# Requirements Document

## Introduction

This document specifies the requirements for fixing i18n routing and hydration issues in the Nuxt 4 portfolio application. The issues include Vue Router warnings when switching languages, hydration mismatches in the Footer component, and accessibility warnings in the language switcher.

## Glossary

- **i18n System**: The internationalization system using @nuxtjs/i18n module for bilingual support (English and Persian)
- **Hydration Mismatch**: A Vue.js error that occurs when server-rendered HTML doesn't match client-side rendered content
- **Vue Router**: The official router for Vue.js applications, integrated with Nuxt
- **Language Switcher**: The UI component that allows users to switch between English and Persian languages
- **Route Prefix**: The language code prefix in URLs (e.g., /en/blog or /fa/blog)
- **localePath**: A helper function from @nuxtjs/i18n that generates locale-aware paths
- **ColorMode**: The dark/light theme system using @nuxtjs/color-mode module
- **ARIA**: Accessible Rich Internet Applications attributes for accessibility

## Requirements

### Requirement 1: Fix Vue Router Warnings for Blog Routes

**User Story:** As a visitor switching languages, I want the blog routes to work correctly, so that I don't encounter navigation errors.

#### Acceptance Criteria

1. WHEN a visitor switches from English to Persian, THE i18n System SHALL correctly resolve blog post routes with /fa/ prefix
2. WHEN a visitor switches from Persian to English, THE i18n System SHALL correctly resolve blog post routes with /en/ prefix
3. THE i18n System SHALL use localePath() helper for all blog navigation links to maintain locale context
4. WHERE a blog post exists in the current language, THE i18n System SHALL navigate to the localized version
5. WHERE a blog post does not exist in the target language, THE i18n System SHALL display a fallback message or redirect to the available version
6. THE i18n System SHALL not generate Vue Router warnings in the browser console during language switching
7. THE i18n System SHALL maintain the current page context when switching languages (e.g., stay on blog listing when switching from /blog to /fa/blog)

### Requirement 2: Fix Hydration Mismatch in Footer Component

**User Story:** As a visitor loading the page, I want the Footer to render without hydration errors, so that I have a smooth initial page load experience.

#### Acceptance Criteria

1. WHEN the page initially loads, THE Footer Component SHALL render identical HTML on server and client
2. THE Footer Component SHALL handle colorMode state without causing hydration mismatches
3. WHERE colorMode is accessed during SSR, THE Footer Component SHALL use a consistent default value
4. THE Footer Component SHALL update colorMode-dependent content only after hydration is complete
5. THE Footer Component SHALL not generate hydration mismatch warnings in the browser console
6. THE Footer Component SHALL display correctly in both light and dark modes after hydration

### Requirement 3: Fix ARIA Accessibility Warning in Language Switcher

**User Story:** As a visitor using assistive technology, I want the language switcher to be properly accessible, so that I can switch languages without accessibility issues.

#### Acceptance Criteria

1. THE Language Switcher SHALL not use aria-hidden on focusable or interactive elements
2. WHERE aria-hidden is used, THE Language Switcher SHALL ensure the element is not focusable
3. THE Language Switcher SHALL provide appropriate ARIA labels for screen readers
4. THE Language Switcher SHALL use semantic HTML for language selection
5. THE Language Switcher SHALL be keyboard navigable (Tab, Enter, Space keys)
6. THE Language Switcher SHALL announce language changes to screen readers
7. THE Language Switcher SHALL not generate ARIA-related warnings in the browser console

### Requirement 4: Improve i18n Route Configuration

**User Story:** As a developer, I want the i18n routing configuration to be correct, so that all routes work properly with language prefixes.

#### Acceptance Criteria

1. THE i18n System SHALL configure route prefixes correctly in nuxt.config.ts
2. THE i18n System SHALL use strategy: 'prefix' or 'prefix_except_default' for consistent URL structure
3. THE i18n System SHALL define all routes with proper locale prefixes
4. THE i18n System SHALL handle dynamic routes (like blog slugs) with locale awareness
5. THE i18n System SHALL provide fallback routes when content is not available in a locale
6. THE i18n System SHALL generate correct sitemap with all localized routes

### Requirement 5: Ensure Consistent Client-Server Rendering

**User Story:** As a visitor, I want the page to load without visual flashes or content shifts, so that I have a smooth browsing experience.

#### Acceptance Criteria

1. WHEN the page loads, THE Application SHALL render identical content on server and client
2. THE Application SHALL defer client-only content until after hydration using ClientOnly component
3. WHERE dynamic content depends on browser APIs, THE Application SHALL use onMounted lifecycle hook
4. THE Application SHALL not cause layout shifts during hydration
5. THE Application SHALL handle localStorage and cookies consistently between server and client
6. THE Application SHALL not generate Suspense-related warnings during hydration

### Requirement 6: Fix Language Switcher Implementation

**User Story:** As a visitor, I want to switch languages smoothly, so that I can view content in my preferred language.

#### Acceptance Criteria

1. WHEN a visitor clicks the language switcher, THE Application SHALL navigate to the equivalent page in the target language
2. THE Language Switcher SHALL use switchLocalePath() helper from @nuxtjs/i18n
3. THE Language Switcher SHALL maintain the current route context (e.g., /blog/post-slug becomes /fa/blog/post-slug)
4. WHERE the current page doesn't exist in the target language, THE Language Switcher SHALL navigate to the home page of that locale
5. THE Language Switcher SHALL update the HTML lang attribute
6. THE Language Switcher SHALL update the document direction (ltr/rtl) for Persian
7. THE Language Switcher SHALL provide visual feedback during language switching

### Requirement 7: Testing and Validation

**User Story:** As a developer, I want to verify that all i18n and routing issues are resolved, so that I can ensure a quality user experience.

#### Acceptance Criteria

1. THE Application SHALL pass manual testing for language switching on all pages
2. THE Application SHALL not generate any hydration warnings in the browser console
3. THE Application SHALL not generate any Vue Router warnings in the browser console
4. THE Application SHALL not generate any ARIA accessibility warnings in the browser console
5. THE Application SHALL maintain proper URL structure with locale prefixes
6. THE Application SHALL handle browser back/forward navigation correctly with localized routes
7. THE Application SHALL work correctly in both development and production builds
