From 71c43e73ab881dac47c5c2f5fddfe1a708fd90ce Mon Sep 17 00:00:00 2001 From: Atemndobs Date: Tue, 10 Dec 2024 12:27:48 +0100 Subject: [PATCH] docs: add Architecture Decision Document (ADD) This commit adds a comprehensive Architecture Decision Document that includes: - Purpose and scope - Current implementation details - Target architecture - Gap analysis - Implementation plan --- architecture.md | 431 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 431 insertions(+) create mode 100644 architecture.md diff --git a/architecture.md b/architecture.md new file mode 100644 index 0000000..13dd80a --- /dev/null +++ b/architecture.md @@ -0,0 +1,431 @@ +# Architecture Decision Document (ADD) + +## Purpose and Scope + +ReadMe-TTS is a Progressive Web Application (PWA) designed to transform written content into high-quality, natural-sounding speech. The application serves users who prefer consuming content through audio, whether for accessibility needs, multitasking capabilities, or personal preference. + +### Core Purpose +- Convert text content (articles, documents, web pages) into natural-sounding speech +- Provide an accessible, user-friendly interface for content consumption +- Enable offline capabilities for uninterrupted listening experience +- Support multiple voice options and playback customization + +### Target Users +1. **Accessibility Users** + - Individuals with visual impairments + - Users with reading difficulties + - People with learning preferences for audio content + +2. **Multitaskers** + - Professionals consuming content while performing other tasks + - Commuters and travelers + - Users engaging in physical activities + +3. **Content Creators** + - Writers checking content flow through audio + - Content publishers providing audio alternatives + - Educational content providers + +### Key Features +1. **Content Processing** + - Text input support + - URL content extraction + - Smart text segmentation + +2. **Audio Generation** + - High-quality text-to-speech conversion + - Multiple voice options + - Customizable speech parameters + +3. **Playback Experience** + - Seamless audio streaming + - Offline playback support + - Progress tracking and navigation + +4. **Progressive Web App** + - Cross-platform compatibility + - Offline functionality + - Installation capabilities + +### Success Criteria +1. **Performance** + - Fast initial content processing + - Minimal latency in audio generation + - Smooth playback experience + +2. **Accessibility** + - WCAG 2.1 compliance + - Screen reader compatibility + - Keyboard navigation support + +3. **User Experience** + - Intuitive interface + - Reliable offline functionality + - Consistent cross-platform behavior + +## Overview +This document outlines the architectural decisions and design patterns implemented in the ReadMe PWA application. The application is built as a Progressive Web App using modern web technologies and follows best practices for performance, accessibility, and user experience. + +## Tech Stack + +### Core Technologies +- **Next.js 15**: Server-side rendering and routing framework +- **TypeScript**: Static typing and enhanced developer experience +- **React**: UI component library +- **Tailwind CSS**: Utility-first CSS framework +- **Shadcn/UI**: Component library built on Radix UI primitives + +### Key Dependencies +- **@mozilla/readability**: Content parsing and readability enhancement +- **IndexedDB**: Client-side storage for offline capabilities +- **next-themes**: Theme management +- **Radix UI**: Accessible component primitives + +## Application Architecture + +### 1. Directory Structure +``` +src/ +├── app/ # Next.js app router and page components +├── components/ # Reusable React components +├── hooks/ # Custom React hooks +├── lib/ # Core business logic and utilities +├── types/ # TypeScript type definitions +└── utils/ # Helper functions and utilities +``` + +### 2. Key Components + +#### Text Processing and TTS +- **URL Content Fetching**: Implemented through `/api/fetch-url` endpoint +- **Text Segmentation**: Custom implementation in `lib/utils/text-segmentation` +- **TTS Service**: Integrated through `/api/tts` endpoint with retry mechanism +- **Error Handling**: Dedicated error classes for TTS and URL fetching + +#### Audio System +The application implements a robust audio system with the following components: +- **Queue Management**: State management via `lib/store/audio-queue` +- **Platform Optimization**: iOS-specific audio handling in `lib/utils/ios-audio` +- **User Interface**: Mini player component with playback controls +- **Audio