<?php

namespace RoosterLMS\Community;

use RoosterLMS\Content\ObjectState;
use RoosterLMS\Data\Db;
use RoosterLMS\Domain\Services;
use RoosterLMS\Domain\Users;
use RoosterLMS\Progress\ProgressStatus;

defined( 'ABSPATH' ) || exit;

final class CourseFacts {

	public const COMING_SOON = 1;

	public const NOTIFY_WAITLIST = 16;

	private static array $rows = array();

	private static array $staff = array();

	public static function forget(): void {
		self::$rows  = array();
		self::$staff = array();
	}

	public static function course( int $course_id ): ?array {
		if ( $course_id <= 0 ) {
			return null;
		}
		if ( ! array_key_exists( $course_id, self::$rows ) ) {
			$row                      = Db::row( 'SELECT id, home_post_id, state, qa_mode, qa_private, reviews_mode, coming_soon_flags, available_from FROM %i WHERE id = %d', Db::table( 'courses' ), $course_id );
			self::$rows[ $course_id ] = null === $row ? false : $row;
		}
		$row = self::$rows[ $course_id ];
		return false === $row ? null : $row;
	}

	public static function prime( array $course_ids ): void {
		$ids = array();
		foreach ( $course_ids as $id ) {
			$id = (int) $id;
			if ( $id > 0 && ! array_key_exists( $id, self::$rows ) ) {
				$ids[ $id ] = $id;
			}
		}
		if ( array() === $ids ) {
			return;
		}
		$ids = array_values( $ids );
		foreach ( $ids as $id ) {
			self::$rows[ $id ] = false;
		}
		foreach ( Db::rows( 'SELECT id, home_post_id, state, qa_mode, qa_private, reviews_mode, coming_soon_flags, available_from FROM %i WHERE id IN (' . implode( ',', array_fill( 0, count( $ids ), '%d' ) ) . ')', array_merge( array( Db::table( 'courses' ) ), $ids ) ) as $row ) {
			self::$rows[ (int) $row['id'] ] = $row;
		}
	}

	public static function exists( int $course_id ): bool {
		$row = self::course( $course_id );
		return null !== $row && ObjectState::TRASHED->value !== (int) $row['state'];
	}

	public static function is_learner( int $user_id, int $course_id ): bool {
		if ( $user_id <= 0 || $course_id <= 0 ) {
			return false;
		}
		$e = Services::enrolment_repo()->for_user( $user_id, array( $course_id ) )[ $course_id ] ?? null;
		return null !== $e && $e->is_active();
	}

	public static function is_staff( int $user_id, int $course_id ): bool {
		if ( $user_id <= 0 || $course_id <= 0 ) {
			return false;
		}
		$key = $user_id . ':' . $course_id;
		if ( ! isset( self::$staff[ $key ] ) ) {
			$row                 = self::course( $course_id );
			self::$staff[ $key ] = null !== $row && (
				Users::can( $user_id, 'manage_options' )
				|| Users::can( $user_id, 'rooster_lms_manage_orgs' )
				|| ( (int) $row['home_post_id'] > 0 && Users::can( $user_id, 'edit_post', (int) $row['home_post_id'] ) )
				|| null !== Services::course_staff()->role_of( $user_id, $course_id )
				|| null !== Services::gate()->staff_access( $user_id, $course_id )
			);
		}
		return self::$staff[ $key ];
	}

	public static function is_member( int $user_id, int $course_id ): bool {
		return self::is_staff( $user_id, $course_id ) || self::is_learner( $user_id, $course_id );
	}

	public static function progress( int $user_id, int $course_id ): array {
		$p = Services::progress_repo()->for_user( $user_id, array( $course_id ) )[ $course_id ] ?? null;
		return null === $p ? array( ProgressStatus::NOT_STARTED, 0 ) : array( $p->status, $p->percent );
	}

	public static function placed( int $course_id, int $unit_id ): bool {
		return $course_id > 0 && $unit_id > 0 && null !== Db::value( 'SELECT 1 FROM %i WHERE course_id = %d AND unit_id = %d LIMIT 1', Db::table( 'items' ), $course_id, $unit_id );
	}

	public static function qa_mode( int $course_id ): int {
		if ( true !== CommunitySettings::get( 'qa_enabled' ) ) {
			return 1;
		}
		$row  = self::course( $course_id );
		$mode = null === $row ? 0 : (int) $row['qa_mode'];
		return $mode >= 1 && $mode <= 5 ? $mode : (int) CommunitySettings::get( 'qa_mode' );
	}

	public static function qa_private( int $course_id ): bool {
		$row  = self::course( $course_id );
		$mode = null === $row ? 0 : (int) ( $row['qa_private'] ?? 0 );
		if ( 1 === $mode || 2 === $mode ) {
			return 2 === $mode;
		}
		return true === CommunitySettings::get( 'qa_private' );
	}

	public static function reviews_on( int $course_id ): bool {
		$row  = self::course( $course_id );
		$mode = null === $row ? 0 : (int) $row['reviews_mode'];
		if ( 1 === $mode || 2 === $mode ) {
			return 2 === $mode;
		}
		return true === CommunitySettings::get( 'reviews_enabled' );
	}

	public static function coming_soon( int $course_id ): bool {
		$row = self::course( $course_id );
		return null !== $row && ( (int) $row['coming_soon_flags'] & self::COMING_SOON ) > 0;
	}
}