Contributing to Location Data

Location data services provide comprehensive information about Ghana's administrative regions, districts, constituencies, and other geographic divisions. This guide will help you contribute to location-related features.

🏛️ Current Location Features

Implemented Features

• Regional Data - Information about Ghana's 16 administrative regions
• District Information - Details about metropolitan, municipal, and district assemblies
• Constituency Data - Electoral constituency boundaries and information
• Administrative Hierarchy - Relationships between regions, districts, and localities

Feature Areas for Contribution

📊 Data Completeness & Accuracy

• Verify and update administrative boundaries
• Add missing district and constituency information
• Population and demographic data integration
• Economic and development indicators

🗺️ Geographic Information

• GPS coordinates for administrative centers
• Boundary polygon data (GeoJSON)
• Elevation and topographic information
• Land area calculations and statistics

🏘️ Local Government Integration

• Assembly member information
• Local government contact details
• Service delivery points and facilities
• Development project tracking

🔍 Search & Discovery

• Smart location search algorithms
• Hierarchical location browsing
• Location-based service discovery
• Proximity and distance calculations

🛠️ Technical Architecture

File Structure

backend/src/locations/
├── locations.controller.ts          # API route handlers
├── locations.service.ts             # Business logic
├── locations.module.ts              # Module configuration
├── dto/
│   ├── region.dto.ts               # Region data transfer objects
│   └── district.dto.ts             # District data transfer objects
├── entities/
│   └── location.entity.ts          # Database entities (placeholder)
└── data/
    └── regions.json                # Static region and district data

Key Services

LocationsService

@Injectable()
export class LocationsService {
  getRegions(): RegionDto[] {
    // Returns all 16 administrative regions
  }

  getDistricts(regionId: string): DistrictDto[] {
    // Returns all districts within a specific region
  }
}

LocationsController

@Controller("locations")
export class LocationsController {
  @Get("regions")
  getRegions() {
    // Lists all regions
  }

  @Get("districts/:regionId")
  getDistricts(@Param("regionId") regionId: string) {
    // Gets districts for a region
  }
}

🚀 Getting Started

Prerequisites

• Node.js 18+ and npm
• Basic knowledge of TypeScript and NestJS
• Understanding of Ghana's administrative structure

Development Setup

1. Clone and Install Dependencies

   cd backend
   npm install

2. Start Development Server

   npm run start:dev

3. Test the API

   # Get all regions
   curl http://localhost:3000/locations/regions
   
   # Get districts for Ahafo Region
   curl http://localhost:3000/locations/districts/AR

📝 Contribution Guidelines

Adding New Regions or Districts

1. Update Data Source

   • Edit backend/src/locations/data/regions.json
   • Follow the existing structure:

   {
     "code": "NEW",
     "label": "New Region",
     "capital": "Capital City",
     "districts": [
       {
         "code": "ND1",
         "label": "New District 1",
         "category": "Municipal",
         "capital": "District Capital"
       }
     ]
   }

2. Update DTOs if Needed

   • Modify region.dto.ts or district.dto.ts for new fields
   • Ensure proper validation and documentation

3. Add Tests

   • Create unit tests in locations.service.spec.ts
   • Add integration tests for new endpoints

Adding New Features

Geographic Coordinates

// Add to district.dto.ts
export class DistrictDto {
  @ApiProperty() code: string;
  @ApiProperty() label: string;
  @ApiProperty() category: string;
  @ApiProperty() capital: string;
  @ApiProperty({ required: false }) coordinates?: {
    lat: number;
    lng: number;
  };
}

Search Functionality

// Add to locations.service.ts
async searchLocations(query: string): Promise<LocationDto[]> {
  const searchTerm = query.toLowerCase();
  const results: LocationDto[] = [];

  // Search regions
  const regions = this.getRegions();
  for (const region of regions) {
    if (region.label.toLowerCase().includes(searchTerm)) {
      results.push({ ...region, type: 'region' });
    }
  }

  // Search districts
  for (const region of regions) {
    const districts = this.getDistricts(region.code);
    for (const district of districts) {
      if (district.label.toLowerCase().includes(searchTerm)) {
        results.push({ ...district, type: 'district', region: region.code });
      }
    }
  }

  return results;
}

Database Integration

The current implementation uses static JSON data. To integrate with a database:

1. Update Prisma Schema

   model Region {
     id        String     @id @default(cuid())
     code      String     @unique
     label     String
     capital   String
     districts District[]
     createdAt DateTime   @default(now())
     updatedAt DateTime   @updatedAt
   }
   
   model District {
     id       String @id @default(cuid())
     code     String @unique
     label    String
     category String
     capital  String
     regionId String
     region   Region @relation(fields: [regionId], references: [id])
     createdAt DateTime @default(now())
     updatedAt DateTime @updatedAt
   }

2. Update Service

   @Injectable()
   export class LocationsService {
     constructor(private prisma: PrismaService) {}
   
     async getRegions(): Promise<RegionDto[]> {
       const regions = await this.prisma.region.findMany({
         select: { code: true, label: true },
       });
       return regions;
     }
   
     async getDistricts(regionId: string): Promise<DistrictDto[]> {
       const districts = await this.prisma.district.findMany({
         where: { region: { code: regionId } },
         select: { code: true, label: true, category: true, capital: true },
       });
       return districts;
     }
   }

🧪 Testing

Unit Tests

describe("LocationsService", () => {
  let service: LocationsService;

  beforeEach(async () => {
    const module = await Test.createTestingModule({
      providers: [LocationsService],
    }).compile();

    service = module.get<LocationsService>(LocationsService);
  });

  it("should return all regions", () => {
    const regions = service.getRegions();
    expect(regions).toBeDefined();
    expect(regions.length).toBeGreaterThan(0);
  });

  it("should return districts for a valid region", () => {
    const districts = service.getDistricts("AR");
    expect(districts).toBeDefined();
    expect(districts.length).toBeGreaterThan(0);
  });
});

Integration Tests

describe("LocationsController (e2e)", () => {
  let app: INestApplication;

  beforeEach(async () => {
    const moduleFixture = await Test.createTestingModule({
      imports: [AppModule],
    }).compile();

    app = moduleFixture.createNestApplication();
    await app.init();
  });

  it("/locations/regions (GET)", () => {
    return request(app.getHttpServer())
      .get("/locations/regions")
      .expect(200)
      .expect((res) => {
        expect(Array.isArray(res.body)).toBe(true);
        expect(res.body.length).toBeGreaterThan(0);
      });
  });
});

📊 Data Validation

Region Data Validation

• Code: Must be 2-3 characters, unique across all regions
• Label: Must be a valid region name, properly capitalized
• Capital: Must be a valid city name within the region
• Districts: Must be a non-empty array

District Data Validation

• Code: Must be 3-4 characters, unique across all districts
• Label: Must be a valid district name
• Category: Must be one of: "Municipal", "Metropolitan", "District"
• Capital: Must be a valid town/city name

🔄 Future Enhancements

Planned Features

1. Geographic Boundaries

   • GeoJSON polygon data for regions and districts
   • Spatial queries and calculations
   • Map visualization endpoints

2. Enhanced Search

   • Fuzzy search with typo tolerance
   • Search by coordinates (reverse geocoding)
   • Search by postal codes

3. Population Data

   • Integration with Ghana Statistical Service data
   • Population density calculations
   • Demographic statistics

4. Local Government Data

   • Assembly member information
   • Contact details for local authorities
   • Service delivery points

Contribution Priorities

1. High Priority

   • Add GPS coordinates for all administrative centers
   • Implement comprehensive search functionality
   • Add data validation and error handling

2. Medium Priority

   • Database integration with Prisma
   • Add constituency data
   • Implement caching for better performance

3. Low Priority

   • Geographic boundary data
   • Population and demographic integration
   • Advanced analytics features

🤝 Contributing Process

1. Fork the Repository
2. Create a Feature Branch

   git checkout -b feature/locations-enhancement

3. Make Your Changes
   • Follow the coding standards
   • Add appropriate tests
   • Update documentation
4. Test Your Changes

   npm run test
   npm run test:e2e

5. Submit a Pull Request
   • Provide clear description of changes
   • Include test results
   • Reference any related issues

📚 Resources

• Ghana Statistical Service
• Local Government Service
• NestJS Documentation
• Prisma Documentation

🆘 Getting Help

• Issues: Create an issue for bugs or feature requests
• Discussions: Use GitHub Discussions for questions
• Documentation: Check existing docs and examples
• Community: Join our Discord or Slack channels

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Thank you for contributing to Ghana's location data services! Your contributions help make geographic information more accessible and accurate for everyone.