<?php

declare(strict_types=1);

namespace App\Repository;

use App\Support\Database;
use PDO;
use PDOException;

/**
 * Data access for the `users` table. Rows are returned as associative arrays.
 * There is no password: an account is created (if needed) and authenticated
 * entirely by opening an emailed magic link.
 *
 * @phpstan-type UserRow array{id: int, email: string, email_verified_at: string|null, verification_email_sent_at: string|null, created_at: string, updated_at: string}
 */
final class UserRepository
{
    public function __construct(private readonly PDO $pdo)
    {
    }

    /**
     * @return UserRow|null
     */
    public function findByEmail(string $email): ?array
    {
        $stmt = $this->pdo->prepare('SELECT * FROM users WHERE email = :email');
        $stmt->execute(['email' => $email]);

        $row = $stmt->fetch();

        return $row === false ? null : $this->cast($row);
    }

    /**
     * @return UserRow|null
     */
    public function findById(int $id): ?array
    {
        $stmt = $this->pdo->prepare('SELECT * FROM users WHERE id = :id');
        $stmt->execute(['id' => $id]);

        $row = $stmt->fetch();

        return $row === false ? null : $this->cast($row);
    }

    /**
     * @return UserRow
     */
    public function create(string $email): array
    {
        $stmt = $this->pdo->prepare('INSERT INTO users (email) VALUES (:email)');
        $stmt->execute(['email' => $email]);

        /** @var UserRow $user */
        $user = $this->findById((int) $this->pdo->lastInsertId());

        return $user;
    }

    /**
     * The user for this address, creating one (unverified) if it doesn't exist
     * yet -- this is the only "sign up".
     *
     * @return UserRow
     */
    public function findOrCreateByEmail(string $email): array
    {
        $existing = $this->findByEmail($email);
        if ($existing !== null) {
            return $existing;
        }

        try {
            return $this->create($email);
        } catch (PDOException $e) {
            // Lost a race with a concurrent request for the same address.
            $row = $this->findByEmail($email);
            if ($row === null) {
                throw $e;
            }

            return $row;
        }
    }

    public function markEmailVerified(int $id): void
    {
        $now = Database::nowExpr();
        $this->pdo->prepare(
            "UPDATE users SET email_verified_at = {$now}, updated_at = {$now} WHERE id = :id"
        )->execute(['id' => $id]);
    }

    /**
     * Apply a confirmed email change: set the address and mark it verified.
     */
    public function updateEmail(int $id, string $email): void
    {
        $now = Database::nowExpr();
        $this->pdo->prepare(
            "UPDATE users SET email = :email, email_verified_at = {$now}, updated_at = {$now} WHERE id = :id"
        )->execute(['email' => $email, 'id' => $id]);
    }

    public function markVerificationEmailSent(int $id): void
    {
        $this->pdo->prepare(
            'UPDATE users SET verification_email_sent_at = ' . Database::nowExpr() . ' WHERE id = :id'
        )->execute(['id' => $id]);
    }

    /**
     * @param array<string, mixed> $row
     * @return UserRow
     */
    private function cast(array $row): array
    {
        $row['id'] = (int) $row['id'];

        /** @var UserRow $row */
        return $row;
    }
}