From 3d522f7f2457a56d0508c04e824b81e822e7b7c6 Mon Sep 17 00:00:00 2001
From: caandt <caandt@twoha.cc>
Date: Tue, 1 Oct 2024 00:01:04 -0500
Subject: [PATCH] add latex support

---
 .gitignore |  4 +++-
 Makefile   |  8 ++++++++
 build.py   | 21 +++++++++++++++++----
 shell.nix  | 12 ++++++++++++
 4 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/.gitignore b/.gitignore
index 36e99fc..c14e1fe 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 __pycache__/
-music/
+/music/
 *.ttf
+/static/fonts
+/static/katex.min.css
diff --git a/Makefile b/Makefile
index f4d8eb3..e4f1696 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,8 @@ OUT=/tmp/2h
 FLAGS=
 CTF=$(patsubst %.md,$(OUT)/%.html,$(wildcard ctf/**/*.md))
 
+KATEX_PATH=$(shell nix path-info nixpkgs#nodePackages.katex)/lib/node_modules/katex/dist
+
 all: $(OUT) $(OUT)/ctf $(CTF)
 
 $(OUT): pages templates static rootstatic build.py static/songlist.json build.py static/highlight.css
@@ -23,6 +25,12 @@ static/songlist.json: music build.py
 static/highlight.css: build.py
 	python build.py highlight $(FLAGS)
 
+static/katex.min.css:
+	ln -sf "$(KATEX_PATH)"/katex.min.css static/katex.min.css
+
+static/fonts:
+	ln -sf "$(KATEX_PATH)"/fonts static/fonts
+
 server: all
 	@trap 'kill 0' SIGINT; \
 	flask run & \
diff --git a/build.py b/build.py
index d3476a0..ba94f1d 100644
--- a/build.py
+++ b/build.py
@@ -114,19 +114,32 @@ def format_tags(tags):
 def md_to_html(path):
     import markdown
     from markdown.extensions.codehilite import CodeHiliteExtension
-    from markdown.extensions.tables import TableExtension
     import frontmatter
     input = frontmatter.load(path)
+    import markdown_katex.extension
+    import markdown_katex.wrapper
+    ext = ['fenced_code', 'toc', 'tables', 'markdown_katex']
+    markdown_katex.extension.KATEX_STYLES = ''
+    sheets = ['/static/highlight.css']
     if minimal:
-        ext = ['fenced_code', 'toc', TableExtension()]
+        import latex2mathml.converter
+        def convert(t, _):
+            return latex2mathml.converter.convert(t)
+        markdown_katex.wrapper.tex2html = convert
     else:
-        ext = ['fenced_code', CodeHiliteExtension(css_class='hl'), 'toc', TableExtension()]
+        real = markdown_katex.wrapper.tex2html
+        def convert(*args):
+            sheets.append('/static/katex.min.css')
+            markdown_katex.wrapper.tex2html = real
+            return real(*args)
+        markdown_katex.wrapper.tex2html = convert
+        ext.append(CodeHiliteExtension(css_class='hl'))
     if 'toc' in input:
         input.content = '[TOC]\n' + input.content
     html = markdown.markdown(input.content, extensions=ext)
     return f'''---
 title: {repr(input['title'])}
-sheets: ["/static/highlight.css"]
+sheets: {repr(sheets)}
 ---
 <div class="container">
 <article class="panel">
diff --git a/shell.nix b/shell.nix
index 768cd44..600b399 100644
--- a/shell.nix
+++ b/shell.nix
@@ -7,6 +7,17 @@ pkgs.mkShell {
     python311Packages.mutagen
     python311Packages.flask
     python311Packages.beautifulsoup4
+    (python311Packages.buildPythonPackage rec {
+      pname = "markdown-katex";
+      version = "202406.1035";
+      src = pkgs.fetchurl {
+        url = "https://files.pythonhosted.org/packages/f4/34/780748d7d78fb4024dd1a290844374dd0d9830da35593c534638a4e9e54e/markdown_katex-202406.1035-py2.py3-none-any.whl";
+        hash = "sha256-wXE+hYVN3stkGtliQ6i2zWc2e/G/jTm0OzaA1/KxiE0=";
+      };
+      format = "wheel";
+      doCheck = false;
+    })
+    python311Packages.latex2mathml
     (python311Packages.buildPythonPackage rec {
       pname = "minify-html";
       version = "0.15.0";
@@ -27,5 +38,6 @@ pkgs.mkShell {
     python311
     nginx
     inotify-tools
+    nodePackages.katex
   ];
 }