niki/vendor/github.com/go-openapi/spec/ref.go

// Copyright 2015 go-swagger maintainers

//

// 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 spec

import (
	"bytes"
	"encoding/gob"
	"encoding/json"
	"net/http"
	"os"
	"path/filepath"

	"github.com/go-openapi/jsonreference"
)

// Refable is a struct for things that accept a $ref property

type Refable struct {
	Ref Ref
}

// MarshalJSON marshals the ref to json

func (r Refable) MarshalJSON() ([]byte, error) {

	return r.Ref.MarshalJSON()

}

// UnmarshalJSON unmarshalss the ref from json

func (r *Refable) UnmarshalJSON(d []byte) error {

	return json.Unmarshal(d, &r.Ref)

}

// Ref represents a json reference that is potentially resolved

type Ref struct {
	jsonreference.Ref
}

// RemoteURI gets the remote uri part of the ref

func (r *Ref) RemoteURI() string {

	if r.String() == "" {

		return ""

	}

	u := *r.GetURL()

	u.Fragment = ""

	return u.String()

}

// IsValidURI returns true when the url the ref points to can be found

func (r *Ref) IsValidURI(basepaths ...string) bool {

	if r.String() == "" {

		return true

	}

	v := r.RemoteURI()

	if v == "" {

		return true

	}

	if r.HasFullURL {

		//nolint:noctx,gosec

		rr, err := http.Get(v)

		if err != nil {

			return false

		}

		defer rr.Body.Close()

		return rr.StatusCode/100 == 2

	}

	if !(r.HasFileScheme || r.HasFullFilePath || r.HasURLPathOnly) {

		return false

	}

	// check for local file

	pth := v

	if r.HasURLPathOnly {

		base := "."

		if len(basepaths) > 0 {

			base = filepath.Dir(filepath.Join(basepaths...))

		}

		p, e := filepath.Abs(filepath.ToSlash(filepath.Join(base, pth)))

		if e != nil {

			return false

		}

		pth = p

	}

	fi, err := os.Stat(filepath.ToSlash(pth))

	if err != nil {

		return false

	}

	return !fi.IsDir()

}

// Inherits creates a new reference from a parent and a child

// If the child cannot inherit from the parent, an error is returned

func (r *Ref) Inherits(child Ref) (*Ref, error) {

	ref, err := r.Ref.Inherits(child.Ref)

	if err != nil {

		return nil, err

	}

	return &Ref{Ref: *ref}, nil

}

// NewRef creates a new instance of a ref object

// returns an error when the reference uri is an invalid uri

func NewRef(refURI string) (Ref, error) {

	ref, err := jsonreference.New(refURI)

	if err != nil {

		return Ref{}, err

	}

	return Ref{Ref: ref}, nil

}

// MustCreateRef creates a ref object but panics when refURI is invalid.

// Use the NewRef method for a version that returns an error.

func MustCreateRef(refURI string) Ref {

	return Ref{Ref: jsonreference.MustCreateRef(refURI)}

}

// MarshalJSON marshals this ref into a JSON object

func (r Ref) MarshalJSON() ([]byte, error) {

	str := r.String()

	if str == "" {

		if r.IsRoot() {

			return []byte(`{"$ref":""}`), nil

		}

		return []byte("{}"), nil

	}

	v := map[string]interface{}{"$ref": str}

	return json.Marshal(v)

}

// UnmarshalJSON unmarshals this ref from a JSON object

func (r *Ref) UnmarshalJSON(d []byte) error {

	var v map[string]interface{}

	if err := json.Unmarshal(d, &v); err != nil {

		return err

	}

	return r.fromMap(v)

}

// GobEncode provides a safe gob encoder for Ref

func (r Ref) GobEncode() ([]byte, error) {

	var b bytes.Buffer

	raw, err := r.MarshalJSON()

	if err != nil {

		return nil, err

	}

	err = gob.NewEncoder(&b).Encode(raw)

	return b.Bytes(), err

}

// GobDecode provides a safe gob decoder for Ref

func (r *Ref) GobDecode(b []byte) error {

	var raw []byte

	buf := bytes.NewBuffer(b)

	err := gob.NewDecoder(buf).Decode(&raw)

	if err != nil {

		return err

	}

	return json.Unmarshal(raw, r)

}

func (r *Ref) fromMap(v map[string]interface{}) error {

	if v == nil {

		return nil

	}

	if vv, ok := v["$ref"]; ok {

		if str, ok := vv.(string); ok {

			ref, err := jsonreference.New(str)

			if err != nil {

				return err

			}

			*r = Ref{Ref: ref}

		}

	}

	return nil

}