Cleanup and prepare for instanced link handler (allowing the use of twitter, imgur, etc)

default.go

@@ -19,7 +19,7 @@ const (
 	maxBodySizeBytes = 20971520
 )
 
-func defaultLinkHandler(link string) (*LinkInfo, error) {
+func (api *LinkInfoApi) DefaultLinkHandler(link string) (*LinkInfo, error) {
 	redirects := make([]string, 0)
 
 	u, err := url.Parse(link)
@@ -31,7 +31,7 @@ func defaultLinkHandler(link string) (*LinkInfo, error) {
 	var res *http.Response
 
 	for i := 0; i < 10; i++ {
-		res, err = Client.Head(link)
+		res, err = api.Client.Head(link)
 
 		if err != nil {
 			return nil, err
@@ -52,7 +52,7 @@ func defaultLinkHandler(link string) (*LinkInfo, error) {
 	contentType := res.Header.Get("Content-Type")
 
 	if contentType == "" {
-		contentType = detectContentType(link, "application/octet-stream")
+		contentType = api.detectContentType(link, "application/octet-stream")
 	}
 
 	if idx := strings.Index(contentType, ";"); idx != -1 {
@@ -73,7 +73,7 @@ func defaultLinkHandler(link string) (*LinkInfo, error) {
 	switch contentType {
 	case contentTypeHtml:
 		if contentLength > 0 && contentLength < maxBodySizeBytes {
-			err = retrieveHtmlLinkTitle(ret, link)
+			err = api.retrieveHtmlLinkTitle(ret, link)
 			break
 		}
 		fallthrough
@@ -84,7 +84,7 @@ func defaultLinkHandler(link string) (*LinkInfo, error) {
 	return ret, err
 }
 
-func detectContentType(link, defaultType string) string {
+func (api *LinkInfoApi) detectContentType(link, defaultType string) string {
 	req, err := http.NewRequest("GET", link, nil)
 
 	if err != nil {
@@ -93,7 +93,7 @@ func detectContentType(link, defaultType string) string {
 
 	req.Header.Set("Range", "bytes=0-512")
 
-	res, err := Client.Do(req)
+	res, err := api.Client.Do(req)
 
 	if err != nil {
 		return defaultType
@@ -120,8 +120,8 @@ var (
 	attrKeys = []string{"property", "name", "itemprop"}
 )
 
-func retrieveHtmlLinkTitle(i *LinkInfo, link string) error {
-	res, err := Client.Get(link)
+func (api *LinkInfoApi) retrieveHtmlLinkTitle(i *LinkInfo, link string) error {
+	res, err := api.Client.Get(link)
 
 	if err != nil {
 		return err

default_test.go

@@ -5,8 +5,10 @@ import (
 	"testing"
 )
 
-func Test_detectContentType(t *testing.T) {
-	contentType := detectContentType("http://example.com", "")
+func Test_LinkInfoApi_detectContentType(t *testing.T) {
+	api := &LinkInfoApi{}
+
+	contentType := api.detectContentType("http://example.com", "")
 
 	if contentType == "" {
 		t.Fatal("Unable to test example.com, returned empty type")
@@ -21,7 +23,7 @@ func Test_detectContentType(t *testing.T) {
 	}
 }
 
-func Test_defaultLinkHandler(t *testing.T) {
+func Test_LinkInfoApi_defaultLinkHandler(t *testing.T) {
 	type expectedData struct {
 		Link  string
 		Title string
@@ -33,8 +35,10 @@ func Test_defaultLinkHandler(t *testing.T) {
 		{"http://techslides.com/demos/sample-videos/small.mp4", "", "video/mp4"},
 	}
 
+	api := &LinkInfoApi{}
+
 	for _, link := range testLinks {
-		l, err := defaultLinkHandler(link.Link)
+		l, err := api.DefaultLinkHandler(link.Link)
 
 		if err != nil {
 			t.Fatal("Unable to retrieve link info:", err)
@@ -50,10 +54,12 @@ func Test_defaultLinkHandler(t *testing.T) {
 	}
 }
 
-func Test_retrieveHtmlLinkTitle(t *testing.T) {
+func Test_LinkInfoApi_retrieveHtmlLinkTitle(t *testing.T) {
 	ret := &LinkInfo{}
 
-	if err := retrieveHtmlLinkTitle(ret, "http://example.com"); err != nil {
+	api := &LinkInfoApi{}
+
+	if err := api.retrieveHtmlLinkTitle(ret, "http://example.com"); err != nil {
 		t.Fatal("Unable to retrieve html link title:", err)
 	}
 

imgur.go

@@ -0,0 +1,9 @@
+package linkinfo
+
+var (
+	imgurHosts = []string{"imgur.com", "i.imgur.com"}
+)
+
+func (i *LinkInfoApi) ImgurLinkHandler(link string) (*LinkInfo, error) {
+	return nil, nil
+}

linkinfo.go

@@ -5,14 +5,14 @@ import (
 	"net/url"
 )
 
-type linkHandler struct {
-	hosts   []string
-	handler func(link string) (*LinkInfo, error)
+type LinkHandler struct {
+	Hosts   []string
+	Handler func(link string) (*LinkInfo, error)
 }
 
 type LinkInfoApi struct {
-	client  *http.Client
-	ImgurId string
+	Client       *http.Client
+	linkHandlers []*LinkHandler
 }
 
 type LinkInfo struct {
@@ -24,14 +24,20 @@ type LinkInfo struct {
 	Redirects     []string `json:"redirects,omitempty"`
 }
 
-var (
-	linkHandlers = []*linkHandler{
-		{hosts: []string{"youtube.com", "youtu.be"}, handler: youtubeLinkHandler},
-	}
-)
-
 func New() *LinkInfoApi {
-	return &LinkInfoApi{}
+	api := &LinkInfoApi{}
+
+	api.registerDefaultHandlers()
+
+	return api
+}
+
+func (i *LinkInfoApi) registerDefaultHandlers() {
+	i.linkHandlers = []*LinkHandler{
+		{Hosts: youtubeHosts, Handler: i.YoutubeLinkHandler},
+		{Hosts: imgurHosts, Handler: i.ImgurLinkHandler},
+		{Hosts: twitterHosts, Handler: i.TwitterLinkHandler},
+	}
 }
 
 func (i *LinkInfoApi) Retrieve(link string) (*LinkInfo, error) {
@@ -41,13 +47,13 @@ func (i *LinkInfoApi) Retrieve(link string) (*LinkInfo, error) {
 		return nil, err
 	}
 
-	for _, handler := range linkHandlers {
-		for _, host := range handler.hosts {
+	for _, handler := range i.linkHandlers {
+		for _, host := range handler.Hosts {
 			if host == u.Hostname() {
-				return handler.handler(link)
+				return handler.Handler(link)
 			}
 		}
 	}
 
-	return defaultLinkHandler(link)
+	return i.DefaultLinkHandler(link)
 }

twitter.go

@@ -0,0 +1,9 @@
+package linkinfo
+
+var (
+	twitterHosts = []string{"twitter.com"}
+)
+
+func (i *LinkInfoApi) TwitterLinkHandler(link string) (*LinkInfo, error) {
+	return nil, nil
+}

youtube.go

@@ -1,5 +1,9 @@
 package linkinfo
 
-func youtubeLinkHandler(link string) (*LinkInfo, error) {
+var (
+	youtubeHosts = []string{"youtube.com", "youtu.be"}
+)
+
+func (i *LinkInfoApi) YoutubeLinkHandler(link string) (*LinkInfo, error) {
 	return nil, nil
 }