From 90dac31216b5d3f59e65ec5778e21a308a744e11 Mon Sep 17 00:00:00 2001
From: Ben Schlegel <31989404+benschlegel@users.noreply.github.com>
Date: Fri, 1 Sep 2023 19:09:58 +0200
Subject: [PATCH] feat: Implement search for tags (#436)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

* Quartz sync: Aug 29, 2023, 10:17 PM

* style: add basic style to tags in search

* feat: add SearchType + tags to search preview

* feat: support multiple matches

* style(search): add style to matching tags

* feat(search): add content to preview for tag search

* fix: only display tags on tag search

* feat: support basic + tag search

* refactor: extract common `fillDocument`, format

* feat: add hotkey to search for tags

* chore: remove logs

* fix: dont render empty `<ul>` if tags not present

* fix(search-tag): make case insensitive

* refactor: clean `hideSearch` and `showSearch`

* feat: trim content similar to `description.ts`

* fix(search-tag): hotkey for windows

* perf: re-use main index for tag search
---
 quartz/components/scripts/search.inline.ts | 163 ++++++++++++++++++---
 quartz/components/styles/search.scss       |  38 +++++
 2 files changed, 179 insertions(+), 22 deletions(-)

diff --git a/quartz/components/scripts/search.inline.ts b/quartz/components/scripts/search.inline.ts
index ef26ba380..806a746e6 100644
--- a/quartz/components/scripts/search.inline.ts
+++ b/quartz/components/scripts/search.inline.ts
@@ -1,4 +1,4 @@
-import { Document } from "flexsearch"
+import { Document, SimpleDocumentSearchResultSetUnit } from "flexsearch"
 import { ContentDetails } from "../../plugins/emitters/contentIndex"
 import { registerEscapeHandler, removeAllChildren } from "./util"
 import { FullSlug, resolveRelative } from "../../util/path"
@@ -8,12 +8,20 @@ interface Item {
   slug: FullSlug
   title: string
   content: string
+  tags: string[]
 }
 
 let index: Document<Item> | undefined = undefined
 
+// Can be expanded with things like "term" in the future
+type SearchType = "basic" | "tags"
+
+// Current searchType
+let searchType: SearchType = "basic"
+
 const contextWindowWords = 30
 const numSearchResults = 5
+const numTagResults = 3
 function highlight(searchTerm: string, text: string, trim?: boolean) {
   // try to highlight longest tokens first
   const tokenizedTerms = searchTerm
@@ -87,9 +95,12 @@ document.addEventListener("nav", async (e: unknown) => {
     if (results) {
       removeAllChildren(results)
     }
+
+    searchType = "basic" // reset search type after closing
   }
 
-  function showSearch() {
+  function showSearch(searchTypeNew: SearchType) {
+    searchType = searchTypeNew
     if (sidebar) {
       sidebar.style.zIndex = "1"
     }
@@ -98,10 +109,18 @@ document.addEventListener("nav", async (e: unknown) => {
   }
 
   function shortcutHandler(e: HTMLElementEventMap["keydown"]) {
-    if (e.key === "k" && (e.ctrlKey || e.metaKey)) {
+    if (e.key === "k" && (e.ctrlKey || e.metaKey) && !e.shiftKey) {
       e.preventDefault()
       const searchBarOpen = container?.classList.contains("active")
-      searchBarOpen ? hideSearch() : showSearch()
+      searchBarOpen ? hideSearch() : showSearch("basic")
+    } else if (e.shiftKey && (e.ctrlKey || e.metaKey) && e.key.toLowerCase() === "k") {
+      // Hotkey to open tag search
+      e.preventDefault()
+      const searchBarOpen = container?.classList.contains("active")
+      searchBarOpen ? hideSearch() : showSearch("tags")
+
+      // add "#" prefix for tag search
+      if (searchBar) searchBar.value = "#"
     } else if (e.key === "Enter") {
       const anchor = document.getElementsByClassName("result-card")[0] as HTMLInputElement | null
       if (anchor) {
@@ -110,21 +129,77 @@ document.addEventListener("nav", async (e: unknown) => {
     }
   }
 
+  function trimContent(content: string) {
+    // works without escaping html like in `description.ts`
+    const sentences = content.replace(/\s+/g, " ").split(".")
+    let finalDesc = ""
+    let sentenceIdx = 0
+
+    // Roughly estimate characters by (words * 5). Matches description length in `description.ts`.
+    const len = contextWindowWords * 5
+    while (finalDesc.length < len) {
+      const sentence = sentences[sentenceIdx]
+      if (!sentence) break
+      finalDesc += sentence + "."
+      sentenceIdx++
+    }
+
+    // If more content would be available, indicate it by finishing with "..."
+    if (finalDesc.length < content.length) {
+      finalDesc += ".."
+    }
+
+    return finalDesc
+  }
+
   const formatForDisplay = (term: string, id: number) => {
     const slug = idDataMap[id]
     return {
       id,
       slug,
       title: highlight(term, data[slug].title ?? ""),
-      content: highlight(term, data[slug].content ?? "", true),
+      // if searchType is tag, display context from start of file and trim, otherwise use regular highlight
+      content:
+        searchType === "tags"
+          ? trimContent(data[slug].content)
+          : highlight(term, data[slug].content ?? "", true),
+      tags: highlightTags(term, data[slug].tags),
     }
   }
 
