feat: Segment article text for improved playback

Splits article content into smaller audio segments. This allows for more granular control over playback, faster processing, and improved user experience by enabling auto-scrolling to the currently read segment.

Updates `types.ts` to include `AudioSegment` interface and modify `Article` to hold `segments`, `currentSegmentIndex`, and `audioUrl` per segment.

Introduces `segmentText` utility in `services/textUtils.ts` for robust text segmentation logic.

Modifies `App.tsx` to utilize the new segmentation approach for fetching and processing audio.

Enhances `components/ReaderView.tsx` to display and auto-scroll through segmented text, highlighting the current segment during playback.

App.tsx

@@ -1,10 +1,12 @@
+
 import React, { useState, useRef, useEffect, useCallback } from 'react';
 import { v4 as uuidv4 } from 'uuid';
 import { Plus, Play, Pause, SkipForward, SkipBack, Volume2, Gauge, Layout } from 'lucide-react';
-import { Article, PlaybackStatus, PlayerState, VoiceName } from './types';
+import { Article, PlaybackStatus, PlayerState, VoiceName, AudioSegment } from './types';
 import { AVAILABLE_VOICES, MIN_SPEED, MAX_SPEED, SPEED_STEP } from './constants';
 import { extractArticleContent, generateSpeechFromText } from './services/geminiService';
 import { base64ToUint8Array, createWavBlob } from './services/audioUtils';
+import { segmentText } from './services/textUtils';
 import { QueueItem } from './components/QueueItem';
 import { VoiceSelector } from './components/VoiceSelector';
 import { ReaderView } from './components/ReaderView';
@@ -13,7 +15,7 @@ export default function App() {
   // -- State --
   const [inputUrl, setInputUrl] = useState('');
   const [queue, setQueue] = useState<Article[]>([]);
-  // Selected article for reading (defaults to playing article)
+  // Selected article for viewing text (separate from playing)
   const [viewId, setViewId] = useState<string | null>(null);
   
   const [playerState, setPlayerState] = useState<PlayerState>({
@@ -25,141 +27,248 @@ export default function App() {
 
   // -- Refs --
   const audioRef = useRef<HTMLAudioElement>(new Audio());
-  const audioSrcRef = useRef<string | null>(null);
+  // Track active processing to prevent duplicate fetch calls
+  const processingRef = useRef<Set<string>>(new Set());
 
   // -- Helpers --
   const getCurrentArticle = () => queue.find(a => a.id === playerState.currentArticleId);
+  
   const getViewingArticle = () => {
-    // If user manually selected an article to view, show that. 
-    // Otherwise show the currently playing one.
-    // Otherwise show the first one.
     if (viewId) return queue.find(a => a.id === viewId);
     if (playerState.currentArticleId) return queue.find(a => a.id === playerState.currentArticleId);
     if (queue.length > 0) return queue[0];
     return null;
   };
-  
+
-  const updateArticleStatus = (id: string, status: PlaybackStatus, errorMessage?: string, audioUrl?: string, title?: string, text?: string) => {
+  // -- State Updaters --
-    setQueue(prev => prev.map(item => {
+
-      if (item.id !== id) return item;
+  const updateArticle = (id: string, updates: Partial<Article>) => {
-      return {
+    setQueue(prev => prev.map(item => item.id === id ? { ...item, ...updates } : item));
-        ...item,
+  };
-        status,
+
-        errorMessage,
+  const updateSegment = (articleId: string, segmentId: string, updates: Partial<AudioSegment>) => {
-        audioUrl: audioUrl || item.audioUrl,
+    setQueue(prev => prev.map(article => {
-        title: title || item.title,
+      if (article.id !== articleId) return article;
-        text: text || item.text
+      
-      };
+      const newSegments = article.segments.map(seg => 
+        seg.id === segmentId ? { ...seg, ...updates } : seg
+      );
+      
+      return { ...article, segments: newSegments };
     }));
   };
 
