refactor: extract magic numbers to named constants for better readability

Limits.ts

@@ -1,26 +1,68 @@
-// PROJECT FREE 
+// ============================================================
+// Project Limits - Free Tier
+// ============================================================
+
+/** Maximum number of projects a free-tier user can create */
 export const maxNumberOfProjectsFree = 1;
-export const maxProjectSizeFree = 25000;
-export const maxNumberOfProjectChatsFree = 3; 
 
-// PROJECT PRO 
+/** Maximum project size in characters for free-tier users */
+export const maxProjectSizeFree = 25_000;
+
+/** Maximum number of chats per project for free-tier users */
+export const maxNumberOfProjectChatsFree = 3;
+
+// ============================================================
+// Project Limits - Pro Tier
+// ============================================================
+
+/** Maximum number of projects a pro-tier user can create */
 export const maxNumberOfProjectsPro = 15;
-export const maxProjectSizePro = 100000;
+
+/** Maximum project size in characters for pro-tier users */
+export const maxProjectSizePro = 100_000;
+
+/** Maximum number of chats per project for pro-tier users */
 export const maxNumberOfProjectChatsPro = 100;
 
-// REGENERATE ARCHITECTURE FREE
+// ============================================================
+// Architecture Regeneration Limits - Free Tier
+// ============================================================
+
+/** Maximum number of files changed allowed per regeneration for free-tier users */
 export const maxFilesChangedFree = 50;
-export const maxLinesChangedFree = 5000;
+
+/** Maximum number of lines changed allowed per regeneration for free-tier users */
+export const maxLinesChangedFree = 5_000;
+
+/** Maximum number of architecture regenerations for free-tier users */
 export const maxFreeArchitectureRegenerations = 5;
 
-// REGENERATE ARCHITECTURE PRO
+// ============================================================
+// Architecture Regeneration Limits - Pro Tier
+// ============================================================
+
+/** Maximum number of files changed allowed per regeneration for pro-tier users */
 export const maxFilesChangedPro = 300;
-export const maxLinesChangedPro = 50000;
 
-// CHAT FREE 
+/** Maximum number of lines changed allowed per regeneration for pro-tier users */
+export const maxLinesChangedPro = 50_000;
+
+// ============================================================
+// Chat Limits - Free Tier
+// ============================================================
+
+/** Maximum number of chats for free-tier users */
 export const maxFreeChats = 3;
-export const maxChatCharactersLimitFree = 20000;
 
-// CHAT PRO 
-export const maxProChats = 100; 
-export const maxChatCharactersLimitPro = 100000; 
+/** Maximum total characters across all messages in a chat for free-tier users */
+export const maxChatCharactersLimitFree = 20_000;
+
+// ============================================================
+// Chat Limits - Pro Tier
+// ============================================================
+
+/** Maximum number of chats for pro-tier users */
+export const maxProChats = 100;
+
+/** Maximum total characters across all messages in a chat for pro-tier users */
+export const maxChatCharactersLimitPro = 100_000;

actions/chat.ts

@@ -3,6 +3,7 @@
 import { db } from "@/lib/db";
 import { auth } from "@clerk/nextjs/server";
 import { revalidatePath } from "next/cache";
+import { CHAT_TITLE_FROM_MESSAGE_LENGTH } from "@/constants";
 
 export interface ChatMessage {
   id: string;
@@ -50,8 +51,8 @@ export async function createChatWithId(chatId: string, initialMessage: string) {
         id: chatId,
         userId: userId,
         messages: [initialMessageObj] as any,
-        title: initialMessage.length > 50 
-          ? initialMessage.substring(0, 50) + "..." 
+        title: initialMessage.length > CHAT_TITLE_FROM_MESSAGE_LENGTH
+          ? initialMessage.substring(0, CHAT_TITLE_FROM_MESSAGE_LENGTH) + "..."
           : initialMessage,
       },
     });

actions/project.ts

@@ -6,6 +6,7 @@ import { ChatOpenAI } from "@langchain/openai";
 import { PromptTemplate } from "@langchain/core/prompts";
 import { StringOutputParser } from "@langchain/core/output_parsers";
 import { generateEasyMediumPrompt, generateNthProjectPhase, generateProjectPlanDocs, initialDocsGenerationPrompt, ultraProjectChatBotPrompt } from "../prompts/ReverseArchitecture";
+import { LATEST_ARCHITECTURES_FETCH_LIMIT, CHAT_TITLE_PREVIEW_LENGTH } from "@/constants";
 const openaiKey = process.env.OPENAI_API_KEY;
 const llm = new ChatOpenAI({
   openAIApiKey: openaiKey,
@@ -68,7 +69,7 @@ export async function getProject(projectId: string) {
                 orderBy: {
                     createdAt: 'desc', // Latest first
                 },
-                take: 5, // Only fetch latest 5
+                take: LATEST_ARCHITECTURES_FETCH_LIMIT,
             },
             detailedAnalysis: true,
             ProjectChat: {
@@ -333,8 +334,8 @@ export async function addMessageToProjectChat(projectId: string, chatId: string,
 