Processing**: + - Segment-based audio processing + - Retry mechanism for failed TTS requests + - Custom audio queue implementation + +#### State Management +- **Settings Store**: Manages voice selection and input handling +- **Audio Queue Store**: Controls playback state and queue management +- **Custom Hooks**: Provides reactive state management + +#### UI Components +- Built on Radix UI primitives for accessibility +- Themed using Tailwind CSS for consistent styling +- Responsive design for various screen sizes + +### 3. Key Features +1. **Progressive Web App** + - Offline capabilities + - Installable on devices + - Service worker for caching + +2. **Content Processing** + - Mozilla Readability for content parsing + - Article text extraction and formatting + - Text-to-speech conversion + +3. **Audio Playback** + - Queue management + - Platform-specific optimizations + - Background playback support + +## Target Architecture Overview +ReadMe-TTS is designed as a Progressive Web App (PWA) for converting web content and text into high-quality speech output. The system aims to provide a seamless, customizable audio experience through three core functionalities: + +### Text Extraction and Processing +- User input support for raw text and URLs +- Mozilla's Readability.js for clean content extraction +- Smart text segmentation for optimized processing + +### Text-to-Speech Conversion +- External TTS service (http://45.94.111.107:6080/v1/audio/speech) +- Asynchronous processing with real-time streaming +- High-quality speech synthesis + +### Audio Playback and Management +- Seamless audio segment integration +- Comprehensive playback controls +- Voice customization options +- Offline support for saved content + +## Gap Analysis and Implementation Plan + +### 1. Text Processing +**Current State:** +- Basic URL content fetching through local API +- Custom text segmentation implementation +- Limited content cleaning capabilities + +**Gaps:** +- No Mozilla Readability.js integration +- Limited content extraction capabilities +- Basic text segmentation without optimization + +**Implementation Plan:** +1. Integrate Mozilla Readability.js + - Add as dependency + - Implement content extraction service + - Add content cleaning pipeline + +2. Enhance Text Segmentation + - Implement smart chunking algorithm + - Add support for different content types + - Optimize segment sizes for TTS processing + +### 2. TTS Service +**Current Architecture:** +- Next.js API route (`/api/tts`) proxying requests to external TTS API (`http://45.94.111.107:6080/v1/audio/speech`) +- Voice model support in format: `voice-[language]-[region]-[name]-low` +- Binary audio response handling +- Basic error handling and retry logic +- Audio queue management with Zustand store + +**Gaps:** +- Single request-response cycle per segment +- Limited feedback during conversion process +- Basic error handling for API failures +- Sequential processing of segments + +**Implementation Plan:** +1. Enhanced Frontend Processing + - Implement progressive segment loading + - Add parallel segment processing (within browser limits) + - Optimize segment size based on content type + - Add intelligent segment prioritization + +2. Improved User Experience + - Add detailed progress tracking + - Implement predictive loading + - Enhance error feedback and recovery + - Add conversion status indicators + +3. Queue Management Optimization + - Add sophisticated segment state management + - Implement intelligent retry strategies + - Enhance error recovery mechanisms + - Add detailed progress reporting + +4. Audio Processing Enhancements + - Implement audio buffer management + - Add cross-fade between segments + - Optimize memory usage + - Add adaptive quality control + +**Technical Implementation Details:** + +1. Enhanced API Integration +```typescript +interface TTSRequestConfig { + retryStrategy: { + maxAttempts: number; + backoffFactor: number; + }; + timeout: number; + errorHandling: { + retryableErrors: string[]; + fallbackBehavior: 'skip' | 'retry' | 'fail'; + }; +} +``` + +2. Progress Tracking +```typescript +interface ConversionProgress { + totalSegments: number; + convertedSegments: number; + bufferedSegments: number; + estimatedTimeRemaining: number; + currentSegmentProgress: number; +} +``` + +3. Queue Management +```typescript +interface QueueOptimization { + preloadStrategy: 'eager' | 'lazy' | 'adaptive'; + bufferStrategy: { + minBuffer: number; + maxBuffer: number; + clearThreshold: number; + }; +} +``` + +**Benefits:** +1. Improved User Experience + - Better progress feedback + - Smoother playback transitions + - Enhanced error handling + - Reduced loading interruptions + +2. Resource Optimization + - Efficient API usage + - Better error recovery + - Improved memory management + - Optimized network requests + +3. Enhanced Reliability + - Robust error handling + - Consistent playback experience + - Better failure recovery + - Detailed user feedback + +### 3. Offline Capabilities +**Current State:** +- Basic IndexedDB implementation +- Limited offline support +- No background sync + +**Gaps:** +- No Dexie.js integration +- Limited offline content management +- Missing service worker features + +**Implementation Plan:** +1. Enhanced Storage Layer + - Integrate Dexie.js + - Implement robust offline storage + - Add content syncing mechanism + +2. PWA Enhancement + - Implement service worker + - Add background sync + - Enable offline-first architecture + +### 4. Audio Management +**Current State:** +- Basic audio queue system +- Platform-specific handling +- Limited playback controls + +**Gaps:** +- Limited seamless playback +- Basic queue management +- Missing advanced controls + +**Implementation Plan:** +1. Enhanced Audio Engine + - Implement advanced queue management + - Add seamless segment transitions + - Improve platform compatibility + +2. Playback Features + - Add seeking capability + - Implement speed control + - Add playlist management + +## Implementation Priorities + +### Phase 1: Core Functionality +1. Mozilla Readability.js integration +2. External TTS service setup +3. Basic offline storage with Dexie.js + +### Phase 2: Enhanced Features +1. Advanced audio management +2. Voice customization options +3. Service worker implementation + +### Phase 3: Polish and Optimization +1. Seamless playback improvements +2. Background sync +3. Performance optimizations + +## Timeline and Resources + +### Estimated Timeline +- Phase 1: 4-6 weeks +- Phase 2: 4-6 weeks +- Phase 3: 2-4 weeks + +### Resource Requirements +1. Development Team + - Frontend Developer (Next.js, TypeScript) + - Backend Developer (TTS service integration) + - UX Designer (audio interface) + +2. Infrastructure + - TTS service setup + - CDN for audio delivery + - Storage solutions for offline content + +## Design Decisions + +### 1. Framework Choice +- **Next.js**: Chosen for its server-side rendering capabilities, optimized performance, and excellent developer experience +- **TypeScript**: Ensures type safety and improves maintainability + +### 2. Component Architecture +- Atomic design principles +- Composition over inheritance +- Reusable component patterns + +### 3. Styling Approach +- Tailwind CSS for utility-first styling +- Component-level styles for specific customizations +- Theme support for dark/light modes + +## Challenges and Recommendations + +### Current Challenges + +1. **TTS Service Integration** + - Current implementation uses local API endpoints + - Potential for service scaling issues + + *Recommendation*: Consider implementing a distributed TTS service architecture + +2. **Audio Processing** + - Complex segment management + - Platform-specific audio handling requirements + + *Recommendation*: Implement a unified audio processing layer + +3. **Offline Support** + - Complex state management for offline-first functionality + - Storage limitations + + *Recommendation*: Implement smart caching strategies and clear storage policies + +4. **Performance Optimization** + - Large article processing overhead + - Audio queue management + + *Recommendation*: + - Implement web workers for heavy processing + - Add lazy loading for non-critical components + - Optimize audio chunk size and loading strategies + +5. **State Management Complexity** + - Multiple contexts and stores + + *Recommendation*: Consider implementing a more robust state management solution like Zustand or Jotai + +### Future Improvements + +1. **Architecture Enhancements** + - Implement module federation for better code splitting + - Add comprehensive error boundaries + - Enhance testing coverage + +2. **Performance Optimizations** + - Implement streaming SSR + - Add prefetching strategies + - Optimize asset loading + +3. **Developer Experience** + - Add comprehensive documentation + - Implement stricter type checking + - Add more development tools and debugging capabilities + +## Conclusion +The ReadMe PWA demonstrates a well-structured architecture that prioritizes performance, accessibility, and user experience. The challenges identified can be addressed through the suggested improvements, leading to an even more robust and maintainable application.