From 3bd168de0024873e4ab06aa3ae2e49700b67541e Mon Sep 17 00:00:00 2001
From: Niko Abeler <niko@rerere.org>
Date: Sat, 27 Aug 2022 23:01:14 +0200
Subject: [PATCH] missing files

---
 webmention.go      | 83 ++++++++++++++++++++++++++++++++++++++++++++++
 webmention_test.go | 36 ++++++++++++++++++++
 2 files changed, 119 insertions(+)
 create mode 100644 webmention.go
 create mode 100644 webmention_test.go

diff --git a/webmention.go b/webmention.go
new file mode 100644
index 0000000..53dee9a
--- /dev/null
+++ b/webmention.go
@@ -0,0 +1,83 @@
+package owl
+
+import (
+	"bytes"
+	"errors"
+	"net/http"
+	"strings"
+
+	"golang.org/x/net/html"
+)
+
+type HttpRetriever interface {
+	Get(url string) ([]byte, error)
+}
+
+type OwlHttpRetriever struct{}
+
+type ParsedHEntry struct {
+	Title string
+}
+
+func (ret *OwlHttpRetriever) Get(url string) ([]byte, error) {
+	resp, err := http.Get(url)
+	if err != nil {
+		return []byte{}, err
+	}
+	var data []byte
+	_, err = resp.Body.Read(data)
+	// TODO: encoding
+	return data, err
+}
+
+func collectText(n *html.Node, buf *bytes.Buffer) {
+	if n.Type == html.TextNode {
+		buf.WriteString(n.Data)
+	}
+	for c := n.FirstChild; c != nil; c = c.NextSibling {
+		collectText(c, buf)
+	}
+}
+
+func ParseHEntry(data []byte) (ParsedHEntry, error) {
+	doc, err := html.Parse(strings.NewReader(string(data)))
+	if err != nil {
+		return ParsedHEntry{}, err
+	}
+
+	var interpretHFeed func(*html.Node, *ParsedHEntry, bool) (ParsedHEntry, error)
+	interpretHFeed = func(n *html.Node, curr *ParsedHEntry, parent bool) (ParsedHEntry, error) {
+		attrs := n.Attr
+		for _, attr := range attrs {
+			if attr.Key == "class" && strings.Contains(attr.Val, "p-name") {
+				buf := &bytes.Buffer{}
+				collectText(n, buf)
+				curr.Title = buf.String()
+				return *curr, nil
+			}
+		}
+
+		for c := n.FirstChild; c != nil; c = c.NextSibling {
+			interpretHFeed(c, curr, false)
+		}
+		return *curr, nil
+	}
+
+	var findHFeed func(*html.Node) (ParsedHEntry, error)
+	findHFeed = func(n *html.Node) (ParsedHEntry, error) {
+		attrs := n.Attr
+		for _, attr := range attrs {
+			if attr.Key == "class" && strings.Contains(attr.Val, "h-entry") {
+				return interpretHFeed(n, &ParsedHEntry{}, true)
+			}
+		}
+		for c := n.FirstChild; c != nil; c = c.NextSibling {
+			entry, err := findHFeed(c)
+			if err == nil {
+				return entry, nil
+			}
+		}
+		return ParsedHEntry{}, errors.New("no h-entry found")
+	}
+	return findHFeed(doc)
+}
diff --git a/webmention_test.go b/webmention_test.go
new file mode 100644
index 0000000..c9abf6c
--- /dev/null
+++ b/webmention_test.go
@@ -0,0 +1,36 @@
+package owl_test
+
+import (
+	"h4kor/owl-blogs"
+	"testing"
+)
+
+//
+// https://www.w3.org/TR/webmention/#h-webmention-verification
+//
+
+func TestParseValidHEntry(t *testing.T) {
+	html := []byte("<div class=\"h-entry\"><div class=\"p-name\">Foo</div></div>")
+
+	entry, err := owl.ParseHEntry(html)
+
+	if err != nil {
+		t.Errorf("Unable to parse feed: %v", err)
+	}
+	if entry.Title != "Foo" {
+		t.Errorf("Wrong Title. Expected %v, got %v", "Foo", entry.Title)
+	}
+}
+
+func TestParseValidHEntryWithoutTitle(t *testing.T) {
+	html := []byte("<div class=\"h-entry\"></div><div class=\"p-name\">Foo</div>")
+
+	entry, err := owl.ParseHEntry(html)
+
+	if err != nil {
+		t.Errorf("Unable to parse feed: %v", err)
+	}
+	if entry.Title != "" {
+		t.Errorf("Wrong Title. Expected %v, got %v", "Foo", entry.Title)
+	}
+}