1 files changed, 115 insertions, 0 deletions
diff --git a/vrsite/tree.go b/vrsite/tree.go
new file mode 100644
index 0000000..e7891c6
--- /dev/null
+++ b/vrsite/tree.go
@@ -0,0 +1,115 @@
+// tree.go — the repository tree, one fragment shared by every page.
+package main
+
+import (
+	"fmt"
+	"html"
+	"path/filepath"
+	"strings"
+)
+
+type treeNode struct {
+	Name      string
+	Dirs      []*treeNode
+	Files     []*File
+	Mask      uint8 // union of traced masks underneath
+	HasNotes  bool
+	HasTraced bool
+}
+
+func aggregate(n *treeNode) {
+	for _, f := range n.Files {
+		if f.Traced {
+			n.HasTraced = true
+			n.Mask |= f.Mask
+			if len(f.Notes) > 0 {
+				n.HasNotes = true
+			}
+		}
+	}
+	for _, d := range n.Dirs {
+		aggregate(d)
+		n.Mask |= d.Mask
+		n.HasNotes = n.HasNotes || d.HasNotes
+		n.HasTraced = n.HasTraced || d.HasTraced
+	}
+}
+
+func buildTree(files []*File) *treeNode {
+	root := &treeNode{}
+	for _, f := range files {
+		parts := strings.Split(f.Path, "/")
+		node := root
+		for _, d := range parts[:len(parts)-1] {
+			var next *treeNode
+			for _, c := range node.Dirs {
+				if c.Name == d {
+					next = c
+				}
+			}
+			if next == nil {
+				next = &treeNode{Name: d}
+				node.Dirs = append(node.Dirs, next)
+			}
+			node = next
+		}
+		node.Files = append(node.Files, f)
+	}
+	return root
+}
+
+// treeHTML renders one unified tree: traced files carry coverage bars, dirs
+// with traced content underneath get a mixed-color dot (and ◆ for notes) and
+// default open. prefix is the dir path so far, used for state persistence;
+// link maps a repo path to the href for that file's page.
+func treeHTML(b *strings.Builder, n *treeNode, link func(path string) string, prefix string) {
+	for _, d := range n.Dirs {
+		dp := d.Name
+		if prefix != "" {
+			dp = prefix + "/" + d.Name
+		}
+		openAttr, cls := "", ""
+		if d.HasTraced {
+			openAttr, cls = " open", ` class="t"`
+		}
+		fmt.Fprintf(b, `<details%s%s data-path="%s"><summary>%s`, cls, openAttr, html.EscapeString(dp), html.EscapeString(d.Name))
+		if d.HasTraced {
+			fmt.Fprintf(b, `<span class="dot trace-only am%d"></span>`, d.Mask)
+		}
+		if d.HasNotes {
+			b.WriteString(`<span class="nmark notes-only">◆</span>`)
+		}
+		b.WriteString(`</summary>`)
+		treeHTML(b, d, link, dp)
+		b.WriteString(`</details>`)
+	}
+	if len(n.Files) == 0 {
+		return
+	}
+	b.WriteString("<ul>")
+	for _, f := range n.Files {
+		name := html.EscapeString(filepath.Base(f.Path))
+		path := html.EscapeString(f.Path)
+		if !f.Traced {
+			fmt.Fprintf(b, `<li><a class="file plain" data-path="%s" href="%s">%s</a></li>`, path, html.EscapeString(link(f.Path)), name)
+			continue
+		}
+		noted := ""
+		if len(f.Notes) > 0 {
+			noted = " has-notes"
+		}
+		fmt.Fprintf(b,
+			`<li><a class="file am%d%s" data-path="%s" href="%s" style="--pct:%d%%" title="%d%% read, %d notes">%s</a></li>`,
+			f.Mask, noted, path, html.EscapeString(link(f.Path)), f.Pct, f.Pct, len(f.Notes), name)
+	}
+	b.WriteString("</ul>")
+}
+
+// renderTree is the whole fragment for a file set.
+func renderTree(files []*File, link func(string) string) string {
+	root := buildTree(files)
+	aggregate(root)
+	var b strings.Builder
+	treeHTML(&b, root, link, "")
+	return b.String()
+}