web: hierarchical tags list on desktop

web/index.html

@@ -143,6 +143,9 @@ blockquote[type="cite"],
 .tags-menu .menu-list a {
   padding: 0.25em 0.5em;
 }
+.tags-menu .tag-indent {
+  padding-left: 1em;
+}
 .navbar {
   border: none;
 }

web/src/lib.rs

@@ -1235,6 +1235,24 @@ fn view_desktop(model: &Model) -> Node<Msg> {
             pager,
         } => view_search_results(&query, results.as_slice(), *count, pager),
     };
+    fn view_tag_li(display_name: &str, indent: usize, t: &Tag) -> Node<Msg> {
+        li![a![
+            attrs! {
+                At::Href => urls::search(&format!("tag:{}", t.name), 0)
+            },
+            style! {
+                St::BackgroundColor => t.bg_color,
+                St::Color => t.fg_color,
+            },
+            (0..indent).map(|_| span![C!["tag-indent"], ""]),
+            display_name
+        ]]
+    }
+    fn matches(a: &[&str], b: &[&str]) -> usize {
+        std::iter::zip(a.iter(), b.iter())
+            .take_while(|(a, b)| a == b)
+            .count()
+    }
     div![
         C!["desktop-main-content"],
         aside![
@@ -1242,16 +1260,38 @@ fn view_desktop(model: &Model) -> Node<Msg> {
             p![C!["menu-label"], "Tags"],
             ul![
                 C!["menu-list"],
-                model.tags.as_ref().map(|tags| tags.iter().map(|t| li![a![
-                    attrs! {
-                        At::Href => urls::search(&format!("tag:{}", t.name), 0)
-                    },
-                    style! {
-                        St::BackgroundColor => t.bg_color,
-                        St::Color => t.fg_color,
-                    },
-                    &t.name
-                ]]))
+                model.tags.as_ref().map(|tags| {
+                    let mut lis = Vec::new();
+                    let mut last = Vec::new();
+                    for t in tags {
+                        let parts: Vec<_> = t.name.split('/').collect();
+                        let mut n = matches(&last, &parts);
+                        if t.name.starts_with("ZZCrap/Free") {
+                            info!("n: {n}, parts: {parts:?} last: {last:?}");
+                        }
+                        if n <= parts.len() - 2 && parts.len() > 1 {
+                            // Synthesize fake tags for proper indenting.
+                            for i in n..parts.len() - 1 {
+                                let display_name = parts[n];
+                                lis.push(view_tag_li(
+                                    &display_name,
+                                    n,
+                                    &Tag {
+                                        name: parts[..i + 1].join("/"),
+                                        bg_color: "#000".to_string(),
+                                        fg_color: "#fff".to_string(),
+                                    },
+                                ));
+                            }
+                            last = parts[..parts.len() - 1].to_vec();
+                            n = parts.len() - 1;
+                        }
+                        let display_name = parts[n];
+                        lis.push(view_tag_li(&display_name, n, t));
+                        last = parts;
+                    }
+                    lis
+                })
             ]
         ],
         div![