+  // -- Audio Generation Pipeline --
+
+  /**
+   * Fetches audio for a specific segment.
+   */
+  const processSegmentAudio = useCallback(async (articleId: string, segmentId: string, text: string, voice: VoiceName) => {
+    const uniqueKey = `${articleId}-${segmentId}`;
+    if (processingRef.current.has(uniqueKey)) return;
+    
+    processingRef.current.add(uniqueKey);
+    updateSegment(articleId, segmentId, { isLoading: true });
+
+    try {
+      const base64Audio = await generateSpeechFromText(text, voice);
+      const pcmData = base64ToUint8Array(base64Audio);
+      const wavBlob = createWavBlob(pcmData);
+      const audioUrl = URL.createObjectURL(wavBlob);
+      
+      updateSegment(articleId, segmentId, { audioUrl, isLoading: false });
+    } catch (error) {
+      console.error("Segment generation failed", error);
+      updateSegment(articleId, segmentId, { isLoading: false, hasError: true });
+    } finally {
+      processingRef.current.delete(uniqueKey);
+    }
+  }, []);
+
+  /**
+   * Manages the buffer. ensure current segment + next 2 are ready.
+   */
+  const manageBuffer = useCallback(async (article: Article) => {
+    const currentIndex = article.currentSegmentIndex;
+    const segmentsToBuffer = article.segments.slice(currentIndex, currentIndex + 3);
+
+    for (const seg of segmentsToBuffer) {
+      if (!seg.audioUrl && !seg.isLoading && !seg.hasError) {
+        // No await here - we want them to fire in parallel/background
+        processSegmentAudio(article.id, seg.id, seg.text, playerState.selectedVoice);
+      }
+    }
+  }, [playerState.selectedVoice, processSegmentAudio]);
+
   // -- Handlers --
 
-  // 1. Add URL to Queue
   const handleAddUrl = async () => {
     if (!inputUrl.trim()) return;
+    
     const id = uuidv4();
     const newArticle: Article = {
       id,
       url: inputUrl,
       title: 'Fetching info...',
       text: '',
+      segments: [],
+      currentSegmentIndex: 0,
       status: PlaybackStatus.LOADING_TEXT
     };
     
     setQueue(prev => [...prev, newArticle]);
     setInputUrl('');
-    // Auto view the new article while loading
+    if (!playerState.isPlaying) setViewId(id);
-    if (!playerState.isPlaying) {
-        setViewId(id);
-    }
 
-    // Start fetching text immediately
     try {
       const { title, text } = await extractArticleContent(newArticle.url);
-      updateArticleStatus(id, PlaybackStatus.IDLE, undefined, undefined, title, text);
-    } catch (error: any) {
-      updateArticleStatus(id, PlaybackStatus.ERROR, error.message || "Failed to load article");
-    }
-  };
-
-  // 2. Generate Audio for an article
-  const prepareAudio = async (articleId: string): Promise<string | null> => {
-    const article = queue.find(a => a.id === articleId);
-    if (!article) return null;
-    
-    // If already has audio return it
-    if (article.audioUrl) return article.audioUrl;
-
-    updateArticleStatus(articleId, PlaybackStatus.LOADING_AUDIO);
-
-    try {
-      if (!article.text || article.text.length < 10) {
-          throw new Error("No text available to read.");
-      }
-      const base64Audio = await generateSpeechFromText(article.text, playerState.selectedVoice);
-      const pcmData = base64ToUint8Array(base64Audio);
-      const wavBlob = createWavBlob(pcmData);
-      const audioUrl = URL.createObjectURL(wavBlob);
       
