seperate routes, provide robust handler types, use mux

server/ctrlsubsonic/ctrl.go

@@ -0,0 +1,98 @@
+package ctrlsubsonic
+
+import (
+	"encoding/json"
+	"encoding/xml"
+	"io"
+	"log"
+	"net/http"
+
+	"senan.xyz/g/gonic/server/ctrlbase"
+	"senan.xyz/g/gonic/server/ctrlsubsonic/spec"
+	"senan.xyz/g/gonic/server/parsing"
+)
+
+type Controller struct {
+	*ctrlbase.Controller
+}
+
+func New(base *ctrlbase.Controller) *Controller {
+	return &Controller{
+		Controller: base,
+	}
+}
+
+type metaResponse struct {
+	XMLName        xml.Name `xml:"subsonic-response" json:"-"`
+	*spec.Response `json:"subsonic-response"`
+}
+
+type errWriter struct {
+	w   io.Writer
+	err error
+}
+
+func (ew *errWriter) write(buf []byte) {
+	if ew.err != nil {
+		return
+	}
+	_, ew.err = ew.w.Write(buf)
+}
+
+func writeResp(w http.ResponseWriter, r *http.Request, resp *spec.Response) {
+	res := metaResponse{Response: resp}
+	ew := &errWriter{w: w}
+	switch parsing.GetStrParam(r, "f") {
+	case "json":
+		w.Header().Set("Content-Type", "application/json")
+		data, err := json.Marshal(res)
+		if err != nil {
+			log.Printf("could not marshall to json: %v\n", err)
+			return
+		}
+		ew.write(data)
+	case "jsonp":
+		w.Header().Set("Content-Type", "application/javascript")
+		data, err := json.Marshal(res)
+		if err != nil {
+			log.Printf("could not marshall to json: %v\n", err)
+			return
+		}
+		ew.write([]byte(parsing.GetStrParamOr(r, "callback", "cb")))
+		ew.write([]byte("("))
+		ew.write(data)
+		ew.write([]byte(");"))
+	default:
+		w.Header().Set("Content-Type", "application/xml")
+		data, err := xml.MarshalIndent(res, "", "    ")
+		if err != nil {
+			log.Printf("could not marshall to xml: %v\n", err)
+			return
+		}
+		ew.write(data)
+	}
+	if ew.err != nil {
+		log.Printf("error writing to response: %v\n", ew.err)
+	}
+}
+
+type subsonicHandler func(r *http.Request) *spec.Response
+
+func (c *Controller) H(h subsonicHandler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// TODO: write a non 200 if has err
+		response := h(r)
+		writeResp(w, r, response)
+	})
+}
+
+type subsonicHandlerRaw func(w http.ResponseWriter, r *http.Request) *spec.Response
+
+func (c *Controller) HR(h subsonicHandlerRaw) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// TODO: write a non 200 if has err
+		// TODO: ensure no mixed return/writer
+		response := h(w, r)
+		writeResp(w, r, response)
+	})
+}