Opening the Random Wikipedia Page

wikirandom.go

package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"os/exec"
	"runtime"
)

const (
	RandomURL  = "https://en.wikipedia.org/w/api.php?action=query&list=random&rnnamespace=0&rnlimit=10&format=json"
	PageFormat = "http://en.wikipedia.org/wiki?curid=%d"
)

type RandomPageQuery struct {
	Query struct {
		Random []struct {
			ID    int    `json:"id"`
			Title string `json:"title"`
		} `json:"random"`
	} `json:"query"`
}

func main() {
	// Fetch JSON
	resp, err := http.Get(RandomURL)
	if err != nil {
		log.Fatalf("unable to fetch random page: %v", err)
	}
	defer resp.Body.Close()

	// Decode JSON
	var rand RandomPageQuery
	err = json.NewDecoder(resp.Body).Decode(&rand)
	if err != nil {
		log.Fatalf("unable to decode json: %v", err)
	}

	// Interactively ask user about reading article
	fmt.Println("Welcome to Wikipedia's Random Pages!")
	fmt.Println("------------------------------------")
	for _, page := range rand.Query.Random {
		fmt.Printf("Would you like to read about %s?\t", page.Title)
		if askForConfirmation() {
			open(fmt.Sprintf(PageFormat, page.ID))
			break
		}
	}
}

// askForConfirmation uses Scanln to parse user input. A user must type in "yes" or "no" and
// then press enter. It has fuzzy matching, so "y", "Y", "yes", "YES", and "Yes" all count as
// confirmations. If the input is not recognized, it will ask again. The function does not return
// until it gets a valid response from the user.
func askForConfirmation() bool {
	var response string
	_, err := fmt.Scanln(&response)
	if err != nil {
		log.Fatal(err)
	}
	okayResponses := []string{"y", "Y", "yes", "Yes", "YES"}
	nokayResponses := []string{"n", "N", "no", "No", "NO"}
	if containsString(okayResponses, response) {
		return true
	} else if containsString(nokayResponses, response) {
		return false
	} else {
		fmt.Println("Please type yes or no and then press enter:")
		return askForConfirmation()
	}
}

func containsString(l []string, s string) bool {
	for _, b := range l {
		if b == s {
			return true
		}
	}
	return false
}

// open uses open or xdg-open depending on the platform to open a browser to the URL selected
func open(URL string) {
	switch runtime.GOOS {
	case "linux":
		exec.Command("xdg-open", URL).Start()
	case "windows", "darwin":
		exec.Command("open", URL).Start()
	default:
		log.Fatal("unsupported platform")
	}
}