From 432ed4ea1d02755a5d9c273882a8728ea94b9527 Mon Sep 17 00:00:00 2001
From: Camila Belo <camilaibs@gmail.com>
Date: Fri, 20 May 2022 15:38:47 +0200
Subject: [PATCH] feat(techdocs): extract typeset rules

Signed-off-by: Camila Belo <camilaibs@gmail.com>
---
 .../transformers/styles/rules/typeset.ts      | 109 ++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 plugins/techdocs/src/reader/transformers/styles/rules/typeset.ts

diff --git a/plugins/techdocs/src/reader/transformers/styles/rules/typeset.ts b/plugins/techdocs/src/reader/transformers/styles/rules/typeset.ts
new file mode 100644
index 0000000000..e24b61da83
--- /dev/null
+++ b/plugins/techdocs/src/reader/transformers/styles/rules/typeset.ts
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2022 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { RuleOptions } from './types';
+
+type TypographyHeadings = Pick<
+  RuleOptions['theme']['typography'],
+  'h1' | 'h2' | 'h3' | 'h4' | 'h5' | 'h6'
+>;
+
+type TypographyHeadingsKeys = keyof TypographyHeadings;
+
+const headings: TypographyHeadingsKeys[] = ['h1', 'h2', 'h3', 'h4', 'h5', 'h6'];
+
+export default ({ theme }: RuleOptions) => `
+/*==================  Typeset  ==================*/
+
+.md-typeset {
+  font-size: var(--md-typeset-font-size);
+}
+
+${headings.reduce<string>((style, heading) => {
+  const styles = theme.typography[heading];
+  const { lineHeight, fontFamily, fontWeight, fontSize } = styles;
+  const calculate = (value: typeof fontSize) => {
+    let factor: number | string = 1;
+    if (typeof value === 'number') {
+      // 60% of the size defined because it is too big
+      factor = (value / 16) * 0.6;
+    }
+    if (typeof value === 'string') {
+      factor = value.replace('rem', '');
+    }
+    return `calc(${factor} * var(--md-typeset-font-size))`;
+  };
+  return style.concat(`
+    .md-typeset ${heading} {
+      color: var(--md-default-fg-color);
+      line-height: ${lineHeight};
+      font-family: ${fontFamily};
+      font-weight: ${fontWeight};
+      font-size: ${calculate(fontSize)};
+    }
+  `);
+}, '')}
+
+.md-typeset .md-content__button {
+  color: var(--md-default-fg-color);
+}
+
+.md-typeset hr {
+  border-bottom: 0.05rem dotted ${theme.palette.divider};
+}
+
+.md-typeset details {
+  font-size: var(--md-typeset-font-size) !important;
+}
+.md-typeset details summary {
+  padding-left: 2.5rem !important;
+}
+.md-typeset details summary:before,
+.md-typeset details summary:after {
+  top: 50% !important;
+  width: 20px !important;
+  height: 20px !important;
+  transform: rotate(0deg) translateY(-50%) !important;
+}
+.md-typeset details[open] > summary:after {
+  transform: rotate(90deg) translateX(-50%) !important;
+}
+
+.md-typeset blockquote {
+  color: var(--md-default-fg-color--light);
+  border-left: 0.2rem solid var(--md-default-fg-color--light);
+}
+
+.md-typeset table:not([class]) {
+  font-size: var(--md-typeset-font-size);
+  border: 1px solid var(--md-default-fg-color);
+  border-bottom: none;
+  border-collapse: collapse;
+}
+.md-typeset table:not([class]) th {
+  font-weight: bold;
+}
+.md-typeset table:not([class]) td, .md-typeset table:not([class]) th {
+  border-bottom: 1px solid var(--md-default-fg-color);
+}
+
+.md-typeset pre > code::-webkit-scrollbar-thumb {
+  background-color: hsla(0, 0%, 0%, 0.32);
+}
+.md-typeset pre > code::-webkit-scrollbar-thumb:hover {
+  background-color: hsla(0, 0%, 0%, 0.87);
+}
+`;