         // If this is a user message and it's the first message in the chat, update the title
         if (message.type === 'user' && currentMessages.length === 0) {
-            const title = message.content.length > 20 
-                ? message.content.substring(0, 20) + '...' 
+            const title = message.content.length > CHAT_TITLE_PREVIEW_LENGTH
+                ? message.content.substring(0, CHAT_TITLE_PREVIEW_LENGTH) + '...'
                 : message.content;
             updateData.title = title;
         }
@@ -663,8 +664,8 @@ export async function saveInitialMessageForInngestRevArchitecture(
         };
 
         // Title from initial message
-        const title = initialMessage.length > 20
-            ? initialMessage.substring(0, 20) + '...'
+        const title = initialMessage.length > CHAT_TITLE_PREVIEW_LENGTH
+            ? initialMessage.substring(0, CHAT_TITLE_PREVIEW_LENGTH) + '...'
             : initialMessage;
 
         const updatedProjectChat = await db.projectChat.update({

actions/projectDocs.ts

@@ -15,13 +15,22 @@ import { webResearchAgentPrompt, summarizeProjectDocsContextPrompt } from "../pr
 import openai from "openai";
 
 import { RunnableLambda } from "@langchain/core/runnables";
+import {
+    DEFAULT_MAX_INPUT_TOKENS,
+    DEFAULT_MAX_OUTPUT_TOKENS,
+    WEB_SEARCH_MAX_INPUT_TOKENS,
+    WEB_SEARCH_MAX_OUTPUT_TOKENS,
+    MIN_REMAINING_TOKENS_THRESHOLD,
+    FALLBACK_TRUNCATION_LENGTH,
+    TOKEN_TRUNCATION_SAFETY_MARGIN,
+} from "@/constants";
 
 // Custom context window manager class
 class ContextWindowManager {
     private maxInputTokens: number;
     private maxOutputTokens: number;
 
-    constructor(maxInputTokens: number = 8000, maxOutputTokens: number = 2000) {
+    constructor(maxInputTokens: number = DEFAULT_MAX_INPUT_TOKENS, maxOutputTokens: number = DEFAULT_MAX_OUTPUT_TOKENS) {
         this.maxInputTokens = maxInputTokens;
         this.maxOutputTokens = maxOutputTokens;
     }
@@ -37,7 +46,7 @@ class ContextWindowManager {
         if (estimatedTokens <= maxTokens) return text;
 
         const ratio = maxTokens / estimatedTokens;
-        const truncatedLength = Math.floor(text.length * ratio * 0.9); // 10% safety margin
+        const truncatedLength = Math.floor(text.length * ratio * TOKEN_TRUNCATION_SAFETY_MARGIN);
         return text.substring(0, truncatedLength) + "...[truncated]";
     }
 
@@ -56,7 +65,7 @@ class ContextWindowManager {
             if (totalTokens + messageTokens > this.maxInputTokens) {
                 // Truncate this message to fit remaining space
                 const remainingTokens = this.maxInputTokens - totalTokens;
-                if (remainingTokens > 100) { // Only include if we have reasonable space
+                if (remainingTokens > MIN_REMAINING_TOKENS_THRESHOLD) {
                     content = this.truncateToTokens(content, remainingTokens);
                     processedMessages.unshift({ ...message, content });
                 }
@@ -132,7 +141,7 @@ export async function summarizeProjectDocsContext(userQuery: string, projectFram
 
 export async function generateWebSearchDocs(summarizedContext: string, framework: string) {
 
-    const contextManager = new ContextWindowManager(12000, 5000);
+    const contextManager = new ContextWindowManager(WEB_SEARCH_MAX_INPUT_TOKENS, WEB_SEARCH_MAX_OUTPUT_TOKENS);
 
 
 
