From 14c26f77e10c72358049857f7aec0c2b89229b7a Mon Sep 17 00:00:00 2001
From: Travis Cline <travis.cline@gmail.com>
Date: Mon, 11 Jul 2022 11:35:49 -0700
Subject: [PATCH] protoc-gen-apidocs: Separate hugo-specific output

---
 main.go                      |  32 +++++++-
 templates/hugo-markdown.tmpl | 146 +++++++++++++++++++++++++++++++++++
 2 files changed, 177 insertions(+), 1 deletion(-)
 create mode 100644 templates/hugo-markdown.tmpl

diff --git a/main.go b/main.go
index bbad373..c2de346 100644
--- a/main.go
+++ b/main.go
@@ -49,7 +49,8 @@ type GenOpts struct {
 }
 
 var formatFileSuffixes = map[string]string{
-	"markdown": "md",
+	"markdown":      "md",
+	"hugo-markdown": "md",
 }
 
 // generateFile generates a _ascii.pb.go file containing gRPC service definitions.
@@ -66,6 +67,19 @@ func (o *GenOpts) generateFile(gen *protogen.Plugin, file *protogen.File) error
 	return nil
 }
 
+func (o *GenOpts) relPath(t1, t2 protoreflect.Descriptor) string {
+	path := ""
+	cpf := filepath.Base(fmt.Sprint(t1.ParentFile().Path()))
+	rpf := filepath.Base(fmt.Sprint(t2.ParentFile().Path()))
+	if cpf != rpf {
+		path, _ = filepath.Rel(cpf, rpf)
+		path = strings.TrimSuffix(path, filepath.Ext(path))
+		path = strings.TrimPrefix(path, ".")
+		path = fmt.Sprintf("%s.%s", path, formatFileSuffixes[o.Format])
+	}
+	return path
+}
+
 func longName(d protoreflect.Descriptor) string {
 	p := d.Parent()
 	if p != nil && p.Parent() != nil {
@@ -125,6 +139,22 @@ func (o *GenOpts) templateFuncMap() template.FuncMap {
 			return false
 		},
 		"type_link": func(f *protogen.Field) string {
+			var t1, t2 protoreflect.Descriptor
+			t1 = f.Desc
+			if f.Message != nil {
+				t2 = f.Message.Desc
+			}
+			if f.Enum != nil {
+				t2 = f.Enum.Desc
+			}
+			if strings.HasPrefix(string(t2.FullName()), "google.") {
+				return string(t2.FullName())
+			}
+			fn := o.relPath(t1, t2)
+			typ := anchor(fmt.Sprint(t2.FullName()))
+			return fmt.Sprintf(`%s#%s`, fn, typ)
+		},
+		"type_link_hugo": func(f *protogen.Field) string {
 			// exclude google types:
 
