# Surgical Fix Report: Work Order Start Tracking Error
## Date: November 27, 2025
## Strategy: Diagnosis → Plan → Implementation

---

## STEP 1: DIAGNOSIS

### Error Received
```
TypeError: Cannot set properties of undefined (setting 'trackingEnabled')
at Function [Work Order buttons]:143:37
```

### Root Cause Analysis

**Node:** Work Order buttons
**Line:** 143
**Problem:** `msg.payload` was **undefined**

**Code that failed:**
```javascript
msg._mode = "production-state";
msg.productionStarted = true;
msg.machineOnline = true;

// ❌ ERROR HERE - msg.payload doesn't exist!
msg.payload.trackingEnabled = true;
msg.payload.productionStarted = true;
msg.payload.machineOnline = true;
```

**Why it failed:** The `msg` object in Node-RED doesn't automatically have a `payload` property. We were trying to set properties on an object that didn't exist, causing `Cannot set properties of undefined`.

### Secondary Issue: Mold Presets Handler Noise

**Node:** Mold Presets Handler
**Problem:** Logging warnings for every message it receives, including non-mold topics like `machineStatus`, `kpis`, `chartsData`, etc.

**Debug output:**
```
"Unknown topic: selectMoldPreset"
"Received: "
"Unknown topic: "
```

**Why:** No filter to silently ignore messages not meant for this handler.

---

## STEP 2: THE FIX PLAN

### Fix 1: Initialize msg.payload Before Use

**Architectural Decision:**
- Initialize `msg.payload = {}` before setting properties
- Set state flags at BOTH `msg` level AND `msg.payload` level for maximum compatibility
- Preserve all existing global.set() calls (especially `kpiBuffer` clearing)

**Compatibility Reasoning:**
The "Back to UI" node reads: `msg.payload?.trackingEnabled ?? msg.trackingEnabled`

This means it checks BOTH locations. By setting flags in both places, we ensure compatibility regardless of which path the message takes.

### Fix 2: Silent Ignore for Mold Presets Handler

**Architectural Decision:**
- Add early return for non-mold topics
- Define explicit list of ignored topics
- Only log messages for mold-related operations

**Topics to silently ignore:**
- `machineStatus` - Dashboard state updates
- `kpis` - KPI calculations
- `chartsData` - Graph data
- `activeWorkOrder` - Work order updates
- `workOrderCycle` - Cycle updates
- `workOrdersList` - Work order list
- `scrapPrompt` - Scrap entry prompts
- `uploadStatus` - Upload confirmations
- Empty string (`""`)

---

## STEP 3: IMPLEMENTATION

### Fix 1: Work Order buttons - "start" action

**Before (Lines 136-146):**
```javascript
msg._mode = "production-state";
msg.productionStarted = true;
msg.machineOnline = true;

// Send through output 2 to trigger KPI calculation
// Add state info to the msg itself (will be sent to Calculate KPIs)
msg.payload.trackingEnabled = true;        // ❌ ERROR
msg.productionStarted = true;
msg.payload.productionStarted = true;
msg.machineOnline = true;
msg.payload.machineOnline = true;

return [null, msg, null, null];
```

**After (Lines 136-148):**
```javascript
msg._mode = "production-state";

// Initialize payload object BEFORE setting properties
msg.payload = msg.payload || {};

// Set state flags at both msg and msg.payload levels for compatibility
msg.trackingEnabled = true;
msg.productionStarted = true;
msg.machineOnline = true;

msg.payload.trackingEnabled = true;
msg.payload.productionStarted = true;
msg.payload.machineOnline = true;

return [null, msg, null, null];
```

**What was preserved:**
✅ `global.set("trackingEnabled", true)`
✅ `global.set("kpiBuffer", [])`
✅ `node.warn('[START] Cleared kpiBuffer for fresh production run')`
✅ All other global.set() calls
✅ Return statement structure
✅ Output routing

---

### Fix 2: Mold Presets Handler - Silent ignore

**Before (Lines 1-4):**
```javascript
const topic = msg.topic || '';
const payload = msg.payload || {};

// Log every incoming request
node.warn(`Received: ${topic}`);
```

**After (Lines 1-19):**
```javascript
const topic = msg.topic || '';
const payload = msg.payload || {};

// ===== IGNORE NON-MOLD TOPICS SILENTLY =====
// These are KPI/dashboard messages not meant for this handler
const ignoredTopics = [
    'machineStatus',
    'kpis',
    'chartsData',
    'activeWorkOrder',
    'workOrderCycle',
    'workOrdersList',
    'scrapPrompt',
    'uploadStatus'
];

if (ignoredTopics.includes(topic) || topic === '') {
    return null;  // Silent ignore
}

// Log only mold-related requests
node.warn(`Received: ${topic}`);
```

