<?php
/**
 * The Rooster LMS adapter (PLAN §11, work package A2): the bridge from the LMS's existing data to the library's
 * contract, so that E (the LMS on the library) is a deletion of its chrome, not a rewrite of its data.
 *
 * - product() and entries() read the LMS's own registry (`RoosterLMS\Admin\Home\Registry`: data/capabilities.php,
 *   create.php and cards/*.php, already expanded and validated by the LMS) and emit the library's product and rows.
 *   Nothing is typed twice: the LMS keeps its data files.
 * - id_of() is the id table: an LMS id keeps its name under the product's prefix, so users' pins survive;
 *   migrate_pins() moves a user's pins from the LMS's ui_prefs table into the one row, once (Prefs::migrate()).
 * - entity_icons() names the LMS's entities' icons (the theme's slots wear them today); capability() answers the
 *   LMS's own capability word (`grading`).
 *
 * register() hooks the two bridges only. register_product() is E's switch: the LMS calls it on
 * `rooster/admin/register` the day its own chrome goes; until then nothing here registers the product, so WP Developer
 * shows one chrome per screen.
 *
 * @package RoosterAdmin
 */

namespace Rooster\Admin\Adapters;

use Rooster\Admin\Prefs;
use Rooster\Admin\Registry;

defined( 'ABSPATH' ) || exit;

/**
 * Static.
 */
final class RoosterLms {

	/**
	 * The product slug.
	 */
	public const PRODUCT = 'rooster-lms';

	/**
	 * The LMS's classes (strings: the adapter loads without the LMS).
	 */
	private const LMS_REGISTRY = '\RoosterLMS\Admin\Home\Registry';
	private const LMS_ICONS    = '\RoosterLMS\Admin\Home\Icons';
	private const LMS_PREFS    = '\RoosterLMS\Admin\Home\Prefs';
	private const LMS_SECTIONS = '\RoosterLMS\Admin\AdminMenuSections';
	private const LMS_CHROME   = '\RoosterLMS\Admin\Home\Chrome';
	private const LMS_ADMIN    = '\RoosterLMS\Admin\AdminModule';

	/**
	 * The product's colour: the LMS's green (the theme's Learning section wears it too).
	 */
	private const COLOUR = '#8fe03a';

	/**
	 * The sections' colours: the LMS's own palette (assets/admin/menu.css). In the rooster's order (0.68.4, the owner):
	 * after the blue the green, then the red; the red a proper one (it was #ff8080, its ink a brick).
	 */
	private const COLOURS = array(
		'create'     => '#1e63ce',
		'content'    => '#75beff',
		'assessment' => '#8fe03a',
		'orgs'       => '#ff4d4d',
		'progress'   => '#ffde00',
		'packages'   => '#b794f6',
		'tools'      => '#a1a1aa',
	);

	/**
	 * The names the LMS's template slots (contract C3) use for its entities, where they differ from the icon map's
	 * keys: slot name => icon key.
	 */
	private const SLOT_ALIASES = array(
		'course-archive'     => 'course',
		'account'            => 'account_page',
		'org-portal'         => 'portal',
		'register'           => 'registration_form',
		'certificate-verify' => 'certificate_verification',
	);

	/**
	 * Whether the LMS and its icon map are loaded.
	 */
	public static function present(): bool {
		return defined( 'ROOSTER_LMS_VERSION' ) && class_exists( self::LMS_ICONS ) && defined( self::LMS_ICONS . '::KEYS' );
	}

	/**
	 * Whether the LMS's registry is loaded (the admin: its Home module).
	 */
	public static function registry_present(): bool {
		return self::present() && class_exists( self::LMS_REGISTRY ) && class_exists( self::LMS_SECTIONS ) && class_exists( self::LMS_ADMIN );
	}

