cuelang.org/go@v0.10.1/internal/encoding/detect.go (about)

     1  // Copyright 2020 CUE Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package encoding
    16  
    17  import (
    18  	"net/url"
    19  	"path"
    20  	"strings"
    21  
    22  	"cuelang.org/go/cue"
    23  	"cuelang.org/go/cue/build"
    24  )
    25  
    26  // Detect detects the interpretation.
    27  func Detect(v cue.Value) (i build.Interpretation) {
    28  	switch {
    29  	case isOpenAPI(v):
    30  		return build.OpenAPI
    31  	case isJSONSchema(v):
    32  		return build.JSONSchema
    33  	}
    34  	return i
    35  }
    36  
    37  func isOpenAPI(v cue.Value) bool {
    38  	s, _ := v.LookupPath(cue.MakePath(cue.Str("openapi"))).String()
    39  	if !strings.HasPrefix(s, "3.") {
    40  		return false
    41  	}
    42  	if _, err := v.LookupPath(cue.MakePath(cue.Str("info"), cue.Str("title"))).String(); err != nil {
    43  		return false
    44  	}
    45  	if _, err := v.LookupPath(cue.MakePath(cue.Str("info"), cue.Str("version"))).String(); err != nil {
    46  		return false
    47  	}
    48  	return true
    49  }
    50  
    51  func isJSONSchema(v cue.Value) bool {
    52  	s, err := v.LookupPath(cue.MakePath(cue.Str("$schema"))).String()
    53  	if err != nil {
    54  		return false
    55  	}
    56  	u, err := url.Parse(s)
    57  	if err != nil {
    58  		return false
    59  	}
    60  	if u.Hostname() != "json-schema.org" {
    61  		return false
    62  	}
    63  	if _, base := path.Split(u.EscapedPath()); base != "schema" {
    64  		return false
    65  	}
    66  	return true
    67  }