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components/previews/MarkdownPreview.tsx

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+import { useEffect, FunctionComponent } from 'react'
+import axios from 'axios'
+import useSWR from 'swr'
+import Prism from 'prismjs'
+import ReactMarkdown from 'react-markdown'
+import gfm from 'remark-gfm'
+import remarkMath from 'remark-math'
+import rehypeKatex from 'rehype-katex'
+
+import 'katex/dist/katex.min.css'
+import 'github-markdown-css/github-markdown.css'
+
+import FourOhFour from '../FourOhFour'
+import Loading from '../Loading'
+import DownloadBtn from '../DownloadBtn'
+
+const fetcher = (url: string) => axios.get(url).then(res => res.data)
+
+const MarkdownPreview: FunctionComponent<{ file: any }> = ({ file }) => {
+  const { data, error } = useSWR(file['@microsoft.graph.downloadUrl'], fetcher)
+  useEffect(() => {
+    if (typeof window !== 'undefined') {
+      Prism.highlightAll()
+    }
+  }, [data])
+
+  if (error) {
+    return (
+      <div className="shadow bg-white rounded p-3">
+        <FourOhFour errorMsg={error.message} />
+      </div>
+    )
+  }
+  if (!data) {
+    return (
+      <div className="shadow bg-white rounded p-3">
+        <Loading loadingText="Loading file content..." />
+      </div>
+    )
+  }
+
+  return (
+    <>
+      <div className="markdown-body shadow bg-white rounded p-3">
+        <ReactMarkdown remarkPlugins={[gfm, remarkMath]} rehypePlugins={[rehypeKatex]}>
+          {data}
+        </ReactMarkdown>
+      </div>
+      <div className="mt-4">
+        <DownloadBtn downloadUrl={file['@microsoft.graph.downloadUrl']} />
+      </div>
+    </>
+  )
+}
+
+export default MarkdownPreview