<?php
declare(strict_types=1);

namespace NeonBlog;

use PDO;

final class CommentService
{
    private PDO $pdo;
    private Config $config;

    public function __construct(PDO $pdo, Config $config)
    {
        $this->pdo = $pdo;
        $this->config = $config;
    }

    /** @return array<int, array<string, mixed>> */
    public function approvedFor(string $slug): array
    {
        $statement = $this->pdo->prepare(
            'SELECT * FROM comments WHERE slug = :slug AND status = "approved" ORDER BY created_at ASC'
        );
        $statement->execute(['slug' => $slug]);

        return $statement->fetchAll();
    }

    /** @return array{ok: bool, stored: bool, message: string} */
    public function add(string $slug, array $data): array
    {
        $honeypot = (string) $this->config->get('comments.honeypot_field', 'website_url');
        if (trim((string) ($data[$honeypot] ?? '')) !== '') {
            return [
                'ok' => true,
                'stored' => false,
                'message' => 'Thanks. Your comment is awaiting review.',
            ];
        }

        $author = trim((string) ($data['author'] ?? ''));
        $email = trim((string) ($data['email'] ?? ''));
        $website = trim((string) ($data['site_url'] ?? ''));
        $body = trim((string) ($data['body'] ?? ''));

        if ($author === '' || $email === '' || $body === '') {
            return ['ok' => false, 'stored' => false, 'message' => 'Name, email, and comment are required.'];
        }
        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
            return ['ok' => false, 'stored' => false, 'message' => 'Please enter a valid email address.'];
        }
        if ($website !== '' && !filter_var($website, FILTER_VALIDATE_URL)) {
            return ['ok' => false, 'stored' => false, 'message' => 'Please enter a valid website URL or leave it blank.'];
        }
        if (mb_strlen($body) > 5000) {
            return ['ok' => false, 'stored' => false, 'message' => 'Comments must stay under 5,000 characters.'];
        }

        $now = date('c');
        $status = $this->config->get('comments.moderate', true) ? 'pending' : 'approved';
        $statement = $this->pdo->prepare(
            'INSERT INTO comments
                (slug, author, email, website, body, status, ip_hash, user_agent, created_at, updated_at)
             VALUES
                (:slug, :author, :email, :website, :body, :status, :ip_hash, :user_agent, :created_at, :updated_at)'
        );
        $statement->execute([
            'slug' => $slug,
            'author' => $author,
            'email' => $email,
            'website' => $website,
            'body' => $body,
            'status' => $status,
            'ip_hash' => $this->ipHash(),
            'user_agent' => substr((string) ($_SERVER['HTTP_USER_AGENT'] ?? 'cli'), 0, 300),
            'created_at' => $now,
            'updated_at' => $now,
        ]);

        return [
            'ok' => true,
            'stored' => true,
            'message' => $status === 'approved'
                ? 'Thanks. Your comment is live.'
                : 'Thanks. Your comment is awaiting review.',
        ];
    }

    /** @return array<int, array<string, mixed>> */
    public function list(?string $status = null, ?string $slug = null): array
    {
        $where = [];
        $params = [];
        if ($status !== null) {
            $where[] = 'status = :status';
            $params['status'] = $status;
        }
        if ($slug !== null) {
            $where[] = 'slug = :slug';
            $params['slug'] = $slug;
        }

        $sql = 'SELECT * FROM comments';
        if ($where !== []) {
            $sql .= ' WHERE ' . implode(' AND ', $where);
        }
        $sql .= ' ORDER BY created_at DESC';

        $statement = $this->pdo->prepare($sql);
        $statement->execute($params);

        return $statement->fetchAll();
    }

    public function setStatus(int $id, string $status): bool
    {
        if (!in_array($status, ['pending', 'approved', 'spam'], true)) {
            return false;
        }

        $statement = $this->pdo->prepare('UPDATE comments SET status = :status, updated_at = :updated_at WHERE id = :id');
        $statement->execute([
            'id' => $id,
            'status' => $status,
            'updated_at' => date('c'),
        ]);

        return $statement->rowCount() > 0;
    }

    public function delete(int $id): bool
    {
        $statement = $this->pdo->prepare('DELETE FROM comments WHERE id = :id');
        $statement->execute(['id' => $id]);

        return $statement->rowCount() > 0;
    }

    private function ipHash(): string
    {
        $ip = (string) ($_SERVER['REMOTE_ADDR'] ?? 'cli');
        $salt = (string) $this->config->get('stats.hash_salt', 'change-me');

        return hash_hmac('sha256', $ip, $salt);
    }
}