1// Copyright 2019 DeepMap, Inc.
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.
14package codegen
15
16import (
17	"bufio"
18	"bytes"
19	"compress/gzip"
20	"encoding/base64"
21	"fmt"
22	"text/template"
23
24	"github.com/getkin/kin-openapi/openapi3"
25)
26
27// This generates a gzipped, base64 encoded JSON representation of the
28// swagger definition, which we embed inside the generated code.
29func GenerateInlinedSpec(t *template.Template, importMapping importMap, swagger *openapi3.T) (string, error) {
30	// Marshal to json
31	encoded, err := swagger.MarshalJSON()
32	if err != nil {
33		return "", fmt.Errorf("error marshaling swagger: %s", err)
34	}
35
36	// gzip
37	var buf bytes.Buffer
38	zw, err := gzip.NewWriterLevel(&buf, gzip.BestCompression)
39	if err != nil {
40		return "", fmt.Errorf("error creating gzip compressor: %s", err)
41	}
42	_, err = zw.Write(encoded)
43	if err != nil {
44		return "", fmt.Errorf("error gzipping swagger file: %s", err)
45	}
46	err = zw.Close()
47	if err != nil {
48		return "", fmt.Errorf("error gzipping swagger file: %s", err)
49	}
50	str := base64.StdEncoding.EncodeToString(buf.Bytes())
51
52	var parts []string
53	const width = 80
54
55	// Chop up the string into an array of strings.
56	for len(str) > width {
57		part := str[0:width]
58		parts = append(parts, part)
59		str = str[width:]
60	}
61	if len(str) > 0 {
62		parts = append(parts, str)
63	}
64
65	// Generate inline code.
66	buf.Reset()
67	w := bufio.NewWriter(&buf)
68	err = t.ExecuteTemplate(w, "inline.tmpl", struct {
69		SpecParts     []string
70		ImportMapping importMap
71	}{SpecParts: parts, ImportMapping: importMapping})
72	if err != nil {
73		return "", fmt.Errorf("error generating inlined spec: %s", err)
74	}
75	err = w.Flush()
76	if err != nil {
77		return "", fmt.Errorf("error flushing output buffer for inlined spec: %s", err)
78	}
79	return buf.String(), nil
80}
81