package subscriber

import (
	"bytes"
	"context"
	"encoding/base64"
	"encoding/json"
	"encoding/xml"
	"fmt"
	"git.nspix.com/golang/micro/broker"
	"net/http"
	"strconv"
	"time"
)

var (
	MaxHttpTimeout = time.Second * 10 //最大的HTTP处理超时时间
)

var (
	httpClient = &http.Client{
		Timeout: MaxHttpTimeout,
	}
)

type Http struct {
	Id     string   `json:"id"`
	Url    string   `json:"url"`
	Topics []string `json:"topics"`
	Format string   `json:"format"`
}

func (sub *Http) ID() string {
	return sub.Id
}

func (sub *Http) HasTopic(topic string) bool {
	for _, s := range sub.Topics {
		if topic == s {
			return true
		}
	}
	return false
}

func (sub *Http) OnAttach() (err error) {
	return
}

func (sub *Http) Process(ctx context.Context, e *broker.Event) (err error) {
	var (
		req  *http.Request
		resp *http.Response
		buf  []byte
	)
	if sub.Format == "xml" {
		if buf, err = json.Marshal(e); err != nil {
			return
		}
	} else {
		if buf, err = xml.Marshal(e); err != nil {
			return
		}
	}
	if req, err = http.NewRequest(http.MethodPost, sub.Url, bytes.NewReader(buf)); err != nil {
		return
	}
	if sub.Format == "xml" {
		req.Header.Set("Content-Type", "application/xml")
	} else {
		req.Header.Set("Content-Type", "application/json")
	}
	req.Header.Set("X-Event-Name", e.Name)
	req.Header.Set("X-Event-Timestamp", strconv.FormatInt(e.Timestamp, 10))
	req.Header.Set("User-Agent", "micro")
	if resp, err = httpClient.Do(req.WithContext(ctx)); err != nil {
		return
	}
	if resp.StatusCode != http.StatusOK {
		err = fmt.Errorf("request \"%s\" got status code %d", sub.Url, resp.StatusCode)
	}
	_ = resp.Body.Close()
	return
}

func (sub *Http) OnDetach() (err error) {
	return
}

func NewHttpSubscriber(topics []string, url string) *Http {
	return &Http{
		Id:     base64.StdEncoding.EncodeToString([]byte(url)),
		Url:    url,
		Topics: topics,
		Format: "json",
	}
}