package httpclient

import (
    "sync"

    "github.com/valyala/fasthttp"
)

// FastHTTPClient 使用 fasthttp 实现 HTTPClient 接口
type FastHTTPClient struct {
    client   *fasthttp.Client
    reqPool  *sync.Pool
    respPool *sync.Pool
}

// NewFastHTTPClient 返回一个初始化的 FastHTTPClient
func NewFastHTTPClient() *FastHTTPClient {
    return &FastHTTPClient{
        client: &fasthttp.Client{},
        reqPool: &sync.Pool{New: func() interface{} { return new(fasthttp.Request) }},
        respPool: &sync.Pool{New: func() interface{} { return new(fasthttp.Response) }},
    }
}

// Do 发送非流式请求
func (c *FastHTTPClient) Do(req *Request) (*Response, error) {
    fr := c.reqPool.Get().(*fasthttp.Request)
    defer c.reqPool.Put(fr)
    fr.Header.SetMethod(req.Method)
    fr.SetRequestURI(req.URL)
    if len(req.Body) > 0 {
        fr.SetBody(req.Body)
    }
    for k, v := range req.Headers {
        fr.Header.Set(k, v)
    }
    fresp := c.respPool.Get().(*fasthttp.Response)
    defer c.respPool.Put(fresp)
    if err := c.client.Do(fr, fresp); err != nil {
        return nil, err
    }
    resp := &Response{
        StatusCode: fresp.StatusCode(),
        Body:       append([]byte(nil), fresp.Body()...),
        Headers:    make(map[string]string),
    }
    fresp.Header.VisitAll(func(k, v []byte) {
        resp.Headers[string(k)] = string(v)
    })
    return resp, nil
}

// Stream 发送流式请求，逐块通过 callback 回调 SSE 数据
// 目前使用 net/http 实现 SSE 解析，后续可优化为 fasthttp 原生实现
func (c *FastHTTPClient) Stream(req *Request, callback func(chunk SSEChunk) error) error {
    return NewNetHTTPClient().Stream(req, callback)
}