feat: Add database migration, seeding, and testing commands with Makefile integration

backend/Makefile

@@ -0,0 +1,77 @@
+# Time Tracker Backend Makefile
+
+.PHONY: db-start db-stop db-test model-test run build clean migrate seed help
+
+# Default target
+.DEFAULT_GOAL := help
+
+# Variables
+BINARY_NAME=timetracker
+DB_CONTAINER=timetracker_db
+
+# Help target
+help:
+	@echo "Time Tracker Backend Makefile"
+	@echo ""
+	@echo "Usage:"
+	@echo "  make db-start    - Start the PostgreSQL database container"
+	@echo "  make db-stop     - Stop the PostgreSQL database container"
+	@echo "  make db-test     - Test the database connection"
+	@echo "  make model-test  - Test the database models"
+	@echo "  make run         - Run the application"
+	@echo "  make build       - Build the application"
+	@echo "  make clean       - Remove build artifacts"
+	@echo "  make migrate     - Run database migrations"
+	@echo "  make seed        - Seed the database with initial data"
+	@echo "  make help        - Show this help message"
+
+# Start the database
+db-start:
+	@echo "Starting PostgreSQL database container..."
+	@cd .. && docker-compose up -d db
+	@echo "Database container started"
+
+# Stop the database
+db-stop:
+	@echo "Stopping PostgreSQL database container..."
+	@cd .. && docker-compose stop db
+	@echo "Database container stopped"
+
+# Test the database connection
+db-test:
+	@echo "Testing database connection..."
+	@go run cmd/dbtest/main.go
+
+# Test the database models
+model-test:
+	@echo "Testing database models..."
+	@go run cmd/modeltest/main.go
+
+# Run the application
+run:
+	@echo "Running the application..."
+	@go run cmd/api/main.go
+
+# Build the application
+build:
+	@echo "Building the application..."
+	@go build -o $(BINARY_NAME) cmd/api/main.go
+	@echo "Build complete: $(BINARY_NAME)"
+
+# Clean build artifacts
+clean:
+	@echo "Cleaning build artifacts..."
+	@rm -f $(BINARY_NAME)
+	@echo "Clean complete"
+
+# Run database migrations
+migrate:
+	@echo "Running database migrations..."
+	@go run -mod=mod cmd/migrate/main.go
+	@echo "Migrations complete"
+
+# Seed the database with initial data
+seed:
+	@echo "Seeding the database..."
+	@go run -mod=mod cmd/seed/main.go
+	@echo "Seeding complete"

backend/README.md

@@ -0,0 +1,147 @@
+# Time Tracker Backend
+
+This is the backend service for the Time Tracker application, built with Go, Gin, and GORM.
+
+## Database Setup
+
+The application uses PostgreSQL as its database. The database connection is configured using GORM, a popular Go ORM library.
+
+### Configuration
+
+Database configuration is handled through the `models.DatabaseConfig` struct in `internal/models/db.go`. The application uses sensible defaults that can be overridden with environment variables:
+
+- `DB_HOST`: Database host (default: "localhost")
+- `DB_PORT`: Database port (default: 5432)
+- `DB_USER`: Database user (default: "timetracker")
+- `DB_PASSWORD`: Database password (default: "password")
+- `DB_NAME`: Database name (default: "timetracker")
+- `DB_SSLMODE`: SSL mode (default: "disable")
+
+### Running with Docker
+
+The easiest way to run the database is using Docker Compose:
+
+```bash
+# Start the database
+docker-compose up -d db
+
+# Check if the database is running
+docker-compose ps
+```
+
+### Database Migrations
+
+The application automatically migrates the database schema on startup using GORM's AutoMigrate feature. This creates all necessary tables based on the model definitions.
+
+### Initial Data Seeding
+
+The application seeds the database with initial data if it's empty. This includes:
+
+- A default company
+- An admin user with email "admin@example.com" and password "Admin@123456"
+
+## Running the Application
+
+### Using Make Commands
+
+The project includes a Makefile with common commands:
+
+```bash
+# Start the database
+make db-start
+
+# Test the database connection
+make db-test
+
+# Run database migrations
+make migrate
+
+# Seed the database with initial data
+make seed
+
+# Test the database models
+make model-test
+
+# Run the application
+make run
+
+# Build the application
+make build
+
+# Show all available commands
+make help
+```
+
+### Manual Commands
+
+If you prefer not to use Make, you can run the commands directly:
+
+```bash
+# Start the database
+cd /path/to/timetracker
+docker-compose up -d db
+
+# Test the database connection
+cd backend
+go run cmd/dbtest/main.go
+
+# Run database migrations
+cd backend
+go run cmd/migrate/main.go
+
+# Seed the database with initial data
+cd backend
+go run cmd/seed/main.go
+
+# Run the backend application
+cd backend
+go run cmd/api/main.go
+```
+
+The API will be available at http://localhost:8080/api and the Swagger documentation at http://localhost:8080/swagger/index.html.
+
+### Environment Variables
+
+You can configure the database connection using environment variables:
+
+```bash
+# Example: Connect to a different database
+DB_HOST=my-postgres-server DB_PORT=5432 DB_USER=myuser DB_PASSWORD=mypassword DB_NAME=mydb go run cmd/api/main.go
+```
+
+## Database Models
+
+The application uses the following models:
+
+- `User`: Represents a user in the system
+- `Company`: Represents a company
+- `Customer`: Represents a customer
+- `Project`: Represents a project
+- `Activity`: Represents an activity
+- `TimeEntry`: Represents a time entry
+
+Each model has corresponding CRUD operations and relationships defined in the `internal/models` directory.
+
+## GORM Best Practices
+
+The application follows these GORM best practices:
+
+1. **Connection Pooling**: Configured with sensible defaults for maximum idle connections, maximum open connections, and connection lifetime.
+
+2. **Migrations**: Uses GORM's AutoMigrate to automatically create and update database tables.
+
+3. **Transactions**: Uses transactions for operations that require multiple database changes to ensure data consistency.
+
+4. **Soft Deletes**: Uses GORM's soft delete feature to mark records as deleted without actually removing them from the database.
+
+5. **Relationships**: Properly defines relationships between models using GORM's relationship features.
+
+6. **Error Handling**: Properly handles database errors and returns appropriate error messages.
+
+7. **Context Support**: Uses context for database operations to support timeouts and cancellation.
+
+8. **Logging**: Configures GORM's logger for appropriate logging based on the environment.
+
+9. **Graceful Shutdown**: Properly closes database connections when the application shuts down.
+
+10. **Validation**: Implements validation for model fields before saving to the database.

