<?php
// SPDX-License-Identifier: GPL-3.0-or-later
declare(strict_types=1);
namespace Aiwend\Chat;

use Aiwend\Db\Connection;
use Aiwend\Policy\Principal;
use Aiwend\Support\Clock;

/** One replaceable rating per assistant answer; only its authenticated session holder can write. */
final class Feedback
{
    public function __construct(private Connection $db, private Clock $clock) {}

    public function rate(Principal $principal, string $requestId, int $rating): bool
    {
        if ($principal->chatSessionId === null || !in_array($rating, [-1, 0, 1], true) || !\Aiwend\Support\RequestId::isValid($requestId)) {
            return false;
        }
        return $this->db->transaction(function () use ($principal, $requestId, $rating): bool {
            $lock = $this->db->driver() === 'mysql' ? ' FOR UPDATE' : '';
            // Same first row lock as message appending and erasure: no resurrection after deletion.
            $session = $this->db->selectOne('SELECT user_id, expires_at, revoked FROM {chat_sessions} WHERE site_id = ? AND id = ?' . $lock, [$principal->siteId, $principal->chatSessionId]);
            if ($session === null || (int) $session['revoked'] !== 0 || (int) $session['expires_at'] <= $this->clock->now()
                || ($session['user_id'] === null ? null : (int) $session['user_id']) !== $principal->userId) {
                return false;
            }
            $message = $this->db->selectOne("SELECT id FROM {messages} WHERE site_id = ? AND session_id = ? AND request_id = ? AND role = 'assistant' AND (outcome IS NULL OR outcome <> 'stopped')", [$principal->siteId, $principal->chatSessionId, $requestId]);
            if ($message === null) { return false; }
            $this->db->execute('DELETE FROM {message_feedback} WHERE site_id = ? AND message_id = ?', [$principal->siteId, $message['id']]);
            if ($rating !== 0) {
                $this->db->insert('message_feedback', ['site_id' => $principal->siteId, 'session_id' => $principal->chatSessionId, 'message_id' => $message['id'], 'rating' => $rating, 'updated_at' => $this->clock->now()]);
            }
            return true;
        });
    }
}