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+# NUPST Migration Plan: Node.js → Deno v4.0.0
+
+**Migration Goal**: Convert NUPST from Node.js to Deno with single-executable distribution
+**Version**: 3.1.2 → 4.0.0 (breaking changes)
+**Platforms**: Linux x64/ARM64, macOS x64/ARM64, Windows x64
+
+---
+
+## Phase 0: Planning & Preparation
+
+- [x] Research Deno compilation targets and npm: specifier support
+- [x] Analyze current codebase structure and dependencies
+- [x] Define CLI command structure simplification
+- [x] Create detailed migration task list
+- [ ] Create feature branch: `migration/deno-v4`
+- [ ] Backup current working state with git tag: `v3.1.2-pre-deno-migration`
+
+---
+
+## Phase 1: Dependency Migration (4-6 hours)
+
+### 1.1 Analyze Current Dependencies
+- [ ] List all production dependencies from `package.json`
+  - Current: `net-snmp@3.20.0`
+- [ ] List all dev dependencies to be removed
+  - `@git.zone/tsbuild`, `@git.zone/tsrun`, `@git.zone/tstest`, `@push.rocks/qenv`, `@push.rocks/tapbundle`, `@types/node`
+- [ ] Identify Node.js built-in module usage
+  - `child_process` (execSync)
+  - `https` (for version checking)
+  - `fs` (readFileSync, writeFileSync, existsSync, mkdirSync)
+  - `path` (join, dirname, resolve)
+
+### 1.2 Create Deno Configuration
+- [ ] Create `deno.json` with project configuration
+  ```json
+  {
+    "name": "@serve.zone/nupst",
+    "version": "4.0.0",
+    "exports": "./mod.ts",
+    "tasks": {
+      "dev": "deno run --allow-all mod.ts",
+      "compile": "deno task compile:all",
+      "compile:all": "bash scripts/compile-all.sh",
+      "test": "deno test --allow-all tests/",
+      "check": "deno check mod.ts"
+    },
+    "lint": {
+      "rules": {
+        "tags": ["recommended"]
+      }
+    },
+    "fmt": {
+      "useTabs": false,
+      "lineWidth": 100,
+      "indentWidth": 2,
+      "semiColons": true
+    },
+    "compilerOptions": {
+      "lib": ["deno.window"],
+      "strict": true
+    },
+    "imports": {
+      "@std/cli": "jsr:@std/cli@^1.0.0",
+      "@std/fmt": "jsr:@std/fmt@^1.0.0",
+      "@std/path": "jsr:@std/path@^1.0.0"
+    }
+  }
+  ```
+
+### 1.3 Update Import Statements
+- [ ] `ts/snmp/manager.ts`: Change `import * as snmp from 'net-snmp'` to `import * as snmp from "npm:net-snmp@3.20.0"`
+- [ ] `ts/cli.ts`: Change `import { execSync } from 'child_process'` to `import { execSync } from "node:child_process"`
+- [ ] `ts/nupst.ts`: Change `import * as https from 'https'` to `import * as https from "node:https"`
+- [ ] Search for all `fs` imports and update to `node:fs`
+- [ ] Search for all `path` imports and update to `node:path`
+- [ ] Update all relative imports to use `.ts` extension instead of `.js`
+  - Example: `'./nupst.js'` → `'./nupst.ts'`
+
+### 1.4 Test npm: Specifier Compatibility
+- [ ] Create test file: `tests/snmp_compatibility_test.ts`
+- [ ] Test SNMP v1 connection with npm:net-snmp
+- [ ] Test SNMP v2c connection with npm:net-snmp
+- [ ] Test SNMP v3 connection with npm:net-snmp
+- [ ] Verify native addon loading works in compiled binary
+
+---
+
+## Phase 2: Code Structure Refactoring (3-4 hours)
+
+### 2.1 Create Main Entry Point
+- [ ] Create `mod.ts` as main Deno entry point:
+  ```typescript
+  #!/usr/bin/env -S deno run --allow-all
+
+  /**
+   * NUPST - UPS Shutdown Tool for Deno
+   *
+   * Required Permissions:
+   * --allow-net: SNMP communication with UPS devices
+   * --allow-read: Configuration file access (/etc/nupst/config.json)
+   * --allow-write: Configuration file updates
+   * --allow-run: System commands (systemctl, shutdown)
+   * --allow-sys: System information (hostname, OS info)
+   * --allow-env: Environment variables
+   */
+
+  import { NupstCli } from './ts/cli.ts';
+
+  const cli = new NupstCli();
+  await cli.parseAndExecute(Deno.args);
+  ```
+
+### 2.2 Update All Import Extensions
+Files to update (change .js → .ts in imports):
+- [ ] `ts/index.ts`
+- [ ] `ts/cli.ts` (imports from ./nupst.js, ./logger.js)
+- [ ] `ts/nupst.ts` (imports from ./snmp/manager.js, ./daemon.js, etc.)
