prologic-saltyim/internal/pwa/utils/lookup.go

package utils

import (
	"encoding/json"
	"io/ioutil"
	"net/http"

	"github.com/maxence-charriere/go-app/v9/pkg/app"
	"go.mills.io/saltyim"
)

// LookupAddr performs a lookup of a Salty Addr directly and if the request
// fails for whatever reason (usuaully due to Cross-Orogin-Resource-Sharing
// policies / CORS) it  uses the Salty Broker the PWA was served from
// initially to perform the lookup by proxying the lookup through the broker.
// Why? CORS sucks.
func LookupAddr(user string) (saltyim.Addr, error) {
	addr, err := saltyim.LookupAddr(user)
	if err == nil {
		return addr, nil
	}

	// Fallback to proxying the lookup through the broker...

	res, err := saltyim.Request(http.MethodGet, app.Getenv("LookupEndpoint")+user, nil, nil)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()

	data, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return nil, err
	}

	if err := json.Unmarshal(data, &addr); err != nil {
		return nil, err
	}

	return addr, nil
}