-      updateArticleStatus(articleId, PlaybackStatus.READY, undefined, audioUrl);
+      // 1. Split text into segments immediately
-      return audioUrl;
+      const segments = segmentText(text);
+      
+      updateArticle(id, {
+        title,
+        text,
+        segments,
+        status: PlaybackStatus.LOADING_AUDIO
+      });
+
+      // 2. Trigger audio for the first segment immediately
+      if (segments.length > 0) {
+        // We manually call the processor for the first one to ensure fast start
+        const firstSeg = segments[0];
+        await processSegmentAudio(id, firstSeg.id, firstSeg.text, playerState.selectedVoice);
+        
+        // Once first segment is ready, we are effectively ready to play
+        updateArticle(id, { status: PlaybackStatus.READY });
+        
+        // If nothing else is playing, auto-play this
+        setQueue(prev => {
+            const current = prev.find(a => a.id === id);
+            if (current && current.segments[0].audioUrl && !playerState.isPlaying) {
+                playArticle(id);
+            }
+            return prev;
+        });
+      } else {
+         updateArticle(id, { status: PlaybackStatus.ERROR, errorMessage: "No readable text found." });
+      }
+
     } catch (error: any) {
-      updateArticleStatus(articleId, PlaybackStatus.ERROR, error.message || "Failed to generate speech");
+      updateArticle(id, { 
-      return null;
+        status: PlaybackStatus.ERROR, 
+        errorMessage: error.message || "Failed to load article" 
+      });
     }
   };
 
-  // 3. Play Logic
+  // -- Playback Control --
+
   const playArticle = useCallback(async (id: string) => {
-    const article = queue.find(a => a.id === id);
-    if (!article) return;
-
-    // If currently playing a different one, pause it.
-    if (playerState.currentArticleId && playerState.currentArticleId !== id) {
-      audioRef.current.pause();
-    }
-
     setPlayerState(prev => ({ ...prev, currentArticleId: id, isPlaying: true }));
-    // Also switch view to the playing article
     setViewId(id);
+    updateArticle(id, { status: PlaybackStatus.PLAYING });
     
-    let src = article.audioUrl;
+    // The actual audio switching is handled by the useEffect monitoring currentArticleId + currentSegmentIndex
-    
+  }, []);
-    // Check if we need to generate audio
-    if (!src) {
-      src = await prepareAudio(id);
-    }
-
-    if (src) {
-      // Only update src if it's different to avoid reload
-      if (audioSrcRef.current !== src) {
-        audioRef.current.src = src;
-        audioSrcRef.current = src;
-        // Apply current speed
-        audioRef.current.playbackRate = playerState.playbackRate;
-      }
-      
-      try {
-        await audioRef.current.play();
-        updateArticleStatus(id, PlaybackStatus.PLAYING);
-      } catch (e) {
-        console.error("Play error", e);
-        setPlayerState(prev => ({ ...prev, isPlaying: false }));
-      }
-    }
-  }, [queue, playerState.currentArticleId, playerState.playbackRate, playerState.selectedVoice]);
 
   const pausePlayback = useCallback(() => {
     audioRef.current.pause();
     setPlayerState(prev => ({ ...prev, isPlaying: false }));
     if (playerState.currentArticleId) {
-      updateArticleStatus(playerState.currentArticleId, PlaybackStatus.PAUSED);
+      updateArticle(playerState.currentArticleId, { status: PlaybackStatus.PAUSED });
     }
   }, [playerState.currentArticleId]);
 