+- [ ] `ts/daemon.ts` (imports from ./snmp/manager.js, ./logger.js, ./helpers/)
+- [ ] `ts/systemd.ts` (imports from ./daemon.js, ./logger.js)
+- [ ] `ts/cli/service-handler.ts`
+- [ ] `ts/cli/group-handler.ts`
+- [ ] `ts/cli/ups-handler.ts`
+- [ ] `ts/snmp/index.ts`
+- [ ] `ts/snmp/manager.ts` (imports from ./types.js, ./oid-sets.js)
+- [ ] `ts/snmp/oid-sets.ts` (imports from ./types.js)
+- [ ] `ts/helpers/index.ts`
+- [ ] `ts/logger.ts`
+
+### 2.3 Update process.argv References
+- [ ] `ts/cli.ts`: Replace `process.argv` with `Deno.args` (adjust indexing: process.argv[2] → Deno.args[0])
+- [ ] Update parseAndExecute method to work with Deno.args (0-indexed vs 2-indexed)
+
+### 2.4 Update File System Operations
+- [ ] Search for `fs.readFileSync()` → Consider using `Deno.readTextFile()` or keep node:fs
+- [ ] Search for `fs.writeFileSync()` → Consider using `Deno.writeTextFile()` or keep node:fs
+- [ ] Search for `fs.existsSync()` → Keep node:fs or use Deno.stat
+- [ ] Search for `fs.mkdirSync()` → Keep node:fs or use Deno.mkdir
+- [ ] Decision: Keep node:fs for consistency or migrate to Deno APIs?
+
+### 2.5 Update Path Operations
+- [ ] Verify all `path.join()`, `path.resolve()`, `path.dirname()` work with node:path
+- [ ] Consider using `@std/path` from JSR for better Deno integration
+
+### 2.6 Handle __dirname and __filename
+- [ ] Find all `__dirname` usage
+- [ ] Replace with `import.meta.dirname` (Deno) or `dirname(fromFileUrl(import.meta.url))`
+- [ ] Find all `__filename` usage
+- [ ] Replace with `import.meta.filename` or `fromFileUrl(import.meta.url)`
+
+---
+
+## Phase 3: CLI Command Simplification (3-4 hours)
+
+### 3.1 Design New Command Structure
+Current → New mapping:
+```
+OLD                          NEW
+===                          ===
+nupst enable                 → nupst service enable
+nupst disable                → nupst service disable
+nupst daemon-start           → nupst service start-daemon
+nupst logs                   → nupst service logs
+nupst stop                   → nupst service stop
+nupst start                  → nupst service start
+nupst status                 → nupst service status
+
+nupst add                    → nupst ups add
+nupst edit [id]              → nupst ups edit [id]
+nupst delete <id>            → nupst ups remove <id>
+nupst list                   → nupst ups list
+nupst setup                  → nupst ups edit (removed alias)
+nupst test                   → nupst ups test
+
+nupst group list             → nupst group list
+nupst group add              → nupst group add
+nupst group edit <id>        → nupst group edit <id>
+nupst group delete <id>      → nupst group remove <id>
+
+nupst config                 → nupst config show
