kit/transport/http/codec.go

package http

import (
	"bytes"
	"fmt"
	"git.diulo.com/mogfee/kit/encoding"
	"git.diulo.com/mogfee/kit/errors"
	"git.diulo.com/mogfee/kit/internal/httputil"
	"git.diulo.com/mogfee/kit/transport/http/binding"
	"github.com/gorilla/mux"
	"io"
	"net/http"
	"net/url"
)

const SupportPackageIsVersion1 = true

type Redirector interface {
	Redirect() (string, int)
}
type Request = http.Request
type ResponseWriter = http.ResponseWriter
type Flusher = http.Flusher
type DecodeRequestFunc func(*http.Request, any) error
type EncodeResponseFunc func(http.ResponseWriter, *http.Request, any) error
type EncodeErrorFunc func(w http.ResponseWriter, r *http.Request, err error)

func DefaultRequestVars(r *http.Request, v any) error {
	raws := mux.Vars(r)
	vars := make(url.Values, len(raws))
	for k, v := range raws {
		vars[k] = []string{v}
	}
	return binding.BindQuery(vars, v)
}
func DefaultRequestQuery(r *http.Request, v any) error {
	return binding.BindQuery(r.URL.Query(), v)
}
func DefaultRequestDecoder(r *http.Request, v any) error {
	codec, ok := CodeForRequest(r, "Content-type")
	if !ok {
		return errors.BadRequest("CODEC", fmt.Sprintf("unregister Content-Type: %s", codec))
	}
	data, err := io.ReadAll(r.Body)
	if err != nil {
		return errors.BadRequest("CODEC", err.Error())
	}
	r.Body = io.NopCloser(bytes.NewBuffer(data))
	if len(data) == 0 {
		return nil
	}
	if err = codec.Unmarshal(data, v); err != nil {
		return errors.BadRequest("CODEC", err.Error())
	}
	return nil
}
func DefaultResponseEncoder(w http.ResponseWriter, r *http.Request, v any) error {
	if v == nil {
		return nil
	}
	if rd, ok := v.(Redirector); ok {
		url, code := rd.Redirect()
		http.Redirect(w, r, url, code)
		return nil
	}
	codec, _ := CodeForRequest(r, "Accept")
	data, err := codec.Marshal(v)
	if err != nil {
		return err
	}
	w.Header().Set("Content-type", httputil.ContentType(codec.Name()))
	_, err = w.Write(data)
	return err
}
func DefaultErrorEncoder(w http.ResponseWriter, r *http.Request, err error) {
	se := errors.FromError(err)
	codec, _ := CodeForRequest(r, "Accept")
	body, err := codec.Marshal(se)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", httputil.ContentType(codec.Name()))
	w.WriteHeader(int(se.Status))
	_, _ = w.Write(body)
}
func CodeForRequest(r *http.Request, name string) (encoding.Codec, bool) {
	for _, accept := range r.Header[name] {
		codec := encoding.GetCodec(httputil.ContentSubtype(accept))
		if codec != nil {
			return codec, true
		}
	}
	return encoding.GetCodec("json"), false
}