package utils

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net"
	"net/http"
	"sync"
	"time"
)

var once sync.Once
var _client *http.Client

func GetHttpClient() *http.Client {
	once.Do(func() {
		_client = &http.Client{
			Timeout: time.Minute * 1, //设置超时时间
			Transport: &http.Transport{
				Proxy: http.ProxyFromEnvironment,
				DialContext: (&net.Dialer{
					Timeout:   30 * time.Second,
					KeepAlive: 30 * time.Second,
				}).DialContext,
				TLSHandshakeTimeout:   10 * time.Second, //限制 TLS握手的时间
				ResponseHeaderTimeout: 10 * time.Second, //限制读取response header的时间,默认 timeout + 5*time.Second
				ExpectContinueTimeout: 1 * time.Second,  //限制client在发送包含 Expect: 100-continue的header到收到继续发送body的response之间的时间等待。
				MaxIdleConns:          100,              //所有host的连接池最大连接数量，默认无穷大
				MaxIdleConnsPerHost:   30,               //每个host的连接池最大空闲连接数,默认2
				MaxConnsPerHost:       10,               //每个host的最大连接数量
				IdleConnTimeout:       3 * time.Minute,  //how long an idle connection is kept in the connection pool.
			},
		}
	})
	return _client
}

func getBytes(request interface{}) ([]byte, error) {
	var body []byte
	switch t := request.(type) {
	case []byte:
		body = t
	case string:
		body = []byte(t)
	default:
		var err error
		body, err = json.Marshal(request)
		if err != nil {
			return nil, err
		}
	}
	return body, nil
}

type OnHttpResponse func(res *http.Response) error

func HttpRequest(req *http.Request, onResponse OnHttpResponse) error {
	client := GetHttpClient()
	res, err := client.Do(req)
	if err != nil {
		return err
	}
	defer res.Body.Close()
	if onResponse != nil {
		err = onResponse(res)
	}
	return err
}

func HttpMethod(url, method string, header http.Header, body io.Reader, onResponse OnHttpResponse) error {
	req, err := http.NewRequest(method, url, body)
	if err != nil {
		return err
	}
	if header != nil {
		req.Header = header
	}
	return HttpRequest(req, onResponse)
}

func HttpGet(url string, header http.Header, body io.Reader, onResponse OnHttpResponse) error {
	return HttpMethod(url, http.MethodGet, header, body, onResponse)
}

func HttpPost(url string, header http.Header, body io.Reader, onResponse OnHttpResponse) error {
	return HttpMethod(url, http.MethodPost, header, body, onResponse)
}

func HttpPostRequestJson(url string, request interface{}, resp interface{}) error {
	header := make(http.Header)
	header.Set("Content-Type", "application/json")
	body, err := getBytes(request)
	if err != nil {
		return err
	}
	return HttpPost(url, header, bytes.NewReader(body), func(res *http.Response) error {
		if res.StatusCode != http.StatusOK {
			return fmt.Errorf("http request (%s) error %s", url, res.Status)
		}
		content, err := io.ReadAll(res.Body)
		if err != nil {
			return err
		}
		return json.Unmarshal(content, resp)
	})
}