backend/cmd/api/docs/docs.go

@@ -0,0 +1,62 @@
+// Package docs Code generated by swaggo/swag. DO NOT EDIT
+package docs
+
+import "github.com/swaggo/swag"
+
+const docTemplate = `{
+    "schemes": {{ marshal .Schemes }},
+    "swagger": "2.0",
+    "info": {
+        "description": "{{escape .Description}}",
+        "title": "{{.Title}}",
+        "contact": {},
+        "version": "{{.Version}}"
+    },
+    "host": "{{.Host}}",
+    "basePath": "{{.BasePath}}",
+    "paths": {
+        "/": {
+            "get": {
+                "description": "Get a hello message",
+                "produces": [
+                    "text/plain"
+                ],
+                "summary": "Say hello",
+                "operationId": "hello",
+                "responses": {
+                    "200": {
+                        "description": "Hello from the Time Tracker Backend!",
+                        "schema": {
+                            "type": "string"
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "securityDefinitions": {
+        "BearerAuth": {
+            "type": "apiKey",
+            "name": "Authorization",
+            "in": "header"
+        }
+    }
+}`
+
+// SwaggerInfo holds exported Swagger Info so clients can modify it
+var SwaggerInfo = &swag.Spec{
+	Version:          "1.0",
+	Host:             "localhost:8080",
+	BasePath:         "/api",
+	Schemes:          []string{},
+	Title:            "Time Tracker API",
+	Description:      "This is a simple time tracker API.",
+	InfoInstanceName: "swagger",
+	SwaggerTemplate:  docTemplate,
+	LeftDelim:        "{{",
+	RightDelim:       "}}",
+}
+
+func init() {
+	swag.Register(SwaggerInfo.InstanceName(), SwaggerInfo)
+}

backend/cmd/api/docs/swagger.json

@@ -0,0 +1,38 @@
+{
+    "swagger": "2.0",
+    "info": {
+        "description": "This is a simple time tracker API.",
+        "title": "Time Tracker API",
+        "contact": {},
+        "version": "1.0"
+    },
+    "host": "localhost:8080",
+    "basePath": "/api",
+    "paths": {
+        "/": {
+            "get": {
+                "description": "Get a hello message",
+                "produces": [
+                    "text/plain"
+                ],
+                "summary": "Say hello",
+                "operationId": "hello",
+                "responses": {
+                    "200": {
+                        "description": "Hello from the Time Tracker Backend!",
+                        "schema": {
+                            "type": "string"
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "securityDefinitions": {
+        "BearerAuth": {
+            "type": "apiKey",
+            "name": "Authorization",
+            "in": "header"
+        }
+    }
+}

backend/cmd/api/docs/swagger.yaml

@@ -0,0 +1,26 @@
+basePath: /api
+host: localhost:8080
+info:
+  contact: {}
+  description: This is a simple time tracker API.
+  title: Time Tracker API
+  version: "1.0"
+paths:
+  /:
+    get:
+      description: Get a hello message
+      operationId: hello
+      produces:
+      - text/plain
+      responses:
+        "200":
+          description: Hello from the Time Tracker Backend!
+          schema:
+            type: string
+      summary: Say hello
+securityDefinitions:
+  BearerAuth:
+    in: header
+    name: Authorization
+    type: apiKey
+swagger: "2.0"

backend/cmd/api/main.go

@@ -1,9 +1,14 @@
 package main
 
 import (
+	"context"
 	"fmt"
 	"log"
 	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
 
 	"github.com/gin-gonic/gin"
 	swaggerFiles "github.com/swaggo/files"
@@ -12,6 +17,7 @@ import (
 	"github.com/timetracker/backend/internal/api/routes"
 	"github.com/timetracker/backend/internal/models"
 	_ "gorm.io/driver/postgres"
+	"gorm.io/gorm/logger"
 	// GORM IMPORTS MARKER
 )
 
@@ -24,39 +30,76 @@ import (
 //	@in							header
 //	@name						Authorization
 
-//	@x-extension	ulid.ULID string
-
-//	@Summary		Say hello
-//	@Description	Get a hello message
-//	@ID				hello
-//	@Produce		plain
-//	@Success		200	{string}	string	"Hello from the Time Tracker Backend!"
-//	@Router			/ [get]
+// @Summary		Say hello
+// @Description	Get a hello message
+// @ID				hello
+// @Produce		plain
+// @Success		200	{string}	string	"Hello from the Time Tracker Backend!"
+// @Router			/ [get]
 func helloHandler(c *gin.Context) {
 	c.String(http.StatusOK, "Hello from the Time Tracker Backend!")
 }
 
 func main() {
-	// Configure database
-	dbConfig := models.DatabaseConfig{
-		Host:     "localhost",
-		Port:     5432,
-		User:     "postgres",
-		Password: "password",
-		DBName:   "mydatabase",
-		SSLMode:  "disable", // For development environment
+	// Get database configuration with sensible defaults
+	dbConfig := models.DefaultDatabaseConfig()
+
+	// Override with environment variables if provided
+	if host := os.Getenv("DB_HOST"); host != "" {
+		dbConfig.Host = host
+	}
+	if port := os.Getenv("DB_PORT"); port != "" {
+		var portInt int
+		if _, err := fmt.Sscanf(port, "%d", &portInt); err == nil && portInt > 0 {
+			dbConfig.Port = portInt
+		}
+	}
+	if user := os.Getenv("DB_USER"); user != "" {
+		dbConfig.User = user
+	}
+	if password := os.Getenv("DB_PASSWORD"); password != "" {
+		dbConfig.Password = password
+	}
+	if dbName := os.Getenv("DB_NAME"); dbName != "" {
+		dbConfig.DBName = dbName
+	}
+	if sslMode := os.Getenv("DB_SSLMODE"); sslMode != "" {
+		dbConfig.SSLMode = sslMode
+	}
+
+	// Set log level based on environment
+	if gin.Mode() == gin.ReleaseMode {
+		dbConfig.LogLevel = logger.Error // Only log errors in production
+	} else {
+		dbConfig.LogLevel = logger.Info // Log more in development
 	}
 
