<?php
namespace JVBase\managers\SEO;

use JVBase\managers\CacheManager;
use JVBase\utility\Features;
use WP_Post;
use WP_Term;

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

/**
 * Breadcrumb Manager
 *
 * Generates breadcrumb navigation arrays and HTML output
 * Integrates with SchemaOutputManager for structured data
 */
class BreadcrumbManager
{
	private CacheManager $cache;
	private static ?self $instance = null;

	private function __construct()
	{
		$this->cache = CacheManager::for('breadcrumbs', MONTH_IN_SECONDS)->connectTo('all');
	}

	public static function getInstance(): self
	{
		if (self::$instance === null) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	/**
	 * Get breadcrumb array for current page
	 *
	 * @return array Array of breadcrumb items with 'name', 'url', optional 'icon' and 'id'
	 */
	public function getCrumbs(): array
	{
		if (is_front_page()) {
			return [];
		}

		$key = get_queried_object_id() ?: 'home';
		$crumbs = $this->cache->get($key);

		if ($crumbs !== false) {
			return $crumbs;
		}

		$crumbs = $this->buildCrumbs();
		$this->cache->set($key, $crumbs);

		return $crumbs;
	}

	/**
	 * Build breadcrumb array based on current page context
	 */
	private function buildCrumbs(): array
	{
		$crumbs = [];

		// Always start with home
		$crumbs[] = [
			'name' => 'Home',
			'icon' => jvbIcon('house'),
			'url'  => get_home_url(),
		];

		$obj = get_queried_object();

		if (is_tax()) {
			$crumbs = $this->addTaxonomyCrumbs($crumbs, $obj);
		} elseif (is_singular()) {
			$crumbs = $this->addArchiveCrumbs($crumbs, $obj);
			$crumbs = $this->addSingularCrumbs($crumbs, $obj);
		} elseif (is_post_type_archive() && !is_post_type_archive(BASE.'dash')) {
			$crumbs = $this->addArchiveCrumbs($crumbs, $obj);
		}

		return $crumbs;
	}

	/**
	 * Add taxonomy-specific breadcrumbs
	 */
	private function addTaxonomyCrumbs(array $crumbs, WP_Term $term): array
	{
		$tax = jvbNoBase($term->taxonomy);
		$config = Features::getConfig($tax, 'term');

		// Add parent content archive if taxonomy is for single content type
		if (count($config['for_content']) === 1) {
			$contentConfig = JVB_CONTENT[$config['for_content'][0]];
			$crumbs[] = [
				'name' => $contentConfig['breadcrumb'] ?? $contentConfig['plural'],
				'url'  => get_post_type_archive_link(jvbCheckBase($config['for_content'][0])),
			];
			$crumbs[] = [
				'name' => 'By ' . $config['singular'],
				'url'  => false,
			];
		}

		// Add directory if exists
		if (Features::forTaxonomy($tax)->has('directory')) {
			$directory = jvbDirectories($tax);
			$crumbs[] = [
				'name' => $directory['title'],
				'url'  => $directory['url']
			];
		}

		// Add term hierarchy
		$crumbs = array_merge($crumbs, $this->buildTermHierarchy($term));

		return $crumbs;
	}

	/**
	 * Add singular post breadcrumbs
	 */
	private function addSingularCrumbs(array $crumbs, WP_Post $post): array
	{
		// Add directory if exists
		$directory = jvbDirectories(jvbNoBase($post->post_type));
		if (!empty($directory)) {
			$crumbs[] = [
				'name' => $directory['title'],
				'url'  => $directory['url']
			];
		}

		// Handle directory posts specially
		if (jvbIsDirectory()) {
			$pos = jvbGetDirectoryInfo();
			if (!empty($pos)) {
				// Special case for map
				if ($pos['title'] == 'Map') {
					$crumbs[] = [
						'name' => 'Tattoo Shops',
						'url'  => jvbDirectories(BASE.'shop')['url']
					];
				}

