<?php

namespace RoosterLMS\CourseBuilder\Lessons;

use RoosterLMS\Content\Course;
use RoosterLMS\Content\UnlockRule;
use RoosterLMS\CourseBuilder\Rev;
use RoosterLMS\CourseBuilder\Tabs;
use RoosterLMS\Domain\Services;
use RoosterLMS\Rest\CurriculumController;

defined( 'ABSPATH' ) || exit;

final class CurriculumData {

	public static function register(): void {
		if ( false === has_filter( 'rooster_lms_course_builder_tab_data', array( self::class, 'filter' ) ) ) {
			add_filter( 'rooster_lms_course_builder_tab_data', array( self::class, 'filter' ), 5, 5 );
		}
	}

	public static function filter( $data, $tab, $course, $lang, $user_id ) {
		if ( 'curriculum' !== $tab || ! is_array( $data ) || ! $course instanceof Course || ! isset( $data['items'] ) ) {
			return $data;
		}
		return self::enrich( $data, (int) $user_id );
	}

	public static function shape( int $course_id, string $lang, int $user_id ): array {
		return self::enrich( CurriculumController::shape( $course_id, Tabs::text_lang( $lang ) ), $user_id );
	}

	private static function enrich( array $data, int $user_id ): array {
		$items    = is_array( $data['items'] ) ? $data['items'] : array();
		$unit_ids = array_map( static fn( array $i ): int => (int) $i['unit_id'], $items );
		$item_ids = array_map( static fn( array $i ): int => (int) $i['id'], $items );
		$kinds    = Kinds::of_units( $unit_ids );
		$rules    = array() === $item_ids ? array() : Services::curriculum_repo()->items( $item_ids );
		foreach ( $items as $i => $row ) {
			$item                     = $rules[ (int) $row['id'] ] ?? null;
			$items[ $i ]['kind']      = $kinds[ (int) $row['unit_id'] ] ?? ( 'quiz' === $row['type'] ? 'quiz' : (string) ( $row['lesson_kind'] ?? 'text' ) );
			$items[ $i ]             += self::availability( $item );
			$items[ $i ]['flags_rev'] = self::flags_rev( $items[ $i ] );
		}
		$data['items']  = $items;
		$data['picker'] = Kinds::picker( $user_id, false );
		return $data;
	}

	public static function availability( $item ): array {
		$rule = null === $item ? UnlockRule::NONE : $item->rules->unlock;
		return array(
			'unlock' => self::rule_slug( $rule ),
			'days'   => null === $item ? null : $item->rules->days,
			'at'     => null === $item ? null : $item->rules->at,
		);
	}

	public static function flags_rev( array $row ): string {
		return Rev::of(
			array(
				(bool) ( $row['required'] ?? false ),
				(bool) ( $row['preview'] ?? false ),
				(string) ( $row['unlock'] ?? 'none' ),
				$row['days'] ?? null,
				$row['at'] ?? null,
			)
		);
	}

	public static function rule_slug( UnlockRule $rule ): string {
		return match ( $rule ) {
			UnlockRule::AFTER_PREVIOUS => 'after_previous',
			UnlockRule::DAYS_AFTER_ENROLMENT => 'days',
			UnlockRule::ON_DATE => 'date',
			default => 'none',
		};
	}

	public static function rule_of( string $slug ): ?UnlockRule {
		return match ( $slug ) {
			'none' => UnlockRule::NONE,
			'after_previous' => UnlockRule::AFTER_PREVIOUS,
			'days' => UnlockRule::DAYS_AFTER_ENROLMENT,
			'date' => UnlockRule::ON_DATE,
			default => null,
		};
	}
}