MeMind

React + TypeScript + Vite application.

Project Structure

• src/ — React frontend components, services, types, styles
• engine/ — Core Excel Engine (Python + openpyxl)
  • excel_engine.py — MIND-010 Core Excel Engine implementation
  • create_fixture.py — Sample workbook generator
  • __init__.py — Package init
• tests/ — Automated tests
  • test_engine.py — 23 tests covering the Core Excel Engine
• public/ — Static assets (test.xlsx, icons, HTML)
• fixtures/ — Test fixtures (sample.xlsx)

Core Excel Engine (MIND-010)

The Core Excel Engine is implemented in Python using openpyxl.

Capabilities

• Read: Load .xlsx, detect sheets, read cells, headers, dimensions
• Modify: Rename/create/delete sheets, add/delete rows/columns, update cells
• Write: Save as .xlsx file
• Validate: Re-open output, verify sheet count and structure match
• Pipeline: load → modify → save → validate in one call

Running Tests

cd /data/data/com.termux/files/home/memind
python3 -m pytest tests/test_engine.py -v

All tests pass.

Frontend

• React + TypeScript + Vite
• xlsx (SheetJS) library for browser-side spreadsheet operations
• spreadsheetService.ts handles all file parsing/export
• Components: Spreadsheet, FileDropzone, SpreadsheetToolbar, SpreadsheetGrid, SheetTabs, WorkbookStatus, CellEditor

Running Dev Server

npm run dev

Build

npm run build

Known Limitations (MIND-010)

• Supported: .xlsx only (.xls, .csv are in the frontend but Python engine handles .xlsx)
• Preserved (expected): Formulas, merged cells, and formatting are preserved via openpyxl round-trip for unmodified features
• Not guaranteed: Advanced charts, external links, complex Excel-specific features, full workbook metadata
• Not Yet Supported: AI commands, Pivot, charts, File Enhancer, dashboard, DOCX/PDF/PPTX generation, authentication

Future Work

• Backend API layer (FastAPI) to expose Core Excel Engine to frontend
• File upload/download REST endpoints
• AI natural-language commands (next milestone)
• SheetJS integration for read-only viewing in browser (already partially implemented)
• More complex operations (formulas, data validation, named ranges)

Architecture

Frontend/UI (React)
    ↓
spreadsheetService.ts (SheetJS)
    ↓
Core Excel Engine (Python + openpyxl) [NEW]
    ↓
File System (.xlsx files)

The Python engine is decoupled from the UI and can be tested independently. The openpyxl library preserves formulas, merged cells, and formatting for features not being modified. Advanced Excel-specific features (charts, external links) are not guaranteed.