metricator/internal/httpserver/handler.go

54 lines
1.2 KiB
Go

package httpserver
import (
"context"
"net/http"
"strings"
"go.dev.pztrn.name/metricator/internal/common"
)
// HTTP requests handler.
type handler struct {
handlers map[string]common.HTTPHandlerFunc
}
// Registers request's handler.
func (h *handler) register(name string, hndl common.HTTPHandlerFunc) {
h.handlers[name] = hndl
}
// ServeHTTP handles every HTTP request.
func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if !strings.HasPrefix(r.URL.Path, "/api") {
w.WriteHeader(http.StatusBadRequest)
_, _ = w.Write([]byte("400 Bad Request - invalid path"))
return
}
// Request validation.
pathSplitted := strings.Split(r.URL.Path, "/")
if len(pathSplitted) < 3 {
w.WriteHeader(http.StatusBadRequest)
_, _ = w.Write([]byte("400 Bad Request - invalid path"))
}
handler, found := h.handlers[pathSplitted[2]]
if !found {
w.WriteHeader(http.StatusBadRequest)
_, _ = w.Write([]byte("400 Bad Request - invalid application name"))
return
}
requestContext := r.Context()
// Compose metric name.
metricName := strings.Join(pathSplitted[3:], "/")
ctx := context.WithValue(requestContext, common.ContextKeyMetric, metricName)
w.WriteHeader(http.StatusOK)
_, _ = w.Write([]byte(handler(ctx)))
}