appview: pages/blob: toggle render for markdown files

Also sets up a pages/markup package with extensible rendering for future markup languages that we may support.
We may also want an interface or something for markup.RenderMarkdown (maybe just markup.Render), but don't have to bother with that now.

appview/pages/funcmap.go

···
 	"time"
 
 	"github.com/dustin/go-humanize"
+	"tangled.sh/tangled.sh/core/appview/pages/markup"
 )
 
 func funcMap() template.FuncMap {
···
 			return v.Slice(start, end).Interface()
 		},
 		"markdown": func(text string) template.HTML {
-			return template.HTML(renderMarkdown(text))
+			return template.HTML(markup.RenderMarkdown(text))
 		},
 		"isNil": func(t any) bool {
 			// returns false for other "zero" values

appview/pages/markdown.go appview/pages/markup/markdown.go

···
-package pages
+// Package markup is an umbrella package for all markups and their renderers.
+package markup
 
 import (
 	"bytes"
···
 	"github.com/yuin/goldmark/parser"
 )
 
-func renderMarkdown(source string) string {
+func RenderMarkdown(source string) string {
 	md := goldmark.New(
 		goldmark.WithExtensions(extension.GFM),
 		goldmark.WithParserOptions(

appview/pages/markup/readme.go

···
+package markup
+
+import "strings"
+
+type Format string
+
+const (
+	FormatMarkdown Format = "markdown"
+	FormatText     Format = "text"
+)
+
+var FileTypes map[Format][]string = map[Format][]string{
+	FormatMarkdown: []string{".md", ".markdown", ".mdown", ".mkdn", ".mkd"},
+}
+
+func GetFormat(filename string) Format {
+	for format, extensions := range FileTypes {
+		for _, extension := range extensions {
+			if strings.HasSuffix(filename, extension) {
+				return format
+			}
+		}
+	}
+	// default format
+	return FormatText
+}

appview/pages/pages.go

···
 	"github.com/microcosm-cc/bluemonday"
 	"tangled.sh/tangled.sh/core/appview/auth"
 	"tangled.sh/tangled.sh/core/appview/db"
+	"tangled.sh/tangled.sh/core/appview/pages/markup"
 	"tangled.sh/tangled.sh/core/appview/state/userutil"
 	"tangled.sh/tangled.sh/core/types"
 )
···
 		ext := filepath.Ext(params.ReadmeFileName)
 		switch ext {
 		case ".md", ".markdown", ".mdown", ".mkdn", ".mkd":
-			htmlString = renderMarkdown(params.Readme)
+			htmlString = markup.RenderMarkdown(params.Readme)
 			params.Raw = false
 			params.HTMLReadme = template.HTML(bluemonday.UGCPolicy().Sanitize(htmlString))
 		default:
···
 }
 
 type RepoBlobParams struct {
-	LoggedInUser *auth.User
-	RepoInfo     RepoInfo
-	Active       string
-	BreadCrumbs  [][]string
+	LoggedInUser     *auth.User
+	RepoInfo         RepoInfo
+	Active           string
+	BreadCrumbs      [][]string
+	ShowRendered     bool
+	RenderedContents template.HTML
 	types.RepoBlobResponse
 }
 
···
 	b := style.Builder()
 	b.Add(chroma.LiteralString, "noitalic")
 	style, _ = b.Build()
+
+	if params.ShowRendered {
+		switch markup.GetFormat(params.Path) {
+		case markup.FormatMarkdown:
+			params.RenderedContents = template.HTML(markup.RenderMarkdown(params.Contents))
+		}
+	}
 
 	if params.Lines < 5000 {
 		c := params.Contents

appview/pages/templates/repo/blob.html

···
                 <span>{{ byteFmt .SizeHint }}</span>
                 <span class="select-none px-1 md:px-2 [&:before]:content-['·']"></span>
                 <a href="/{{ .RepoInfo.FullName }}/blob/{{ .Ref }}/raw/{{ .Path }}">view raw</a>
+                <span class="select-none px-1 md:px-2 [&:before]:content-['·']"></span>
+                <a 
+                href="/{{ .RepoInfo.FullName }}/blob/{{ .Ref }}/{{ .Path }}?code={{ .ShowRendered }}" 
+                hx-boost="true"
+                >view {{ if .ShowRendered }}code{{ else }}rendered{{ end }}</a>
             </div>
         </div>
     </div>
···
         </p>
     {{ else }}
     <div class="overflow-auto relative">
-        <div class="whitespace-pre peer-target:bg-yellow-200 dark:peer-target:bg-yellow-900">{{ $.Contents | escapeHtml }}</div>
+        {{ if .ShowRendered }}
+        <div id="blob-contents" class="prose dark:prose-invert p-6">{{ .RenderedContents }}</div>
+        {{ else }}
+        <div id="blob-contents" class="whitespace-pre peer-target:bg-yellow-200 dark:peer-target:bg-yellow-900">{{ $.Contents | escapeHtml }}</div>
+        {{ end }}
     </div>
     {{ end }}
 {{ end }}

appview/state/repo.go

···
 	"tangled.sh/tangled.sh/core/appview/auth"
 	"tangled.sh/tangled.sh/core/appview/db"
 	"tangled.sh/tangled.sh/core/appview/pages"
+	"tangled.sh/tangled.sh/core/appview/pages/markup"
 	"tangled.sh/tangled.sh/core/types"
 
 	comatproto "github.com/bluesky-social/indigo/api/atproto"
···
 		}
 	}
 
+	var showRendered = false
+	if markup.GetFormat(result.Path) == markup.FormatMarkdown {
+		showRendered = true
+	}
+
+	if r.URL.Query().Get("code") == "true" {
+		showRendered = false
+	}
+
 	user := s.auth.GetUser(r)
 	s.pages.RepoBlob(w, pages.RepoBlobParams{
 		LoggedInUser:     user,
 		RepoInfo:         f.RepoInfo(s, user),
 		RepoBlobResponse: result,
 		BreadCrumbs:      breadcrumbs,
+		ShowRendered:     showRendered,
 	})
 	return
 }