	/**
	 * Hooks the bridges: the entity icons and the LMS's capability word.
	 */
	public static function register(): void {
		if ( ! self::present() ) {
			return;
		}
		add_filter( 'rooster/admin/entity_icons', array( self::class, 'entity_icons' ) );
		add_filter( 'rooster/admin/capability', array( self::class, 'capability' ), 10, 2 );
	}

	/**
	 * Filter rooster/admin/capability: `grading` is the LMS's (a grading scope of the current user).
	 *
	 * @param bool|null $can  The answer so far.
	 * @param string    $spec The spec.
	 * @return bool|null
	 */
	public static function capability( $can, string $spec ) {
		if ( 'grading' === $spec && self::registry_present() ) {
			return (bool) call_user_func( array( self::LMS_REGISTRY, 'can' ), array( 'caps' => array( 'grading' ) ) );
		}
		return $can;
	}

	/**
	 * Filter rooster/admin/entity_icons: `rooster-lms/<entity>` => Lucide name from the LMS's map, plus its slots'
	 * names.
	 *
	 * @param array<string, string>      $icons Icons so far.
	 * @param array<string, string>|null $keys  The LMS's map (null = read from the LMS; tests pass one).
	 * @return array<string, string>
	 */
	public static function entity_icons( array $icons, ?array $keys = null ): array {
		if ( null === $keys ) {
			if ( ! self::present() ) {
				return $icons;
			}
			$keys = (array) constant( self::LMS_ICONS . '::KEYS' );
		}
		foreach ( $keys as $entity => $name ) {
			if ( is_string( $entity ) && is_string( $name ) ) {
				$icons[ 'rooster-lms/' . str_replace( '_', '-', $entity ) ] = $name;
			}
		}
		foreach ( self::SLOT_ALIASES as $slot => $entity ) {
			if ( isset( $keys[ $entity ] ) ) {
				$icons[ 'rooster-lms/' . $slot ] = (string) $keys[ $entity ];
			}
		}
		return $icons;
	}

	/**
	 * The id table: an LMS id under the product's prefix ('' for none).
	 *
	 * @param string $old An id of the LMS's registry (also a pin of its ui_prefs table).
	 */
	public static function id_of( string $old ): string {
		$old = trim( $old );
		return '' === $old || 1 !== preg_match( '/^[a-z0-9_]{1,40}$/', $old ) ? '' : self::PRODUCT . '/' . $old;
	}

