Files
zenfeed/pkg/util/rpc/rpc.go
glidea 8b33df8a05 init
2025-04-19 15:50:26 +08:00

98 lines
2.6 KiB
Go

// Copyright (C) 2025 wangyusong
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
package rpc
import (
"context"
"encoding/json"
"errors"
"net/http"
)
type Handler[Request any, Response any] func(ctx context.Context, req *Request) (*Response, error)
var (
ErrBadRequest = func(err error) Error { return newError(http.StatusBadRequest, err) }
ErrNotFound = func(err error) Error { return newError(http.StatusNotFound, err) }
ErrInternal = func(err error) Error { return newError(http.StatusInternalServerError, err) }
)
type Error struct {
Code int `json:"code"`
Message string `json:"message"`
}
func (e Error) Error() string {
return e.Message
}
func newError(code int, err error) Error {
return Error{
Code: code,
Message: err.Error(),
}
}
func API[Request any, Response any](handler Handler[Request, Response]) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
allowCORS(w)
if r.Method == "OPTIONS" {
return
}
var req Request
if r.Body != http.NoBody {
if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
}
resp, err := handler(r.Context(), &req)
if err != nil {
var rpcErr Error
if errors.As(err, &rpcErr) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(rpcErr.Code)
_ = json.NewEncoder(w).Encode(rpcErr)
return
}
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "application/json")
if err := json.NewEncoder(w).Encode(resp); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
})
}
func allowCORS(w http.ResponseWriter) {
w.Header().Set("Access-Control-Allow-Origin", "*")
w.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
w.Header().Set("Access-Control-Allow-Headers",
"Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization",
)
}