 	// Initialize database
 	if err := models.InitDB(dbConfig); err != nil {
 		log.Fatalf("Error initializing database: %v", err)
 	}
+	defer func() {
+		if err := models.CloseDB(); err != nil {
+			log.Printf("Error closing database connection: %v", err)
+		}
+	}()
+
+	// Migrate database schema
+	if err := models.MigrateDB(); err != nil {
+		log.Fatalf("Error migrating database: %v", err)
+	}
+
+	// Seed database with initial data if needed
+	ctx := context.Background()
+	if err := models.SeedDB(ctx); err != nil {
+		log.Fatalf("Error seeding database: %v", err)
+	}
 
 	// Create Gin router
 	r := gin.Default()
 
 	// Basic route for health check
-	r.GET("/", helloHandler)
+	r.GET("/api", helloHandler)
 
 	// Setup API routes
 	routes.SetupRouter(r)
@@ -64,7 +107,34 @@ func main() {
 	// Swagger documentation
 	r.GET("/swagger/*any", ginSwagger.WrapHandler(swaggerFiles.Handler))
 
-	// Start server
-	fmt.Println("Server listening on port 8080")
-	r.Run(":8080")
+	// Create a server with graceful shutdown
+	srv := &http.Server{
+		Addr:    ":8080",
+		Handler: r,
+	}
+
+	// Start server in a goroutine
+	go func() {
+		fmt.Println("Server listening on port 8080")
+		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Fatalf("Error starting server: %v", err)
+		}
+	}()
+
+	// Wait for interrupt signal to gracefully shut down the server
+	quit := make(chan os.Signal, 1)
+	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
+	<-quit
+	log.Println("Shutting down server...")
+
+	// Create a deadline for server shutdown
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	// Shutdown the server
+	if err := srv.Shutdown(ctx); err != nil {
+		log.Fatalf("Server forced to shutdown: %v", err)
+	}
+
+	log.Println("Server exited properly")
 }

backend/cmd/dbtest/main.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/timetracker/backend/internal/models"
+)
+
+func main() {
+	// Get database configuration with sensible defaults
+	dbConfig := models.DefaultDatabaseConfig()
+
+	// Initialize database
+	fmt.Println("Connecting to database...")
+	if err := models.InitDB(dbConfig); err != nil {
+		log.Fatalf("Error initializing database: %v", err)
+	}
+	defer func() {
+		if err := models.CloseDB(); err != nil {
+			log.Printf("Error closing database connection: %v", err)
+		}
+	}()
+	fmt.Println("✓ Database connection successful")
+
+	// Test a simple query
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	// Get the database engine
+	db := models.GetEngine(ctx)
+
+	// Test database connection with a simple query
+	var result int
+	err := db.Raw("SELECT 1").Scan(&result).Error
+	if err != nil {
+		log.Fatalf("Error executing test query: %v", err)
+	}
+	fmt.Println("✓ Test query executed successfully")
+
+	// Check if tables exist
+	fmt.Println("Checking database tables...")
+	var tables []string
+	err = db.Raw("SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'").Scan(&tables).Error
+	if err != nil {
+		log.Fatalf("Error checking tables: %v", err)
+	}
+
+	if len(tables) == 0 {
+		fmt.Println("No tables found. You may need to run migrations.")
+		fmt.Println("Attempting to run migrations...")
+
+		// Run migrations
+		if err := models.MigrateDB(); err != nil {
+			log.Fatalf("Error migrating database: %v", err)
+		}
+		fmt.Println("✓ Migrations completed successfully")
+	} else {
+		fmt.Println("Found tables:")
+		for _, table := range tables {
+			fmt.Printf("  - %s\n", table)
+		}
+	}
+
+	// Count users
+	var userCount int64
+	err = db.Model(&models.User{}).Count(&userCount).Error
+	if err != nil {
+		log.Fatalf("Error counting users: %v", err)
+	}
+	fmt.Printf("✓ User count: %d\n", userCount)
+
+	// Count companies
+	var companyCount int64
+	err = db.Model(&models.Company{}).Count(&companyCount).Error
+	if err != nil {
+		log.Fatalf("Error counting companies: %v", err)
+	}
+	fmt.Printf("✓ Company count: %d\n", companyCount)
+
+	fmt.Println("\nDatabase test completed successfully!")
+}

backend/cmd/migrate/main.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/timetracker/backend/internal/models"
+	"gorm.io/gorm/logger"
+)
+
+func main() {
+	// Parse command line flags
+	verbose := false
+	for _, arg := range os.Args[1:] {
+		if arg == "--verbose" || arg == "-v" {
+			verbose = true
+		}
+	}
+
+	if verbose {
+		fmt.Println("Running in verbose mode")
+	}
+
+	// Get database configuration with sensible defaults
+	dbConfig := models.DefaultDatabaseConfig()
+
+	// Override with environment variables if provided
+	if host := os.Getenv("DB_HOST"); host != "" {
+		dbConfig.Host = host
+	}
+	if port := os.Getenv("DB_PORT"); port != "" {
+		var portInt int
+		if _, err := fmt.Sscanf(port, "%d", &portInt); err == nil && portInt > 0 {
+			dbConfig.Port = portInt
+		}
+	}
+	if user := os.Getenv("DB_USER"); user != "" {
+		dbConfig.User = user
+	}
+	if password := os.Getenv("DB_PASSWORD"); password != "" {
+		dbConfig.Password = password
+	}
+	if dbName := os.Getenv("DB_NAME"); dbName != "" {
+		dbConfig.DBName = dbName
+	}
+	if sslMode := os.Getenv("DB_SSLMODE"); sslMode != "" {
+		dbConfig.SSLMode = sslMode
+	}
+
+	// Set log level
+	dbConfig.LogLevel = logger.Info
+
+	// Initialize database
+	fmt.Println("Connecting to database...")
+	if err := models.InitDB(dbConfig); err != nil {
+		log.Fatalf("Error initializing database: %v", err)
+	}
+	defer func() {
+		if err := models.CloseDB(); err != nil {
+			log.Printf("Error closing database connection: %v", err)
+		}
+	}()
+	fmt.Println("✓ Database connection successful")
+
+	// Run migrations
+	fmt.Println("Running database migrations...")
+	if err := models.MigrateDB(); err != nil {
+		log.Fatalf("Error migrating database: %v", err)
+	}
+	fmt.Println("✓ Database migrations completed successfully")
+}