+nupst update                 → nupst update
+nupst uninstall              → nupst uninstall
+nupst help                   → nupst help / nupst --help
+(new)                        → nupst --version
+```
+
+### 3.2 Update CLI Parser (ts/cli.ts)
+- [ ] Refactor `parseAndExecute()` to handle new command structure
+- [ ] Add `service` subcommand handler
+- [ ] Add `ups` subcommand handler
+- [ ] Keep `group` subcommand handler (already exists, just update delete→remove)
+- [ ] Add `config` subcommand handler with `show` default
+- [ ] Add `--version` flag handler
+- [ ] Update `help` command to show new structure
+- [ ] Add command aliases: `rm` → `remove`, `ls` → `list`
+- [ ] Add `--json` flag for machine-readable output (future enhancement)
+
+### 3.3 Update Command Handlers
+- [ ] `ts/cli/service-handler.ts`: Update method names if needed
+- [ ] `ts/cli/ups-handler.ts`: Rename `delete()` → `remove()`, remove `setup` method
+- [ ] `ts/cli/group-handler.ts`: Rename `delete()` → `remove()`
+
+### 3.4 Improve Help Messages
+- [ ] Update `showHelp()` in ts/cli.ts with new command structure
+- [ ] Update `showGroupHelp()` in ts/cli.ts
+- [ ] Add `showServiceHelp()` method
+- [ ] Add `showUpsHelp()` method
+- [ ] Add `showConfigHelp()` method
+- [ ] Include usage examples in help text
+
+### 3.5 Add Version Command
+- [ ] Read version from deno.json
+- [ ] Create `--version` handler in CLI
+- [ ] Display version with build info
+
+---
+
+## Phase 4: Compilation & Distribution (2-3 hours)
+
+### 4.1 Create Compilation Script
+- [ ] Create directory: `scripts/`
+- [ ] Create `scripts/compile-all.sh`:
+  ```bash
+  #!/bin/bash
+  set -e
+
+  VERSION=$(cat deno.json | jq -r '.version')
+  BINARY_DIR="dist/binaries"
+
+  echo "Compiling NUPST v${VERSION} for all platforms..."
+  mkdir -p "$BINARY_DIR"
+
+  # Linux x86_64
+  echo "→ Linux x86_64..."
+  deno compile --allow-all --output "$BINARY_DIR/nupst-linux-x64" \
+    --target x86_64-unknown-linux-gnu mod.ts
+
+  # Linux ARM64
+  echo "→ Linux ARM64..."
+  deno compile --allow-all --output "$BINARY_DIR/nupst-linux-arm64" \
+    --target aarch64-unknown-linux-gnu mod.ts
+
+  # macOS x86_64
+  echo "→ macOS x86_64..."
+  deno compile --allow-all --output "$BINARY_DIR/nupst-macos-x64" \
+    --target x86_64-apple-darwin mod.ts
+
+  # macOS ARM64
+  echo "→ macOS ARM64..."
+  deno compile --allow-all --output "$BINARY_DIR/nupst-macos-arm64" \
+    --target aarch64-apple-darwin mod.ts
+
+  # Windows x86_64
+  echo "→ Windows x86_64..."
+  deno compile --allow-all --output "$BINARY_DIR/nupst-windows-x64.exe" \
+    --target x86_64-pc-windows-msvc mod.ts
+
+  echo ""
+  echo "✓ Compilation complete!"
