feat: add first metadata implementation

lib/download.go

@@ -30,7 +30,12 @@ func (app *App) Download(url string, outputFolder string, serviceString string)
 		serviceString = DEFAULT_DOWNLOAD_SERVICE
 	}
 
-	_ = GetUrlType(url)
+	_, err := app.GetMetadata(url)
+	if err != nil {
+		return err
+	}
+
+	_ = ParseUrlType(url)
 
 	return errors.New("Invalid URL.")
 }

lib/metadata.go

@@ -1,6 +1,7 @@
 package lib
 
 import (
+	"encoding/json"
 	"errors"
 )
 
@@ -25,9 +26,41 @@ type Metadata struct {
 }
 
 func (app *App) GetMetadata(url string) (Metadata, error) {
-	return Metadata{}, nil
+	urlType := ParseUrlType(url)
+
+	switch urlType {
+	case UrlTypeTrack:
+		app.GetTrackMetadata(url)
+	}
+
+	return Metadata{}, errors.New("Invalid URL.")
+}
+
+func (app *App) GetTrackMetadata(url string) error {
+	client := NewSpotifyClient()
+
+	err := client.Initialize()
+	if err != nil {
+		return errors.New("Unable to fetch Spotify metadata.")
+	}
+
+	trackId, err := ParseTrackId(url)
+	if err != nil {
+		return err
+	}
+
+	payload := BuildSpotifyReqPayloadTrack(trackId)
+
+	rawMetadata, err := client.Query(payload)
+	if err != nil {
+		return err
+	}
+	a, err := json.Marshal(rawMetadata)
+	println(string(a))
+
+	return nil
 }
 
 func (app *App) PrintMetadata(url string) error {
-	return errors.New("Invalid URL.")
+	return errors.New("Unimplemented.")
 }

lib/utils.go

@@ -1,6 +1,7 @@
 package lib
 
 import (
+	"errors"
 	"strings"
 )
 
@@ -12,7 +13,7 @@ const (
 	UrlTypeInvalid
 )
 
-func GetUrlType(url string) UrlType {
+func ParseUrlType(url string) UrlType {
 	if strings.Contains(url, "https://open.spotify.com/track") {
 		return UrlTypeTrack
 	}
@@ -23,3 +24,13 @@ func GetUrlType(url string) UrlType {
 
 	return UrlTypeInvalid
 }
+
+func ParseTrackId(url string) (string, error) {
+	tmp := strings.Split(url, "/")
+
+	if len(tmp) == 0 {
+		return "", errors.New("Invalid URL.")
+	}
+
+	return tmp[len(tmp)-1], nil
+}