backend/cmd/modeltest/main.go

@@ -0,0 +1,207 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/oklog/ulid/v2"
+	"github.com/timetracker/backend/internal/models"
+)
+
+func main() {
+	// Get database configuration with sensible defaults
+	dbConfig := models.DefaultDatabaseConfig()
+
+	// Initialize database
+	fmt.Println("Connecting to database...")
+	if err := models.InitDB(dbConfig); err != nil {
+		log.Fatalf("Error initializing database: %v", err)
+	}
+	defer func() {
+		if err := models.CloseDB(); err != nil {
+			log.Printf("Error closing database connection: %v", err)
+		}
+	}()
+	fmt.Println("✓ Database connection successful")
+
+	// Create context with timeout
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	// Test Company model
+	fmt.Println("\n=== Testing Company Model ===")
+	testCompanyModel(ctx)
+
+	// Test User model
+	fmt.Println("\n=== Testing User Model ===")
+	testUserModel(ctx)
+
+	// Test relationships
+	fmt.Println("\n=== Testing Relationships ===")
+	testRelationships(ctx)
+
+	fmt.Println("\nModel tests completed successfully!")
+}
+
+func testCompanyModel(ctx context.Context) {
+	// Create a new company
+	companyCreate := models.CompanyCreate{
+		Name: "Test Company",
+	}
+
+	company, err := models.CreateCompany(ctx, companyCreate)
+	if err != nil {
+		log.Fatalf("Error creating company: %v", err)
+	}
+	fmt.Printf("✓ Created company: %s (ID: %s)\n", company.Name, company.ID)
+
+	// Get the company by ID
+	retrievedCompany, err := models.GetCompanyByID(ctx, company.ID)
+	if err != nil {
+		log.Fatalf("Error getting company: %v", err)
+	}
+	if retrievedCompany == nil {
+		log.Fatalf("Company not found")
+	}
+	fmt.Printf("✓ Retrieved company: %s\n", retrievedCompany.Name)
+
+	// Update the company
+	newName := "Updated Test Company"
+	companyUpdate := models.CompanyUpdate{
+		ID:   company.ID,
+		Name: &newName,
+	}
+
+	updatedCompany, err := models.UpdateCompany(ctx, companyUpdate)
+	if err != nil {
+		log.Fatalf("Error updating company: %v", err)
+	}
+	fmt.Printf("✓ Updated company name to: %s\n", updatedCompany.Name)
+
+	// Get all companies
+	companies, err := models.GetAllCompanies(ctx)
+	if err != nil {
+		log.Fatalf("Error getting all companies: %v", err)
+	}
+	fmt.Printf("✓ Retrieved %d companies\n", len(companies))
+}
+
+func testUserModel(ctx context.Context) {
+	// Get a company to associate with the user
+	companies, err := models.GetAllCompanies(ctx)
+	if err != nil || len(companies) == 0 {
+		log.Fatalf("Error getting companies or no companies found: %v", err)
+	}
+	companyID := companies[0].ID
+
+	// Create a new user
+	userCreate := models.UserCreate{
+		Email:      "test@example.com",
+		Password:   "Test@123456",
+		Role:       models.RoleUser,
+		CompanyID:  companyID,
+		HourlyRate: 50.0,
+	}
+
+	user, err := models.CreateUser(ctx, userCreate)
+	if err != nil {
+		log.Fatalf("Error creating user: %v", err)
+	}
+	fmt.Printf("✓ Created user: %s (ID: %s)\n", user.Email, user.ID)
+
+	// Get the user by ID
+	retrievedUser, err := models.GetUserByID(ctx, user.ID)
+	if err != nil {
+		log.Fatalf("Error getting user: %v", err)
+	}
+	if retrievedUser == nil {
+		log.Fatalf("User not found")
+	}
+	fmt.Printf("✓ Retrieved user: %s\n", retrievedUser.Email)
+
+	// Get the user by email
+	emailUser, err := models.GetUserByEmail(ctx, user.Email)
+	if err != nil {
+		log.Fatalf("Error getting user by email: %v", err)
+	}
+	if emailUser == nil {
+		log.Fatalf("User not found by email")
+	}
+	fmt.Printf("✓ Retrieved user by email: %s\n", emailUser.Email)
+
+	// Update the user
+	newEmail := "updated@example.com"
+	newRole := models.RoleAdmin
+	newHourlyRate := 75.0
+	userUpdate := models.UserUpdate{
+		ID:         user.ID,
+		Email:      &newEmail,
+		Role:       &newRole,
+		HourlyRate: &newHourlyRate,
+	}
+
+	updatedUser, err := models.UpdateUser(ctx, userUpdate)
+	if err != nil {
+		log.Fatalf("Error updating user: %v", err)
+	}
+	fmt.Printf("✓ Updated user email to: %s, role to: %s\n", updatedUser.Email, updatedUser.Role)
+
+	// Test authentication
+	authUser, err := models.AuthenticateUser(ctx, updatedUser.Email, "Test@123456")
+	if err != nil {
+		log.Fatalf("Error authenticating user: %v", err)
+	}
+	if authUser == nil {
+		log.Fatalf("Authentication failed")
+	}
+	fmt.Printf("✓ User authentication successful\n")
+
+	// Get all users
+	users, err := models.GetAllUsers(ctx)
+	if err != nil {
+		log.Fatalf("Error getting all users: %v", err)
+	}
+	fmt.Printf("✓ Retrieved %d users\n", len(users))
+
+	// Get users by company ID
+	companyUsers, err := models.GetUsersByCompanyID(ctx, companyID)
+	if err != nil {
+		log.Fatalf("Error getting users by company ID: %v", err)
+	}
+	fmt.Printf("✓ Retrieved %d users for company ID: %s\n", len(companyUsers), companyID)
+}
+
+func testRelationships(ctx context.Context) {
+	// Get a user with company
+	users, err := models.GetAllUsers(ctx)
+	if err != nil || len(users) == 0 {
+		log.Fatalf("Error getting users or no users found: %v", err)
+	}
+	userID := users[0].ID
+
+	// Get user with company
+	user, err := models.GetUserWithCompany(ctx, userID)
+	if err != nil {
+		log.Fatalf("Error getting user with company: %v", err)
+	}
+	if user == nil {
+		log.Fatalf("User not found")
+	}
+	if user.Company == nil {
+		log.Fatalf("User's company not loaded")
+	}
+	fmt.Printf("✓ Retrieved user %s with company %s\n", user.Email, user.Company.Name)
+
+	// Test invalid ID
+	invalidID := ulid.MustNew(ulid.Timestamp(time.Now()), ulid.DefaultEntropy())
+	invalidUser, err := models.GetUserByID(ctx, invalidID)
+	if err != nil {
+		log.Fatalf("Error getting user with invalid ID: %v", err)
+	}
+	if invalidUser != nil {
+		log.Fatalf("User found with invalid ID")
+	}
+	fmt.Printf("✓ Correctly handled invalid user ID\n")
+}