+  ls -lh "$BINARY_DIR/"
+  ```
+- [ ] Make script executable: `chmod +x scripts/compile-all.sh`
+
+### 4.2 Test Local Compilation
+- [ ] Run `deno task compile` to compile for all platforms
+- [ ] Verify all 5 binaries are created
+- [ ] Check binary sizes (should be reasonable, < 100MB each)
+- [ ] Test local binary on current platform: `./dist/binaries/nupst-linux-x64 --version`
+
+### 4.3 Update Installation Scripts
+- [ ] Update `install.sh`:
+  - Remove Node.js download logic (lines dealing with vendor/node-*)
+  - Add detection for binary download from GitHub releases
+  - Simplify to download appropriate binary based on OS/arch
+  - Place binary in `/opt/nupst/bin/nupst`
+  - Create symlink: `/usr/local/bin/nupst → /opt/nupst/bin/nupst`
+  - Update to v4.0.0 in script
+- [ ] Simplify or remove `setup.sh` (no longer needed without Node.js)
+- [ ] Update `bin/nupst` launcher:
+  - Option A: Keep as simple wrapper
+  - Option B: Remove and symlink directly to binary
+- [ ] Update `uninstall.sh`:
+  - Remove vendor directory cleanup
+  - Update paths to new binary location
+
+### 4.4 Update Systemd Service
+- [ ] Update systemd service file path in `ts/systemd.ts`
+- [ ] Verify ExecStart points to correct binary location: `/opt/nupst/bin/nupst daemon-start`
+- [ ] Remove Node.js environment variables if any
+- [ ] Test service installation and startup
+
+---
+
+## Phase 5: Testing & Validation (4-6 hours)
+
+### 5.1 Create Deno Test Suite
+- [ ] Create `tests/` directory (or migrate from existing `test/`)
+- [ ] Create `tests/snmp_test.ts`: Test SNMP manager functionality
+- [ ] Create `tests/config_test.ts`: Test configuration loading/saving
+- [ ] Create `tests/cli_test.ts`: Test CLI parsing and command routing
+- [ ] Create `tests/daemon_test.ts`: Test daemon logic
+- [ ] Remove dependency on @git.zone/tstest and @push.rocks/tapbundle
+- [ ] Use Deno's built-in test runner (`Deno.test()`)
+
+### 5.2 Unit Tests
+- [ ] Test SNMP connection with mock responses
+- [ ] Test configuration validation
+- [ ] Test UPS status parsing for different models
+- [ ] Test group logic (redundant/non-redundant modes)
+- [ ] Test threshold checking
+- [ ] Test version comparison logic
+
+### 5.3 Integration Tests
+- [ ] Test CLI command parsing for all commands
+- [ ] Test config file creation and updates
+- [ ] Test UPS add/edit/remove operations
+- [ ] Test group add/edit/remove operations
+- [ ] Mock systemd operations for testing
+
+### 5.4 Binary Testing
+- [ ] Test compiled binary on Linux x64
+- [ ] Test compiled binary on Linux ARM64 (if available)
+- [ ] Test compiled binary on macOS x64 (if available)
+- [ ] Test compiled binary on macOS ARM64 (if available)
+- [ ] Test compiled binary on Windows x64 (if available)
+- [ ] Verify SNMP functionality works in compiled binary
+- [ ] Verify config file operations work in compiled binary
+- [ ] Test systemd integration with compiled binary
+
+### 5.5 Performance Testing
+- [ ] Measure binary size for each platform
+- [ ] Measure startup time: `time ./nupst-linux-x64 --version`
+- [ ] Measure memory footprint during daemon operation
+- [ ] Compare with Node.js version performance
+- [ ] Document performance metrics
+
+### 5.6 Upgrade Path Testing
+- [ ] Create test with v3.x config
+- [ ] Verify v4.x can read existing config
+- [ ] Test migration from old commands to new commands
+- [ ] Verify systemd service upgrade path
+
+---
+
