package agent

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"time"

	"github.com/ituoke/ituoke/internal/protocol"
)

// ============================================================
// [Agent 桥] JSON-RPC HTTP 客户端（Go → Python）
// Python 侧应对齐 protocol.Request / Response
// 换 gRPC 时：保留 Service 方法，只替换本文件实现
// ============================================================

type Client struct {
	baseURL    string
	httpClient *http.Client
}

func NewClient(addr string) *Client {
	return &Client{
		baseURL: "http://" + addr,
		httpClient: &http.Client{
			Timeout: 120 * time.Second, // 多模态可能较慢
		},
	}
}

// Call 发起版本化 JSON-RPC 风格请求
func (c *Client) Call(id, method string, params any) (*protocol.Response, error) {
	reqBody := protocol.Request{
		ProtocolVersion: protocol.Version,
		ID:              id,
		Method:          method,
		Params:          params,
	}
	raw, err := json.Marshal(reqBody)
	if err != nil {
		return nil, err
	}

	httpReq, err := http.NewRequest(http.MethodPost, c.baseURL+"/rpc", bytes.NewReader(raw))
	if err != nil {
		return nil, err
	}
	httpReq.Header.Set("Content-Type", "application/json")

	httpRes, err := c.httpClient.Do(httpReq)
	if err != nil {
		return nil, fmt.Errorf("agent unreachable: %w", err)
	}
	defer httpRes.Body.Close()

	var res protocol.Response
	if err := json.NewDecoder(httpRes.Body).Decode(&res); err != nil {
		return nil, err
	}
	if res.Error != nil {
		return &res, fmt.Errorf("agent error %d: %s", res.Error.Code, res.Error.Message)
	}
	return &res, nil
}