@@ -169,7 +178,7 @@ export async function generateWebSearchDocs(summarizedContext: string, framework
     } catch (error) {
         console.error("Context window exceeded:", error);
         // Fallback with even more aggressive truncation
-        const veryShortContext = truncatedContext.substring(0, 1000);
+        const veryShortContext = truncatedContext.substring(0, FALLBACK_TRUNCATION_LENGTH);
         const response = await chain.invoke({
             summarizedContext: veryShortContext,
             framework: framework

src/app/project/[projectId]/page.tsx

@@ -20,6 +20,24 @@ import { submitFeedback } from '../../../../actions/feedback';
 import { maxChatCharactersLimitFree, maxChatCharactersLimitPro, maxFreeChats, maxNumberOfProjectChatsFree, maxNumberOfProjectChatsPro } from '../../../../Limits';
 import useUserSubscription from '@/hooks/useSubscription';
 import PricingDialog from '@/components/PricingDialog';
+import {
+  POLLING_MAX_ATTEMPTS,
+  POLLING_INITIAL_PHASE_DURATION_MS,
+  POLLING_INITIAL_INTERVAL_MS,
+  POLLING_FINAL_INTERVAL_MS,
+  POSITION_SAVE_DEBOUNCE_MS,
+  FEEDBACK_SUCCESS_CLOSE_DELAY_MS,
+  COPY_FEEDBACK_RESET_DELAY_MS,
+  TEXTAREA_MAX_HEIGHT_PX,
+  PANEL_MIN_WIDTH_PERCENT,
+  PANEL_MAX_WIDTH_PERCENT,
+  MOBILE_BREAKPOINT_PX,
+  TREE_INDENT_PER_DEPTH_PX,
+  TREE_DIRECTORY_PADDING_PX,
+  TREE_FILE_PADDING_PX,
+  CHAT_TITLE_PREVIEW_LENGTH,
+  MAX_PROMPTS_PER_CHAT,
+} from '@/constants';
 
 interface ProjectChat {
   id: bigint;
@@ -174,7 +192,7 @@ const ProjectPage = () => {
         setTimeout(() => {
           setIsFeedbackOpen(false);
           setFeedbackMessage(null);
-        }, 2000);
+        }, FEEDBACK_SUCCESS_CLOSE_DELAY_MS);
       } else {
         setFeedbackMessage({
           type: 'error',
@@ -304,7 +322,7 @@ const ProjectPage = () => {
               className={`flex items-center w-full py-1 px-2 rounded text-left group transition-colors ${
                 isHighlighted ? highlightStyles.bg : 'hover:bg-gray-800/50'
               }`}
-              style={{ paddingLeft: `${depth * 16 + 8}px` }}
+              style={{ paddingLeft: `${depth * TREE_INDENT_PER_DEPTH_PX + TREE_DIRECTORY_PADDING_PX}px` }}
             >
               <ChevronRight
                 className={`h-3 w-3 mr-1 transition-transform duration-200 ${isExpanded ? 'rotate-90' : ''} ${
@@ -340,7 +358,7 @@ const ProjectPage = () => {
             className={`flex items-center py-1 px-2 rounded cursor-default group transition-colors ${
               isHighlighted ? highlightStyles.bg : 'hover:bg-gray-800/50'
             }`}
-            style={{ paddingLeft: `${depth * 16 + 24}px` }}
+            style={{ paddingLeft: `${depth * TREE_INDENT_PER_DEPTH_PX + TREE_FILE_PADDING_PX}px` }}
             title={filePath}
           >
             {getFileIcon(fileName)}
@@ -447,7 +465,7 @@ const ProjectPage = () => {
       clearTimeout(debounceTimerRef.current);
     }
 
-    // Debounced save to database (only save after user stops dragging for 500ms)
+    // Debounced save to database (only save after user stops dragging)
     debounceTimerRef.current = setTimeout(async () => {
       if (projectId) {
         try {
@@ -456,16 +474,16 @@ const ProjectPage = () => {
           console.error('Failed to save positions:', error);
         }
       }
-    }, 500);
+    }, POSITION_SAVE_DEBOUNCE_MS);
   };
 
   // Function to poll for project architecture completion
   const pollForProjectArchitecture = async () => {
-    const maxAttempts = 120; // Poll for up to 10 minutes total
+    const maxAttempts = POLLING_MAX_ATTEMPTS;
     let attempts = 0;
-    const initialPhaseDuration = 4 * 60 * 1000; // 4 minutes in milliseconds
-    const initialPollInterval = 15 * 1000; // 15 seconds for first 4 minutes
-    const finalPollInterval = 5 * 1000; // 5 seconds after 4 minutes
+    const initialPhaseDuration = POLLING_INITIAL_PHASE_DURATION_MS;
+    const initialPollInterval = POLLING_INITIAL_INTERVAL_MS;
+    const finalPollInterval = POLLING_FINAL_INTERVAL_MS;
     const startTime = Date.now();
 
     const poll = async () => {
@@ -575,10 +593,10 @@ const ProjectPage = () => {
       await navigator.clipboard.writeText(prompt);
       setCopiedPrompts(prev => ({ ...prev, [messageId]: true }));
 