+  // -- Effects --
+
+  // 1. Audio Player Loop
+  // This effect reacts to changes in article/segment index and loads the correct audio source
+  useEffect(() => {
+    const article = queue.find(a => a.id === playerState.currentArticleId);
+    if (!article || !playerState.isPlaying) return;
+
+    const currentSegment = article.segments[article.currentSegmentIndex];
+    
+    // If finished all segments
+    if (!currentSegment) {
+      updateArticle(article.id, { status: PlaybackStatus.COMPLETED });
+      setPlayerState(prev => ({ ...prev, isPlaying: false }));
+      return;
+    }
+
+    // Check if audio is ready
+    if (currentSegment.audioUrl) {
+        // Only switch src if we aren't already playing it
+        // We use a custom attribute on the audio element to track current url to avoid state race conditions
+        const audioEl = audioRef.current;
+        const currentSrc = audioEl.getAttribute('data-current-src');
+        
+        if (currentSrc !== currentSegment.audioUrl) {
+            audioEl.src = currentSegment.audioUrl;
+            audioEl.setAttribute('data-current-src', currentSegment.audioUrl);
+            audioEl.playbackRate = playerState.playbackRate;
+            audioEl.play().catch(e => console.warn("Playback interrupted", e));
+        } else if (audioEl.paused) {
+            audioEl.play().catch(e => console.warn("Resume failed", e));
+        }
+    } else {
+        // Buffer stalled?
+        // If it's loading, show loading state. If not loading and no url, trigger load.
+        if (!currentSegment.isLoading && !currentSegment.hasError) {
+            processSegmentAudio(article.id, currentSegment.id, currentSegment.text, playerState.selectedVoice);
+        }
+    }
+
+    // Always try to buffer ahead
+    manageBuffer(article);
+
+  }, [queue, playerState.currentArticleId, playerState.isPlaying, playerState.playbackRate, playerState.selectedVoice, manageBuffer, processSegmentAudio]);
+
+
+  // 2. Handle 'Ended' event to advance segment
+  useEffect(() => {
+    const audio = audioRef.current;
+    
+    const handleEnded = () => {
+      const currentId = playerState.currentArticleId;
+      // We need to get the *latest* queue state to find the current index
+      // Since we can't easily access 'queue' inside this event listener without recreating the listener constantly,
+      // we rely on the state setters functional update or a ref. 
+      // However, for simplicity in this specific React structure, let's use the state update pattern.
+      
+      setQueue(prevQueue => {
+        const article = prevQueue.find(a => a.id === currentId);
+        if (!article) return prevQueue;
+
+        const nextIndex = article.currentSegmentIndex + 1;
+        
+        // If we have a next segment, advance index
+        if (nextIndex < article.segments.length) {
+           return prevQueue.map(a => a.id === currentId ? { ...a, currentSegmentIndex: nextIndex } : a);
+        } else {
+           // Article finished
+           // Try to play next article in queue
+           const artIndex = prevQueue.findIndex(a => a.id === currentId);
+           if (artIndex !== -1 && artIndex < prevQueue.length - 1) {
+             // Queue next article
+             setTimeout(() => playArticle(prevQueue[artIndex + 1].id), 100); // Small delay to let state settle
+             return prevQueue.map(a => a.id === currentId ? { ...a, status: PlaybackStatus.COMPLETED } : a);
+           } else {
+             // End of queue
+             setPlayerState(ps => ({ ...ps, isPlaying: false }));
+             return prevQueue.map(a => a.id === currentId ? { ...a, status: PlaybackStatus.COMPLETED } : a);
+           }
+        }
+      });
+    };
+
+    audio.addEventListener('ended', handleEnded);
+    return () => audio.removeEventListener('ended', handleEnded);
+  }, [playerState.currentArticleId, playArticle]); // removed 'queue' from dependency to avoid re-attaching listener on every segment update
+
+  // 3. Handle Speed Change
   const handleSpeedChange = (newSpeed: number) => {
-    // Clamp
     const speed = Math.max(MIN_SPEED, Math.min(MAX_SPEED, newSpeed));
     setPlayerState(prev => ({ ...prev, playbackRate: speed }));
     if (audioRef.current) {
@@ -167,32 +276,6 @@ export default function App() {
     }
   };
 
-  // Auto-Advance Logic
-  useEffect(() => {
-    const audio = audioRef.current;
-    
-    const handleEnded = () => {
-      const currentId = playerState.currentArticleId;
-      if (currentId) {
-        updateArticleStatus(currentId, PlaybackStatus.COMPLETED);
-        
-        // Find next
-        const currentIndex = queue.findIndex(a => a.id === currentId);
-        if (currentIndex !== -1 && currentIndex < queue.length - 1) {
-          const nextId = queue[currentIndex + 1].id;
-          playArticle(nextId);
-        } else {
-          setPlayerState(prev => ({ ...prev, isPlaying: false }));
-        }
-      }
-    };
-
-    audio.addEventListener('ended', handleEnded);
-    return () => {
-      audio.removeEventListener('ended', handleEnded);
-    };
-  }, [playerState.currentArticleId, queue, playArticle]);
-
 
   // -- Render --
   
@@ -219,12 +302,12 @@ export default function App() {
         </div>
       </header>
 
