<?php
/**
 * WordPress hooks, editor registration and content insertion.
 *
 * @package Tocnest
 */

defined( 'ABSPATH' ) || exit;

/** Connects rendering to WordPress content and block APIs. */
class Tocnest_Plugin {
	/**
	 * Heading context prepared before blocks and shortcodes run.
	 *
	 * @var array
	 */
	private static $context = array();

	/** Register hooks. */
	public static function boot() {
		add_action( 'init', array( __CLASS__, 'init' ) );
		add_filter( 'the_content', array( __CLASS__, 'prepare' ), 8 );
		add_filter( 'the_content', array( __CLASS__, 'insert' ), 20 );
		add_action( 'wp_footer', array( __CLASS__, 'late_styles' ), 5 );
		add_action( 'widgets_init', array( __CLASS__, 'widgets' ) );
	}

	/** Register settings, metadata, shortcodes and dynamic blocks. */
	public static function init() {
		add_shortcode( 'tocnest', array( __CLASS__, 'shortcode' ) );
		wp_register_script( 'tocnest-editor', TOCNEST_URL . 'assets/editor.js', array( 'wp-blocks', 'wp-element', 'wp-i18n', 'wp-components', 'wp-block-editor', 'wp-server-side-render' ), TOCNEST_VERSION, true );
		wp_add_inline_script( 'tocnest-editor', 'window.tocnestEditorDefaults = ' . wp_json_encode( Tocnest_Settings::get(), JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT ) . ';', 'before' );
		wp_set_script_translations( 'tocnest-editor', 'tocnest', TOCNEST_PATH . 'languages' );
		register_block_type( TOCNEST_PATH . 'blocks/toc', array( 'render_callback' => array( __CLASS__, 'block' ) ) );
		$properties = array();
		foreach ( Tocnest_Settings::defaults() as $key => $value ) {
			$property = array( 'type' => is_bool( $value ) ? 'boolean' : ( is_int( $value ) ? 'integer' : ( is_array( $value ) ? 'array' : 'string' ) ) );
			if ( is_array( $value ) ) {
				$property['items'] = array( 'type' => 'levels' === $key ? 'integer' : 'string' );
			}
			$properties[ $key ] = $property;
		}
		$properties['enabled']          = array( 'type' => 'boolean' );
		$properties['process_headings'] = array( 'type' => 'boolean' );
		// Global post metadata also covers custom post types registered later on init.
		register_post_meta(
			'',
			'_tocnest_settings',
			array(
				'type'              => 'object',
				'single'            => true,
				'default'           => array(),
				'sanitize_callback' => array( 'Tocnest_Settings', 'sanitize_meta' ),
				'auth_callback'     => array( __CLASS__, 'meta_auth' ),
				'show_in_rest'      => array(
					'schema' => array(
						'type'                 => 'object',
						'properties'           => $properties,
						'additionalProperties' => false,
					),
				),
			)
		);
	}

	/** Register classic widget. */
	public static function widgets() {
		register_widget( 'Tocnest_Widget' );
	}

	/** Print styles requested after the document head, including widget renders. */
	public static function late_styles() {
		Tocnest_Renderer::late_styles();
	}

	/**
	 * Shared parsed headings for any placement.
	 *
	 * @param WP_Post $post Post.
	 * @param array   $settings Settings.
	 * @return array
	 */
	public static function headings( $post, $settings ) {
		return isset( self::$context[ $post->ID ] ) ? self::$context[ $post->ID ] : Tocnest_Parser::parse( $post->post_content, $post->ID, $settings );
	}

	/**
	 * Parse and add anchors before blocks and shortcodes render.
	 *
	 * @param string $content Post HTML.
	 * @return string
	 */
	public static function prepare( $content ) {
		$post = get_post();
		if ( ! Tocnest_Renderer::allowed( $post ) || ! is_singular() || ! in_the_loop() || ! is_main_query() ) {
			return $content;
		}
		$settings                   = Tocnest_Settings::for_post( $post->ID );
		$parsed                     = Tocnest_Parser::parse( $content, $post->ID, $settings );
		self::$context[ $post->ID ] = $parsed;
		$manual                     = self::manual( $content );
		$anchors                    = in_array( $post->post_type, $settings['anchor_types'], true );
		if ( isset( $settings['process_headings'] ) ) {
			$anchors = $settings['process_headings'];
		}
		$auto   = self::automatic( $post, $settings );
		$enough = count( Tocnest_Parser::select( $parsed['headings'], $settings ) ) >= $settings['min'];
		return $anchors || $manual || self::widget_active() || ( $auto && $enough ) ? $parsed['html'] : $content;
	}

	/**
	 * Detect a classic or block widget that will need content anchors.
	 *
	 * @return bool
	 */
	private static function widget_active() {
		if ( is_active_widget( false, false, 'tocnest_widget', true ) ) {
			return true;
		}
		$widgets  = get_option( 'widget_block', array() );
		$sidebars = (array) get_option( 'sidebars_widgets', array() );
		unset( $sidebars['array_version'] );
		foreach ( $sidebars as $sidebar => $instances ) {
			if ( 'wp_inactive_widgets' === $sidebar ) {
				continue;
			}
			foreach ( (array) $instances as $instance ) {
				if ( preg_match( '/^block-(\d+)$/', $instance, $match ) && isset( $widgets[ $match[1] ]['content'] ) && has_block( 'tocnest/toc', $widgets[ $match[1] ]['content'] ) ) {
					return true;
				}
			}
		}
		return false;
	}