backend/cmd/seed/main.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"time"
+
+	"github.com/timetracker/backend/internal/models"
+	"gorm.io/gorm/logger"
+)
+
+func main() {
+	// Parse command line flags
+	force := false
+	for _, arg := range os.Args[1:] {
+		if arg == "--force" || arg == "-f" {
+			force = true
+		}
+	}
+
+	// Get database configuration with sensible defaults
+	dbConfig := models.DefaultDatabaseConfig()
+
+	// Override with environment variables if provided
+	if host := os.Getenv("DB_HOST"); host != "" {
+		dbConfig.Host = host
+	}
+	if port := os.Getenv("DB_PORT"); port != "" {
+		var portInt int
+		if _, err := fmt.Sscanf(port, "%d", &portInt); err == nil && portInt > 0 {
+			dbConfig.Port = portInt
+		}
+	}
+	if user := os.Getenv("DB_USER"); user != "" {
+		dbConfig.User = user
+	}
+	if password := os.Getenv("DB_PASSWORD"); password != "" {
+		dbConfig.Password = password
+	}
+	if dbName := os.Getenv("DB_NAME"); dbName != "" {
+		dbConfig.DBName = dbName
+	}
+	if sslMode := os.Getenv("DB_SSLMODE"); sslMode != "" {
+		dbConfig.SSLMode = sslMode
+	}
+
+	// Set log level
+	dbConfig.LogLevel = logger.Info
+
+	// Initialize database
+	fmt.Println("Connecting to database...")
+	if err := models.InitDB(dbConfig); err != nil {
+		log.Fatalf("Error initializing database: %v", err)
+	}
+	defer func() {
+		if err := models.CloseDB(); err != nil {
+			log.Printf("Error closing database connection: %v", err)
+		}
+	}()
+	fmt.Println("✓ Database connection successful")
+
+	// Create context with timeout
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	// Check if we need to seed (e.g., no companies exist)
+	if !force {
+		var count int64
+		db := models.GetEngine(ctx)
+		if err := db.Model(&models.Company{}).Count(&count).Error; err != nil {
+			log.Fatalf("Error checking if seeding is needed: %v", err)
+		}
+
+		// If data already exists, skip seeding
+		if count > 0 {
+			fmt.Println("Database already contains data. Use --force to override.")
+			return
+		}
+	}
+
+	// Seed the database
+	fmt.Println("Seeding database with initial data...")
+	if err := models.SeedDB(ctx); err != nil {
+		log.Fatalf("Error seeding database: %v", err)
+	}
+	fmt.Println("✓ Database seeding completed successfully")
+}

backend/internal/api/handlers/activity_handler.go

@@ -26,7 +26,7 @@ func NewActivityHandler() *ActivityHandler {
 //	@Accept			json
 //	@Produce		json
 //	@Security		BearerAuth
-//	@Success		200	{object}	utils.Response{data=[]utils.ActivityResponse}
+//	@Success		200	{object}	utils.Response{data=[]dto.ActivityDto}
 //	@Failure		401	{object}	utils.Response{error=utils.ErrorInfo}
 //	@Failure		500	{object}	utils.Response{error=utils.ErrorInfo}
 //	@Router			/activities [get]
@@ -56,7 +56,7 @@ func (h *ActivityHandler) GetActivities(c *gin.Context) {
 //	@Produce		json
 //	@Security		BearerAuth
 //	@Param			id	path		string	true	"Activity ID"
-//	@Success		200	{object}	utils.Response{data=utils.ActivityResponse}
+//	@Success		200	{object}	utils.Response{data=dto.ActivityDto}
 //	@Failure		400	{object}	utils.Response{error=utils.ErrorInfo}
 //	@Failure		401	{object}	utils.Response{error=utils.ErrorInfo}
 //	@Failure		404	{object}	utils.Response{error=utils.ErrorInfo}

backend/internal/api/handlers/user_handler.go

@@ -261,6 +261,52 @@ func (h *UserHandler) Login(c *gin.Context) {
 	utils.SuccessResponse(c, http.StatusOK, tokenDTO)
 }
 
+// Register handles POST /auth/register
+//
+//	@Summary		Register
+//	@Description	Register a new user and get a JWT token
+//	@Tags			auth
+//	@Accept			json
+//	@Produce		json
+//	@Param			user	body		dto.UserCreateDto	true	"User data"
+//	@Success		201		{object}	utils.Response{data=dto.TokenDto}
+//	@Failure		400		{object}	utils.Response{error=utils.ErrorInfo}
+//	@Failure		500		{object}	utils.Response{error=utils.ErrorInfo}
+//	@Router			/auth/register [post]
+func (h *UserHandler) Register(c *gin.Context) {
+	// Parse request body
+	var userCreateDTO dto.UserCreateDto
+	if err := c.ShouldBindJSON(&userCreateDTO); err != nil {
+		utils.BadRequestResponse(c, "Invalid request body: "+err.Error())
+		return
+	}
+
+	// Convert DTO to model
+	userCreate := convertCreateDTOToModel(userCreateDTO)
+
+	// Create user in the database
+	user, err := models.CreateUser(c.Request.Context(), userCreate)
+	if err != nil {
+		utils.InternalErrorResponse(c, "Error creating user: "+err.Error())
+		return
+	}
+
+	// Generate JWT token
+	token, err := middleware.GenerateToken(user)
+	if err != nil {
+		utils.InternalErrorResponse(c, "Error generating token: "+err.Error())
+		return
+	}
+
+	// Return token
+	tokenDTO := dto.TokenDto{
+		Token: token,
+		User:  convertUserToDTO(user),
+	}
+
+	utils.SuccessResponse(c, http.StatusCreated, tokenDTO)
+}
+
 // GetCurrentUser handles GET /auth/me
 //
 //	@Summary		Get current user

backend/internal/api/routes/router.go

@@ -16,84 +16,92 @@ func SetupRouter(r *gin.Engine) {
 	projectHandler := handlers.NewProjectHandler()
 	timeEntryHandler := handlers.NewTimeEntryHandler()
 