	/**
	 * The product (CONTRACT §2) from the LMS's own data: its sections in menu order with their colours, icons, groups
	 * and stacks; its personas as audiences; its screens.
	 *
	 * @return array<string, mixed>
	 */
	public static function product(): array {
		$lms      = self::LMS_REGISTRY;
		$labels   = (array) call_user_func( array( self::LMS_SECTIONS, 'labels' ) );
		$groups   = (array) call_user_func( array( $lms, 'groups' ) );
		$stacks   = (array) constant( $lms . '::STACKS' );
		$icons    = (array) constant( self::LMS_ICONS . '::SECTIONS' );
		$sections = array();
		foreach ( (array) constant( self::LMS_SECTIONS . '::KEYS' ) as $key ) {
			$key   = (string) $key;
			$named = array();
			foreach ( (array) ( $stacks[ $key ] ?? array() ) as $stack ) {
				foreach ( (array) $stack as $group ) {
					$named[ (string) $group ] = (string) ( $groups[ $group ] ?? $group );
				}
			}
			$sections[ $key ] = array(
				'label'  => (string) ( $labels[ $key ] ?? $key ),
				'colour' => self::COLOURS[ $key ] ?? '#a1a1aa',
				'icon'   => (string) ( $icons[ $key ] ?? 'layout-grid' ),
				'groups' => $named,
				'stacks' => (array) ( $stacks[ $key ] ?? array() ),
			);
		}
		$personas  = include dirname( ( new \ReflectionClass( $lms ) )->getFileName() ) . '/data/personas.php';
		$audiences = array();
		foreach ( is_array( $personas ) ? $personas : array() as $key => $persona ) {
			$audiences[ (string) $key ] = array(
				'label'    => (string) ( $persona['label'] ?? $key ),
				'sentence' => (string) ( $persona['sentence'] ?? '' ),
				'all'      => ! empty( $persona['all'] ),
			);
		}
		$pro   = (bool) call_user_func( array( $lms, 'plugin_active' ), constant( $lms . '::PRO' ) );
		$links = class_exists( self::LMS_CHROME ) ? (array) call_user_func( array( self::LMS_CHROME, 'links' ) ) : array();
		return array(
			'slug'      => self::PRODUCT,
			'name'      => 'Rooster LMS',
			'words'     => array( 'Rooster', 'LMS' ),
			'colour'    => self::COLOUR,
			'version'   => defined( 'ROOSTER_LMS_VERSION' ) ? (string) ROOSTER_LMS_VERSION : '',
			'strapline' => __( 'Courses, live sessions, quizzes, organisations and certificates: the academy on one site.', 'ai-eshop-optimizer' ),
			'links'     => $links,
			'welcome'   => class_exists( self::LMS_CHROME ) && method_exists( self::LMS_CHROME, 'welcome' ) ? (array) call_user_func( array( self::LMS_CHROME, 'welcome' ) ) : array(), // the LMS's words in the welcome's anatomy (0.21.0)
			'tier'      => array(
				'label'  => $pro ? _x( 'Pro', 'the tier pill', 'ai-eshop-optimizer' ) : _x( 'Free', 'the tier pill', 'ai-eshop-optimizer' ),
				'on'     => $pro,
				'detail' => '',
			),
			'home'      => array(
				'parent'     => (string) constant( self::LMS_ADMIN . '::PARENT' ),
				'slug'       => 'rooster-lms-home',
				'capability' => 'read',
			),
			'sections'  => $sections,
			'audiences' => $audiences,
			'screens'   => self::screens(),
		);
	}

	/**
	 * The LMS's screens: its page slugs under the menu, and the list and taxonomy screens of its post types.
	 *
	 * @return array{pages: list<string>, ids: list<string>}
	 */
	private static function screens(): array {
		$pages = array();
		$ids   = array();
		foreach ( self::rows() as $row ) {
			$slug = str_replace( '&amp;', '&', (string) $row['slug'] );
			if ( 1 === preg_match( '/^[a-z0-9_-]+\.php(\?|$)/i', $slug ) ) {
				$query = array();
				parse_str( (string) wp_parse_url( $slug, PHP_URL_QUERY ), $query );
				$file = (string) wp_parse_url( $slug, PHP_URL_PATH );
				if ( 'edit.php' === $file && is_string( $query['post_type'] ?? null ) ) {
					$ids[ 'edit-' . $query['post_type'] ] = true;
				} elseif ( 'edit-tags.php' === $file && is_string( $query['taxonomy'] ?? null ) ) {
					$ids[ 'edit-' . $query['taxonomy'] ] = true;
				}
			} else {
				$pages[ $slug ] = true;
			}
		}
		return array(
			'pages' => array_keys( $pages ),
			'ids'   => array_keys( $ids ),
		);
	}

	/**
	 * The LMS's expanded rows, every kind (id => row).
	 *
	 * @return array<string, array<string, mixed>>
	 */
	private static function rows(): array {
		if ( ! self::registry_present() ) {
			return array();
		}
		$lms = self::LMS_REGISTRY;
		return (array) call_user_func( array( $lms, 'entries' ), (array) constant( $lms . '::KINDS' ) );
	}