**What was preserved:**
✅ All mold preset handling logic
✅ Lock/dedupe mechanisms
✅ Database operations
✅ Error handling
✅ Existing functionality unchanged

---

## STEP 4: VERIFICATION

### Verification Checklist

**Fix 1: Work Order buttons**
- ✅ `msg.payload = msg.payload || {};` - Initialization added
- ✅ `msg.trackingEnabled = true;` - Top-level flag set
- ✅ `msg.payload.trackingEnabled = true;` - Nested flag set
- ✅ `global.set("kpiBuffer", [])` - Buffer clearing preserved
- ✅ `[START] Cleared kpiBuffer` - Warning message preserved
- ✅ No duplicate flag settings
- ✅ Clean code structure

**Fix 2: Mold Presets Handler**
- ✅ `ignoredTopics` array defined
- ✅ `machineStatus` in ignore list
- ✅ `kpis` in ignore list
- ✅ `chartsData` in ignore list
- ✅ Early return for ignored topics
- ✅ Silent operation (no warnings for ignored topics)
- ✅ Original logging preserved for mold topics

---

## EXPECTED BEHAVIOR AFTER DEPLOYMENT

### Before Fix
```
User clicks START
  ↓
❌ Error: Cannot set properties of undefined (setting 'trackingEnabled')
❌ Production does not start
❌ Debug panel full of "Unknown topic" warnings
```

### After Fix
```
User clicks START
  ↓
✅ [START] Cleared kpiBuffer for fresh production run
✅ Production starts successfully
✅ trackingEnabled = true at global, msg, and msg.payload levels
✅ Button changes from START to STOP
✅ KPIs update continuously
✅ No "Unknown topic" warnings in debug panel
✅ Clean, noise-free debug output
```

---

## TESTING INSTRUCTIONS

1. **Deploy the updated flows.json in Node-RED**

2. **Test Fix 1 - START button:**
   ```
   - Load Home dashboard
   - Verify active work order exists
   - Click START button
   - Expected: No errors in debug panel
   - Expected: Message "[START] Cleared kpiBuffer for fresh production run"
   - Expected: Button changes to STOP
   - Expected: Production tracking begins
   ```

3. **Test Fix 2 - Silent ignore:**
   ```
   - Monitor debug panel
   - Navigate between dashboard tabs
   - Expected: No "Unknown topic" warnings for machineStatus, kpis, etc.
   - Expected: Only mold-related messages logged
   ```

4. **Integration test:**
   ```
   - Complete a full production cycle
   - Submit scrap
   - Verify KPIs update
   - Check graphs display data
   - Verify no errors throughout
   ```

---

## ARCHITECTURAL NOTES

### Message Flow (Corrected)

```
START button click
  ↓
Work Order buttons (case "start")
  ├─ Sets: global.set("trackingEnabled", true)
  ├─ Clears: global.set("kpiBuffer", [])
  ├─ Initializes: msg.payload = {}
  ├─ Sets: msg.trackingEnabled = true
  ├─ Sets: msg.payload.trackingEnabled = true
  └─ Sends: [null, msg, null, null] → Output 2
       ↓
Calculate KPIs (receives msg with _mode="production-state")
  ├─ Reads: global.get("trackingEnabled") ✅
  ├─ Performs: KPI calculations
  └─ Sends: Output 1 → Refresh Trigger
       ↓
Refresh Trigger (sees _mode="production-state")
  └─ Routes: [null, msg] → Output 2
       ↓
Back to UI (sees mode="production-state")
  ├─ Reads: msg.payload?.trackingEnabled ?? msg.trackingEnabled ✅
  ├─ Creates: homeMsg with topic="machineStatus"
  └─ Sends: [null, homeMsg, null, null]
       ↓
link out → Home Template
  └─ Updates: scope.isProductionRunning = msg.payload.trackingEnabled ✅
       ↓
Button displays: STOP ✅
```

### Why Both msg and msg.payload?

The "Back to UI" node uses optional chaining:
```javascript
trackingEnabled: msg.payload?.trackingEnabled ?? msg.trackingEnabled ?? false
```

This checks:
1. `msg.payload?.trackingEnabled` first (nested)
2. Falls back to `msg.trackingEnabled` (top-level)
3. Defaults to `false`

By setting both, we ensure compatibility regardless of how the message is processed or which properties survive through the flow.

---

## FILES MODIFIED

- `/home/mdares/.node-red/projects/Plastico/flows.json`
  - Work Order buttons node (ID: `9bbd4fade968036d`)
  - Mold Presets Handler node

---

## ROLLBACK INSTRUCTIONS

If issues occur:
```bash
cd /home/mdares/.node-red/projects/Plastico/
cp flows.json.backup_20251127_124628 flows.json
# Restart Node-RED
```

---

**Status: SURGICAL FIX COMPLETE ✅**
**Deployment: READY**
**Risk Level: LOW** (Isolated changes, preservation verified)