Implement Imgur info

.drone.yml

@@ -7,3 +7,6 @@ steps:
     image: golang
     commands:
       - go test
+    environment:
+      IMGUR_CLIENT_ID:
+        from_secret: imgur_client_id

imgur.go

@@ -1,9 +1,140 @@
 package linkinfo
 
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/url"
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+const imgurApiUrl = "https://api.imgur.com/3/%s/%s.json"
+
 var (
 	imgurHosts = []string{"imgur.com", "i.imgur.com"}
+
+	imgurAlbumRegexp = regexp.MustCompile("^/(a|gallery)/")
 )
 
-func (i *LinkInfoApi) ImgurLinkHandler(link string) (*LinkInfo, error) {
+type ImgurOptions struct {
-	return nil, nil
+	Option
+
+	ClientId string
+}
+
+type ImgurInfoApi struct {
+	api  *LinkInfoApi
+	opts *ImgurOptions
+}
+
+type imgurResponse struct {
+	Success bool      `json:"success"`
+	Data    imgurData `json:"data"`
+}
+
+type imgurData struct {
+	Type        string `json:"type"`
+	Title       string `json:"title"`
+	Description string `json:"description"`
+	Width       int    `json:"width"`
+	Height      int    `json:"height"`
+	Animated    bool   `json:"animated"`
+	Nsfw        bool   `json:"nsfw"`
+}
+
+func (i *ImgurInfoApi) Handler(link string) (*LinkInfo, error) {
+	if i.opts.ClientId == "" {
+		return nil, errors.New("invalid client id")
+	}
+
+	u, err := url.Parse(link)
+
+	if err != nil {
+		return nil, err
+	}
+
+	id := filepath.Base(u.Path)
+
+	extension := filepath.Ext(id)
+
+	if extension != "" {
+		id = id[0 : len(id)-len(extension)]
+	}
+
+	imageType := "image"
+
+	if imgurAlbumRegexp.MatchString(link) {
+		imageType = "album"
+	}
+
+	req, err := http.NewRequest("GET", fmt.Sprintf(imgurApiUrl, imageType, id), nil)
+
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Authorization", "Client-ID "+i.opts.ClientId)
+
+	res, err := i.api.Client.Do(req)
+
+	if err != nil {
+		return nil, err
+	}
+
+	defer res.Body.Close()
+
+	var response imgurResponse
+
+	if err := json.NewDecoder(res.Body).Decode(&response); err != nil {
+		return nil, err
+	}
+
+	if !response.Success {
+		return nil, errors.New("imgur api returned success=false")
+	}
+
+	var title string
+
+	if response.Data.Title != "" {
+		title = "Imgur - " + response.Data.Title
+	} else {
+		title = "Imgur - " + id
+
+		switch response.Data.Type {
+		case "image/jpeg":
+			title += ".jpg"
+		case "image/png":
+			title += ".png"
+		case "image/gif":
+			title += ".gif"
+		}
+	}
+
+	attribs := make([]string, 0)
+
+	if imageType == "album" {
+		attribs = append(attribs, "Album")
+	} else {
+		attribs = append(attribs, fmt.Sprintf("%dx%d", response.Data.Width, response.Data.Height))
+
+		if response.Data.Animated {
+			attribs = append(attribs, "Animated")
+		}
+	}
+
+	title += " (" + strings.Join(attribs, ", ") + ")"
+
+	if response.Data.Nsfw {
+		attribs = append(attribs, "NSFW")
+	}
+
+	info := &LinkInfo{
+		Title:       title,
+		Description: response.Data.Description,
+	}
+
+	return info, nil
 }

imgur_test.go

@@ -0,0 +1,22 @@
+package linkinfo
+
+import (
+	"os"
+	"testing"
+)
+
+func TestImgurInfoApi_Handler(t *testing.T) {
+	api := New(&ImgurOptions{
+		ClientId: os.Getenv("IMGUR_CLIENT_ID"),
+	})
+
+	info, err := api.Imgur.Handler("https://i.imgur.com/1GKJg79.gifv")
+
+	if err != nil {
+		t.Fatal("Error getting imgur info:", err)
+	}
+
+	if info.Title != "Imgur - Approaching the weekend like (720x404, Animated)" {
+		t.Fatal("Unexpected title", info.Title)
+	}
+}

linkinfo.go

@@ -12,7 +12,9 @@ type LinkHandler struct {
 }
 
 type LinkInfoApi struct {
-	Client       *http.Client
+	Client *http.Client
+
+	Imgur        *ImgurInfoApi
 	linkHandlers []*LinkHandler
 }
 
@@ -25,26 +27,45 @@ type LinkInfo struct {
 	Redirects     []string `json:"redirects,omitempty"`
 }
 
-func New() *LinkInfoApi {
+func New(opts ...Option) *LinkInfoApi {
 	api := &LinkInfoApi{
 		Client: &http.Client{
 			Timeout: 60 * time.Second,
 		},
 	}
 
+	for _, opt := range opts {
+		switch opt.(type) {
+		case *ImgurOptions:
+			api.Imgur = &ImgurInfoApi{api, opt.(*ImgurOptions)}
+		}
+	}
+
 	api.registerDefaultHandlers()
 
 	return api
 }
 
 func (i *LinkInfoApi) registerDefaultHandlers() {
+	i.linkHandlers = make([]*LinkHandler, 0)
+
+	if i.Imgur != nil {
+		i.linkHandlers = append(i.linkHandlers, &LinkHandler{
+			Hosts:   imgurHosts,
+			Handler: i.Imgur.Handler,
+		})
+	}
+
 	i.linkHandlers = []*LinkHandler{
 		{Hosts: youtubeHosts, Handler: i.YoutubeLinkHandler},
-		{Hosts: imgurHosts, Handler: i.ImgurLinkHandler},
 		{Hosts: twitterHosts, Handler: i.TwitterLinkHandler},
 	}
 }
 
+func (i *LinkInfoApi) AddHandler(handler *LinkHandler) {
+	i.linkHandlers = append(i.linkHandlers, handler)
+}
+
 func (i *LinkInfoApi) Retrieve(link string) (*LinkInfo, error) {
 	u, err := url.Parse(link)
 

options.go

@@ -0,0 +1,4 @@
+package linkinfo
+
+type Option interface {
+}