<?php
declare(strict_types=1);

namespace Unsupervised\Schedular\GroupClass;

class GroupAccessRepository {

	private string $table;

	public function __construct( private \wpdb $db ) {
		$this->table = $db->prefix . 'us_group_access';
	}

	public function insert( GroupAccess $access ): int {
		$this->db->insert(
			$this->table,
			[
				'offering_id' => $access->offeringId,
				'student_id'  => $access->studentId,
				'email'       => $access->email,
				'invite_id'   => $access->inviteId,
				'status'      => $access->status,
				'invited_by'  => $access->invitedBy,
				'created_at'  => current_time( 'mysql' ),
			],
			[ '%d', '%d', '%s', '%d', '%s', '%d', '%s' ]
		);

		return $this->db->insert_id;
	}

	/**
	 * Whether a student holds a live (invited or enrolled) grant for an offering.
	 */
	public function hasGrant( int $offeringId, int $studentId ): bool {
		$count = (int) $this->db->get_var(
			$this->db->prepare(
				'SELECT COUNT(*) FROM %i WHERE offering_id = %d AND student_id = %d AND status IN ( %s, %s )',
				$this->table,
				$offeringId,
				$studentId,
				GroupAccess::STATUS_INVITED,
				GroupAccess::STATUS_ENROLLED
			)
		);

		return $count > 0;
	}

	/**
	 * The offering ids a student holds a live grant for — the invite-only classes
	 * to fold into their catalogue view.
	 *
	 * @return list<int>
	 */
	public function findGrantedOfferingIds( int $studentId ): array {
		$rows = $this->db->get_col(
			$this->db->prepare(
				'SELECT DISTINCT offering_id FROM %i WHERE student_id = %d AND status IN ( %s, %s )',
				$this->table,
				$studentId,
				GroupAccess::STATUS_INVITED,
				GroupAccess::STATUS_ENROLLED
			)
		);

		return array_values( array_map( \Unsupervised\Schedular\Val::int( ... ), $rows ) );
	}

	/**
	 * All grants for an offering, newest first.
	 *
	 * @return list<GroupAccess>
	 */
	public function findByOffering( int $offeringId ): array {
		$rows = $this->db->get_results(
			$this->db->prepare(
				'SELECT * FROM %i WHERE offering_id = %d ORDER BY id DESC',
				$this->table,
				$offeringId
			)
		);

		return array_map( GroupAccess::fromRow( ... ), $rows ?? [] );
	}

	/**
	 * Point email-invite grants for an address at the account created when the
	 * invitation was accepted, so the granted class unlocks for the new student.
	 * Only grants still awaiting an account (`student_id` NULL) are linked.
	 */
	public function linkStudentByEmail( string $email, int $studentId ): bool {
		if ( '' === $email ) {
			return false;
		}

		$sql = $this->db->prepare(
			'UPDATE %i SET student_id = %d WHERE email = %s AND student_id IS NULL',
			$this->table,
			$studentId,
			$email
		);

		return null !== $sql && false !== $this->db->query( $sql );
	}

	/**
	 * Flip a student's live grant for an offering to enrolled.
	 */
	public function markEnrolled( int $offeringId, int $studentId ): bool {
		return false !== $this->db->update(
			$this->table,
			[ 'status' => GroupAccess::STATUS_ENROLLED ],
			[
				'offering_id' => $offeringId,
				'student_id'  => $studentId,
			],
			[ '%s' ],
			[ '%d', '%d' ]
		);
	}

	public function revoke( int $id ): bool {
		return false !== $this->db->update(
			$this->table,
			[ 'status' => GroupAccess::STATUS_REVOKED ],
			[ 'id' => $id ],
			[ '%s' ],
			[ '%d' ]
		);
	}
}