	/**
	 * The catalogue rows (CONTRACT §3) from the LMS's: the same ids under the prefix, kinds page, tab and card as
	 * they are, a tab or card under its page (or its parent tab), the LMS's capability specs unchanged, its tier as
	 * `available` and a badge, its icon keys resolved by the LMS's own map.
	 *
	 * @return list<array<string, mixed>>
	 */
	public static function entries(): array {
		$lms   = self::LMS_REGISTRY;
		$icons = self::LMS_ICONS;
		$out   = array();
		foreach ( self::rows() as $id => $row ) {
			if ( ! self::offered( $row ) ) {
				continue;
			}
			$out[] = self::map_row(
				(string) $id,
				$row,
				(string) call_user_func( array( $lms, 'page_url' ), $row ),
				(string) call_user_func( array( $icons, 'of_entry' ), $row ),
				(bool) call_user_func( array( $lms, 'plugin_active' ), (string) ( $row['plugin'] ?? '' ) )
			);
		}
		return self::rooted( $out );
	}

	/**
	 * Whether the LMS offers a row as a destination: a page always; a tab or card unless it says `pin` false, the LMS's
	 * mark of a drill-down panel, an add-flow step or a "not found" state, which its own chrome kept out of the menus,
	 * Home, the palette and the pins (ADMIN-CARDS-CONTRACT §4.3). The adapter keeps it out of the catalogue too
	 * (MENU-AUDIT round 2: 265 such cards reached the menu bar, 46 of the 53 under SCORM, xAPI & AI not even on the
	 * screen their link opens). Pure.
	 *
	 * @param array<string, mixed> $row The LMS row.
	 */
	public static function offered( array $row ): bool {
		return 'page' === (string) ( $row['kind'] ?? 'page' ) || false !== ( $row['pin'] ?? true );
	}

	/**
	 * Rows whose parent is not among the rows stand on their own (the product's data names a page it does not
	 * list; the registry would record a problem and do the same).
	 *
	 * @param list<array<string, mixed>> $rows Rows.
	 * @return list<array<string, mixed>>
	 */
	public static function rooted( array $rows ): array {
		$ids = array_fill_keys( array_column( $rows, 'id' ), true );
		foreach ( $rows as &$row ) {
			if ( '' !== $row['parent'] && ! isset( $ids[ $row['parent'] ] ) ) {
				$row['parent'] = '';
			}
		}
		return $rows;
	}

	/**
	 * One of the LMS's rows as a catalogue row (pure: the URL, the icon and the plugin's state come in).
	 *
	 * @param string               $id        The LMS id.
	 * @param array<string, mixed> $row       The LMS row.
	 * @param string               $url       Its URL (Registry::page_url()).
	 * @param string               $icon      Its Lucide name (Icons::of_entry()).
	 * @param bool                 $available Whether its plugin is active.
	 * @return array<string, mixed>
	 */
	public static function map_row( string $id, array $row, string $url, string $icon, bool $available ): array {
		$kind   = (string) ( $row['kind'] ?? 'page' );
		$parent = '';
		if ( 'page' !== $kind ) {
			// A tab or card under its page; under its parent tab when it names one (the LMS's `parent` is the tab's
			// key: the tab's id is t_<page>_<key>, Registry::tab_id()).
			$page   = (string) ( $row['page'] ?? '' );
			$parent = self::id_of( '' !== (string) ( $row['parent'] ?? '' ) ? 't_' . $page . '_' . (string) $row['parent'] : $page );
		}
		return array(
			'id'           => self::id_of( $id ),
			'kind'         => $kind,
			'product'      => self::PRODUCT,
			'section'      => (string) ( $row['section'] ?? '' ),
			'group'        => (string) ( $row['group'] ?? '' ),
			'title'        => (string) ( $row['title'] ?? $id ),
			'description'  => (string) ( $row['desc'] ?? '' ),
			'url'          => $url,
			'icon'         => $icon,
			'capabilities' => array_values( array_map( 'strval', (array) ( $row['caps'] ?? array() ) ) ),
			'audiences'    => array_values( array_map( 'strval', (array) ( $row['audiences'] ?? array() ) ) ),
			'keywords'     => array_values( array_filter( explode( ' ', (string) ( $row['keywords'] ?? '' ) ) ) ),
			'pin'          => ! empty( $row['pin'] ),
			// A card of a record tab (the last organisation's members, say) is a panel of one record: the palette and
			// the pins keep it, the menus and Home do not (MENU-AUDIT round 2: 60 of Organisations' 63 folded cards).
			'listed'       => ( ! isset( $row['listed'] ) || ! empty( $row['listed'] ) ) && ( 'card' !== $kind || '' === (string) ( $row['record'] ?? '' ) ),
			'current'      => ! isset( $row['current'] ) || ! empty( $row['current'] ),
			'available'    => $available,
			'badge'        => $available ? '' : ( 'rooster-lti' === (string) ( $row['plugin'] ?? '' ) ? 'LTI' : 'Pro' ),
			'parent'       => $parent,
		);
	}