-	// Public routes
-	r.POST("/auth/login", userHandler.Login)
-
-	// API routes (protected)
+	// API routes
 	api := r.Group("/api")
-	api.Use(middleware.AuthMiddleware())
 	{
-		// Auth routes
+		// Auth routes (public)
 		auth := api.Group("/auth")
 		{
-			auth.GET("/me", userHandler.GetCurrentUser)
+			auth.POST("/login", userHandler.Login)
+			auth.POST("/register", userHandler.Register)
 		}
 
-		// User routes
-		users := api.Group("/users")
+		// Protected routes
+		protected := api.Group("")
+		protected.Use(middleware.AuthMiddleware())
 		{
-			users.GET("", userHandler.GetUsers)
-			users.GET("/:id", userHandler.GetUserByID)
-			users.POST("", middleware.RoleMiddleware("admin"), userHandler.CreateUser)
-			users.PUT("/:id", middleware.RoleMiddleware("admin"), userHandler.UpdateUser)
-			users.DELETE("/:id", middleware.RoleMiddleware("admin"), userHandler.DeleteUser)
-		}
+			// Auth routes (protected)
+			protectedAuth := protected.Group("/auth")
+			{
+				protectedAuth.GET("/me", userHandler.GetCurrentUser)
+			}
 
-		// Activity routes
-		activities := api.Group("/activities")
-		{
-			activities.GET("", activityHandler.GetActivities)
-			activities.GET("/:id", activityHandler.GetActivityByID)
-			activities.POST("", middleware.RoleMiddleware("admin"), activityHandler.CreateActivity)
-			activities.PUT("/:id", middleware.RoleMiddleware("admin"), activityHandler.UpdateActivity)
-			activities.DELETE("/:id", middleware.RoleMiddleware("admin"), activityHandler.DeleteActivity)
-		}
+			// User routes
+			users := protected.Group("/users")
+			{
+				users.GET("", userHandler.GetUsers)
+				users.GET("/:id", userHandler.GetUserByID)
+				users.POST("", middleware.RoleMiddleware("admin"), userHandler.CreateUser)
+				users.PUT("/:id", middleware.RoleMiddleware("admin"), userHandler.UpdateUser)
+				users.DELETE("/:id", middleware.RoleMiddleware("admin"), userHandler.DeleteUser)
+			}
 
-		// Company routes
-		companies := api.Group("/companies")
-		{
-			companies.GET("", companyHandler.GetCompanies)
-			companies.GET("/:id", companyHandler.GetCompanyByID)
-			companies.POST("", middleware.RoleMiddleware("admin"), companyHandler.CreateCompany)
-			companies.PUT("/:id", middleware.RoleMiddleware("admin"), companyHandler.UpdateCompany)
-			companies.DELETE("/:id", middleware.RoleMiddleware("admin"), companyHandler.DeleteCompany)
-		}
+			// Activity routes
+			activities := protected.Group("/activities")
+			{
+				activities.GET("", activityHandler.GetActivities)
+				activities.GET("/:id", activityHandler.GetActivityByID)
+				activities.POST("", middleware.RoleMiddleware("admin"), activityHandler.CreateActivity)
+				activities.PUT("/:id", middleware.RoleMiddleware("admin"), activityHandler.UpdateActivity)
+				activities.DELETE("/:id", middleware.RoleMiddleware("admin"), activityHandler.DeleteActivity)
+			}
 
-		// Customer routes
-		customers := api.Group("/customers")
-		{
-			customers.GET("", customerHandler.GetCustomers)
-			customers.GET("/:id", customerHandler.GetCustomerByID)
-			customers.GET("/company/:companyId", customerHandler.GetCustomersByCompanyID)
-			customers.POST("", middleware.RoleMiddleware("admin"), customerHandler.CreateCustomer)
-			customers.PUT("/:id", middleware.RoleMiddleware("admin"), customerHandler.UpdateCustomer)
-			customers.DELETE("/:id", middleware.RoleMiddleware("admin"), customerHandler.DeleteCustomer)
-		}
+			// Company routes
+			companies := protected.Group("/companies")
+			{
+				companies.GET("", companyHandler.GetCompanies)
+				companies.GET("/:id", companyHandler.GetCompanyByID)
+				companies.POST("", middleware.RoleMiddleware("admin"), companyHandler.CreateCompany)
+				companies.PUT("/:id", middleware.RoleMiddleware("admin"), companyHandler.UpdateCompany)
+				companies.DELETE("/:id", middleware.RoleMiddleware("admin"), companyHandler.DeleteCompany)
+			}
 
-		// Project routes
-		projects := api.Group("/projects")
-		{
-			projects.GET("", projectHandler.GetProjects)
-			projects.GET("/with-customers", projectHandler.GetProjectsWithCustomers)
-			projects.GET("/:id", projectHandler.GetProjectByID)
-			projects.GET("/customer/:customerId", projectHandler.GetProjectsByCustomerID)
-			projects.POST("", middleware.RoleMiddleware("admin"), projectHandler.CreateProject)
-			projects.PUT("/:id", middleware.RoleMiddleware("admin"), projectHandler.UpdateProject)
-			projects.DELETE("/:id", middleware.RoleMiddleware("admin"), projectHandler.DeleteProject)
-		}
+			// Customer routes
+			customers := protected.Group("/customers")
+			{
+				customers.GET("", customerHandler.GetCustomers)
+				customers.GET("/:id", customerHandler.GetCustomerByID)
+				customers.GET("/company/:companyId", customerHandler.GetCustomersByCompanyID)
+				customers.POST("", middleware.RoleMiddleware("admin"), customerHandler.CreateCustomer)
+				customers.PUT("/:id", middleware.RoleMiddleware("admin"), customerHandler.UpdateCustomer)
+				customers.DELETE("/:id", middleware.RoleMiddleware("admin"), customerHandler.DeleteCustomer)
+			}
 
