From 3bb6041df03f59c8188228895fd303b2583c377d Mon Sep 17 00:00:00 2001
From: Utsob Roy <roy@utsob.me>
Date: Wed, 1 Feb 2023 16:14:50 +0600
Subject: [PATCH] fixed backlink

---
 src/helpers/linkUtils.js         | 76 +++++++++++++++++---------------
 src/site/index.11tydata.js       |  3 +-
 src/site/notes/notes.11tydata.js |  2 +
 3 files changed, 44 insertions(+), 37 deletions(-)

diff --git a/src/helpers/linkUtils.js b/src/helpers/linkUtils.js
index 630dfe1..c563250 100644
--- a/src/helpers/linkUtils.js
+++ b/src/helpers/linkUtils.js
@@ -1,6 +1,10 @@
 const wikiLinkRegex = /\[\[(.*?\|.*?)\]\]/g;
 const internalLinkRegex = /href="\/(.*?)"/g;
 
+function caselessCompare(a, b) {
+  return a.toLowerCase() === b.toLowerCase();
+}
+
 function extractLinks(content) {
   return [
     ...(content.match(wikiLinkRegex) || []).map(
@@ -26,47 +30,47 @@ function extractLinks(content) {
   ];
 }
 
-function shuffle(a) {
-  var j, x, i;
-  for (i = a.length - 1; i > 0; i--) {
-    j = Math.floor(Math.random() * (i + 1));
-    x = a[i];
-    a[i] = a[j];
-    a[j] = x;
+function getBacklinks(data) {
+  const notes = data.collections.note;
+  if (!notes) {
+    return [];
   }
-  return a;
-}
+  const currentFileSlug = data.page.filePathStem
+    .replace("/notes/", "")
+    .split("#")[0];
+  const currentURL = data.page.url;
 
-function sliceIntoChunks(arr, chunkSize) {
-  const res = [];
-  for (let i = 0; i < arr.length; i += chunkSize) {
-    const chunk = arr.slice(i, i + chunkSize);
-    res.push(chunk);
+  let backlinks = [];
+  let uniqueLinks = new Set();
+  let counter = 1;
+
+  for (const otherNote of notes) {
+    const noteContent = otherNote.template.frontMatter.content;
+    const backLinks = extractLinks(noteContent);
+
+    if (
+      !uniqueLinks.has(otherNote.url) &&
+      backLinks.some(
+        (link) =>
+          caselessCompare(link, currentFileSlug) ||
+          currentURL == link.split("#")[0]
+      )
+    ) {
+      let preview = noteContent.slice(0, 240);
+      backlinks.push({
+        url: otherNote.url,
+        title: otherNote.data.title || otherNote.data.page.fileSlug,
+        preview,
+        id: counter++,
+        isHome: otherNote.data["dg-home"] || false,
+      });
+      uniqueLinks.add(otherNote.url);
+    }
   }
-  return res;
-}
-
-function getPositions(trees) {
-  let minInRow = Math.floor(Math.sqrt(trees.length));
-  let maxInRow = Math.ceil(Math.sqrt(trees.length));
-  if (minInRow < maxInRow) {
-    trees = trees.concat(
-      Array(Math.pow(maxInRow, 2) - trees.length).fill([0, "", ""])
-    );
-  }
-  trees = shuffle([...trees]);
-  let levels = sliceIntoChunks(trees, maxInRow);
-  return levels;
-}
-
-function forestData(data) {
-  const canvasTrees = data.collections.note.map((n) => {
-    return [n.data.maturity || 1, n.url, n.data.title || n.fileSlug];
-  });
-  return getPositions(canvasTrees);
+  return backlinks;
 }
 
 exports.wikiLinkRegex = wikiLinkRegex;
 exports.internalLinkRegex = internalLinkRegex;
 exports.extractLinks = extractLinks;
-exports.forestData = forestData;
+exports.getBacklinks = getBacklinks;
diff --git a/src/site/index.11tydata.js b/src/site/index.11tydata.js
index 2a5974f..164a9e4 100644
--- a/src/site/index.11tydata.js
+++ b/src/site/index.11tydata.js
@@ -5,11 +5,12 @@ const markdownIt = require("markdown-it");
 const md = markdownIt({
   html: true,
 }).use(require("../helpers/utils").namedHeadingsFilter);
-
+const { getBacklinks } = require("../helpers/linkUtils");
 const allSettings = settings.ALL_NOTE_SETTINGS;
 
 module.exports = {
   eleventyComputed: {
+    backlinks: (data) => getBacklinks(data),
     settings: (data) => {
       const currentnote =
         data.collections.gardenEntry && data.collections.gardenEntry[0];
diff --git a/src/site/notes/notes.11tydata.js b/src/site/notes/notes.11tydata.js
index c036a74..f3b4049 100644
--- a/src/site/notes/notes.11tydata.js
+++ b/src/site/notes/notes.11tydata.js
@@ -1,10 +1,12 @@
 require("dotenv").config();
 const settings = require("../../helpers/constants");
+const { getBacklinks } = require("../../helpers/linkUtils");
 
 const allSettings = settings.ALL_NOTE_SETTINGS;
 
 module.exports = {
   eleventyComputed: {
+    backlinks: (data) => getBacklinks(data),
     settings: (data) => {
       const noteSettings = {};
       allSettings.forEach((setting) => {