refactor(middlewares,router): follow http package structure and interfaces

internals/router/router.go

@@ -0,0 +1,64 @@
+package router
+
+import (
+	"log"
+	"net/http"
+	"strings"
+)
+
+type Route struct {
+	Pattern  string
+	Handler  http.Handler
+	Children *[]Route
+}
+
+type Router struct {
+	routes      []Route
+	middlewares []Middleware
+	mux         *http.ServeMux
+	serveHTTP   http.HandlerFunc
+}
+
+func NewRouter(rs []Route) *Router {
+	mux := http.NewServeMux()
+	Router{}.registerAllRoutes("/", rs, mux)
+	return &Router{rs, []Middleware{}, mux, mux.ServeHTTP}
+}
+
+func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	r.serveHTTP(w, req)
+}
+
+func (r *Router) AddMiddleware(m Middleware) {
+	r.middlewares = append(r.middlewares, m)
+	r.serveHTTP = r.wrapMiddleares(r.middlewares, r.serveHTTP)
+}
+
+func (router Router) wrapMiddleares(ms []Middleware, h http.HandlerFunc) http.HandlerFunc {
+	fh := h.ServeHTTP
+	for _, m := range ms {
+		fh = m.Serve(fh)
+	}
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		mw := NewMiddlewaredResponse(w)
+		fh(mw, r)
+		_, _ = mw.ReallyWriteHeader()
+	}
+}
+
+func (router Router) registerAllRoutes(p string, rs []Route, mux *http.ServeMux) {
+	for _, r := range rs {
+		pattern := strings.Join([]string{
+			strings.TrimSuffix(p, "/"),
+			strings.TrimPrefix(r.Pattern, "/"),
+		}, "/")
+		log.Printf("registering route %s", pattern)
+
+		mux.Handle(pattern, r.Handler)
+
+		if r.Children != nil {
+			router.registerAllRoutes(pattern, *r.Children, mux)
+		}
+	}
+}