-		// Time Entry routes
-		timeEntries := api.Group("/time-entries")
-		{
-			timeEntries.GET("", timeEntryHandler.GetTimeEntries)
-			timeEntries.GET("/me", timeEntryHandler.GetMyTimeEntries)
-			timeEntries.GET("/range", timeEntryHandler.GetTimeEntriesByDateRange)
-			timeEntries.GET("/:id", timeEntryHandler.GetTimeEntryByID)
-			timeEntries.GET("/user/:userId", timeEntryHandler.GetTimeEntriesByUserID)
-			timeEntries.GET("/project/:projectId", timeEntryHandler.GetTimeEntriesByProjectID)
-			timeEntries.POST("", timeEntryHandler.CreateTimeEntry)
-			timeEntries.PUT("/:id", timeEntryHandler.UpdateTimeEntry)
-			timeEntries.DELETE("/:id", timeEntryHandler.DeleteTimeEntry)
+			// Project routes
+			projects := protected.Group("/projects")
+			{
+				projects.GET("", projectHandler.GetProjects)
+				projects.GET("/with-customers", projectHandler.GetProjectsWithCustomers)
+				projects.GET("/:id", projectHandler.GetProjectByID)
+				projects.GET("/customer/:customerId", projectHandler.GetProjectsByCustomerID)
+				projects.POST("", middleware.RoleMiddleware("admin"), projectHandler.CreateProject)
+				projects.PUT("/:id", middleware.RoleMiddleware("admin"), projectHandler.UpdateProject)
+				projects.DELETE("/:id", middleware.RoleMiddleware("admin"), projectHandler.DeleteProject)
+			}
+
+			// Time Entry routes
+			timeEntries := protected.Group("/time-entries")
+			{
+				timeEntries.GET("", timeEntryHandler.GetTimeEntries)
+				timeEntries.GET("/me", timeEntryHandler.GetMyTimeEntries)
+				timeEntries.GET("/range", timeEntryHandler.GetTimeEntriesByDateRange)
+				timeEntries.GET("/:id", timeEntryHandler.GetTimeEntryByID)
+				timeEntries.GET("/user/:userId", timeEntryHandler.GetTimeEntriesByUserID)
+				timeEntries.GET("/project/:projectId", timeEntryHandler.GetTimeEntriesByProjectID)
+				timeEntries.POST("", timeEntryHandler.CreateTimeEntry)
+				timeEntries.PUT("/:id", timeEntryHandler.UpdateTimeEntry)
+				timeEntries.DELETE("/:id", timeEntryHandler.DeleteTimeEntry)
+			}
 		}
 	}
 }

backend/internal/models/db.go

@@ -4,11 +4,14 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log"
 	"reflect"
 	"strings"
+	"time"
 
 	"gorm.io/driver/postgres" // For PostgreSQL
 	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
 )
 
 // Global variable for the DB connection
@@ -16,12 +19,32 @@ var defaultDB *gorm.DB
 
 // DatabaseConfig contains the configuration data for the database connection
 type DatabaseConfig struct {
-	Host     string
-	Port     int
-	User     string
-	Password string
-	DBName   string
-	SSLMode  string
+	Host         string
+	Port         int
+	User         string
+	Password     string
+	DBName       string
+	SSLMode      string
+	MaxIdleConns int           // Maximum number of idle connections
+	MaxOpenConns int           // Maximum number of open connections
+	MaxLifetime  time.Duration // Maximum lifetime of a connection
+	LogLevel     logger.LogLevel
+}
+
+// DefaultDatabaseConfig returns a default configuration with sensible values
+func DefaultDatabaseConfig() DatabaseConfig {
+	return DatabaseConfig{
+		Host:         "localhost",
+		Port:         5432,
+		User:         "timetracker",
+		Password:     "password",
+		DBName:       "timetracker",
+		SSLMode:      "disable",
+		MaxIdleConns: 10,
+		MaxOpenConns: 100,
+		MaxLifetime:  time.Hour,
+		LogLevel:     logger.Info,
+	}
 }
 
 // InitDB initializes the database connection (once at startup)
@@ -31,22 +54,151 @@ func InitDB(config DatabaseConfig) error {
 	dsn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=%s",
 		config.Host, config.Port, config.User, config.Password, config.DBName, config.SSLMode)
 
-	// Establish database connection
-	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
+	// Configure GORM logger
+	gormLogger := logger.New(
+		log.New(log.Writer(), "\r\n", log.LstdFlags), // io writer
+		logger.Config{
+			SlowThreshold:             200 * time.Millisecond, // Slow SQL threshold
+			LogLevel:                  config.LogLevel,        // Log level
+			IgnoreRecordNotFoundError: true,                   // Ignore ErrRecordNotFound error for logger
+			Colorful:                  true,                   // Enable color
+		},
+	)
+
+	// Establish database connection with custom logger
+	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{
+		Logger: gormLogger,
+	})
 	if err != nil {
 		return fmt.Errorf("error connecting to the database: %w", err)
 	}
 
+	// Configure connection pool
+	sqlDB, err := db.DB()
+	if err != nil {
+		return fmt.Errorf("error getting database connection: %w", err)
+	}
+
+	// Set connection pool parameters
+	sqlDB.SetMaxIdleConns(config.MaxIdleConns)
+	sqlDB.SetMaxOpenConns(config.MaxOpenConns)
+	sqlDB.SetConnMaxLifetime(config.MaxLifetime)
+
 	defaultDB = db
 	return nil
 }
 
