// Package network define struct of network operation
package network

import (
	"fmt"
	"io"
	"net/http"
	"strings"

	"github.com/bitly/go-simplejson"
)

// APIEndpoint defines an api endpoint struct to poll data from dataRT service
type APIEndpoint struct {
	URL         string            `json:"url"`
	Method      string            `json:"method"` // HTTP 方法，如 "GET", "POST"
	Headers     map[string]string `json:"headers"`
	QueryParams map[string]string `json:"query_params"`
	Body        string            `json:"body"`     // 对于 POST 请求需要一个请求体
	Interval    int               `json:"interval"` // 轮询间隔时间（秒）
}

// fetchAPI defines execute http request and return response or error
func fetchAPI(endpoint APIEndpoint) (string, error) {
	client := &http.Client{}

	req, err := http.NewRequest(endpoint.Method, endpoint.URL, nil)
	if err != nil {
		return "", err
	}

	for key, value := range endpoint.Headers {
		req.Header.Set(key, value)
	}

	query := req.URL.Query()
	for key, value := range endpoint.QueryParams {
		query.Set(key, value)
	}
	req.URL.RawQuery = query.Encode()

	if endpoint.Method == "POST" || endpoint.Method == "PUT" {
		req.Body = io.NopCloser(strings.NewReader(endpoint.Body))
		req.Header.Set("Content-Type", "application/json")
	}

	resp, err := client.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}

	return string(body), nil
}

// PollAPIEndpoints defines unmarshal polling data from http request
func PollAPIEndpoints(endpoint APIEndpoint) ([]float64, error) {
	var valueSlice []float64

	respStr, err := fetchAPI(endpoint)
	if err != nil {
		return valueSlice, fmt.Errorf("fetch api failed:%w", err)
	}
	realDataJSON, err := simplejson.NewJson([]byte(respStr))
	if err != nil {
		return valueSlice, fmt.Errorf("format real time data failed:%w", err)
	}
	simplejson.New().UnmarshalJSON([]byte(respStr))
	code := realDataJSON.Get("code").MustInt()
	if code != 0 {
		return valueSlice, fmt.Errorf("polling data api status error:%s", realDataJSON.Get("msg").MustString())
	}

	dataLen := len(realDataJSON.Get("data").MustArray())
	for i := 0; i < dataLen; i++ {
		valueSlice = append(valueSlice, realDataJSON.Get("data").GetIndex(i).Get("value").MustFloat64())
	}
	return valueSlice, nil
}