party/cmd/party/common/handler.go

104 lines
3.0 KiB
Go

package common
import (
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"net/url"
"strconv"
"strings"
"party.at/party/internal/validator"
)
type envelope map[string]interface{}
type apiError struct {
Code ErrorCode `json:"code,omitempty"`
Message string `json:"message"`
Details map[string]string `json:"details,omitempty"`
}
// ── JSON helpers ─────────────────────────────────────────────────────────────
func (app *Application) ReadJSON(w http.ResponseWriter, r *http.Request, dst interface{}) error {
r.Body = http.MaxBytesReader(w, r.Body, 1048576)
dec := json.NewDecoder(r.Body)
dec.DisallowUnknownFields()
err := dec.Decode(dst)
if err != nil {
var syntaxError *json.SyntaxError
var unmarshalTypeError *json.UnmarshalTypeError
var invalidUnmarshalError *json.InvalidUnmarshalError
switch {
case errors.As(err, &syntaxError):
return fmt.Errorf("body contains badly-formed JSON (at character %d)", syntaxError.Offset)
case errors.Is(err, io.ErrUnexpectedEOF):
return errors.New("body contains badly-formed JSON")
case errors.As(err, &unmarshalTypeError):
if unmarshalTypeError.Field != "" {
return fmt.Errorf("body contains incorrect JSON type for field %q", unmarshalTypeError.Field)
}
return fmt.Errorf("body contains incorrect JSON type (at character %d)", unmarshalTypeError.Offset)
case errors.Is(err, io.EOF):
return errors.New("body must not be empty")
case strings.HasPrefix(err.Error(), "json: unknown field "):
fieldName := strings.TrimPrefix(err.Error(), "json: unknown field ")
return fmt.Errorf("body contains unknown key %s", fieldName)
case err.Error() == "http: request body too large":
return fmt.Errorf("body must not be larger than 1048576 bytes")
case errors.As(err, &invalidUnmarshalError):
panic(err)
default:
return err
}
}
err = dec.Decode(&struct{}{})
if err != io.EOF {
return errors.New("body must only contain a single JSON value")
}
return nil
}
func ReadIDParam(r *http.Request) (int64, error) {
id, err := strconv.ParseInt(r.PathValue("id"), 10, 64)
if err != nil || id < 1 {
return 0, errors.New("invalid id parameter")
}
return id, nil
}
func ReadString(qs url.Values, key, defaultValue string) string {
if s := qs.Get(key); s != "" {
return s
}
return defaultValue
}
func ReadInt(qs url.Values, key string, defaultValue int, v *validator.Validator) int {
s := qs.Get(key)
if s == "" {
return defaultValue
}
i, err := strconv.Atoi(s)
if err != nil {
v.AddError(key, "must be an integer value")
return defaultValue
}
return i
}
// ── Error responses ──────────────────────────────────────────────────────────
func (app *Application) LogError(r *http.Request, err error) {
app.Logger.PrintError(err, map[string]string{
"request_method": r.Method,
"request_url": r.URL.String(),
})
}