From ade5da20dfcc224f8139fdb74855760a40c077b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mickae=CC=88l=20Menu?= <mickael.menu@gmail.com>
Date: Fri, 12 Feb 2021 19:34:04 +0100
Subject: [PATCH] Support Markdown autolinking for external links

---
 adapter/markdown/markdown.go      | 45 ++++++++++++++++++++++++-------
 adapter/markdown/markdown_test.go | 16 +++++++++++
 go.mod                            |  1 +
 go.sum                            |  2 ++
 4 files changed, 54 insertions(+), 10 deletions(-)

diff --git a/adapter/markdown/markdown.go b/adapter/markdown/markdown.go
index fbc5956..712daf3 100644
--- a/adapter/markdown/markdown.go
+++ b/adapter/markdown/markdown.go
@@ -8,9 +8,11 @@ import (
 	"github.com/mickael-menu/zk/core/note"
 	"github.com/mickael-menu/zk/util/opt"
 	strutil "github.com/mickael-menu/zk/util/strings"
+	"github.com/mvdan/xurls"
 	"github.com/yuin/goldmark"
 	meta "github.com/yuin/goldmark-meta"
 	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/extension"
 	"github.com/yuin/goldmark/parser"
 	"github.com/yuin/goldmark/text"
 )
@@ -26,6 +28,15 @@ func NewParser() *Parser {
 		md: goldmark.New(
 			goldmark.WithExtensions(
 				meta.Meta,
+				extension.NewLinkify(
+					extension.WithLinkifyAllowedProtocols([][]byte{
+						[]byte("http:"),
+						[]byte("https:"),
+					}),
+					extension.WithLinkifyURLRegexp(
+						xurls.Strict,
+					),
+				),
 			),
 		),
 	}
@@ -127,16 +138,30 @@ func parseLinks(root ast.Node, source []byte) ([]note.Link, error) {
 	links := make([]note.Link, 0)
 
 	err := ast.Walk(root, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
-		if link, ok := n.(*ast.Link); ok && entering {
-			href := string(link.Destination)
-			if href != "" {
-				links = append(links, note.Link{
-					Title:    string(link.Text(source)),
-					Href:     href,
-					Rels:     strings.Fields(string(link.Title)),
-					External: strutil.IsURL(href),
-					Snippet:  extractLines(n.Parent(), source),
-				})
+		if entering {
+			switch link := n.(type) {
+			case *ast.Link:
+				href := string(link.Destination)
+				if href != "" {
+					links = append(links, note.Link{
+						Title:    string(link.Text(source)),
+						Href:     href,
+						Rels:     strings.Fields(string(link.Title)),
+						External: strutil.IsURL(href),
+						Snippet:  extractLines(n.Parent(), source),
+					})
+				}
+
+			case *ast.AutoLink:
+				if href := string(link.URL(source)); href != "" && link.AutoLinkType == ast.AutoLinkURL {
+					links = append(links, note.Link{
+						Title:    string(link.Label(source)),
+						Href:     href,
+						Rels:     []string{},
+						External: true,
+						Snippet:  extractLines(n.Parent(), source),
+					})
+				}
 			}
 		}
 		return ast.WalkContinue, nil
diff --git a/adapter/markdown/markdown_test.go b/adapter/markdown/markdown_test.go
index 8f5bce8..c635349 100644
--- a/adapter/markdown/markdown_test.go
+++ b/adapter/markdown/markdown_test.go
@@ -168,6 +168,8 @@ func TestParseLinks(t *testing.T) {
 Paragraph containing [multiple **links**](stripped-formatting), here's one [relative](../other).
 A link can have [one relation](one "rel-1") or [several relations](several "rel-1 rel-2").
 
+An https://inline-link.com and http://another-inline-link.com.
+
 [External links](http://example.com) are marked [as such](ftp://domain).
 `, []note.Link{
 		{
@@ -209,6 +211,20 @@ A link can have [one relation](one "rel-1") or [several relations](several "rel-
 			Snippet: `Paragraph containing [multiple **links**](stripped-formatting), here's one [relative](../other).
 A link can have [one relation](one "rel-1") or [several relations](several "rel-1 rel-2").`,
 		},
+		{
+			Title:    "https://inline-link.com",
+			Href:     "https://inline-link.com",
+			External: true,
+			Rels:     []string{},
+			Snippet:  "An https://inline-link.com and http://another-inline-link.com.",
+		},
+		{
+			Title:    "http://another-inline-link.com",
+			Href:     "http://another-inline-link.com",
+			External: true,
+			Rels:     []string{},
+			Snippet:  "An https://inline-link.com and http://another-inline-link.com.",
+		},
 		{
 			Title:    "External links",
 			Href:     "http://example.com",
diff --git a/go.mod b/go.mod
index e4b900a..c5dc844 100644
--- a/go.mod
+++ b/go.mod
@@ -18,6 +18,7 @@ require (
 	github.com/mattn/go-runewidth v0.0.10 // indirect
 	github.com/mattn/go-sqlite3 v1.14.6
 	github.com/mickael-menu/pretty v0.2.3
+	github.com/mvdan/xurls v1.1.0
 	github.com/pelletier/go-toml v1.8.1
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
diff --git a/go.sum b/go.sum
index 3d9b994..2de8766 100644
--- a/go.sum
+++ b/go.sum
@@ -133,6 +133,8 @@ github.com/mickael-menu/pretty v0.2.3 h1:AXi5WcBuWxwQV6iY/GhmCFpaoboQO2SLtzfujrn
 github.com/mickael-menu/pretty v0.2.3/go.mod h1:gupeWUSWoo3KX7BItIuouLgTqQLlmRylpaPdIK6IqLk=
 github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db h1:62I3jR2EmQ4l5rM/4FEfDWcRD+abF5XlKShorW5LRoQ=
 github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db/go.mod h1:l0dey0ia/Uv7NcFFVbCLtqEBQbrT4OCwCSKTEv6enCw=
+github.com/mvdan/xurls v1.1.0 h1:OpuDelGQ1R1ueQ6sSryzi6P+1RtBpfQHM8fJwlE45ww=
+github.com/mvdan/xurls v1.1.0/go.mod h1:tQlNn3BED8bE/15hnSL2HLkDeLWpNPAwtw7wkEq44oU=
 github.com/pelletier/go-toml v1.8.1 h1:1Nf83orprkJyknT6h7zbuEGUEjcyVlCxSUGTENmNCRM=
 github.com/pelletier/go-toml v1.8.1/go.mod h1:T2/BmBdy8dvIRq1a/8aqjN41wvWlN4lrapLU/GW4pbc=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=