2 files changed, 102 insertions, 0 deletions
diff --git a/internal/service/service.go b/internal/service/service.go
new file mode 100644
index 0000000..49647fe
--- /dev/null
+++ b/internal/service/service.go
@@ -0,0 +1,66 @@
+package services
+
+// service defines any Music service recognized by song.link
+// Since most services have multiple url version (long, short, etc...),
+// it is allowd to have multiple ones.
+// This allows for seamless song link detection
+type service struct {
+	name     string
+	patterns []string
+}
+
+func GetServices() []service {
+	return []service{
+		*New(
+			"Apple Music",
+			[]string{"https://music.apple.com/"},
+		),
+		*New(
+			"Spotify",
+			[]string{"https://open.spotify.com/track/", "https://open.spotify.com/album/", "https://open.spotify.com/playlist/"},
+		),
+		*New(
+			"Youtube Music",
+			[]string{"https://music.youtube.com/"},
+		),
+		// *New(
+		// 	"Amazon Music",
+		// 	[]string{"https://music.amazon.com/",},
+		// ),
+		*New(
+			"Tidal",
+			[]string{"https://tidal.com/"},
+		),
+		*New(
+			"Deezer",
+			[]string{"https://www.deezer.com/"},
+		),
+		*New(
+			"Pandora",
+			[]string{"https://www.pandora.com/"},
+		),
+	}
+}
+
+func New(name string, patterns []string) *service {
+	return &service{name, patterns}
+}
+
+func (s *service) Name() string {
+	return s.name
+}
+
+func (s *service) Owns(url string) bool {
+	// If the url begins the same as any of the patterns, it is owned by the service
+	for _, pattern := range s.patterns {
+		if len(url) >= len(pattern) && url[:len(pattern)] == pattern {
+			return true
+		}
+	}
+	return false
+}
+
+// Resolve returns the song.link url for the given service url
+func (s *service) Resolve(url string) string {
+	return "https://song.link/" + url
+}
diff --git a/internal/urls/url.go b/internal/urls/url.go
new file mode 100644
index 0000000..bb76594
--- /dev/null
+++ b/internal/urls/url.go
@@ -0,0 +1,36 @@
+package urls
+
+import (
+	"net/http"
+	"regexp"
+)
+
+// Find takes in a string (i.e. a discord message)
+// and returns a list of all the urls it has found in this
+// string.
+func Find(s string) []string {
+	// Regular expression to match URLs starting with https
+	re := regexp.MustCompile(`https://[^\s]+`)
+
+	// Find all matching URLs
+	return re.FindAllString(s, -1)
+}
+
+func Resolve(url string) (string, error) {
+	client := &http.Client{
+		// Automatically follow redirects
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			return nil
+		},
+	}
+
+	resp, err := client.Head(url)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	// The final resolved URL after following redirects
+	finalURL := resp.Request.URL.String()
+	return finalURL, nil
+}