( 'type' => 'string' ),
								'attributes'  => array( 'type' => 'object' ),
								'innerBlocks' => array( 'type' => 'array' ),
							),
						),
					),
				),
				'required' => array( 'blocks' ),
			),
			'output_schema' => array(
				'type'       => 'object',
				'properties' => array(
					'html' => array( 'type' => 'string' ),
				),
			),
			'execute_callback' => function ( $input ) {
				$blocks = $input['blocks'] ?? array();
				return array( 'html' => BlocksToHtml::convert_blocks( $blocks ) );
			},
			'permission_callback' => function () {
				return Security::can_edit_posts();
			},
			'meta' => array(
				'mcp' => array( 'public' => true ),
			),
		) );
	}

	private function register_read_selection() {
		Compat::register_ability( 'wp-ai-builder/read-selection', array(
			'label'       => 'Read Selected Blocks',
			'description' => 'Read the blocks currently selected by the user in the block editor. Returns block data and its HTML representation. The user must have selected blocks.',
			'category'    => 'ai-builder',
			'input_schema'  => array(
				'type'       => 'object',
				'properties' => array(),
			),
			'output_schema' => array(
				'type'       => 'object',
				'properties' => array(
					'post_id' => array( 'type' => 'integer' ),
					'indices' => array( 'type' => 'array' ),
					'blocks'  => array( 'type' => 'array' ),
					'html'    => array( 'type' => 'string' ),
				),
			),
			'execute_callback' => function ( $input ) {
				$selection = SelectionBridge::read_selection();
				if ( ! $selection ) {
					return array(
						'success' => false,
						'message' => 'No blocks selected. Please select one or more blocks in the WordPress editor to read or update them.',
					);
				}
				if ( ! SelectionBridge::is_fresh( $selection ) ) {
					return array(
						'success' => false,
						'message' => 'The selection snapshot expired. Reselect the block or explicitly refresh the selection, then try again.',
					);
				}

				$blocks  = $selection['blocks'] ?? array();
				$html    = ! empty( $selection['html'] )
					? $selection['html']
					: BlocksToHtml::convert_blocks( $blocks );

				return array(
					'post_id' => $selection['post_id'] ?? 0,
					'indices' => $selection['indices'] ?? array(),
					'blocks'  => $blocks,
					'html'    => $html,
				);
			},
			'permission_callback' => function () {
				return Security::can_edit_posts();
			},
			'meta' => array(
				'mcp' => array( 'public' => true ),
			),
		) );
	}

	private function register_update_selection() {
		Compat::register_ability( 'wp-ai-builder/update-selection', array(
			'label'       => 'Update Selected Blocks',
			'description' => 'Replace the currently selected blocks on the page with new block data. Updates the post content live. The editor will refresh to show changes.',
			'category'    => 'ai-builder',
			'input_schema'  => array(
				'type'       => 'object',
				'properties' => array(
					'blocks' => array(
						'type'        => 'array',
						'description' => 'New block data arrays to replace the selected blocks with.',
						'items'       => array(
							'type'       => 'object',
							'properties' => array(
								'name'        => array( 'type' => 'string' ),
								'attributes'  => array( 'type' => 'object' ),
								'innerBlocks' => array( 'type' => 'array' ),
							),
						),
					),
					'html' => array(
						'type'        => 'string',
						'description' => 'Optional: raw HTML to convert to blocks first, then update the page.',
					),
				),
			),
			'output_schema' => array(
				'type'       => 'object',
				'properties' => array(
					'success'  => array( 'type' => 'boolean' ),
					'html'     => array( 'type' => 'string' ),
					'blocks'   => array( 'type' => 'array' ),
					'message'  => array( 'type' => 'string' ),
				),
			),
			'execute_callback' => function ( $input ) {
				$selection = SelectionBridge::read_selection();
				if ( ! $selection ) {
					return array(
						'success' => false,
						'message' => 'No blocks selected. Select blocks in the WordPress editor.',
					);
				}
				if ( ! SelectionBridge::is_fresh( $selection ) ) {
					return array(
						'success' => false,
						'message' => 'The selection snapshot expired. Reselect the block or explicitly refresh the selection, then try again.',
					);
				}

				$post_id  = $selection['post_id'] ?? 0;
				$indices  = $selection['indices'] ?? array();

				if ( ! $post_id ) {
					return array(
						'success' => false,
						'message' => 'Invalid selection data. Post ID is missing.',
					);
				}

				if ( ! Security::can_edit_post( intval( $post_id ) ) ) {
					return array(
						'success' => false,
						'message' => 'Sorry, you are not allowed to edit this post.',
					);
				}

				// Get new blocks: either direct block data or convert from HTML.
				$blocks = $input['blocks'] ?? null;
				if ( ! $blocks && ! empty( $input['html'] ) ) {
					$blocks = HtmlToBlocks::convert( $input['html'] );
				}

				if ( ! $blocks ) {
					return array(
						'success' => false,
						'message' => 'No blocks or HTML provided to update with.',
					);
				}

				// Normalize blocks to WP parser format for serialize_blocks().
				$blocks = BlocksToHtml::normalize_blocks( $blocks );

				// Read the current post content.
				$post = get_post( $post_id );
				if ( ! $post ) {
					return array(
						'success' => false,
						'message' => 'Post not found.',
					);
				}

				// Parse existing blocks.
				$existing_blocks = parse_blocks( $post->post_content );

				if ( empty( $existing_blocks ) ) {
					// Empty post — use the new blocks directly.
					$existing_blocks = $blocks;
				} elseif ( ! empty( $indices ) ) {
					// Replace blocks at the given indices.
					sort( $indices, SORT_NUMERIC );
					$indices = array_reverse( $indices );

					foreach ( $indices as $idx ) {
						if ( isset( $existing_blocks[ $idx ] ) ) {
							array_splice( $existing_blocks, $idx, 1, $blocks );
							break;
						}
					}

					// Fallback: replace at first selected index.
					if ( ! in_array( $blocks, $existing_blocks, true ) ) {
						$first_idx = min( $indices );
						if ( isset( $existing_blocks[ $first_idx ] ) ) {
							array_splice( $existing_blocks, $first_idx, count( $indices ), $blocks );
						}
					}
				} else {
					// No indices available — replace entire post content.
					$existing_blocks = $blocks;
				}

				$new_content = serialize_blocks( $existing_blocks );
				$updated     = wp_update_post( array(
					'ID'           => $post_id,
					'post_content' => $new_content,
				), true );

				if ( is_wp_error( $updated ) ) {
					return array(
						'success' => false,
						'message' => $updated->get_error_message(),
					);
				}

			// Store the result for the JS editor to pick up.
			$result_html = BlocksToHtml::convert_blocks( $blocks );
			SelectionBridge::store_result( array(
				'post_id'         => $post_id,
				'clientIds'       => $selection['clientIds'] ?? array(),
				'blocks'          => $blocks,
				'html'            => $result_html,
				'indices'         => $indices,
				'post_content'    => $new_content,
				'replacement_html' => serialize_blocks( $blocks ),
			) );

				return array(
					'success' => true,
					'html'    => $result_html,
					'blocks'  => $blocks,
					'message' => 'Blocks updated successfully. The editor will refresh to show the changes.',
				);
			},
			'permission_callback' => function () {
				return Security::can_edit_posts();
			},
			'meta' => array(
				'mcp' => array( 'public' => true ),
			),
		) );
	}
}