nested tag support and tag index page

quartz/components/pages/TagContent.tsx

@@ -3,33 +3,75 @@ import { Fragment, jsx, jsxs } from "preact/jsx-runtime"
 import { toJsxRuntime } from "hast-util-to-jsx-runtime"
 import style from "../styles/listPage.scss"
 import { PageList } from "../PageList"
-import { ServerSlug, canonicalizeServer } from "../../path"
+import { ServerSlug, canonicalizeServer, getAllSegmentPrefixes } from "../../path"
+import { QuartzPluginData } from "../../plugins/vfile"
 
+const numPages = 10
 function TagContent(props: QuartzComponentProps) {
   const { tree, fileData, allFiles } = props
   const slug = fileData.slug
 
-  if (slug?.startsWith("tags/")) {
-    const tag = canonicalizeServer(slug.slice("tags/".length) as ServerSlug)
-    const allPagesWithTag = allFiles.filter((file) => (file.frontmatter?.tags ?? []).includes(tag))
-    const listProps = {
-      ...props,
-      allFiles: allPagesWithTag,
+  if (!slug?.startsWith("tags/")) {
+    throw new Error(`Component "TagContent" tried to render a non-tag page: ${slug}`)
+  }
+
+  const tag = canonicalizeServer(slug.slice("tags/".length) as ServerSlug)
+  const allPagesWithTag = (tag: string) =>
+    allFiles.filter((file) =>
+      (file.frontmatter?.tags ?? []).flatMap(getAllSegmentPrefixes).includes(tag),
+    )
+
+  // @ts-ignore
+  const content = toJsxRuntime(tree, { Fragment, jsx, jsxs, elementAttributeNameCase: "html" })
+  if (tag === "") {
+    const tags = [...new Set(allFiles.flatMap((data) => data.frontmatter?.tags ?? []))]
+    const tagItemMap: Map<string, QuartzPluginData[]> = new Map()
+    for (const tag of tags) {
+      tagItemMap.set(tag, allPagesWithTag(tag))
     }
 
-    // @ts-ignore
-    const content = toJsxRuntime(tree, { Fragment, jsx, jsxs, elementAttributeNameCase: "html" })
     return (
       <div class="popover-hint">
         <article>{content}</article>
-        <p>{allPagesWithTag.length} items with this tag.</p>
+        <p>Found {tags.length} total tags.</p>
+        <div>
+          {tags.map((tag) => {
+            const pages = tagItemMap.get(tag)!
+            const listProps = {
+              ...props,
+              allFiles: pages,
+            }
+            return (
+              <div>
+                <h2>
+                  <a class="internal tag-link" href={`./tags/${tag}`}>
+                    #{tag}
+                  </a>
+                </h2>
+                <p>{pages.length} items with this tag. {pages.length > numPages && `Showing first ${numPages}.`}</p>
+                <PageList limit={numPages} {...listProps} />
+              </div>
+            )
+          })}
+        </div>
+      </div>
+    )
+  } else {
+    const pages = allPagesWithTag(tag)
+    const listProps = {
+      ...props,
+      allFiles: pages,
+    }
+
+    return (
+      <div class="popover-hint">
+        <article>{content}</article>
+        <p>{pages.length} items with this tag.</p>
         <div>
           <PageList {...listProps} />
         </div>
       </div>
     )
-  } else {
-    throw new Error(`Component "TagContent" tried to render a non-tag page: ${slug}`)
   }
 }