Add initial HTTP API endpoints

1 files changed, 96 insertions, 0 deletions

diff --git a/internal/mobius/api.go b/internal/mobius/api.go
new file mode 100644
index 0000000..31755b8
--- /dev/null
+++ b/internal/mobius/api.go
@@ -0,0 +1,96 @@
+package mobius
+
+import (
+	"bytes"
+	"encoding/json"
+	"github.com/jhalter/mobius/hotline"
+	"io"
+	"log"
+	"log/slog"
+	"net/http"
+)
+
+type logResponseWriter struct {
+	http.ResponseWriter
+	statusCode int
+	buf        bytes.Buffer
+}
+
+func NewLogResponseWriter(w http.ResponseWriter) *logResponseWriter {
+	return &logResponseWriter{w, http.StatusOK, bytes.Buffer{}}
+}
+
+func (lrw *logResponseWriter) WriteHeader(code int) {
+	lrw.statusCode = code
+	lrw.ResponseWriter.WriteHeader(code)
+}
+
+func (lrw *logResponseWriter) Write(b []byte) (int, error) {
+	lrw.buf.Write(b)
+	return lrw.ResponseWriter.Write(b)
+}
+
+type APIServer struct {
+	hlServer *hotline.Server
+	logger   *slog.Logger
+	mux      *http.ServeMux
+}
+
+func (srv *APIServer) logMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		lrw := NewLogResponseWriter(w)
+		next.ServeHTTP(lrw, r)
+
+		srv.logger.Info("req", "method", r.Method, "url", r.URL.Path, "remoteAddr", r.RemoteAddr, "response_code", lrw.statusCode)
+	})
+}
+
+func NewAPIServer(hlServer *hotline.Server, reloadFunc func(), logger *slog.Logger) *APIServer {
+	srv := APIServer{
+		hlServer: hlServer,
+		logger:   logger,
+		mux:      http.NewServeMux(),
+	}
+
+	srv.mux.Handle("/api/v1/reload", srv.logMiddleware(http.HandlerFunc(srv.ReloadHandler(reloadFunc))))
+	srv.mux.Handle("/api/v1/shutdown", srv.logMiddleware(http.HandlerFunc(srv.ShutdownHandler)))
+	srv.mux.Handle("/api/v1/stats", srv.logMiddleware(http.HandlerFunc(srv.RenderStats)))
+
+	return &srv
+}
+
+func (srv *APIServer) ShutdownHandler(w http.ResponseWriter, r *http.Request) {
+	msg, err := io.ReadAll(r.Body)
+	if err != nil || len(msg) == 0 {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	go srv.hlServer.Shutdown(msg)
+
+	_, _ = io.WriteString(w, `{ "msg": "server shutting down" }`)
+}
+
+func (srv *APIServer) ReloadHandler(reloadFunc func()) func(w http.ResponseWriter, _ *http.Request) {
+	return func(w http.ResponseWriter, _ *http.Request) {
+		reloadFunc()
+
+		_, _ = io.WriteString(w, `{ "msg": "config reloaded" }`)
+	}
+}
+
+func (srv *APIServer) RenderStats(w http.ResponseWriter, _ *http.Request) {
+	u, err := json.Marshal(srv.hlServer.CurrentStats())
+	if err != nil {
+		panic(err)
+	}
+
+	_, _ = io.WriteString(w, string(u))
+}
+
+func (srv *APIServer) Serve(port string) {
+	err := http.ListenAndServe(port, srv.mux)
+	if err != nil {
+		log.Fatal(err)
+	}
+}