STATUS.txt

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VIETNAMESE LUNAR CALENDAR EXPERT ENGINE - PROJECT STATUS
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📊 PHASE 1: FOUNDATION - ✅ COMPLETE
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🎯 WHAT WAS BUILT
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1. Expert Engine Core (engine/ directory)
   ├── index.js      - Main getDayInfo() API (141 lines)
   ├── types.js      - Can/Chi constants & helpers (72 lines)
   ├── canchi.js     - Can Chi calculation formulas (132 lines)
   └── test.js       - Test suite with 6 verified dates (144 lines)
   
   Total: 489 lines of well-documented code

2. Features Implemented
   ✅ Can Chi (干支) - Heavenly Stems & Earthly Branches
      • Day Can Chi   - JD-based: (JD+9)%10, (JD+1)%12
      • Month Can Chi - Lunar month + year stem table
      • Year Can Chi  - Lunar year: (year+6)%10, (year+8)%12
   
   ✅ Con Giáp - Vietnamese Zodiac (12 animals)
   ✅ Ngũ Hành - Five Elements (Mộc, Hỏa, Thổ, Kim, Thủy)
   ✅ Sexagenary cycle (60-cycle index)

3. CLI Integration
   ✅ node index.js today              - Show today with Can Chi
   ✅ node index.js info <d> <m> <y>   - Detailed info for any date
   ✅ node index.js canchi <d> <m> <y> - Alias for 'info'
   ✅ Enhanced help documentation

4. Testing & Verification
   ✅ 6 reference dates verified
      • Tết 2024: Giáp Thìn ✓
      • Tết 2025: Mậu Tuất ✓
      • Tết 2023: Canh Thìn ✓
      • 2024-01-01: Giáp Tý ✓
      • Y2K: Mậu Ngọ ✓
      • 2026-02-05: Canh Tuất ✓
   
   ✅ All tests passing (100%)

5. Documentation
   ✅ README-EXPERT.md     - Comprehensive user guide
   ✅ PHASE1-COMPLETE.md   - Phase 1 summary
   ✅ demo.sh              - Demo script
   ✅ Inline code comments - JSDoc-style documentation


📋 EXAMPLE OUTPUT
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$ node index.js info 10 2 2024

📅 Ngày 2024-02-10 (Thứ Bảy)
🌙 Âm lịch: 1/1/2024
📜 Can Chi:
   • Ngày: Giáp Thìn (Thìn (Rồng))
   • Tháng: Bính Dần
   • Năm: Giáp Thìn (Thìn (Rồng))
🌟 Ngũ hành:
   • Ngày: Mộc (Can) - Thổ (Chi)

💡 Calculation methods:
   • jd-based: (jd+9)%10, (jd+1)%12
   • lunar-month-based with year-stem table
   • lunar-year-based: (year+6)%10, (year+8)%12


💻 LIBRARY API
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const { getDayInfo, formatDayInfo } = require('./engine/index.js');

// Get complete day information
const info = getDayInfo(10, 2, 2024);

// Access Can Chi data
info.canChi.day.full        // "Giáp Thìn"
info.canChi.day.conGiap     // "Thìn (Rồng)"
info.canChi.day.nguHanh     // { can: "Mộc", chi: "Thổ" }
info.canChi.month.full      // "Bính Dần"
info.canChi.year.full       // "Giáp Thìn"

// Pretty print
console.log(formatDayInfo(info));


🏗️ ARCHITECTURE
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amlich-view/
├── Core (Existing)
│   ├── amlich-core.js             # Hồ Ngọc Đức's algorithm
│   ├── vietnamese-holidays.js     # Holiday calculations
│   ├── index.js                   # CLI (enhanced)
│   └── index.html                 # Web viewer
│
└── 🌟 Expert Engine (NEW!)
    └── engine/
        ├── index.js               # Main API: getDayInfo()
        ├── types.js               # Constants & helpers
        ├── canchi.js              # Can Chi formulas
        └── test.js                # Test suite


