new api implemented server-side

4 files changed, 177 insertions, 51 deletions

diff --git a/api.go b/api.go
index fa91ea6..21a2b5f 100644
--- a/api.go
+++ b/api.go
@@ -1,58 +1,58 @@
 package main
 
 import (
-	"fmt"
-	"io"
 	"log"
+	"encoding/json"
 	"net/http"
+	"time"
 )
 
-const youtubeAPI = "https://www.googleapis.com/youtube/v3/"
-
-/* function to make an api request */
-func apiRequest(w http.ResponseWriter, r *http.Request, endpoint string, videoIdParam string, part string) {
-	videoID := r.URL.Query().Get("id")
-	if videoID == "" {
-		msg := "Missing ?id=VIDEO_ID parameter"
-		http.Error(w, msg, http.StatusBadRequest)
-		return
-	}
+type VideoDetails struct {
+	Channel        string     `json:"channel"`
+	DatePublished  time.Time  `json:"datePublished"`
+	Description    string     `json:"description"`
+	NumComments    int        `json:"comments"`
+	NumLikes       int        `json:"likes"`
+	NumViews       int        `json:"views"`
+	Tags           []string   `json:"tags"`
+}
 
-	if apiKey == "" {
-		msg := "API_KEY environment variable not set"
-		http.Error(w, msg, http.StatusInternalServerError)
-		log.Println(msg)
-		return
-	}
+type Comment struct {
+	Author         string      `json:"a"`
+	Body           string      `json:"b"`
+	DatePublished  time.Time   `json:"p"`
+	DateUpdated    time.Time   `json:"u"`
+	Likes          int         `json:"l"`
+	Replies        []*Comment  `json:"r,omitempty"`
+}
 
-	url := fmt.Sprintf("%s?part=%s&%s=%s&key=%s", youtubeAPI + endpoint, part, videoIdParam, videoID, apiKey)
-	resp, err := http.Get(url)
-	if err != nil {
-		msg := "Failed to fetch video info: " + err.Error()
-		http.Error(w, msg, http.StatusInternalServerError)
-		log.Println(msg)
-		return
-	}
-	defer resp.Body.Close()
+type APISource interface {
+	getDetails(id string)   (VideoDetails, error)
+	getComments(id string)  ([]Comment, error)
+}
 
-	if resp.StatusCode != http.StatusOK {
-		msg := "YouTube API error: " + resp.Status
-		http.Error(w, msg, http.StatusBadGateway)
-		log.Println(msg)
-		return
+func apiDataHandler[T any](f func(id string) (T, error)) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		videoID := r.URL.Query().Get("id")
+		if videoID == "" {
+			msg := "Missing ?id=VIDEO_ID parameter"
+			http.Error(w, msg, http.StatusBadRequest)
+			return
+		}
+
+		data, err := f(videoID)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			log.Println(err.Error())
+			return
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(data)
 	}
-
-	w.Header().Set("Content-Type", "application/json")
-	io.Copy(w, resp.Body)
 }
 
-/* routes */
-func setupRoutesAPI() {
-	http.HandleFunc("/api/details", func(w http.ResponseWriter, r *http.Request) {
-		apiRequest(w, r, "videos", "id", "snippet,statistics,topicDetails")
-	})
-
-	http.HandleFunc("/api/comments", func(w http.ResponseWriter, r *http.Request) {
-		apiRequest(w, r, "commentThreads", "videoId", "snippet,replies&maxResults=100")
-	})
+func registerRoutesAPI(mux *http.ServeMux, api APISource) {
+	mux.HandleFunc("/api/details", apiDataHandler(api.getDetails))
+	mux.HandleFunc("/api/comments", apiDataHandler(api.getComments))
 }
diff --git a/main.go b/main.go
index e85649d..2f39712 100644
--- a/main.go
+++ b/main.go
@@ -30,15 +30,16 @@ func main() {
 	apiKey = os.Getenv("API_KEY")
 
 	// setup routes
-	setupRoutesAPI()
-	setupRoutesWatch()
+	mux := http.NewServeMux()
+	registerRoutesAPI(mux, &APISourceOfficial{})
+	registerRoutesWatch(mux)
 	setupHome()
-	http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
-	http.HandleFunc("/", rootHandler)
+	mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
+	mux.HandleFunc("/", rootHandler)
 
