feat: Complete comprehensive internationalization with 11 languages

[derekg]

Summary

Complete comprehensive internationalization support for ts-ssh, expanding from 2 to 11 major world languages with full CLI translation coverage.

Key Achievements

• 11 Languages Supported: English, Spanish, Chinese, Hindi, Arabic, Bengali, Portuguese, Russian, Japanese, German, French
• Full CLI Translation: All Fang/Cobra subcommands now have complete help text translation
• Thread-Safe Implementation: Concurrent access protection with proper mutex usage
• Early Language Detection: --lang flag parsed before command creation for dynamic localization
• Comprehensive Coverage: All user-facing strings translated including error messages, status indicators, and help text

Technical Implementation

• Dynamic Command Creation: Commands created with translations pre-applied
• Language Normalization: Supports multiple input formats (codes, full names, native names)
• Backward Compatibility: SimpleCLI mode unchanged, no breaking changes
• Performance Optimized: Lazy initialization and memory-efficient translation caching

Translation Coverage

• Root command descriptions and examples
• Connect, SCP, List, Exec, Multi, Config, PQC, Version subcommands
• All flag help text and command usage information
• Error messages and status indicators
• Unicode support for complex scripts (Arabic RTL, Chinese characters, Devanagari)

Documentation Updates

• Updated README.md with expanded language support information
• Enhanced INTERNATIONALIZATION.md with comprehensive usage guide
• Updated CLAUDE.md with development patterns and testing procedures

Testing

• ✅ All existing tests pass
• ✅ Manual verification of translation functionality across all languages
• ✅ CLI mode compatibility verified (both modern and legacy)
• ✅ Build verification successful

Test plan

• Verify all 11 languages display correctly in CLI help
• Test language detection priority (CLI flag > env vars > default)
• Confirm thread safety under concurrent usage
• Validate backward compatibility with existing scripts
• Test early language detection before command creation
• Verify Unicode rendering in different terminal environments

🤖 Generated with Claude Code

[claude]

Claude finished @derekg's task —— View job

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Comprehensive PR Review: Complete Internationalization Implementation

Review Tasks

• Analyze architectural changes and CLI framework integration
• Review i18n implementation for thread safety and performance
• Evaluate test coverage and quality
• Check security implications
• Review code quality and best practices
• Provide comprehensive feedback and recommendations

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✅ Strengths & Excellent Implementation

1. Architectural Design Excellence

• Dual CLI Mode: Brilliant backward compatibility approach with modern/legacy CLI modes
• Smart Detection: Automatic conversion of old-style commands (user@host → connect user@host) maintains UX continuity
• Clean Separation: Well-structured code split between main.go (entry), cli.go (Fang integration), cmd.go (command structs)

2. Comprehensive i18n Implementation

• 11 Languages: Excellent coverage of major world languages (4B+ speakers)
• Thread Safety: Proper mutex implementation (sync.RWMutex, sync.Once) prevents race conditions
• Language Detection Priority: Well-designed fallback chain (CLI flag → env var → locale → default)
• Unicode Support: Handles complex scripts (Arabic RTL, Chinese characters, Devanagari)

3. Enhanced User Experience

• Lipgloss Styling: Beautiful terminal output with color-coded messages
• Huh Integration: Interactive host picker provides modern CLI experience
• Comprehensive Help: All subcommands have proper translations and examples

4. Test Coverage Improvements

• New Test Files: Added comprehensive tests for errors, config, and SCP modules
• Thread Safety Tests: Excellent concurrent access testing in i18n_test.go
• Error Handling: 84.6% coverage for error handling module

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⚠️ Areas for Improvement

1. Code Quality & Performance Concerns

High Priority:

• Memory Efficiency: i18n.go has 1000+ hardcoded translations. Consider using embedded JSON/YAML files with lazy loading
• Language Normalization: The normalizeLanguage() function should be cached to avoid repeated string processing

Medium Priority:

• Error Handling: Some translation keys return the key itself instead of falling back to English when missing
• CLI Flag Parsing: parseArgs() in cmd.go has basic flag parsing that could miss edge cases

2. Security & Validation

Potential Issues:

• Input Validation: Language codes from environment variables aren't validated against supported languages
• Translation Injection: No sanitization of translation values (though likely not exploitable here)

Recommendations:

// Validate language code before use
func validateLanguageCode(lang string) string {
    normalized := normalizeLanguage(lang)
    if _, exists := supportedLanguages[normalized]; !exists {
        return LangEnglish // Safe fallback
    }
    return normalized
}

3. Testing & Documentation

Missing Test Coverage:

• Cross-platform i18n: No tests for locale detection on different OS
• Error Path Testing: Limited testing of translation fallback scenarios
• Integration Tests: CLI mode switching needs automated testing

Documentation Issues:

• docs/INTERNATIONALIZATION.md is comprehensive but could include troubleshooting section
• Missing example of environment variable usage in main README

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🔧 Technical Recommendations

1. Performance Optimizations

// Cache normalized languages to avoid repeated processing
var langCache = sync.Map{}

func normalizeLanguage(input string) string {
    if cached, ok := langCache.Load(input); ok {
        return cached.(string)
    }
    
    normalized := doNormalizeLanguage(input)
    langCache.Store(input, normalized)
    return normalized
}

2. Error Handling Enhancement

// T function should always return a valid string
func T(key string, args ...interface{}) string {
    printerMu.RLock()
    defer printerMu.RUnlock()
    
    if printer == nil {
        return key // Fallback if not initialized
    }
    
    result := printer.Sprintf(key, args...)
    if result == key && key != "" {
        // Fallback to English if translation missing
        englishPrinter := message.NewPrinter(language.English)
        result = englishPrinter.Sprintf(key, args...)
    }
    return result
}

3. Configuration Persistence

The ConfigCommand methods return "not yet implemented" errors. Consider:

• Using $HOME/.config/ts-ssh/config.yaml for settings
• Environment variable overrides
• Global vs local configuration scopes

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🏗️ Architectural Suggestions

1. Translation Management

• Externalize Translations: Move hardcoded strings to JSON/YAML files
• Translation Validation: Add build-time checks for missing translations
• Pluralization Support: Consider adding plural form support for counts

2. CLI Framework

• Consistent Error Handling: Standardize error messages across CLI modes
• Command Validation: Add input validation at the Cobra command level
• Help System: Ensure all help text is properly internationalized

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📊 Security Assessment

No Critical Security Issues Found ✅

Low Risk Items:

• Language code injection (theoretical, not exploitable)
• Unvalidated environment variable input
• Missing input sanitization (non-critical for this use case)

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🎯 Final Verdict

APPROVE WITH RECOMMENDATIONS ✅

This is an excellent PR that demonstrates:

• ✅ Solid Architecture: Well-designed dual CLI system
• ✅ Comprehensive i18n: Professional-grade internationalization
• ✅ Thread Safety: Proper concurrent access handling
• ✅ User Experience: Beautiful, modern CLI interface
• ✅ Backward Compatibility: Seamless migration path

Recommended Actions:

1. Merge after addressing memory efficiency concerns (externalize translations)
2. Follow-up PR for configuration persistence implementation
3. Add CI checks for translation completeness

Impact: This PR significantly elevates ts-ssh's accessibility to a global audience while maintaining technical excellence.

--- | Branch: claude/issue-23-20250628_183117