import type { NextApiRequest, NextApiResponse } from 'next';
import { SystemConfig } from '@/models';
import withDatabase from '@/lib/withDatabase';
import { requireAdmin } from '@/lib/auth';

async function handler(req: NextApiRequest, res: NextApiResponse, user: any) {
    if (req.method !== 'POST') {
        return res.status(405).json({ message: 'Method not allowed' });
    }

    const { endpoint, apiKey, assistantId } = req.body;

    if (!endpoint) {
        return res.status(400).json({ message: 'Endpoint is required' });
    }

    try {
        let finalApiKey = apiKey;

        // 如果没有提供 Key 但提供了 ID，尝试从数据库获取
        if (!finalApiKey && assistantId) {
            const config = await SystemConfig.findOne().select('+AI配置列表.API密钥').lean();
            if (config && config.AI配置列表) {
                const assistant = config.AI配置列表.find((a: any) => a._id.toString() === assistantId);
                if (assistant) {
                    finalApiKey = assistant.API密钥;
                }
            }
        }

        if (!finalApiKey) {
            return res.status(400).json({ message: 'API Key is required' });
        }

        // 处理 Endpoint，确保指向 /models
        // 假设用户填写的 endpoint 是 base url (e.g. https://api.openai.com/v1)
        // 或者完整的 chat url (e.g. https://api.openai.com/v1/chat/completions)
        let baseUrl = endpoint.replace(/\/+$/, '');
        if (baseUrl.endsWith('/chat/completions')) {
            baseUrl = baseUrl.replace('/chat/completions', '');
        }

        const url = `${baseUrl}/models`;

        const response = await fetch(url, {
            method: 'GET',
            headers: {
                'Authorization': `Bearer ${finalApiKey}`,
                'Content-Type': 'application/json'
            }
        });

        if (!response.ok) {
            const errorText = await response.text();
            console.error('Fetch Models Error:', errorText);
            return res.status(response.status).json({ message: `Provider Error: ${response.statusText}` });
        }

        const data = await response.json();
        // OpenAI 格式返回 { data: [{ id: 'model-name', ... }] }
        const models = data.data ? data.data.map((m: any) => m.id) : [];

        return res.status(200).json({ models });

    } catch (error) {
        console.error('Fetch Models Internal Error:', error);
        return res.status(500).json({ message: 'Internal Server Error' });
    }
}

export default withDatabase(requireAdmin(handler));