+// MigrateDB performs database migrations for all models
+func MigrateDB() error {
+	if defaultDB == nil {
+		return errors.New("database not initialized")
+	}
+
+	log.Println("Starting database migration...")
+
+	// Add all models that should be migrated here
+	err := defaultDB.AutoMigrate(
+		&Company{},
+		&User{},
+		&Customer{},
+		&Project{},
+		&Activity{},
+		&TimeEntry{},
+	)
+
+	if err != nil {
+		return fmt.Errorf("error migrating database: %w", err)
+	}
+
+	log.Println("Database migration completed successfully")
+	return nil
+}
+
+// SeedDB seeds the database with initial data if needed
+func SeedDB(ctx context.Context) error {
+	if defaultDB == nil {
+		return errors.New("database not initialized")
+	}
+
+	log.Println("Checking if database seeding is needed...")
+
+	// Check if we need to seed (e.g., no companies exist)
+	var count int64
+	if err := defaultDB.Model(&Company{}).Count(&count).Error; err != nil {
+		return fmt.Errorf("error checking if seeding is needed: %w", err)
+	}
+
+	// If data already exists, skip seeding
+	if count > 0 {
+		log.Println("Database already contains data, skipping seeding")
+		return nil
+	}
+
+	log.Println("Seeding database with initial data...")
+
+	// Start a transaction for all seed operations
+	return defaultDB.Transaction(func(tx *gorm.DB) error {
+		// Create a default company
+		defaultCompany := Company{
+			Name: "Default Company",
+		}
+		if err := tx.Create(&defaultCompany).Error; err != nil {
+			return fmt.Errorf("error creating default company: %w", err)
+		}
+
+		// Create an admin user
+		adminUser := User{
+			Email:      "admin@example.com",
+			Role:       RoleAdmin,
+			CompanyID:  defaultCompany.ID,
+			HourlyRate: 100.0,
+		}
+
+		// Hash a default password
+		pwData, err := HashPassword("Admin@123456")
+		if err != nil {
+			return fmt.Errorf("error hashing password: %w", err)
+		}
+
+		adminUser.Salt = pwData.Salt
+		adminUser.Hash = pwData.Hash
+
+		if err := tx.Create(&adminUser).Error; err != nil {
+			return fmt.Errorf("error creating admin user: %w", err)
+		}
+
+		log.Println("Database seeding completed successfully")
+		return nil
+	})
+}
+
 // GetEngine returns the DB instance, possibly with context
 func GetEngine(ctx context.Context) *gorm.DB {
+	if defaultDB == nil {
+		panic("database not initialized")
+	}
 	// If a special transaction is in ctx, you could check it here
 	return defaultDB.WithContext(ctx)
 }
 
+// CloseDB closes the database connection
+func CloseDB() error {
+	if defaultDB == nil {
+		return nil
+	}
+
+	sqlDB, err := defaultDB.DB()
+	if err != nil {
+		return fmt.Errorf("error getting database connection: %w", err)
+	}
+
+	if err := sqlDB.Close(); err != nil {
+		return fmt.Errorf("error closing database connection: %w", err)
+	}
+
+	return nil
+}
+
 // UpdateModel updates a model based on the set pointer fields
 func UpdateModel(ctx context.Context, model any, updates any) error {
 	updateValue := reflect.ValueOf(updates)

docker-compose.yml

@@ -0,0 +1,16 @@
+services:
+  db:
+    image: postgres:14
+    container_name: timetracker_db
+    restart: always
+    ports:
+      - "5432:5432"
+    environment:
+      POSTGRES_USER: timetracker
+      POSTGRES_PASSWORD: password
+      POSTGRES_DB: timetracker
+    volumes:
+      - db_data:/var/lib/postgresql/data
+
+volumes:
+  db_data:

docu/swagger_documentation.md

@@ -0,0 +1,84 @@
+# Swagger Documentation
+
+This document explains how to access and update the Swagger documentation for the Time Tracker API.
+
+## Accessing Swagger UI
+
+After starting the backend server, access the Swagger UI at:
+```
+http://localhost:8080/swagger/index.html
+```
+
+This interactive interface allows you to:
+- Browse all available API endpoints
+- See request parameters and response formats
+- Test API calls directly from the browser
+
+## Updating Swagger Documentation
+
+To update the Swagger documentation for the Time Tracker API, follow these steps:
+
+1. **Add or update Swagger annotations in your code**
+   - Annotations should be added as comments above handler functions
+   - Use the correct types in annotations (e.g., `dto.ActivityDto` instead of `utils.ActivityResponse`)
+   - Make sure all parameters, responses, and types are properly documented
+
+2. **Run the Swagger generation command**
+   ```bash
+   cd backend && swag init -g cmd/api/main.go --output docs
+   ```
+   
+   This command:
+   - Uses `swag` CLI tool to parse your code
+   - Looks for the main entry point in `cmd/api/main.go`
+   - Outputs the generated files to the `docs` directory
+
+3. **Verify the generated files**
+   The command will generate or update three files:
+   - `docs/docs.go` - Go code for the Swagger documentation
+   - `docs/swagger.json` - JSON representation of the API
+   - `docs/swagger.yaml` - YAML representation of the API
+
+4. **Common issues and solutions**
+   - If you encounter "cannot find type definition" errors, check that you're using the correct type names in your annotations
+   - If endpoints are missing, ensure they have proper Swagger annotations
+   - If you change the base path or other global settings, update them in the `main.go` file annotations
+
+## Swagger Annotation Examples
+
+### Main API Information
+
+In `main.go`:
+```go
+//	@title						Time Tracker API
+//	@version					1.0
+//	@description				This is a simple time tracker API.
+//	@host						localhost:8080
+//	@BasePath					/api
+//	@securityDefinitions.apikey	BearerAuth
+//	@in							header
+//	@name						Authorization
+```
+
+### Endpoint Documentation
+
+Example from a handler function:
+```go
+// GetActivities handles GET /activities
+//
+//	@Summary		Get all activities
+//	@Description	Get a list of all activities
+//	@Tags			activities
+//	@Accept			json
+//	@Produce		json
+//	@Security		BearerAuth
+//	@Success		200	{object}	utils.Response{data=[]dto.ActivityDto}
+//	@Failure		401	{object}	utils.Response{error=utils.ErrorInfo}
+//	@Failure		500	{object}	utils.Response{error=utils.ErrorInfo}
+//	@Router			/activities [get]
+func (h *ActivityHandler) GetActivities(c *gin.Context) {
+    // Function implementation
+}
+```
+
+Remember that the Swagger documentation is generated from the annotations in your code, so keeping these annotations up-to-date is essential for accurate API documentation.