+## Phase 6: Distribution Strategy (2-3 hours)
+
+### 6.1 GitHub Actions Workflow
+- [ ] Create `.github/workflows/release.yml`:
+  ```yaml
+  name: Release
+  on:
+    push:
+      tags:
+        - 'v*'
+  jobs:
+    build:
+      runs-on: ubuntu-latest
+      steps:
+        - uses: actions/checkout@v4
+        - uses: denoland/setup-deno@v1
+          with:
+            deno-version: v1.x
+        - name: Compile binaries
+          run: deno task compile
+        - name: Generate checksums
+          run: |
+            cd dist/binaries
+            sha256sum * > SHA256SUMS
+        - name: Create Release
+          uses: softprops/action-gh-release@v1
+          with:
+            files: dist/binaries/*
+            generate_release_notes: true
+  ```
+
+### 6.2 Update package.json for npm
+- [ ] Update version to 4.0.0
+- [ ] Update description to mention Deno
+- [ ] Add postinstall script to symlink appropriate binary:
+  ```json
+  {
+    "name": "@serve.zone/nupst",
+    "version": "4.0.0",
+    "description": "UPS Shutdown Tool - Deno-based single executable",
+    "bin": {
+      "nupst": "bin/nupst-npm-wrapper.js"
+    },
+    "type": "module",
+    "scripts": {
+      "postinstall": "node bin/setup-npm-binary.js"
+    },
+    "files": [
+      "dist/binaries/*",
+      "bin/*"
+    ]
+  }
+  ```
+- [ ] Create `bin/setup-npm-binary.js` to symlink correct binary
+- [ ] Create `bin/nupst-npm-wrapper.js` as entry point
+
+### 6.3 Verify Distribution Methods
+- [ ] Test GitHub release download and installation
+- [ ] Test npm install from tarball
+- [ ] Test direct install.sh script
+- [ ] Verify all methods create working installation
+
+---
+
+## Phase 7: Documentation Updates (2-3 hours)
+
+### 7.1 Update README.md
+- [ ] Remove Node.js requirements section
+- [ ] Update features list (mention Deno, single executable)
+- [ ] Update installation methods:
+  - Method 1: Quick install script (updated)
+  - Method 2: GitHub releases (new)
+  - Method 3: npm (updated with notes)
+- [ ] Update usage section with new command structure
+- [ ] Add command mapping table (v3 → v4)
+- [ ] Update platform support matrix (note: no Windows ARM)
+- [ ] Update "System Changes" section (no vendor directory)
+- [ ] Update security section (remove Node.js mentions)
+- [ ] Update uninstallation instructions
+
+### 7.2 Create MIGRATION.md
+- [ ] Create detailed migration guide from v3.x to v4.x
+- [ ] List all breaking changes:
+  1. CLI command structure reorganization
+  2. No Node.js requirement
+  3. Windows ARM not supported
+  4. Installation path changes
+- [ ] Provide command mapping table
+- [ ] Explain config compatibility
+- [ ] Document upgrade procedure
+- [ ] Add rollback instructions
+
+### 7.3 Update CHANGELOG.md
+- [ ] Add v4.0.0 section with all breaking changes
+- [ ] List new features (Deno, single executable)
+- [ ] List improvements (startup time, binary size)
+- [ ] List removed features (Windows ARM, setup command alias)
+- [ ] Migration guide reference
+
+### 7.4 Update Help Text
+- [ ] Ensure all help commands show new structure
+- [ ] Add examples for common operations
+- [ ] Include migration notes in help output
+
+---
+
+## Phase 8: Cleanup & Finalization (1 hour)
+
+### 8.1 Remove Obsolete Files
+- [ ] Delete `vendor/` directory (Node.js binaries)
+- [ ] Delete `dist/` directory (old compiled JS)
+- [ ] Delete `dist_ts/` directory (old compiled TS)
