goroutines.go

goroutines.go

package main

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

const (
	URL_USERS = "https://gorest.co.in/public/v2/users"
	URL_USER  = "https://gorest.co.in/public/v2/users/%d"
)

type User struct {
	ID     int    `json:"id"`
	Name   string `json:"name"`
	Email  string `json:"email"`
	Gender string `json:"gender"`
	Status string `json:"status"`
}

type Request interface {
	Get(url string) ([]uint8, error)
}

type web struct {
	client http.Client
}

func NewRequest() Request {
	client := http.Client{}
	return &web{client}
}

func (web *web) Get(url string) ([]uint8, error) {
	req, err := http.NewRequest("GET", url, nil)

	if err != nil {
		fmt.Println(err)
		return nil, err
	}

	res, err := web.client.Do(req)
	if err != nil {
		fmt.Println(err)
		return nil, err
	}
	defer res.Body.Close()

	body, err := io.ReadAll(res.Body)
	if err != nil {
		fmt.Println(err)
		return nil, err
	}
	return body, nil
}

func main() {
	var user User
	var users []User
	var waitGroup sync.WaitGroup

	request := NewRequest()
	body, _ := request.Get(URL_USERS)

	json.Unmarshal(body, &users)
	lenUsers := len(users)

	requestsChannel := make(chan User, lenUsers)
	waitGroup.Add(lenUsers)

	handler := func(id int, channel chan User, wg *sync.WaitGroup) {
		defer wg.Done()
		body, _ := request.Get(fmt.Sprintf(URL_USER, id))
		json.Unmarshal(body, &user)
		channel <- user
	}

	for _, user_temp := range users {
		go handler(user_temp.ID, requestsChannel, &waitGroup)
	}

	waitGroup.Wait()

	for _, item := range users {
		fmt.Println(item)
	}

}