	/**
	 * Detect manual placements to prevent duplicate automatic insertion.
	 *
	 * @param string $content Raw content.
	 * @return bool
	 */
	private static function manual( $content ) {
		return has_shortcode( $content, 'tocnest' ) || has_shortcode( $content, 'lwptoc' ) || has_block( 'tocnest/toc', $content ) || has_block( 'luckywp/tableofcontents', $content );
	}

	/**
	 * Decide whether automatic insertion is enabled.
	 *
	 * @param WP_Post $post Post.
	 * @param array   $settings Settings.
	 * @return bool
	 */
	private static function automatic( $post, $settings ) {
		$enabled = $settings['auto'] && in_array( $post->post_type, apply_filters( 'tocnest_post_types', $settings['post_types'] ), true );
		if ( isset( $settings['enabled'] ) ) {
			$enabled = $settings['enabled'];
		}
		$previous = get_option( 'lwptoc_autoInsert', array() );
		if ( Tocnest_Migration::old_active() && ! empty( $previous['enable'] ) && ! $settings['override_previous'] ) {
			$enabled = false;
		}
		return $enabled;
	}

	/**
	 * Insert a TOC after the standard content filters finish.
	 *
	 * @param string $content Rendered content.
	 * @return string
	 */
	public static function insert( $content ) {
		$post = get_post();
		if ( ! Tocnest_Renderer::allowed( $post ) || ! is_singular() || ! in_the_loop() || ! is_main_query() ) {
			return $content;
		}
		$settings = Tocnest_Settings::for_post( $post->ID );
		if ( self::manual( $post->post_content ) || ! self::automatic( $post, $settings ) ) {
			return $content;
		}
		$html = Tocnest_Renderer::render( array(), $post );
		if ( '' === $html ) {
			return $content;
		}
		$position = $settings['position'];
		if ( 'bottom' === $position ) {
			return $content . $html;
		}
		if ( 'top' === $position ) {
			return $html . $content;
		}
		if ( 'afterfirstblock' === $position ) {
			$offset = self::first_block_end( $content );
			return substr_replace( $content, $html, $offset, 0 );
		}
		$parsed = self::headings( $post, $settings );
		if ( $parsed['headings'] ) {
			$first  = $parsed['headings'][0];
			$offset = strpos( $content, $first['opening'] );
			if ( false !== $offset ) {
				if ( 'afterfirstheading' === $position ) {
					$end    = stripos( $content, '</h' . $first['level'], $offset + strlen( $first['opening'] ) );
					$offset = false === $end ? $offset : strpos( $content, '>', $end ) + 1;
				}
				return substr_replace( $content, $html, $offset, 0 );
			}
		}
		return $html . $content;
	}

	/**
	 * Find the first complete top-level block, respecting quoted attributes.
	 *
	 * @param string $content Filtered HTML.
	 * @return int Byte position for insertion.
	 */
	private static function first_block_end( $content ) {
		preg_match_all( '~<!--[\s\S]*?-->|</?([a-z][a-z0-9:-]*)\b(?:[^>"\x27]|"[^"]*"|\x27[^\x27]*\x27)*>~i', $content, $tokens, PREG_SET_ORDER | PREG_OFFSET_CAPTURE );
		$stack = array();
		$void  = array( 'area', 'base', 'br', 'col', 'embed', 'hr', 'img', 'input', 'link', 'meta', 'param', 'source', 'track', 'wbr' );
		foreach ( $tokens as $token ) {
			if ( ! isset( $token[1] ) || '' === $token[1][0] ) {
				continue;
			}
			$name = strtolower( $token[1][0] );
			if ( '</' === substr( $token[0][0], 0, 2 ) ) {
				if ( $stack && end( $stack ) === $name ) {
					array_pop( $stack );
				}
			} elseif ( ! in_array( $name, $void, true ) && '/>' !== substr( $token[0][0], -2 ) ) {
				$stack[] = $name;
			}
			if ( ! $stack ) {
				return $token[0][1] + strlen( $token[0][0] );
			}
		}
		return 0;
	}

	/**
	 * Render the current post shortcode.
	 *
	 * @param array $attributes Shortcode settings.
	 * @return string
	 */
	public static function shortcode( $attributes ) {
		return Tocnest_Renderer::render( is_array( $attributes ) ? $attributes : array() );
	}

	/**
	 * Render a dynamic block, including post context in widget areas.
	 *
	 * @param array    $attributes Block settings.
	 * @param string   $content Saved fallback content.
	 * @param WP_Block $block Block object.
	 * @return string
	 */
	public static function block( $attributes, $content, $block ) {
		$post    = isset( $block->context['postId'] ) ? get_post( $block->context['postId'] ) : get_post();
		$preview = defined( 'REST_REQUEST' ) && REST_REQUEST && isset( $_GET['context'] ) && 'edit' === sanitize_key( wp_unslash( $_GET['context'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Core REST block renderer authenticates and checks edit_post.
		return Tocnest_Renderer::render( $attributes, $post, $preview );
	}

	/**
	 * Authorize per-post meta writes.
	 *
	 * @param bool   $allowed Existing decision.
	 * @param string $meta_key Meta name.
	 * @param int    $post_id Post ID.
	 * @return bool
	 */
	public static function meta_auth( $allowed, $meta_key, $post_id ) {
		return current_user_can( 'edit_post', $post_id );
	}
}