+- [ ] Delete `node_modules/` directory
+- [ ] Remove or update `tsconfig.json` (decide if needed for npm compatibility)
+- [ ] Remove `setup.sh` if no longer needed
+- [ ] Remove old test files in `test/` if migrated to `tests/`
+- [ ] Delete `pnpm-lock.yaml`
+
+### 8.2 Update Git Configuration
+- [ ] Update `.gitignore`:
+  ```
+  # Deno
+  .deno/
+  deno.lock
+
+  # Compiled binaries
+  dist/binaries/
+
+  # Old Node.js artifacts (to be removed)
+  node_modules/
+  vendor/
+  dist/
+  dist_ts/
+  pnpm-lock.yaml
+  ```
+- [ ] Add `deno.lock` to version control
+- [ ] Create `.denoignore` if needed
+
+### 8.3 Final Validation
+- [ ] Run `deno check mod.ts` - verify no type errors
+- [ ] Run `deno lint` - verify code quality
+- [ ] Run `deno fmt --check` - verify formatting
+- [ ] Run `deno task test` - verify all tests pass
+- [ ] Run `deno task compile` - verify all binaries compile
+- [ ] Test each binary manually
+
+### 8.4 Prepare for Release
+- [ ] Create git tag: `v4.0.0`
+- [ ] Push to main branch
+- [ ] Push tags to trigger release workflow
+- [ ] Verify GitHub Actions workflow succeeds
+- [ ] Verify binaries are attached to release
+- [ ] Test installation from GitHub release
+- [ ] Publish to npm: `npm publish`
+- [ ] Test npm installation
+
+---
+
+## Rollback Strategy
+
+If critical issues are discovered:
+- [ ] Keep `v3.1.2` tag available for rollback
+- [ ] Create `v3-stable` branch for continued v3 maintenance
+- [ ] Update install.sh to offer v3/v4 choice
+- [ ] Document known issues in GitHub Issues
+- [ ] Provide downgrade instructions in docs
+
+---
+
+## Success Criteria Checklist
+
+- [ ] ✅ All 5 platform binaries compile successfully
+- [ ] ✅ Binary sizes are reasonable (< 100MB per platform)
+- [ ] ✅ Startup time < 2 seconds
+- [ ] ✅ SNMP v1/v2c/v3 functionality verified on real UPS device
+- [ ] ✅ All CLI commands work with new structure
+- [ ] ✅ Config file compatibility maintained
+- [ ] ✅ Systemd integration works on Linux
+- [ ] ✅ Installation scripts work on fresh systems
+- [ ] ✅ npm package still installable and functional
+- [ ] ✅ All tests pass
+- [ ] ✅ Documentation is complete and accurate
+- [ ] ✅ GitHub release created with binaries
+- [ ] ✅ Migration guide tested by following it step-by-step
+
+---
+
+## Timeline
+
+- **Phase 0**: 1 hour ✓ (in progress)
+- **Phase 1**: 4-6 hours
+- **Phase 2**: 3-4 hours
+- **Phase 3**: 3-4 hours
+- **Phase 4**: 2-3 hours
+- **Phase 5**: 4-6 hours
+- **Phase 6**: 2-3 hours
+- **Phase 7**: 2-3 hours
+- **Phase 8**: 1 hour
+
+**Total Estimate**: 22-31 hours
+
+---
+
+## Notes & Decisions
+
+### Key Decisions Made:
+1. ✅ Use npm:net-snmp (no pure Deno SNMP library available)
+2. ✅ Major version bump to 4.0.0 (breaking changes)
+3. ✅ CLI reorganization with subcommands
+4. ✅ Keep npm publishing alongside binary distribution
+5. ✅ 5 platform targets (Windows ARM not supported by Deno yet)
+
+### Open Questions:
+- [ ] Should we keep tsconfig.json for npm package compatibility?
+- [ ] Should we fully migrate to Deno APIs (Deno.readFile) or keep node:fs?
+- [ ] Should we remove the `bin/nupst` wrapper or keep it?
+- [ ] Should setup.sh be completely removed or kept for dependencies?
+
+### Risk Areas:
+- ⚠️ SNMP native addon compatibility in compiled binaries (HIGH PRIORITY TO TEST)
+- ⚠️ Systemd integration with new binary structure
+- ⚠️ Config migration from v3 to v4
+- ⚠️ npm package installation with embedded binaries