// Copyright 2025-present Gustavo "Guz" L. de Mello
// Copyright 2025-present The Lored.dev Contributors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package problem
import (
"encoding/xml"
"fmt"
"net/http"
"slices"
"text/template"
)
type Problem interface {
Type() string
Title() string
Status() int
Detail() string
Instance() string
Handler(self Problem) http.Handler
http.Handler
}
type RegisteredProblem struct {
TypeURI string `json:"type,omitempty" xml:"type,omitempty"`
TypeTitle string `json:"title,omitempty" xml:"title,omitempty"`
StatusCode int `json:"status,omitempty" xml:"status,omitempty"`
DetailMessage string `json:"detail,omitempty" xml:"detail,omitempty"`
InstanceURI string `json:"instance,omitempty" xml:"instance,omitempty"`
XMLName xml.Name `json:"-" xml:"problem"`
handler Handler `json:"-" xml:"-"`
}
func NewStatus(s int, opts ...Option) RegisteredProblem {
return New(slices.Concat([]Option{WithStatus(s)}, opts)...)
}
func NewDetailed(s int, detail string, opts ...Option) RegisteredProblem {
return New(slices.Concat([]Option{WithStatus(s), WithDetail(detail)}, opts)...)
}
func New(opts ...Option) RegisteredProblem {
p := RegisteredProblem{
TypeURI: DefaultTypeURI,
handler: DefaultHandler,
}
for _, opt := range opts {
opt(&p)
}
return p
}
var (
DefaultTypeURI = "about:blank"
DefaultTemplate = template.Must(template.New("x-smalltrip-problem-template").Parse(`
{{ .Status }} - {{ .Title }}
{{.Status}} - {{ .Title }}
{{ .Type }}
{{ .Detail }}
{{if .Instance}}
Instance: {{ .Instance }}
{{end}}
{{printf "%#v" .}}
`))
DefaultHandler = HandlerMiddleware(HandlerBrowser(DefaultTemplate))
)
func (p RegisteredProblem) Type() string {
return p.TypeURI
}
func (p RegisteredProblem) Title() string {
return p.TypeTitle
}
func (p RegisteredProblem) Status() int {
return p.StatusCode
}
func (p RegisteredProblem) Detail() string {
return p.DetailMessage
}
func (p RegisteredProblem) Instance() string {
return p.InstanceURI
}
func (p RegisteredProblem) Handler(self Problem) http.Handler {
return p.handler(self)
}
func (p RegisteredProblem) ServeHTTP(w http.ResponseWriter, r *http.Request) {
p.Handler(p).ServeHTTP(w, r)
}
func WithType(t string) Option {
return func(p *RegisteredProblem) {
p.TypeURI = t
}
}
func WithTitle(t string) Option {
return func(p *RegisteredProblem) {
p.TypeTitle = t
}
}
func WithStatus(s int) Option {
return func(p *RegisteredProblem) {
if p.TypeTitle == "" {
p.TypeTitle = http.StatusText(s)
}
p.StatusCode = s
}
}
func WithDetail(d string) Option {
return func(p *RegisteredProblem) {
p.DetailMessage = d
}
}
func WithDetailf(f string, args ...any) Option {
return func(p *RegisteredProblem) {
p.DetailMessage = fmt.Sprintf(f, args...)
}
}
func WithError(err error) Option {
return func(p *RegisteredProblem) {
p.DetailMessage = err.Error()
}
}
func WithInstance(i string) Option {
return func(p *RegisteredProblem) {
p.InstanceURI = i
}
}
type Option func(*RegisteredProblem)