1 files changed, 213 insertions, 0 deletions
diff --git a/modules/markup/markdown/goldmark.go b/modules/markup/markdown/goldmark.go
new file mode 100644
index 00000000..0290e131
--- /dev/null
+++ b/modules/markup/markdown/goldmark.go
@@ -0,0 +1,213 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markdown
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/yuin/goldmark/ast"
+	east "github.com/yuin/goldmark/extension/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/renderer/html"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+var byteMailto = []byte("mailto:")
+
+// ASTTransformer is a default transformer of the goldmark tree.
+type ASTTransformer struct{}
+
+func (g *ASTTransformer) applyElementDir(n ast.Node) {
+	if markup.DefaultProcessorHelper.ElementDir != "" {
+		n.SetAttributeString("dir", []byte(markup.DefaultProcessorHelper.ElementDir))
+	}
+}
+
+// Transform transforms the given AST tree.
+func (g *ASTTransformer) Transform(node *ast.Document, reader text.Reader, pc parser.Context) {
+	firstChild := node.FirstChild()
+	tocMode := ""
+	ctx := pc.Get(renderContextKey).(*markup.RenderContext)
+	rc := pc.Get(renderConfigKey).(*RenderConfig)
+
+	tocList := make([]markup.Header, 0, 20)
+	if rc.yamlNode != nil {
+		metaNode := rc.toMetaNode()
+		if metaNode != nil {
+			node.InsertBefore(node, firstChild, metaNode)
+		}
+		tocMode = rc.TOC
+	}
+
+	_ = ast.Walk(node, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
+		if !entering {
+			return ast.WalkContinue, nil
+		}
+
+		switch v := n.(type) {
+		case *ast.Heading:
+			g.transformHeading(ctx, v, reader, &tocList)
+		case *ast.Paragraph:
+			g.applyElementDir(v)
+		case *ast.Image:
+			g.transformImage(ctx, v)
+		case *ast.Link:
+			g.transformLink(ctx, v)
+		case *ast.List:
+			g.transformList(ctx, v, rc)
+		case *ast.Text:
+			if v.SoftLineBreak() && !v.HardLineBreak() {
+				if ctx.Metas["mode"] != "document" {
+					v.SetHardLineBreak(setting.Markdown.EnableHardLineBreakInComments)
+				} else {
+					v.SetHardLineBreak(setting.Markdown.EnableHardLineBreakInDocuments)
+				}
+			}
+		case *ast.CodeSpan:
+			g.transformCodeSpan(ctx, v, reader)
+		}
+		return ast.WalkContinue, nil
+	})
+
+	showTocInMain := tocMode == "true" /* old behavior, in main view */ || tocMode == "main"
+	showTocInSidebar := !showTocInMain && tocMode != "false" // not hidden, not main, then show it in sidebar
+	if len(tocList) > 0 && (showTocInMain || showTocInSidebar) {
+		if showTocInMain {
+			tocNode := createTOCNode(tocList, rc.Lang, nil)
+			node.InsertBefore(node, firstChild, tocNode)
+		} else {
+			tocNode := createTOCNode(tocList, rc.Lang, map[string]string{"open": "open"})
+			ctx.SidebarTocNode = tocNode
+		}
+	}
+
+	if len(rc.Lang) > 0 {
+		node.SetAttributeString("lang", []byte(rc.Lang))
+	}
+}
+
+// NewHTMLRenderer creates a HTMLRenderer to render
+// in the gitea form.
+func NewHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
+	r := &HTMLRenderer{
+		Config: html.NewConfig(),
+	}
+	for _, opt := range opts {
+		opt.SetHTMLOption(&r.Config)
+	}
+	return r
+}
+
+// HTMLRenderer is a renderer.NodeRenderer implementation that
+// renders gitea specific features.
+type HTMLRenderer struct {
+	html.Config
+}
+
+// RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
+func (r *HTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(ast.KindDocument, r.renderDocument)
+	reg.Register(KindDetails, r.renderDetails)
+	reg.Register(KindSummary, r.renderSummary)
+	reg.Register(KindIcon, r.renderIcon)
+	reg.Register(ast.KindCodeSpan, r.renderCodeSpan)
+	reg.Register(KindTaskCheckBoxListItem, r.renderTaskCheckBoxListItem)
+	reg.Register(east.KindTaskCheckBox, r.renderTaskCheckBox)
+}
+
+func (r *HTMLRenderer) renderDocument(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	n := node.(*ast.Document)
+
+	if val, has := n.AttributeString("lang"); has {
+		var err error
+		if entering {
+			_, err = w.WriteString("<div")
+			if err == nil {
+				_, err = w.WriteString(fmt.Sprintf(` lang=%q`, val))
+			}
+			if err == nil {
+				_, err = w.WriteRune('>')
+			}
+		} else {
+			_, err = w.WriteString("</div>")
+		}
+
+		if err != nil {
+			return ast.WalkStop, err
+		}
+	}
+
+	return ast.WalkContinue, nil
+}
+
+func (r *HTMLRenderer) renderDetails(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	var err error
+	if entering {
+		if _, err = w.WriteString("<details"); err != nil {
+			return ast.WalkStop, err
+		}
+		html.RenderAttributes(w, node, nil)
+		_, err = w.WriteString(">")
+	} else {
+		_, err = w.WriteString("</details>")
+	}
+
+	if err != nil {
+		return ast.WalkStop, err
+	}
+
+	return ast.WalkContinue, nil
+}
+
+func (r *HTMLRenderer) renderSummary(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	var err error
+	if entering {
+		_, err = w.WriteString("<summary>")
+	} else {
+		_, err = w.WriteString("</summary>")
+	}
+
+	if err != nil {
+		return ast.WalkStop, err
+	}
+
+	return ast.WalkContinue, nil
+}
+
+var validNameRE = regexp.MustCompile("^[a-z ]+$")
+
+func (r *HTMLRenderer) renderIcon(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	if !entering {
+		return ast.WalkContinue, nil
+	}
+
+	n := node.(*Icon)
+
+	name := strings.TrimSpace(strings.ToLower(string(n.Name)))
+
+	if len(name) == 0 {
+		// skip this
+		return ast.WalkContinue, nil
+	}
+
+	if !validNameRE.MatchString(name) {
+		// skip this
+		return ast.WalkContinue, nil
+	}
+
+	var err error
+	_, err = w.WriteString(fmt.Sprintf(`<i class="icon %s"></i>`, name))
+	if err != nil {
+		return ast.WalkStop, err
+	}
+
+	return ast.WalkContinue, nil
+}