<?php

declare(strict_types=1);

namespace Tests;

use PDO;
use PHPUnit\Framework\TestCase;
use Psr\Http\Message\ResponseInterface;
use Slim\App;
use Slim\Psr7\Factory\ServerRequestFactory;

/**
 * Boots the real Slim app against a throwaway SQLite database with all
 * migrations applied. Email goes to a per-test log file (MAIL_TRANSPORT=log).
 */
abstract class ApiTestCase extends TestCase
{
    protected App $app;
    private string $databasePath;
    private string $mailLogPath;
    private ?PDO $db = null;

    /** @var array<string, string> */
    private array $env = [];

    protected function setUp(): void
    {
        $unique = uniqid('todo-test-', true);
        $this->databasePath = sys_get_temp_dir() . "/{$unique}.sqlite";
        $this->mailLogPath = sys_get_temp_dir() . "/{$unique}.mail.log";

        $this->setEnv([
            'DATABASE_PATH' => $this->databasePath,
            'APP_URL' => 'https://app.test',
            'MAIL_TRANSPORT' => 'log',
            'MAIL_LOG_PATH' => $this->mailLogPath,
        ]);

        $pdo = $this->db();
        $pdo->exec('PRAGMA foreign_keys = ON');
        foreach (glob(dirname(__DIR__) . '/migrations/*.sql') ?: [] as $migration) {
            $pdo->exec((string) file_get_contents($migration));
        }

        $this->app = require dirname(__DIR__) . '/src/bootstrap.php';
    }

    protected function tearDown(): void
    {
        $this->db = null;
        @unlink($this->databasePath);
        @unlink($this->mailLogPath);

        foreach (array_keys($this->env) as $key) {
            putenv($key);
            unset($_ENV[$key], $_SERVER[$key]);
        }
        $this->env = [];
    }

    /** @param array<string, string> $vars */
    private function setEnv(array $vars): void
    {
        foreach ($vars as $key => $value) {
            putenv("{$key}={$value}");
            $_ENV[$key] = $value;
            $_SERVER[$key] = $value;
            $this->env[$key] = $value;
        }
    }

    /** A connection to the test database, for seeding rows directly. */
    protected function db(): PDO
    {
        if ($this->db === null) {
            $this->db = new PDO('sqlite:' . $this->databasePath, null, null, [
                PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            ]);
        }

        return $this->db;
    }

    /**
     * @param array<string, mixed>|null $body
     * @param array<string, string> $headers
     */
    protected function request(
        string $method,
        string $path,
        ?array $body = null,
        array $headers = [],
    ): ResponseInterface {
        $request = (new ServerRequestFactory())->createServerRequest($method, $path);

        foreach ($headers as $name => $value) {
            $request = $request->withHeader($name, $value);
        }

        if ($body !== null) {
            $request = $request->withParsedBody($body)->withHeader('Content-Type', 'application/json');
        }

        return $this->app->handle($request);
    }

    /**
     * Register a fresh user and return an `Authorization` header for them.
     *
     * @return array<string, string>
     */
    protected function authHeader(string $email = 'user@example.com'): array
    {
        $token = $this->decode(
            $this->request('POST', '/api/auth/register', ['email' => $email, 'password' => 'password123']),
        )['token'];

        return ['Authorization' => 'Bearer ' . $token];
    }

    /** All emails sent so far, oldest first. @return list<array{to: string, subject: string, body: string}> */
    protected function sentEmails(): array
    {
        if (!is_file($this->mailLogPath)) {
            return [];
        }

        $lines = array_filter(explode("\n", (string) file_get_contents($this->mailLogPath)));

        return array_map(
            static fn (string $line): array => json_decode($line, true, 512, JSON_THROW_ON_ERROR),
            array_values($lines),
        );
    }

    /** @return array{to: string, subject: string, body: string} */
    protected function lastEmail(): array
    {
        $emails = $this->sentEmails();
        self::assertNotEmpty($emails, 'Expected an email to have been sent.');

        return $emails[array_key_last($emails)];
    }

    /** Pull the magic-link token out of an email body. */
    protected function tokenFromEmail(?array $email = null): string
    {
        $email ??= $this->lastEmail();
        self::assertSame(1, preg_match('/verify-email\?token=([a-f0-9]+)/', $email['body'], $m));

        return $m[1];
    }

    /**
     * @return array<string, mixed>
     */
    protected function decode(ResponseInterface $response): array
    {
        return (array) json_decode((string) $response->getBody(), true, 512, JSON_THROW_ON_ERROR);
    }
}