From 90df14c545125a4c6fe369f2fa0ac02e0a9a6c1f Mon Sep 17 00:00:00 2001
From: Arik Chakma <arikchangma@gmail.com>
Date: Tue, 27 Feb 2024 23:30:41 +0600
Subject: [PATCH] feat: add roadmap stream

---
 .../GenerateRoadmap/GenerateRoadmap.tsx       | 47 ++++++++++++++-----
 src/helper/read-stream.ts                     | 36 ++++++++++++++
 2 files changed, 72 insertions(+), 11 deletions(-)
 create mode 100644 src/helper/read-stream.ts

diff --git a/src/components/GenerateRoadmap/GenerateRoadmap.tsx b/src/components/GenerateRoadmap/GenerateRoadmap.tsx
index f1eea024d..6147d3eaf 100644
--- a/src/components/GenerateRoadmap/GenerateRoadmap.tsx
+++ b/src/components/GenerateRoadmap/GenerateRoadmap.tsx
@@ -2,9 +2,11 @@ import { useRef, useState, type FormEvent } from 'react';
 import './GenerateRoadmap.css';
 import { httpPost } from '../../lib/http';
 import { useToast } from '../../hooks/use-toast';
-import { generateRoadmapFromJSON } from '../../../editor/utils/roadmap-generator';
+import { generateAIRoadmapFromText } from '../../../editor/utils/roadmap-generator';
 import { renderFlowJSON } from '../../../editor/renderer/renderer';
 import { replaceChildren } from '../../lib/dom';
+import { readAIRoadmapStream } from '../../helper/read-stream';
+import { removeAuthToken } from '../../lib/jwt';
 
 export function GenerateRoadmap() {
   const roadmapContainerRef = useRef<HTMLDivElement>(null);
@@ -18,24 +20,47 @@ export function GenerateRoadmap() {
     e.preventDefault();
     setIsLoading(true);
 
-    const { response, error } = await httpPost(
-      `${import.meta.env.PUBLIC_API_URL}/v1-generate-roadmap`,
+    const response = await fetch(
+      `${import.meta.env.PUBLIC_API_URL}/v1-generate-ai-roadmap`,
       {
-        title: roadmapName,
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+        },
+        credentials: 'include',
+        body: JSON.stringify({ title: roadmapName }),
       },
     );
 
-    if (error || !response) {
+    if (!response.ok) {
+      const data = await response.json();
+
+      toast.error(data?.message || 'Something went wrong');
       setIsLoading(false);
-      toast.error(error?.message || 'Something went wrong');
-      return;
+
+      // Logout user if token is invalid
+      if (data.status === 401) {
+        removeAuthToken();
+        window.location.reload();
+      }
     }
 
-    const { nodes, edges } = generateRoadmapFromJSON(response as any);
-    const svg = await renderFlowJSON({ nodes, edges });
-    if (roadmapContainerRef?.current) {
-      replaceChildren(roadmapContainerRef?.current, svg);
+    const reader = response.body?.getReader();
+
+    if (!reader) {
+      setIsLoading(false);
+      toast.error('Something went wrong');
+      return;
     }
+
+    await readAIRoadmapStream(reader, async (result) => {
+      const { nodes, edges } = generateAIRoadmapFromText(result);
+      const svg = await renderFlowJSON({ nodes, edges });
+      if (roadmapContainerRef?.current) {
+        replaceChildren(roadmapContainerRef?.current, svg);
+      }
+    });
+
     setIsLoading(false);
   };
 
diff --git a/src/helper/read-stream.ts b/src/helper/read-stream.ts
new file mode 100644
index 000000000..08aceebf7
--- /dev/null
+++ b/src/helper/read-stream.ts
@@ -0,0 +1,36 @@
+const NEW_LINE = '\n'.charCodeAt(0);
+
+export async function readAIRoadmapStream(
+  reader: ReadableStreamDefaultReader<Uint8Array>,
+  renderRoadmap: (roadmap: string) => void,
+) {
+  const decoder = new TextDecoder('utf-8');
+  let result = '';
+
+  while (true) {
+    const { value, done } = await reader.read();
+    if (done) {
+      break;
+    }
+
+    // We will call the renderRoadmap callback whenever we encounter
+    // a new line with the result until the new line
+    // otherwise, we will keep appending the result to the previous result
+    if (value) {
+      let start = 0;
+      for (let i = 0; i < value.length; i++) {
+        if (value[i] === NEW_LINE) {
+          result += decoder.decode(value.slice(start, i + 1));
+          renderRoadmap(result);
+          start = i + 1;
+        }
+      }
+      if (start < value.length) {
+        result += decoder.decode(value.slice(start));
+      }
+    }
+  }
+
+  reader.releaseLock();
+  renderRoadmap(result);
+}