From ecbbe8584406967725c69a6c5b830b1ccb62aad4 Mon Sep 17 00:00:00 2001
From: Mylloon <kennel.anri@tutanota.com>
Date: Sun, 10 Dec 2023 23:23:27 +0100
Subject: [PATCH] closest i can get with stupid regex, currently not working
 since the regex is eating a character after a match, also its not a proprer
 parsing so any dollar inside a formula will probably break the whole thing

---
 Cargo.lock                       |  1 +
 Cargo.toml                       |  1 +
 src/misc/markdown.rs             | 27 ++++++++++++++++++++++++++-
 static/js/libs/katex.js          | 22 +++++++++++++++-------
 templates/libs/katex_footer.html |  6 ------
 5 files changed, 43 insertions(+), 14 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index c69c76b..1da51cd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -927,6 +927,7 @@ dependencies = [
  "minify-html",
  "minify-js 0.5.6",
  "ramhorns",
+ "regex",
  "reqwest",
  "rss",
  "serde",
diff --git a/Cargo.toml b/Cargo.toml
index ae424b5..afc8f36 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,3 +27,4 @@ chrono = { version = "0.4.30", default-features = false, features = ["clock"]}
 chrono-tz = "0.8"
 rss = { version = "2.0", features = ["atom"] }
 lol_html = "1.2"
+regex = "1.10"
diff --git a/src/misc/markdown.rs b/src/misc/markdown.rs
index bba0e42..9ad3d8f 100644
--- a/src/misc/markdown.rs
+++ b/src/misc/markdown.rs
@@ -3,6 +3,7 @@ use comrak::nodes::{AstNode, NodeValue};
 use comrak::{format_html, parse_document, Arena, ComrakOptions, ListStyleType};
 use lol_html::{element, rewrite_str, RewriteStrSettings};
 use ramhorns::Content;
+use regex::{Captures, Regex};
 use serde::{Deserialize, Deserializer};
 use std::fs;
 
@@ -170,12 +171,35 @@ fn custom_img_size(html: String) -> String {
     .unwrap()
 }
 
+fn math_processing(regex: &str, source: &str) -> String {
+    Regex::new(regex)
+        .unwrap()
+        .replace_all(source, |captures: &Captures| {
+            captures
+                .iter()
+                .skip(1)
+                .filter_map(|capture| {
+                    capture.map(|m| format!("<span data-katex=\"{}\"></span>", m.as_str()))
+                })
+                .collect::<Vec<String>>()
+                .join("")
+        })
+        .to_string()
+}
+
 /// Transform markdown string to File structure
 fn read(raw_text: &str, metadata_type: TypeFileMetadata) -> File {
     let arena = Arena::new();
 
+    // Transform LaTeX formulas
+    let text = math_processing(
+        r"(?U)(\$[^\$|\n]+\$)[^\$]",
+        &math_processing(r"(?U)(\$\$[^\$|\n]+\$\$)", raw_text),
+    );
+    println!("{}", text);
+
     let options = get_options();
-    let root = parse_document(&arena, raw_text, &options);
+    let root = parse_document(&arena, &text, &options);
 
     // Find metadata
     let metadata = get_metadata(root, metadata_type);
@@ -188,6 +212,7 @@ fn read(raw_text: &str, metadata_type: TypeFileMetadata) -> File {
     format_html(root, &options, &mut html).unwrap();
 
     let mut html_content = String::from_utf8(html).unwrap();
+    /* println!("{}", html_content); */
 
     html_content = custom_img_size(html_content);
 
diff --git a/static/js/libs/katex.js b/static/js/libs/katex.js
index 9964bba..8436a0e 100644
--- a/static/js/libs/katex.js
+++ b/static/js/libs/katex.js
@@ -16,12 +16,20 @@ window.addEventListener("load", () => {
     macros[`\\${item[0]}`] = `\\${item[1]}`;
   }
 
-  renderMathInElement(document.body, {
-    delimiters: [
-      { left: "$$", right: "$$", display: true },
-      { left: "$", right: "$", display: false },
-    ],
-    throwOnError: false,
-    macros,
+  document.querySelectorAll("span[data-katex]").forEach((element) => {
+    const rawLaTeXFormula = element.getAttribute("data-katex");
+    const displayMode = rawLaTeXFormula.startsWith("$$");
+    const strip = displayMode ? 2 : 1;
+
+    katex.render(
+      rawLaTeXFormula.slice(strip, rawLaTeXFormula.length - strip),
+      element,
+      {
+        throwOnError: false,
+        macros,
+        displayMode,
+        output: "mathml",
+      }
+    );
   });
 });
diff --git a/templates/libs/katex_footer.html b/templates/libs/katex_footer.html
index 2b2a92b..abd7a9d 100644
--- a/templates/libs/katex_footer.html
+++ b/templates/libs/katex_footer.html
@@ -4,10 +4,4 @@
   integrity="sha384-j/ZricySXBnNMJy9meJCtyXTKMhIJ42heyr7oAdxTDBy/CYA9hzpMo+YTNV5C+1X"
   crossorigin="anonymous"
 ></script>
-<script
-  defer
-  src="//cdn.jsdelivr.net/npm/katex@0.16.6/dist/contrib/auto-render.min.js"
-  integrity="sha384-+VBxd3r6XgURycqtZ117nYw44OOcIax56Z4dCRWbxyPt0Koah1uHoK0o4+/RRE05"
-  crossorigin="anonymous"
-></script>
 <script src="/js/libs/katex.js"></script>