Day30: XKCD cli wrapper

Author: canro91

Day30/go-grab-xkcd/client/xkcd.go

@@ -0,0 +1,93 @@
+package client
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/canro91/30DaysOfGo/Day30/go-grab-xkcd/model"
+	"io"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"time"
+)
+
+const (
+	BaseUrl        string        = "https://xkcd.com"
+	DefaultTimeout time.Duration = 30 * time.Second
+	LatestComic    ComicNumber   = 0
+)
+
+type ComicNumber int
+
+type XKCDClient struct {
+	client  *http.Client
+	baseUrl string
+}
+
+func NewXKCDClient() *XKCDClient {
+	return &XKCDClient{
+		client: &http.Client{
+			Timeout: DefaultTimeout,
+		},
+		baseUrl: BaseUrl,
+	}
+}
+
+func (c *XKCDClient) SetTimeout(d time.Duration) {
+	c.client.Timeout = d
+}
+
+func (c *XKCDClient) Fetch(n ComicNumber, save bool) (model.Comic, error) {
+	response, err := c.client.Get(c.BuildUrl(n))
+	if err != nil {
+		return model.Comic{}, err
+	}
+	defer response.Body.Close()
+
+	var comicResponse model.ComicResponse
+	if err := json.NewDecoder(response.Body).Decode(&comicResponse); err != nil {
+		return model.Comic{}, err
+	}
+
+	if save {
+		if err := c.SaveToDisk(comicResponse.Img, "."); err != nil {
+			fmt.Println("Failed to saved image")
+		}
+	}
+
+	return comicResponse.MapToComic(), nil
+}
+
+func (c *XKCDClient) SaveToDisk(url, savePath string) error {
+	response, err := http.Get(url)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+
+	absolutePath, err := filepath.Abs(savePath)
+	filePath := fmt.Sprintf("%s/%s", absolutePath, path.Base(url))
+	file, err := os.Create(filePath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	_, err = io.Copy(file, response.Body)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *XKCDClient) BuildUrl(n ComicNumber) string {
+	var url string
+	if n == LatestComic {
+		url = fmt.Sprintf("%s/info.0.json", BaseUrl)
+	} else {
+		url = fmt.Sprintf("%s/%d/info.0.json", BaseUrl, n)
+	}
+	return url
+}

Day30/go-grab-xkcd/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"github.com/canro91/30DaysOfGo/Day30/go-grab-xkcd/client"
+	"log"
+	"time"
+)
+
+func main() {
+	comicNumber := flag.Int("n", int(client.LatestComic), "Comic number")
+	clientTimeout := flag.Int64("t", int64(client.DefaultTimeout.Seconds()), "Client timeout in seconds")
+	saveImage := flag.Bool("s", false, "Save image to current directory")
+	outputType := flag.String("o", "text", "Print output in format: text/json")
+	flag.Parse()
+
+	xkcdClient := client.NewXKCDClient()
+	xkcdClient.SetTimeout(time.Duration(*clientTimeout) * time.Second)
+
+	comic, err := xkcdClient.Fetch(client.ComicNumber(*comicNumber), *saveImage)
+	if err != nil {
+		log.Println(err)
+	}
+
+	if *outputType == "json" {
+		fmt.Println(comic.ToJSON())
+	} else {
+		fmt.Println(comic.PrettyPrint())
+	}
+}

Day30/go-grab-xkcd/model/comic.go

@@ -0,0 +1,56 @@
+package model
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+type ComicResponse struct {
+	Month      string `json:"month"`
+	Num        int    `json:"num"`
+	Link       string `json:"link"`
+	Year       string `json:"year"`
+	News       string `json:"news"`
+	SafeTitle  string `json:"safe_title"`
+	Transcript string `json:"transcript"`
+	Alt        string `json:"alt"`
+	Img        string `json:"img"`
+	Title      string `json:"title"`
+	Day        string `json:"day"`
+}
+type Comic struct {
+	Title       string `json:"title"`
+	Number      int    `json:"number"`
+	Date        string `json:"date"`
+	Description string `json:"description"`
+	Image       string `json:"image"`
+}
+
+func (r ComicResponse) FormattedDate() string {
+	return fmt.Sprintf("%s-%s-%s", r.Year, r.Month, r.Day)
+}
+
+func (r ComicResponse) MapToComic() Comic {
+	return Comic{
+		Title:       r.Title,
+		Number:      r.Num,
+		Date:        r.FormattedDate(),
+		Description: r.Alt,
+		Image:       r.Img,
+	}
+}
+
+func (c Comic) PrettyPrint() string {
+	return fmt.Sprintf(
+		"Title: %s\nComic No: %d\nDate: %s\nDescription: %s\nImage: %s\n",
+		c.Title, c.Number, c.Date, c.Description, c.Image)
+}
+
+func (c Comic) ToJSON() string {
+	json, err := json.Marshal(c)
+	if err != nil {
+		return ""
+	}
+
+	return string(json)
+}

README.md

@@ -31,4 +31,8 @@ This is my jounery to learn Go in 30 days throught projects and hand-on tutorial
 * Day 26: [Sync](https://github.com/quii/learn-go-with-tests/blob/master/sync.md)
 * Day 27: [Context](https://github.com/quii/learn-go-with-tests/blob/master/context.md)
 * Day 28: [Roman numerals kata](https://github.com/quii/learn-go-with-tests/blob/master/roman-numerals.md)
-* Day 29: [API Client](https://blog.gopheracademy.com/advent-2019/api-clients-humans/)
+* Day 29: [API Client](https://blog.gopheracademy.com/advent-2019/api-clients-humans/) for Day 23 API
+
+***
+
+* Day 30: [Create a CLI wrapper for XKCD API](https://eryb.space/2020/05/27/diving-into-go-by-building-a-cli-application.html)