<?php

namespace RoosterLMS\CourseBuilder\Lessons;

use RoosterLMS\Content\LessonKind;
use RoosterLMS\Content\PostTypes;
use RoosterLMS\Content\UnitType;
use RoosterLMS\Domain\Actor;
use RoosterLMS\Domain\DomainError;
use RoosterLMS\Domain\ErrorCode;
use RoosterLMS\Domain\Services;
use RoosterLMS\I18n\Names;
use RoosterLMS\I18n\Switcher;

defined( 'ABSPATH' ) || exit;

final class UnitFactory {

	public static function can_create( string $kind, int $user_id ): bool {
		return Kinds::can_create( 'quiz' === $kind ? 'quiz' : 'lesson', $user_id );
	}

	public static function create( int $course_id, string $kind, string $title, int $section_id, int $position, string $rev, Actor $actor, string &$stale = '' ): array {
		$stale = '';
		if ( ! in_array( $kind, Kinds::ALL, true ) && ! in_array( $kind, self::addon_kinds( $actor->user_id ), true ) ) {
			DomainError::raise( ErrorCode::INVALID, array( 'reason' => 'kind' ) );
		}
		if ( '' !== $rev ) {
			$current = Services::curriculum_repo()->rev( $course_id );
			if ( ! hash_equals( $current, $rev ) ) {
				$stale = $current;
				return array( 0, 0, 0 );
			}
		}
		if ( $section_id > 0 && ! in_array( $section_id, array_map( static fn( $s ): int => $s->id, Services::curriculum_repo()->sections_of_courses( array( $course_id ) )[ $course_id ] ?? array() ), true ) ) {
			DomainError::raise( ErrorCode::INVALID );
		}
		$title = trim( sanitize_text_field( $title ) );
		$title = '' !== $title ? mb_substr( $title, 0, 200 ) : self::default_title( $kind );
		if ( in_array( $kind, Kinds::FREE, true ) ) {
			list( $unit_id, $post_id ) = self::free_unit( $kind, $title, $actor );
		} else {
			$unit_id = (int) apply_filters( 'rooster_lms_course_builder_create_unit', 0, $kind, $title, $course_id, $actor->user_id );
			if ( $unit_id <= 0 ) {
				DomainError::raise( ErrorCode::INVALID, array( 'reason' => 'kind_unavailable' ) );
			}
			$post_id = (int) ( Services::unit_repo()->get_many( array( $unit_id ) )[ $unit_id ]->home_post_id ?? 0 );
		}
		try {
			$placed = Placer::place( $course_id, array( $unit_id ), $section_id, $position, '', $actor );
		} catch ( \Throwable $e ) {
			if ( $post_id > 0 ) {
				wp_delete_post( $post_id, true );
			}
			throw $e;
		}
		return array( $unit_id, (int) ( $placed[ $unit_id ] ?? 0 ), $post_id );
	}

	public static function standalone( string $kind, string $title, Actor $actor ): array {
		if ( ! in_array( $kind, Kinds::ALL, true ) && ! in_array( $kind, self::addon_kinds( $actor->user_id ), true ) ) {
			DomainError::raise( ErrorCode::INVALID, array( 'reason' => 'kind' ) );
		}
		$title = trim( sanitize_text_field( $title ) );
		$title = '' !== $title ? mb_substr( $title, 0, 200 ) : self::default_title( $kind );
		if ( in_array( $kind, Kinds::FREE, true ) ) {
			return self::free_unit( $kind, $title, $actor );
		}
		$unit_id = (int) apply_filters( 'rooster_lms_course_builder_create_unit', 0, $kind, $title, 0, $actor->user_id );
		if ( $unit_id <= 0 ) {
			DomainError::raise( ErrorCode::INVALID, array( 'reason' => 'kind_unavailable' ) );
		}
		return array( $unit_id, (int) ( Services::unit_repo()->get_many( array( $unit_id ) )[ $unit_id ]->home_post_id ?? 0 ) );
	}

	private static function free_unit( string $kind, string $title, Actor $actor ): array {
		list( $type, $lesson_kind ) = Kinds::target( $kind );
		$post_id = (int) Switcher::with(
			Names::default_language(),
			static fn() => wp_insert_post(
				array(
					'post_type'    => UnitType::QUIZ === $type ? PostTypes::QUIZ : PostTypes::LESSON,
					'post_title'   => $title,
					'post_content' => UnitType::H5P === $type ? \RoosterLMS\H5P\H5PProvider::BLOCK_MARKUP : '',
					'post_status'  => 'draft',
					'post_author'  => max( 0, $actor->user_id ),
				),
				false,
				false
			),
			false
		);
		if ( $post_id <= 0 ) {
			DomainError::raise( ErrorCode::INVALID, array( 'reason' => 'create' ) );
		}
		$unit_id = Services::courses()->ensure_unit_for_post( $post_id );
		if ( $unit_id <= 0 ) {
			wp_delete_post( $post_id, true );
			DomainError::raise( ErrorCode::INVALID, array( 'reason' => 'create' ) );
		}
		if ( UnitType::ASSIGNMENT === $type || UnitType::LIVE === $type || UnitType::H5P === $type ) {
			Services::courses()->set_unit_type( $unit_id, $type, Actor::system() );
		} elseif ( UnitType::LESSON === $type && LessonKind::TEXT !== $lesson_kind ) {
			Services::media()->update_lesson( $unit_id, array( 'kind' => $lesson_kind ), $actor );
		}
		return array( $unit_id, $post_id );
	}

	private static function addon_kinds( int $user_id ): array {
		$kinds = Kinds::picker( $user_id )['addon_kinds'] ?? array();
		return array_values( array_filter( is_array( $kinds ) ? $kinds : array(), static fn( $k ): bool => is_string( $k ) && 1 === preg_match( '/^[a-z][a-z0-9_-]{0,31}$/', $k ) ) );
	}

	public static function default_title( string $kind ): string {
		return match ( $kind ) {
			'video' => __( 'New video lesson', 'rooster-lms' ),
			'audio' => __( 'New audio lesson', 'rooster-lms' ),
			'pdf' => __( 'New PDF lesson', 'rooster-lms' ),
			'stream' => __( 'New stream', 'rooster-lms' ),
			'live' => __( 'New live lesson', 'rooster-lms' ),
			'quiz' => __( 'New quiz', 'rooster-lms' ),
			'assignment' => __( 'New assignment', 'rooster-lms' ),
			'scorm' => __( 'New SCORM package', 'rooster-lms' ),
			'external' => __( 'New external tool', 'rooster-lms' ),
			default => __( 'New lesson', 'rooster-lms' ),
		};
	}
}