<?php

namespace App\Models;

use App\Config\Database;

class Session
{
    public static function findByUserId(int $userId): array
    {
        $db = Database::getInstance();
        $stmt = $db->prepare('SELECT * FROM sessions WHERE user_id = :user_id ORDER BY updated_at DESC');
        $stmt->execute(['user_id' => $userId]);
        return $stmt->fetchAll();
    }

    public static function findById(int $id): ?array
    {
        $db = Database::getInstance();
        $stmt = $db->prepare('SELECT * FROM sessions WHERE id = :id');
        $stmt->execute(['id' => $id]);
        $result = $stmt->fetch();
        return $result ?: null;
    }

    public static function create(array $data): array
    {
        $db = Database::getInstance();
        $stmt = $db->prepare('INSERT INTO sessions (user_id, name, provider, model, system_prompt, personality_id, thinking_mode) VALUES (:user_id, :name, :provider, :model, :system_prompt, :personality_id, :thinking_mode)');
        $stmt->execute([
            'user_id' => $data['user_id'],
            'name' => $data['name'] ?? '新会话',
            'provider' => $data['provider'] ?? 'newapi',
            'model' => $data['model'] ?? 'gpt-3.5-turbo',
            'system_prompt' => $data['system_prompt'] ?? '',
            'personality_id' => $data['personality_id'] ?? null,
            'thinking_mode' => $data['thinking_mode'] ?? 0,
        ]);

        return self::findById((int) $db->lastInsertId());
    }

    public static function update(int $id, array $data): bool
    {
        $db = Database::getInstance();

        $fields = [];
        $params = ['id' => $id];

        foreach ($data as $key => $value) {
            $fields[] = "{$key} = :{$key}";
            $params[$key] = $value;
        }

        $fields[] = 'updated_at = CURRENT_TIMESTAMP';

        $sql = 'UPDATE sessions SET ' . implode(', ', $fields) . ' WHERE id = :id';
        $stmt = $db->prepare($sql);

        return $stmt->execute($params);
    }

    public static function delete(int $id): bool
    {
        $db = Database::getInstance();

        $db->beginTransaction();
        try {
            $db->prepare('DELETE FROM messages WHERE session_id = :session_id')->execute(['session_id' => $id]);
            $db->prepare('DELETE FROM sessions WHERE id = :id')->execute(['id' => $id]);
            $db->commit();
            return true;
        } catch (\Throwable $e) {
            $db->rollBack();
            throw $e;
        }
    }
}