-      {/* Main Content - Split Layout */}
+      {/* Main Content */}
       <main className="flex-grow px-4 py-6 max-w-7xl mx-auto w-full grid grid-cols-1 lg:grid-cols-12 gap-8">
         
-        {/* Left Column: Controls & Queue (5 cols) */}
+        {/* Left Column: Controls & Queue */}
         <div className="lg:col-span-5 space-y-6">
-            {/* Input Section */}
+            {/* Input */}
             <div className="bg-white p-1 rounded-2xl shadow-sm border border-slate-200 flex gap-2 items-center pl-4">
             <input 
                 type="url" 
@@ -267,8 +350,8 @@ export default function App() {
                             onPause={pausePlayback}
                             onRemove={() => {
                                 if (playerState.currentArticleId === article.id) {
-                                pausePlayback();
+                                    pausePlayback();
-                                setPlayerState(prev => ({ ...prev, currentArticleId: null }));
+                                    setPlayerState(prev => ({ ...prev, currentArticleId: null }));
                                 }
                                 setQueue(prev => prev.filter(a => a.id !== article.id));
                                 if (viewId === article.id) setViewId(null);
@@ -281,12 +364,11 @@ export default function App() {
             </div>
         </div>
 
-        {/* Right Column: Reader View (7 cols) */}
+        {/* Right Column: Reader View */}
         <div className="lg:col-span-7 h-full hidden lg:block">
             <ReaderView article={viewingArticle} />
         </div>
         
-        {/* Mobile: Reader View appears below if selected */}
         <div className="lg:hidden block">
              {viewingArticle && (
                  <div className="mt-8">
@@ -299,26 +381,31 @@ export default function App() {
         </div>
       </main>
 
-      {/* Sticky Player */}
+      {/* Player Bar */}
       <div className="fixed bottom-0 left-0 right-0 bg-white/90 backdrop-blur-lg border-t border-slate-200 p-4 pb-6 shadow-[0_-4px_20px_rgba(0,0,0,0.05)] z-30">
         <div className="max-w-7xl mx-auto flex flex-col sm:flex-row items-center gap-4 sm:gap-8">
           
-          {/* Current Track Info */}
           <div className="flex-grow w-full sm:w-auto min-w-0 text-center sm:text-left">
             {currentArticle ? (
               <div>
                 <h4 className="font-bold text-slate-900 truncate">{currentArticle.title}</h4>
-                <p className="text-xs text-slate-500 truncate">Playing from queue</p>
+                {/* Progress Bar for current segment */}
+                <div className="w-full h-1 bg-slate-200 rounded-full mt-2 overflow-hidden">
+                    <div 
+                        className="h-full bg-blue-500 transition-all duration-300"
+                        style={{ width: `${((currentArticle.currentSegmentIndex + 1) / Math.max(1, currentArticle.segments.length)) * 100}%`}}
+                    />
+                </div>
+                <p className="text-xs text-slate-500 truncate mt-1">
+                    Playing segment {currentArticle.currentSegmentIndex + 1} of {currentArticle.segments.length}
+                </p>
               </div>
             ) : (
               <div className="text-slate-400 text-sm font-medium">Ready to play</div>
             )}
           </div>
 
-          {/* Controls */}
           <div className="flex items-center gap-6">
-            
-            {/* Speed Control */}
             <div className="hidden sm:flex items-center gap-2 group relative">
                <Gauge className="w-4 h-4 text-slate-400" />
                <div className="flex items-center gap-2 bg-slate-100 rounded-lg p-1">
@@ -334,15 +421,19 @@ export default function App() {
                </div>
             </div>
 