	/**
	 * Moves a user's pins from the LMS's ui_prefs table into the one row, once: the result is the row's pins; the
	 * table's row is deleted after.
	 *
	 * @param int $user_id User.
	 * @return list<string>
	 */
	public static function migrate_pins( int $user_id ): array {
		if ( $user_id <= 0 || ! self::registry_present() || ! class_exists( self::LMS_PREFS ) ) {
			return array();
		}
		$old = call_user_func( array( self::LMS_PREFS, 'get' ), $user_id, 'pins', array() );
		if ( ! is_array( $old ) || array() === $old ) {
			return array();
		}
		$pins = Prefs::migrate( $user_id, self::PRODUCT, array_values( array_filter( $old, 'is_string' ) ), array( self::class, 'id_of' ) );
		call_user_func( array( self::LMS_PREFS, 'delete' ), $user_id, 'pins' );
		return $pins;
	}

	/**
	 * Moves a user's chrome preferences from the LMS's ui_prefs table into the one row, once: the pins (migrate_pins())
	 * and the audiences (the "For:" choice, the same persona keys); the Home layout starts afresh (another shape). The
	 * table's three rows are deleted after. Nothing when the table holds none of them.
	 *
	 * @param int $user_id User.
	 */
	public static function migrate_prefs( int $user_id ): void {
		if ( $user_id <= 0 || ! self::registry_present() || ! class_exists( self::LMS_PREFS ) ) {
			return;
		}
		self::migrate_pins( $user_id );
		$audiences = call_user_func( array( self::LMS_PREFS, 'get' ), $user_id, 'audiences', array() );
		if ( is_array( $audiences ) && array() !== $audiences ) {
			$registry = \Rooster\Admin\Library::registry();
			$product  = null !== $registry ? $registry->product( self::PRODUCT ) : null;
			$clean    = null !== $product ? \Rooster\Admin\Personas::clean( $product, array_values( array_filter( $audiences, 'is_string' ) ) ) : array();
			if ( array() !== $clean && array() === (array) Prefs::get( $user_id, Prefs::AUDIENCES, self::PRODUCT, array() ) ) {
				Prefs::set( $user_id, Prefs::AUDIENCES, $clean, self::PRODUCT );
			}
			call_user_func( array( self::LMS_PREFS, 'delete' ), $user_id, 'audiences' );
		}
		if ( null !== call_user_func( array( self::LMS_PREFS, 'get' ), $user_id, 'home_layout', null ) ) {
			call_user_func( array( self::LMS_PREFS, 'delete' ), $user_id, 'home_layout' );
		}
	}

	/**
	 * E's switch: registers the product, its rows and its entities' icons (the LMS calls it on
	 * `rooster/admin/register` the day its own chrome goes).
	 *
	 * @param Registry $registry The registry.
	 */
	public static function register_product( Registry $registry ): void {
		if ( ! self::registry_present() ) {
			return;
		}
		$registry->register_product( self::product() );
		$registry->register_entries( self::entries() );
		$registry->register_entity_icons( self::PRODUCT, (array) constant( self::LMS_ICONS . '::KEYS' ) );
	}
}