<?php
declare(strict_types=1);

require_once __DIR__ . '/../db/config.php';

function ensure_registration_table(): void {
    $sql = <<<SQL
CREATE TABLE IF NOT EXISTS registrations (
    id INT AUTO_INCREMENT PRIMARY KEY,
    reg_code VARCHAR(32) NOT NULL UNIQUE,
    name VARCHAR(190) NOT NULL,
    education VARCHAR(20) NOT NULL,
    major VARCHAR(190) NOT NULL,
    photo_path VARCHAR(255) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
SQL;
    db()->exec($sql);
}

function generate_reg_code(): string {
    return 'REG-' . date('Ymd') . '-' . strtoupper(bin2hex(random_bytes(3)));
}

function insert_registration(array $data): int {
    $stmt = db()->prepare(
        "INSERT INTO registrations (reg_code, name, education, major, photo_path)
         VALUES (:reg_code, :name, :education, :major, :photo_path)"
    );
    $stmt->bindValue(':reg_code', $data['reg_code']);
    $stmt->bindValue(':name', $data['name']);
    $stmt->bindValue(':education', $data['education']);
    $stmt->bindValue(':major', $data['major']);
    $stmt->bindValue(':photo_path', $data['photo_path']);
    $stmt->execute();
    return (int)db()->lastInsertId();
}

function fetch_registrations(): array {
    $stmt = db()->query("SELECT * FROM registrations ORDER BY created_at DESC");
    return $stmt->fetchAll();
}

function fetch_registration(int $id): ?array {
    $stmt = db()->prepare("SELECT * FROM registrations WHERE id = :id");
    $stmt->bindValue(':id', $id, PDO::PARAM_INT);
    $stmt->execute();
    $row = $stmt->fetch();
    return $row ?: null;
}