-  const resultToHTML = ({ slug, title, content }: Item) => {
+  function highlightTags(term: string, tags: string[]) {
+    if (tags && searchType === "tags") {
+      // Find matching tags
+      const termLower = term.toLowerCase()
+      let matching = tags.filter((str) => str.includes(termLower))
+
+      // Substract matching from original tags, then push difference
+      if (matching.length > 0) {
+        let difference = tags.filter((x) => !matching.includes(x))
+
+        // Convert to html (cant be done later as matches/term dont get passed to `resultToHTML`)
+        matching = matching.map((tag) => `<li><p class="match-tag">#${tag}</p></li>`)
+        difference = difference.map((tag) => `<li><p>#${tag}</p></li>`)
+        matching.push(...difference)
+      }
+
+      // Only allow max of `numTagResults` in preview
+      if (tags.length > numTagResults) {
+        matching.splice(numTagResults)
+      }
+
+      return matching
+    } else {
+      return []
+    }
+  }
+
+  const resultToHTML = ({ slug, title, content, tags }: Item) => {
+    const htmlTags = tags.length > 0 ? `<ul>${tags.join("")}</ul>` : ``
     const button = document.createElement("button")
     button.classList.add("result-card")
     button.id = slug
-    button.innerHTML = `<h3>${title}</h3><p>${content}</p>`
+    button.innerHTML = `<h3>${title}</h3>${htmlTags}<p>${content}</p>`
     button.addEventListener("click", () => {
       const targ = resolveRelative(currentSlug, slug)
       window.spaNavigate(new URL(targ, window.location.toString()))
@@ -148,15 +223,45 @@ document.addEventListener("nav", async (e: unknown) => {
   }
 
   async function onType(e: HTMLElementEventMap["input"]) {
-    const term = (e.target as HTMLInputElement).value
-    const searchResults = (await index?.searchAsync(term, numSearchResults)) ?? []
+    let term = (e.target as HTMLInputElement).value
+    let searchResults: SimpleDocumentSearchResultSetUnit[]
+
+    if (term.toLowerCase().startsWith("#")) {
+      searchType = "tags"
+    } else {
+      searchType = "basic"
+    }
+
+    switch (searchType) {
+      case "tags": {
+        term = term.substring(1)
+        searchResults =
+          (await index?.searchAsync({ query: term, limit: numSearchResults, index: ["tags"] })) ??
+          []
+        break
+      }
+      case "basic":
+      default: {
+        searchResults =
+          (await index?.searchAsync({
+            query: term,
+            limit: numSearchResults,
+            index: ["title", "content"],
+          })) ?? []
+      }
+    }
+
     const getByField = (field: string): number[] => {
       const results = searchResults.filter((x) => x.field === field)
       return results.length === 0 ? [] : ([...results[0].result] as number[])
     }
 
     // order titles ahead of content
-    const allIds: Set<number> = new Set([...getByField("title"), ...getByField("content")])
+    const allIds: Set<number> = new Set([
+      ...getByField("title"),
+      ...getByField("content"),
+      ...getByField("tags"),
+    ])
     const finalResults = [...allIds].map((id) => formatForDisplay(term, id))
     displayResults(finalResults)
   }
@@ -167,8 +272,8 @@ document.addEventListener("nav", async (e: unknown) => {
 
   document.addEventListener("keydown", shortcutHandler)
   prevShortcutHandler = shortcutHandler
-  searchIcon?.removeEventListener("click", showSearch)
-  searchIcon?.addEventListener("click", showSearch)
+  searchIcon?.removeEventListener("click", () => showSearch("basic"))
+  searchIcon?.addEventListener("click", () => showSearch("basic"))
   searchBar?.removeEventListener("input", onType)
   searchBar?.addEventListener("input", onType)
 
@@ -190,22 +295,36 @@ document.addEventListener("nav", async (e: unknown) => {
             field: "content",
             tokenize: "reverse",
           },
+          {
+            field: "tags",
+            tokenize: "reverse",
+          },
         ],
       },
     })
 
-    let id = 0
-    for (const [slug, fileData] of Object.entries<ContentDetails>(data)) {
-      await index.addAsync(id, {
-        id,
-        slug: slug as FullSlug,
-        title: fileData.title,
-        content: fileData.content,
-      })
-      id++
-    }
+    fillDocument(index, data)
   }
 
   // register handlers
   registerEscapeHandler(container, hideSearch)
 })
+
+/**
+ * Fills flexsearch document with data
+ * @param index index to fill
+ * @param data data to fill index with
+ */
+async function fillDocument(index: Document<Item, false>, data: any) {
+  let id = 0
+  for (const [slug, fileData] of Object.entries<ContentDetails>(data)) {
+    await index.addAsync(id, {
+      id,
+      slug: slug as FullSlug,
+      title: fileData.title,
+      content: fileData.content,
+      tags: fileData.tags,
+    })
+    id++
+  }
+}
diff --git a/quartz/components/styles/search.scss b/quartz/components/styles/search.scss
index 4d5ad95cd..66f809f97 100644
--- a/quartz/components/styles/search.scss
+++ b/quartz/components/styles/search.scss
@@ -130,6 +130,44 @@
             margin: 0;
           }
 
+          & > ul > li {
+            margin: 0;
+            display: inline-block;
+            white-space: nowrap;
+            margin: 0;
+            overflow-wrap: normal;
+          }
+
+          & > ul {
+            list-style: none;
+            display: flex;
+            padding-left: 0;
+            gap: 0.4rem;
+            margin: 0;
+            margin-top: 0.45rem;
+            // Offset border radius
+            margin-left: -2px;
+            overflow: hidden;
+            background-clip: border-box;
+          }
+
+          & > ul > li > p {
+            border-radius: 8px;
+            background-color: var(--highlight);
+            overflow: hidden;
+            background-clip: border-box;
+            padding: 0.03rem 0.4rem;
+            margin: 0;
+            color: var(--secondary);
+            opacity: 0.85;
+          }
+
+          & > ul > li > .match-tag {
+            color: var(--tertiary);
+            font-weight: bold;
+            opacity: 1;
+          }
+
           & > p {
             margin-bottom: 0;
           }