Sindbad~EG File Manager

# ✅ Duplicate Checking Implementation

## 🎯 Feature: Prevent Duplicate Areas, Districts, and Assemblies

The system now validates and prevents duplicate entries when adding new locations, alerting admins with clear error messages.

---

## 📋 What Was Implemented

### **1. Manual Add Forms**
When using the "Add New" button on management pages:

#### **Areas (areas.php)**
- ✅ Checks if `area_code` already exists
- ✅ Checks if `area_name` already exists
- ✅ Shows error with existing record details

**Example Error:**
```
⚠️ Area with code 'GA' already exists (Name: Greater Accra). Please use a different code.
```

#### **Districts (districts.php)**
- ✅ Checks if `district_code` already exists (globally)
- ✅ Checks if `district_name` already exists in the same area
- ✅ Shows error with existing record details and location

**Example Error:**
```
⚠️ District with code 'MAD' already exists (Name: Madina District in Greater Accra). Please use a different code.
```

#### **Assemblies (assemblies.php)**
- ✅ Checks if `assembly_code` already exists (globally)
- ✅ Checks if `assembly_name` already exists in the same district
- ✅ Shows error with existing record details and full location hierarchy

**Example Error:**
```
⚠️ Assembly with code 'MCA001' already exists (Name: Madina Central Assembly in Madina District, Greater Accra). Please use a different code.
```

---

### **2. Bulk Upload System**
When uploading CSV or Excel files:

#### **All Upload Functions Updated**
- ✅ `insertArea()` - Checks for duplicate `area_code`
- ✅ `insertDistrict()` - Checks for duplicate `district_code`
- ✅ `insertAssembly()` - Checks for duplicate `assembly_code`

**Upload Results Table Shows:**
- 🔴 **Failed rows** with red badge
- **Error message:** "Area/District/Assembly code already exists: [Name]"
- **Row number** for easy reference to Excel file

**Example Upload Result:**
```
Row | Name           | Code   | Status | Message
----|----------------|--------|--------|--------------------------------
2   | Greater Accra  | GA     | Failed | Area code already exists: Greater Accra
3   | Ashanti Region | ASH    | Success| Area created successfully
```

---

## 🔍 Validation Rules

### **Code Uniqueness**
- **Area codes** must be unique across all areas
- **District codes** must be unique across all districts (globally)
- **Assembly codes** must be unique across all assemblies (globally)

### **Name Uniqueness**
- **Area names** must be unique across all areas
- **District names** must be unique within the same area (different areas can have districts with the same name)
- **Assembly names** must be unique within the same district (different districts can have assemblies with the same name)

---

## 💡 User Experience

### **Manual Entry:**
1. Admin fills out the "Add New" form
2. Clicks "Save"
3. **If duplicate exists:**
   - Form submission is prevented
   - Error message appears in red banner at top of page
   - Shows which record already exists
   - Form data is NOT saved
   - Admin can correct the code/name and try again

### **Bulk Upload:**
1. Admin uploads CSV/Excel file
2. System processes each row
3. **For duplicates:**
   - Row is marked as "Failed"
   - Original data is preserved
   - Error message shows existing record name
   - Other rows continue processing
4. Results table shows all successes and failures

---

## 🎨 Error Message Format

### **Areas:**
```
⚠️ Area with code '[CODE]' already exists (Name: [NAME]). Please use a different code.
⚠️ Area with name '[NAME]' already exists (Code: [CODE]). Please use a different name.
```

### **Districts:**
```
⚠️ District with code '[CODE]' already exists (Name: [NAME] in [AREA]). Please use a different code.
⚠️ District with name '[NAME]' already exists in this area (Code: [CODE]). Please use a different name.
```

### **Assemblies:**
```
⚠️ Assembly with code '[CODE]' already exists (Name: [NAME] in [DISTRICT], [AREA]). Please use a different code.
⚠️ Assembly with name '[NAME]' already exists in this district (Code: [CODE]). Please use a different name.
```

---

## 📁 Files Modified

### **Management Pages:**
1. ✅ `modules/administration/areas.php` - Added duplicate checking before insert
2. ✅ `modules/administration/districts.php` - Added duplicate checking before insert
3. ✅ `modules/administration/assemblies.php` - Added duplicate checking before insert

### **Bulk Upload:**
4. ✅ `modules/administration/upload-locations.php` - Added duplicate checking to all insert functions

---

## ✨ Benefits

1. **Data Integrity:** Prevents duplicate records in the database
2. **Clear Feedback:** Users know exactly why their submission failed
3. **Easy Resolution:** Error messages show existing record details for reference
4. **Hierarchical Context:** For districts and assemblies, shows full location hierarchy
5. **Bulk Upload Safety:** Upload continues for valid rows even if some fail
6. **Audit Trail:** Codes are automatically converted to uppercase for consistency

---

## 🧪 Testing Scenarios

### **Test 1: Duplicate Area Code**
1. Try to add area with code "GA" when it already exists
2. **Expected:** Error message showing existing area name

### **Test 2: Duplicate District Name in Same Area**
1. Try to add "Madina District" in "Greater Accra" when it already exists
2. **Expected:** Error message showing existing district code

### **Test 3: Same District Name in Different Area**
1. Add "Central District" in "Greater Accra"
2. Add "Central District" in "Ashanti"
3. **Expected:** Both succeed (different areas)

### **Test 4: Bulk Upload with Duplicates**
1. Upload CSV with 10 areas, 3 have duplicate codes
2. **Expected:** 7 succeed, 3 fail with clear error messages

---

## 📊 Summary

**Duplicate Prevention:** ✅ Active  
**Scope:** Areas, Districts, Assemblies  
**Entry Methods:** Manual forms + Bulk upload  
**Error Display:** User-friendly messages  
**Data Integrity:** Maintained

All location management pages now have robust duplicate detection to prevent data conflicts and improve data quality!