refactor: move api/v1/utils to net/gphttp

internal/net/gphttp/error.go

@@ -0,0 +1,100 @@
+package gphttp
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"syscall"
+
+	"github.com/yusing/go-proxy/internal/gperr"
+	"github.com/yusing/go-proxy/internal/net/gphttp/httpheaders"
+)
+
+// ServerError is for handling server errors.
+//
+// It logs the error and returns http.StatusInternalServerError to the client.
+// Status code can be specified as an argument.
+func ServerError(w http.ResponseWriter, r *http.Request, err error, code ...int) {
+	switch {
+	case err == nil,
+		errors.Is(err, context.Canceled),
+		errors.Is(err, syscall.EPIPE),
+		errors.Is(err, syscall.ECONNRESET):
+		return
+	}
+	LogError(r).Msg(err.Error())
+	if httpheaders.IsWebsocket(r.Header) {
+		return
+	}
+	if len(code) == 0 {
+		code = []int{http.StatusInternalServerError}
+	}
+	http.Error(w, http.StatusText(code[0]), code[0])
+}
+
+// ClientError is for responding to client errors.
+//
+// It returns http.StatusBadRequest with reason to the client.
+// Status code can be specified as an argument.
+//
+// For JSON marshallable errors (e.g. gperr.Error), it returns the error details as JSON.
+// Otherwise, it returns the error details as plain text.
+func ClientError(w http.ResponseWriter, err error, code ...int) {
+	if len(code) == 0 {
+		code = []int{http.StatusBadRequest}
+	}
+	if gperr.IsJSONMarshallable(err) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(err)
+	} else {
+		http.Error(w, err.Error(), code[0])
+	}
+}
+
+// JSONError returns a JSON response of gperr.Error with the given status code.
+func JSONError(w http.ResponseWriter, err gperr.Error, code int) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(code)
+	json.NewEncoder(w).Encode(err)
+}
+
+// BadRequest returns a Bad Request response with the given error message.
+func BadRequest(w http.ResponseWriter, err string, code ...int) {
+	if len(code) == 0 {
+		code = []int{http.StatusBadRequest}
+	}
+	w.WriteHeader(code[0])
+	w.Write([]byte(err))
+}
+
+// Unauthorized returns an Unauthorized response with the given error message.
+func Unauthorized(w http.ResponseWriter, err string) {
+	BadRequest(w, err, http.StatusUnauthorized)
+}
+
+// Forbidden returns a Forbidden response with the given error message.
+func Forbidden(w http.ResponseWriter, err string) {
+	BadRequest(w, err, http.StatusForbidden)
+}
+
+// NotFound returns a Not Found response with the given error message.
+func NotFound(w http.ResponseWriter, err string) {
+	BadRequest(w, err, http.StatusNotFound)
+}
+
+func ErrMissingKey(k string) error {
+	return gperr.New(k + " is required")
+}
+
+func ErrInvalidKey(k string) error {
+	return gperr.New(k + " is invalid")
+}
+
+func ErrAlreadyExists(k, v string) error {
+	return gperr.Errorf("%s %q already exists", k, v)
+}
+
+func ErrNotFound(k, v string) error {
+	return gperr.Errorf("%s %q not found", k, v)
+}