 	// start http server
 	log.Println("Listening on http://localhost:8080")
-	err := http.ListenAndServe(":8080", nil)
+	err := http.ListenAndServe(":8080", mux)
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/official-api.go b/official-api.go
new file mode 100644
index 0000000..39db1b8
--- /dev/null
+++ b/official-api.go
@@ -0,0 +1,125 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+/* function to make an api request */
+const youtubeAPI = "https://www.googleapis.com/youtube/v3/"
+
+func apiRequest[T any](videoId string, endpoint string, videoIdParam string, part string) (T, error) {
+	var zero T
+	if apiKey == "" {
+		return zero, fmt.Errorf("API_KEY environment variable not set")
+	}
+
+	url := fmt.Sprintf("%s?part=%s&%s=%s&key=%s", youtubeAPI + endpoint, part, videoIdParam, videoId, apiKey)
+	resp, err := http.Get(url)
+	if err != nil {
+		return zero, fmt.Errorf("Failed to fetch video info: " + err.Error())
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return zero, fmt.Errorf("YouTube API error: " + resp.Status)
+	}
+
+	var data T
+	err = json.NewDecoder(resp.Body).Decode(&data)
+	if err != nil {
+		return zero, fmt.Errorf("Failed to decode YouTube API response: " + err.Error())
+	}
+
+	return data, nil
+}
+
+/* youtube api types */
+type ytVideoDetails struct {
+	Items []struct {
+		Snippet struct {
+			Channel        string     `json:"channel"`
+			Description    string     `json:"description"`
+			PublishedAt    time.Time  `json:"publishedAt"`
+			Tags           []string   `json:"tags"`
+		} `json:"snippet"`
+		Statistics struct {
+			CommentCount int  `json:"commentCount"`
+			LikeCount    int  `json:"likeCount"`
+			ViewCount    int  `json:"viewCount"`
+		} `json:"statistics"`
+	} `json:"items"`
+}
+
+type ytComment struct {
+	Snippet struct {
+		AuthorDisplayName  string     `json:"authorDisplayName"`
+		TextDisplay        string     `json:"textDisplay"`
+		PublishedAt        time.Time  `json:"publishedAt"`
+		UpdatedAt          time.Time  `json:"updatedAt"`
+		LikeCount          int        `json:"likeCount"`
+	} `json:"snippet"`
+}
+
+type ytComments struct {
+	Items []struct {
+		Snippet struct {
+			TopLevelComment  ytComment  `json:"topLevelComment"`
+		} `json:"snippet"`
+		Replies struct {
+			Comments  []ytComment  `json:"comments,omitempty"`
+		} `json:"replies"`
+	} `json:"items"`
+}
+
+/* api source interface definition */
+type APISourceOfficial struct {}
+
+func (a *APISourceOfficial) getDetails(videoId string) (VideoDetails, error) {
+	d, err := apiRequest[ytVideoDetails](videoId, "videos", "id", "snippet,statistics,topicDetails")
+
+	n := d.Items[0].Snippet
+	t := d.Items[0].Statistics
+	return VideoDetails{
+		Channel:        n.Channel,
+		DatePublished:  n.PublishedAt,
+		Description:    n.Description,
+		NumComments:    t.CommentCount,
+		NumLikes:       t.LikeCount,
+		NumViews:       t.ViewCount,
+		Tags:           n.Tags,
+	}, err
+}
+
+func genComment(c ytComment, r []ytComment) Comment {
+	n := c.Snippet
+	var replies []*Comment
+	for _, rc := range r {
+		temp := genComment(rc, []ytComment{}) // NOTE temp variable required here
+		replies = append(replies, &temp) // cannot reference return value of genComment w/o temp var
+	}
+
+	return Comment{
+		Author:         n.AuthorDisplayName,
+		Body:           n.TextDisplay,
+		DatePublished:  n.PublishedAt,
+		DateUpdated:    n.UpdatedAt,
+		Likes:          n.LikeCount,
+		Replies:        replies,
+	}
+}
+
+func (a *APISourceOfficial) getComments(videoId string) ([]Comment, error) {
+	const maxResults = 100
+	d, err := apiRequest[ytComments](videoId, "commentThreads", "videoId", "snippet,replies&maxResults=" + fmt.Sprint(maxResults)) // TODO configure max results
+
+	var comments []Comment
+	for _, c := range d.Items {
+		tlc := c.Snippet.TopLevelComment
+		r := c.Replies.Comments
+		comments = append(comments, genComment(tlc, r))
+	}
+	return comments, err
+}
diff --git a/watch.go b/watch.go
index 8352e62..81f0d86 100644
--- a/watch.go
+++ b/watch.go
@@ -26,8 +26,8 @@ func renderWatchTemplate(w http.ResponseWriter, id string) {
 }
 
 /* routes */
-func setupRoutesWatch() {
-	http.HandleFunc("/watch", func(w http.ResponseWriter, r *http.Request) {
+func registerRoutesWatch(mux *http.ServeMux) {
+	mux.HandleFunc("/watch", func(w http.ResponseWriter, r *http.Request) {
 		id := r.URL.Query().Get("v")
 		renderWatchTemplate(w, id)
 	})