 			if f.Message != nil {
diff --git a/templates/hugo-markdown.tmpl b/templates/hugo-markdown.tmpl
new file mode 100644
index 0000000..2c146ef
--- /dev/null
+++ b/templates/hugo-markdown.tmpl
@@ -0,0 +1,146 @@
+{{/***************************************************************
+Markdown template for protoc-gen-apidocs
+
+This template is rendered once per incoming .proto file and 
+defines the resulting output documentation.
+
+This file is organized into blocks via the go template "define"
+function and they are executed with the "template" function.
+***************************************************************/}}
+
+{{/***************************************************************
+Main output block
+***************************************************************/}}
+{{define "output" -}}
+
+---
+title: {{ .Desc.Package }}
+description: API Specification for the {{ .Desc.Package }} package.
+---
+
+<a name="{{.Desc.Path |base | anchor}}"></a><p align="right"><a href="#top">Top</a></p>
+
+<!-- begin services -->
+{{range .Services}}
+{{template "service" .}}
+{{end}}
+<!-- begin services -->
+
+{{ range .Messages }}
+{{template "message" .}}
+{{end}} <!-- end messages -->
+
+<!-- begin file-level enums -->
+{{range .Enums}}
+{{template "enum" .}}
+{{end}} <!-- end file-level enums -->
+
+<!-- begin file-level extensions -->
+{{if .Extensions}}
+<a name="{{.Desc.Path |base | anchor}}-extensions"></a>
+
+### Extensions
+| Extension | Type | Extension Point | Number | Description |
+| --------- | ---- | ---- | ------ | ----------- |
+{{range .Extensions -}}
+  | {{.Desc.Name}} | {{.Desc.FullName}} | {{ .Extendee | message_type }} | {{.Desc.Number}} | {{ .Comments.Leading | description | nobr}} {{ .Comments.Trailing | description | nobr}} |
+{{end}}
+{{end}} <!-- end file-level extensions -->
+
+{{end}}
+
+
+{{/***************************************************************
+Service template
+***************************************************************/}}
+{{define "service"}}
+<a name="{{.Desc.FullName | anchor}}"></a>
+
+### {{.Desc.Name}}
+
+{{.Comments.Leading | description}}
+{{.Comments.Trailing | description}}
+
+| Method Name | Request Type | Response Type | Description |
+| ----------- | ------------ | ------------- | ------------|
+{{range .Methods -}}
+  | {{.Desc.Name}} | [{{ .Input | message_type }}](#{{ .Input | full_message_type | anchor }}) | [{{ .Output | message_type }}](#{{ .Output | full_message_type | anchor }}){{if .Desc.IsStreamingServer}} stream{{end}} | {{ .Comments.Leading | description | nobr}} {{ .Comments.Trailing | description | nobr}} |
+{{end}}
+{{end}}
+
+
+
+{{/***************************************************************
+Message template
+***************************************************************/}}
+{{define "message"}}
+<a name="{{.Desc.FullName | anchor}}"></a>
+
+### {{.Desc.Name}}
+
+{{.Comments.Leading | description}}
+{{.Comments.Trailing | description}}
+
+{{if .Fields}}
+| Field | Type | Description |
+| ----- | ---- | ----------- |
+{{range .Fields}}{{ if (not .Desc.ContainingOneof) }}{{template "field" .}}{{end}}{{end}}
+{{- end -}}
+{{range .Oneofs}}{{template "oneof" .}}{{end}}
+
+{{if .Extensions}}
+| Extension | Type | Base | Number | Description |
+| --------- | ---- | ---- | ------ | ----------- |
+{{range .Extensions -}}
+  | {{.Desc.Name}} | {{.Desc | long_name}} | {{.Parent | message_type}} | {{.Desc.Number}} | {{ .Comments.Leading | description | nobr}} {{ .Comments.Trailing | description | nobr}} |
+{{end}}
+{{end}}
+
+{{ range .Messages }}
+{{template "message" .}}
+{{end}} <!-- end nested messages -->
+
+{{range .Enums}}
+{{template "enum" .}}
+{{end}} <!-- end nested enums -->
+
+{{end}}
+
+{{/***************************************************************
+Field template
+***************************************************************/}}
+{{define "field" -}}
+  | {{.Desc.Name}}{{ if .Desc.IsList }}[]{{ end }} | 
+{{- if (or (is_primitive .) (is_google_type .)) -}}
+ {{ field_type . }}
+{{- else -}}
+ [{{ .| field_type }}]({{ hugo_type_link . }})
+{{- end -}}
+| {{ .Comments.Leading | description | nobr}} {{ .Comments.Trailing | description | nobr }} |
+{{end}}
+
+{{/***************************************************************
+Oneof template
+This is kind of gross since GFM doesn't support colspan.
+***************************************************************/}}
+{{define "oneof" -}}
+|<tr><td colspan=2>Union field `{{ .Desc.Name }}`. {{ .Comments.Leading | description | nobr}} {{ .Comments.Trailing | description | nobr }} `{{ .Desc.Name }}` can be only one of the following:</td></tr>|
+{{range .Fields}}{{template "field" .}}{{end}}
+{{end}}
+
+{{/***************************************************************
+Enum template
+***************************************************************/}}
+{{define "enum" }}
+<a name="{{.Desc.FullName | anchor}}"></a>
+
+### {{.Desc | long_name}}
+{{.Comments.Leading | description}}
+{{.Comments.Trailing | description}}
+
+| Name | Number | Description |
+| ---- | ------ | ----------- |
+{{range .Values -}}
+  | {{.Desc.Name}} | {{.Desc.Number}} | {{ .Comments.Leading | description | nobr}} {{ .Comments.Trailing | description | nobr}} |
+{{end}}
+{{end}}