mark2web/pkg/helper/webrequest.go

package helper

import (
	"encoding/json"
	"fmt"
	"image"
	"io/ioutil"
	"net/http"
	"strings"

	"gitbase.de/apairon/mark2web/pkg/logger"
)

type wrImageEntry struct {
	img    image.Image
	format string
}

type wrJSONEntry struct {
	data interface{}
}

var wrImageCache = make(map[string]*wrImageEntry)
var wrJSONCache = make(map[string]*wrJSONEntry)

// WebRequest will fetch an url and returns reponse
func WebRequest(url string, opts interface{}) (*http.Response, error) {
	logger.Log.Noticef("requesting url via GET %s", url)

	return http.Get(url)
}

// JSONWebRequest will GET a json object/array from a given URL
func JSONWebRequest(url string) interface{} {
	cached := wrJSONCache[url]
	if cached == nil {
		resp, err := WebRequest(url, nil)
		if err != nil {
			logger.Log.Panicf("could not get url '%s': %s", url, err)
		}
		defer resp.Body.Close()

		body, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			logger.Log.Panicf("could not read body from url '%s': %s", url, err)
		}

		logger.Log.Debugf("output from url '%s':\n%s", url, string(body))

		if resp.StatusCode >= 400 {
			logger.Log.Panicf("bad status '%d - %s' from url '%s'", resp.StatusCode, resp.Status, url)
		}

		contentType := resp.Header.Get("Content-Type")

		if strings.Contains(contentType, "json") {

		} else {
			logger.Log.Panicf("is not json '%s' from url '%s'", contentType, url)
		}

		cached = new(wrJSONEntry)

		jsonMap := make(map[string]interface{})
		err = json.Unmarshal(body, &jsonMap)
		if err == nil {
			cached.data = jsonMap
		} else {
			jsonArrayMap := make([]map[string]interface{}, 0)
			err = json.Unmarshal(body, &jsonArrayMap)
			if err == nil {
				cached.data = jsonArrayMap
			} else {
				logger.P("could not read json from '%s': invalid type", url)
			}
		}

		wrJSONCache[url] = cached

	}
	return cached.data
}

// ImageWebRequest gets an image from an url
func ImageWebRequest(url string) (image.Image, string, error) {
	cached := wrImageCache[url]
	if cached == nil {
		resp, err := WebRequest(url, nil)
		if err != nil {
			return nil, "", fmt.Errorf("could not get url '%s': %s", url, err)
		}

		img, format, err := image.Decode(resp.Body)
		if err != nil {
			return nil, "", fmt.Errorf("could read body from url '%s': %s", url, err)
		}

		cached = &wrImageEntry{
			img:    img,
			format: format,
		}

		wrImageCache[url] = cached
	}

	return cached.img, cached.format, nil
}