-      // Reset the copied state after 2 seconds
+      // Reset the copied state after delay
       setTimeout(() => {
         setCopiedPrompts(prev => ({ ...prev, [messageId]: false }));
-      }, 2000);
+      }, COPY_FEEDBACK_RESET_DELAY_MS);
     } catch (error) {
       console.error('Failed to copy prompt:', error);
     }
@@ -886,7 +904,7 @@ const ProjectPage = () => {
   // Check if mobile on mount and resize
   useEffect(() => {
     const checkMobile = () => {
-      setIsMobile(window.innerWidth < 768);
+      setIsMobile(window.innerWidth < MOBILE_BREAKPOINT_PX);
     };
 
     checkMobile();
@@ -905,7 +923,7 @@ const ProjectPage = () => {
     const totalCharacters = calculateTotalCharacters(messages);
     const existingPromptCount = messages.filter(m => m.type === 'assistant' && (m as any).prompt).length;
     setIsCharacterLimitReached(totalCharacters >= MAX_CHARACTERS);
-    setIsPromptLimitReached(existingPromptCount >= 3);
+    setIsPromptLimitReached(existingPromptCount >= MAX_PROMPTS_PER_CHAT);
   }, [messages]);
 
 
@@ -918,8 +936,8 @@ const ProjectPage = () => {
         const containerWidth = containerRect.width;
         const newLeftWidth = (newX / containerWidth) * 100;
 
-        // Constrain between 25% and 75%
-        const constrainedWidth = Math.min(75, Math.max(25, newLeftWidth));
+        // Constrain between min and max panel width
+        const constrainedWidth = Math.min(PANEL_MAX_WIDTH_PERCENT, Math.max(PANEL_MIN_WIDTH_PERCENT, newLeftWidth));
         setLeftPanelWidth(constrainedWidth);
       }
     };
@@ -949,14 +967,12 @@ const ProjectPage = () => {
     const textarea = e.target;
     textarea.style.height = 'auto';
     const scrollHeight = textarea.scrollHeight;
-    const maxHeight = 180;
-
-    if (scrollHeight <= maxHeight) {
+    if (scrollHeight <= TEXTAREA_MAX_HEIGHT_PX) {
       textarea.style.height = scrollHeight + 'px';
       setTextareaHeight(scrollHeight + 'px');
     } else {
-      textarea.style.height = maxHeight + 'px';
-      setTextareaHeight(maxHeight + 'px');
+      textarea.style.height = TEXTAREA_MAX_HEIGHT_PX + 'px';
+      setTextareaHeight(TEXTAREA_MAX_HEIGHT_PX + 'px');
     }
   };
 
@@ -994,8 +1010,8 @@ const ProjectPage = () => {
 
       // Update chat title in local state if this is the first user message
       if (saveResult.success && messages.length === 0) {
-        const title = currentInput.length > 20 
-          ? currentInput.substring(0, 20) + '...' 
+        const title = currentInput.length > CHAT_TITLE_PREVIEW_LENGTH
+          ? currentInput.substring(0, CHAT_TITLE_PREVIEW_LENGTH) + '...'
           : currentInput;
 
         setProjectChats(prevChats => 

src/app/project/page.tsx

@@ -38,6 +38,13 @@ import { useEffect, useState } from "react"
 import { submitFeedback } from "../../../actions/feedback"
 import Nav from "@/components/core/Nav"
 import GithubOAuthDeprecatedNotice from "@/components/GithubOAuthDeprecatedNotice"
+import {
+  SWR_DEDUPING_INTERVAL_MS,
+  SWR_REFRESH_INTERVAL_MS,
+  SWR_ERROR_RETRY_COUNT,
+  SWR_ERROR_RETRY_INTERVAL_MS,
+  FEEDBACK_SUCCESS_CLOSE_DELAY_MS,
+} from '@/constants'
 
 interface Project {
   id: string;
@@ -74,10 +81,10 @@ export default function ProjectsPage() {
     {
       revalidateOnFocus: false, // Don't refetch when window gains focus
       revalidateOnReconnect: true, // Refetch when reconnecting to the internet
-      dedupingInterval: 60000, // Dedupe requests within 1 minute
-      refreshInterval: 5 * 60 * 1000, // Refresh every 5 minutes
-      errorRetryCount: 3, // Retry on error 3 times
-      errorRetryInterval: 1000, // Wait 1 second between retries
+      dedupingInterval: SWR_DEDUPING_INTERVAL_MS,
+      refreshInterval: SWR_REFRESH_INTERVAL_MS,
+      errorRetryCount: SWR_ERROR_RETRY_COUNT,
+      errorRetryInterval: SWR_ERROR_RETRY_INTERVAL_MS,
     }
   );
 
@@ -102,7 +109,7 @@ export default function ProjectsPage() {
         setTimeout(() => {
           setIsFeedbackOpen(false);
           setFeedbackMessage(null);
-        }, 2000);
+        }, FEEDBACK_SUCCESS_CLOSE_DELAY_MS);
       } else {
         setFeedbackMessage({
           type: 'error',