				$crumbs[] = [
					'name' => $pos['title'],
					'url'  => $pos['url']
				];
			}
		} else {
			// Add post hierarchy
			$crumbs = array_merge($crumbs, $this->buildPostHierarchy($post));
		}

		return $crumbs;
	}

	/**
	 * Add archive breadcrumbs
	 */
	private function addArchiveCrumbs(array $crumbs, object $obj): array
	{
		$type = is_singular() ? $obj->post_type : $obj -> name;
		$name = jvbNoBase($type);
		if (array_key_exists($name, JVB_CONTENT)) {
			$crumbs[] = [
				'name' => JVB_CONTENT[$name]['breadcrumb'] ?? JVB_CONTENT[$name]['plural'],
				'url'  => get_post_type_archive_link($type),
			];
		}

		return $crumbs;
	}

	/**
	 * Build term hierarchy recursively
	 */
	private function buildTermHierarchy(WP_Term $term, array $crumbs = []): array
	{
		$url = get_term_link($term->term_id);
		array_unshift($crumbs, [
			'name' => $term->name,
			'url'  => $url,
			'id'   => $term->term_id,
		]);

		if ($term->parent !== 0) {
			$parent = get_term($term->parent, $term->taxonomy);
			if ($parent && !is_wp_error($parent)) {
				$crumbs = $this->buildTermHierarchy($parent, $crumbs);
			}
		}

		return $crumbs;
	}

	/**
	 * Build post hierarchy recursively
	 */
	private function buildPostHierarchy(WP_Post $post, array $crumbs = []): array
	{
		array_unshift($crumbs, [
			'name' => $post->post_title,
			'url'  => get_the_permalink($post->ID),
			'id'   => $post->ID,
		]);

		if ($post->post_parent !== 0) {
			$parent = get_post($post->post_parent);
			if ($parent) {
				$crumbs = $this->buildPostHierarchy($parent, $crumbs);
			}
		}

		return $crumbs;
	}

	/**
	 * Render breadcrumb navigation HTML
	 *
	 * @return string HTML breadcrumb navigation
	 */
	public function renderNavigation(): string
	{
		if (is_front_page()) {
			return '';
		}

		$crumbs = $this->getCrumbs();
		if (empty($crumbs)) {
			return '';
		}

		$out = '<nav id="breadcrumbs">';
		$out .= '<ol itemscope itemtype="https://schema.org/BreadcrumbList">';

		$position = 1;
		foreach ($crumbs as $crumb) {
			$label = '<span itemprop="name">' . strtolower($crumb['name']) . '</span>';

			// Replace label with icon if present
			if (isset($crumb['icon'])) {
				$label = $crumb['icon'] . '<span class="screen-reader-text" itemprop="name">' . $crumb['name'] . '</span>';
			}

			$aOpen = $aClose = '';

			// Add link if URL exists and not current page
			if ($crumb['url'] !== false) {
				$isCurrent = isset($crumb['id']) && $crumb['id'] === get_queried_object_id();
				if (!$isCurrent) {
					$aOpen = '<a itemprop="item" href="' . esc_url($crumb['url']) . '" title="' . esc_attr($crumb['name']) . '">';
					$aClose = '</a>';
				}
			}

			$out .= '<li itemprop="itemListElement" itemscope itemtype="https://schema.org/ListItem">';
			$out .= $aOpen . $label . $aClose;
			$out .= '<meta itemprop="position" content="' . $position . '" />';
			$out .= '</li>';

			$position++;
		}

		$out .= '</ol>';
		$out .= '</nav>';

		return $out;
	}

	/**
	 * Convert breadcrumb array to schema.org format
	 * Used by SchemaOutputManager
	 *
	 * @return array Schema.org BreadcrumbList
	 */
	public function toSchema(): array
	{
		$crumbs = $this->getCrumbs();
		if (empty($crumbs)) {
			return [];
		}

		$items = [];
		$position = 1;

		foreach ($crumbs as $crumb) {
			// Schema requires a URL
			if ($crumb['url'] === false) {
				$crumb['url'] = get_permalink();
			}

			$items[] = [
				'@type'    => 'ListItem',
				'position' => $position,
				'name'     => $crumb['name'],
				'item'     => $crumb['url'],
			];

			$position++;
		}

		return [
			'@type'           => 'BreadcrumbList',
			'@id'             => get_permalink() . '/#breadcrumbs',
			'itemListElement' => $items
		];
	}

	/**
	 * Invalidate breadcrumb cache for specific object
	 */
	public function invalidateCache(?int $objectId = null): void
	{
		if ($objectId) {
			$this->cache->delete($objectId);
		} else {
			$this->cache->clear();
		}
	}
}