Initial commit

furcadia/util.go

@@ -0,0 +1,77 @@
+package furcadia
+
+import (
+	"fmt"
+	"strings"
+	"unicode"
+)
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// FUNCTIONS //////////////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+// GetShortName returns a "shortname" derived from a given Furcadia display name
+func GetShortName(displayName string) string {
+	sb := &strings.Builder{}
+	for _, r := range displayName {
+		if unicode.IsLetter(r) || unicode.IsNumber(r) {
+			sb.WriteRune(unicode.ToLower(r))
+		}
+	}
+	return sb.String()
+}
+
+// GetShortDreamURL converts a regular "furc://uploader:name/" dream url into
+// a "short" form that can be used as a hash key (e.g., "uploader:name").
+//
+// ErrInvalidDreamURL is returned if the given url is not a valid dream URL.
+func GetShortDreamURL(url string) (string, error) {
+	// cut prefix
+	u, found := strings.CutPrefix(strings.ToLower(url), "furc://")
+	if !found {
+		return "", ErrInvalidDreamURL
+	}
+
+	// cut suffix
+	u = strings.SplitN(u, "/", 2)[0]
+
+	// split uploader name and dream name
+	var uploaderName string
+	var dreamName string
+
+	elements := strings.Split(u, ":")
+	switch len(elements) {
+	case 0:
+		panic(fmt.Sprintf("len(%v) == 0", elements))
+	case 1:
+		uploaderName = elements[0]
+		dreamName = ""
+	case 2:
+		uploaderName = elements[0]
+		dreamName = elements[1]
+	default:
+		return "", ErrInvalidDreamURL
+	}
+
+	short := GetShortDreamURLFromName(uploaderName, dreamName)
+	if short == "" || short[0] == ':' {
+		// furc://
+		// furc:///
+		// furc://:/
+		// furc://:something/
+		return "", ErrInvalidDreamURL
+	}
+
+	return short, nil
+}
+
+func GetShortDreamURLFromName(uploaderName, dreamName string) (short string) {
+	shortName := GetShortName(uploaderName)
+	shortDream := GetShortName(dreamName)
+	if shortDream == "" {
+		short = shortName
+	} else {
+		short = shortName + ":" + shortDream
+	}
+	return
+}