-            {/* Main Transport */}
             <div className="flex items-center gap-4">
               <button 
                 className="p-2 text-slate-400 hover:text-slate-600 transition-colors"
                 onClick={() => {
-                   const idx = queue.findIndex(a => a.id === playerState.currentArticleId);
+                   if (currentArticle && currentArticle.currentSegmentIndex > 0) {
-                   if (idx > 0) playArticle(queue[idx - 1].id);
+                       // Go back one segment
+                       setQueue(prev => prev.map(a => a.id === currentArticle.id ? { ...a, currentSegmentIndex: a.currentSegmentIndex - 1 } : a));
+                   } else {
+                       // Prev article
+                       const idx = queue.findIndex(a => a.id === playerState.currentArticleId);
+                       if (idx > 0) playArticle(queue[idx - 1].id);
+                   }
                 }}
-                disabled={!playerState.currentArticleId || queue.findIndex(a => a.id === playerState.currentArticleId) <= 0}
               >
                 <SkipBack className="w-5 h-5" />
               </button>
@@ -362,10 +453,15 @@ export default function App() {
               <button 
                 className="p-2 text-slate-400 hover:text-slate-600 transition-colors"
                 onClick={() => {
-                   const idx = queue.findIndex(a => a.id === playerState.currentArticleId);
+                   if (currentArticle && currentArticle.currentSegmentIndex < currentArticle.segments.length - 1) {
-                   if (idx !== -1 && idx < queue.length - 1) playArticle(queue[idx + 1].id);
+                       // Next segment
+                       setQueue(prev => prev.map(a => a.id === currentArticle.id ? { ...a, currentSegmentIndex: a.currentSegmentIndex + 1 } : a));
+                   } else {
+                       // Next article
+                       const idx = queue.findIndex(a => a.id === playerState.currentArticleId);
+                       if (idx !== -1 && idx < queue.length - 1) playArticle(queue[idx + 1].id);
+                   }
                 }}
-                disabled={!playerState.currentArticleId || queue.findIndex(a => a.id === playerState.currentArticleId) >= queue.length - 1}
               >
                 <SkipForward className="w-5 h-5" />
               </button>

components/ReaderView.tsx

@@ -1,4 +1,5 @@
-import React from 'react';
+
+import React, { useEffect, useRef } from 'react';
 import { Article } from '../types';
 import { FileText } from 'lucide-react';
 
@@ -7,6 +8,18 @@ interface ReaderViewProps {
 }
 
 export const ReaderView: React.FC<ReaderViewProps> = ({ article }) => {
+  const scrollRef = useRef<HTMLDivElement>(null);
+
+  // Auto-scroll to active segment
+  useEffect(() => {
+    if (!article || article.status !== 'PLAYING') return;
+    
+    const activeEl = document.getElementById(`segment-${article.currentSegmentIndex}`);
+    if (activeEl && scrollRef.current) {
+      activeEl.scrollIntoView({ behavior: 'smooth', block: 'center' });
+    }
+  }, [article?.currentSegmentIndex, article?.status]);
+
   if (!article) {
     return (
       <div className="h-full flex flex-col items-center justify-center text-slate-400 p-12 border-2 border-dashed border-slate-200 rounded-2xl bg-slate-50/50">
@@ -17,11 +30,6 @@ export const ReaderView: React.FC<ReaderViewProps> = ({ article }) => {
     );
   }
 
-  // Split text by newlines to create paragraphs
-  const paragraphs = article.text 
-    ? article.text.split('\n').filter(p => p.trim().length > 0)
-    : [];
-
   return (
     <div className="bg-white rounded-2xl border border-slate-200 shadow-sm overflow-hidden h-[calc(100vh-12rem)] flex flex-col">
       <div className="p-6 border-b border-slate-100 bg-white sticky top-0 z-10">
@@ -38,18 +46,34 @@ export const ReaderView: React.FC<ReaderViewProps> = ({ article }) => {
         </a>
       </div>
       