🎯 NEXT STEPS (FUTURE PHASES)
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Phase 2: Solar Terms (24 Tiết khí)
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□ Add tietkhi.js module
□ Use existing SunLongitude() function
□ Map 360° → 24 terms (each 15°)
□ Vietnamese term names
□ Integration with getDayInfo()

Files to create:
  engine/tietkhi.js
  data/tiet-khi-names.json

Phase 3: Hour & Day Classifications
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□ Giờ Hoàng Đạo - Auspicious hours (lookup table)
□ 12 Trực - Day officers (formula)
□ Ngày Hoàng Đạo/Hắc Đạo - Day classifications

Files to create:
  engine/gio-hoang-dao.js
  engine/truc.js
  engine/hoang-dao-day.js

Phase 4: Advanced Features
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□ Nạp Âm - 60-cycle element mapping
□ Nhị thập bát tú - 28 star mansions
□ Xung/Hợp - Conflict/harmony relations

Files to create:
  engine/nap-am.js
  engine/28-tu.js
  engine/xung-hop.js


📚 TECHNICAL DETAILS
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Calculation Methods:
  • Day Can Chi: Julian Day Number based
  • Month Can Chi: Lunar month + year stem table
  • Year Can Chi: Lunar year formula
  • Timezone: UTC+7 (Vietnam)
  • Accuracy: 1900-2199

Verification:
  • Tested against multiple Tết dates
  • Cross-referenced with traditional almanacs
  • Metadata included with every calculation

Data Structures:
  • Can: Array[10] - Thiên Can (Heavenly Stems)
  • Chi: Array[12] - Địa Chi (Earthly Branches)
  • Con Giáp: Array[12] - Zodiac animals
  • Ngũ Hành: Array[10], Array[12] - Five Elements


🚀 HOW TO USE
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Quick Start:
  ./demo.sh                    # Run demo script
  node engine/test.js          # Run tests
  node index.js today          # Try it out
  node index.js info 10 2 2024 # Tết 2024

Library Usage:
  const { getDayInfo } = require('./engine/index.js');
  const info = getDayInfo(10, 2, 2024);
  console.log(info.canChi.day.full);

Export Calendar:
  node index.js export-ics 2024


📊 PROJECT STATS
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Files:
  Total files: 16
  Core files: 6 (existing)
  Engine files: 4 (new)
  Documentation: 6

Lines of Code:
  Engine: 489 lines
  Total project: ~2,000 lines

Test Coverage:
  Reference dates: 6
  Pass rate: 100%

Dependencies:
  External: 0 (Pure Node.js!)
  Core modules: fs


✅ PHASE 1 CHECKLIST
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Implementation:
  ✅ Create engine/ directory structure
  ✅ Implement types.js (Can/Chi constants)
  ✅ Implement canchi.js (formulas)
  ✅ Implement index.js (getDayInfo API)
  ✅ Add formatDayInfo() pretty printer

Testing:
  ✅ Create test suite
  ✅ Verify against Tết dates
  ✅ Test Y2K reference
  ✅ All tests passing

Integration:
  ✅ Update CLI (today command)
  ✅ Add new 'info' command
  ✅ Add new 'canchi' alias
  ✅ Update help text

Documentation:
  ✅ Create README-EXPERT.md
  ✅ Create PHASE1-COMPLETE.md
  ✅ Create demo.sh
  ✅ Add inline code comments
  ✅ Create this status file


🎉 PHASE 1 STATUS: COMPLETE!
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The Vietnamese Lunar Calendar Expert Engine foundation is complete and ready!

Key achievements:
  • Accurate Can Chi calculations (verified)
  • Clean, modular architecture
  • Comprehensive test suite (100% pass)
  • CLI integration
  • Library API
  • Full documentation

The engine is production-ready for Phase 1 features and ready to expand with
Phase 2 (Solar Terms) whenever you're ready!


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END OF STATUS REPORT
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