markdownをセクションごとに分割

Author: na-trium-144

app/[docs_id]/page.tsx

@@ -2,8 +2,9 @@ import { notFound } from "next/navigation";
 import { ChatForm } from "./chatForm";
 import { StyledMarkdown } from "./markdown";
 import { getCloudflareContext } from "@opennextjs/cloudflare";
-import { readFile } from "node:fs/promises"; 
+import { readFile } from "node:fs/promises";
 import { join } from "node:path";
+import { splitMarkdown } from "./splitMarkdown";
 
 export default async function Page({
   params,
@@ -14,13 +15,13 @@ export default async function Page({
 
   let mdContent: string;
   try {
-    if (process.env.NODE_ENV === 'development') {
+    if (process.env.NODE_ENV === "development") {
       mdContent = await readFile(
         join(process.cwd(), "public", "docs", `${docs_id}.md`),
         "utf-8"
       );
     } else {
-	  const cfAssets = getCloudflareContext().env.ASSETS;
+      const cfAssets = getCloudflareContext().env.ASSETS;
       mdContent = await cfAssets!
         .fetch(`https://assets.local/docs/${docs_id}.md`)
         .then((res) => res.text());
@@ -30,9 +31,13 @@ export default async function Page({
     notFound();
   }
 
+  const splitMdContent: string[] = await splitMarkdown(mdContent);
+
   return (
     <div className="p-4">
-      <StyledMarkdown content={mdContent} />
+      {splitMdContent.map((section, index) => (
+        <StyledMarkdown key={index} content={section} />
+      ))}
       <ChatForm />
     </div>
   );

app/[docs_id]/splitMarkdown.ts

@@ -0,0 +1,31 @@
+"use server";
+
+import { unified } from "unified";
+import remarkParse from "remark-parse";
+import remarkGfm from "remark-gfm";
+
+export async function splitMarkdown(content: string): Promise<string[]> {
+  const tree = unified().use(remarkParse).use(remarkGfm).parse(content);
+  // console.log(tree.children.map(({ type, position }) => ({ type, position: JSON.stringify(position) })));
+  const headingNodes = tree.children.filter((node) => node.type === "heading");
+  const splitContent = content.split("\n");
+  const sections: string[] = [];
+  for (let i = 0; i < headingNodes.length; i++) {
+    const startLine = headingNodes.at(i)?.position?.start.line;
+    if (startLine === undefined) {
+      continue;
+    }
+    let endLine: number | undefined = undefined;
+    for (let j = i + 1; j < headingNodes.length; j++) {
+      if (headingNodes.at(j)?.position?.start.line !== undefined) {
+        endLine = headingNodes.at(j)!.position!.start.line;
+        break;
+      }
+    }
+    const sectionContent = splitContent
+      .slice(startLine - 1, endLine !== undefined ? endLine - 1 : undefined)
+      .join("\n");
+    sections.push(sectionContent);
+  }
+  return sections;
+}