-      <div className="flex-grow overflow-y-auto p-6 sm:p-8 space-y-6 custom-scrollbar bg-white">
+      <div ref={scrollRef} className="flex-grow overflow-y-auto p-6 sm:p-8 space-y-6 custom-scrollbar bg-white">
-        {paragraphs.length > 0 ? (
+        {article.segments.length > 0 ? (
-          paragraphs.map((paragraph, idx) => (
+          article.segments.map((segment, idx) => {
-            <p key={idx} className="text-lg text-slate-700 leading-relaxed font-serif">
+            const isActive = article.currentSegmentIndex === idx;
-              {paragraph}
+            return (
-            </p>
+              <p 
-          ))
+                key={segment.id} 
+                id={`segment-${idx}`}
+                className={`text-lg leading-relaxed font-serif transition-colors duration-300 ${
+                  isActive 
+                    ? 'text-slate-900 bg-blue-50 p-2 rounded-lg -mx-2 border-l-4 border-blue-500' 
+                    : 'text-slate-700'
+                }`}
+              >
+                {segment.text}
+              </p>
+            );
+          })
         ) : (
+          // Loading State skeleton
           <div className="space-y-4 animate-pulse">
-            <div className="h-4 bg-slate-100 rounded w-3/4"></div>
+             {[1,2,3,4].map(i => (
-            <div className="h-4 bg-slate-100 rounded w-full"></div>
+                 <div key={i} className="space-y-2">
-            <div className="h-4 bg-slate-100 rounded w-5/6"></div>
+                    <div className="h-4 bg-slate-100 rounded w-full"></div>
+                    <div className="h-4 bg-slate-100 rounded w-full"></div>
+                    <div className="h-4 bg-slate-100 rounded w-3/4"></div>
+                 </div>
+             ))}
             <p className="text-slate-400 italic mt-4">Extracting article content...</p>
           </div>
         )}

services/textUtils.ts

@@ -0,0 +1,60 @@
+
+import { v4 as uuidv4 } from 'uuid';
+import { AudioSegment } from '../types';
+
+/**
+ * Splits a long text string into manageable segments for audio generation.
+ * It prioritizes splitting by newlines (paragraphs), then by sentence endings
+ * if a paragraph is too long.
+ */
+export const segmentText = (fullText: string): AudioSegment[] => {
+  if (!fullText) return [];
+
+  // 1. Split by double newlines (paragraphs)
+  const rawParagraphs = fullText.split(/\n\s*\n/);
+  
+  const segments: AudioSegment[] = [];
+
+  for (const rawPara of rawParagraphs) {
+    const cleanPara = rawPara.trim();
+    if (!cleanPara) continue;
+
+    // If paragraph is reasonably sized (< 500 chars), keep it as one
+    if (cleanPara.length < 500) {
+      segments.push({
+        id: uuidv4(),
+        text: cleanPara,
+        isLoading: false,
+        hasError: false
+      });
+    } else {
+      // If paragraph is huge, split by sentences to avoid timeouts
+      const sentences = cleanPara.match(/[^.!?]+[.!?]+["']?|.+/g) || [cleanPara];
+      let currentChunk = "";
+
+      for (const sentence of sentences) {
+        if (currentChunk.length + sentence.length > 400) {
+          segments.push({
+            id: uuidv4(),
+            text: currentChunk.trim(),
+            isLoading: false,
+            hasError: false
+          });
+          currentChunk = sentence;
+        } else {
+          currentChunk += " " + sentence;
+        }
+      }
+      if (currentChunk.trim()) {
+        segments.push({
+          id: uuidv4(),
+          text: currentChunk.trim(),
+          isLoading: false,
+          hasError: false
+        });
+      }
+    }
+  }
+
+  return segments;
+};

types.ts

@@ -1,3 +1,4 @@
+
 export enum VoiceName {
   Puck = 'Puck',
   Charon = 'Charon',
@@ -17,12 +18,23 @@ export enum PlaybackStatus {
   COMPLETED = 'COMPLETED'
 }
 
+export interface AudioSegment {
+  id: string;
+  text: string;
+  audioUrl?: string; // Blob URL for this specific segment
+  isLoading: boolean;
+  hasError: boolean;
+}
+
 export interface Article {
   id: string;
   url: string;
   title: string;
+  // We keep the full text for display/reference
   text: string;
-  audioUrl?: string; // Blob URL for the WAV file
+  // We split content into segments for faster playback
+  segments: AudioSegment[];
+  currentSegmentIndex: number; 
   status: PlaybackStatus;
   errorMessage?: string;
 }
@@ -32,4 +44,4 @@ export interface PlayerState {
   playbackRate: number;
   currentArticleId: string | null;
   selectedVoice: VoiceName;
-}
+}